in this issue - American Radio History
radio, communication, industrial
IN THIS ISSUE
s o
. .
engineering and manufacture
AIRCRAFT ANTENNA CHARTS will help the men who design radio equipment for such ships as the Douglas "Dauntless" dive- bombers, above.
www.americanradiohistory.com
MILITARY today
-
INDUSTRIAL tomorrow
U.
AMPEREX Electronic Tubes
S.
NAVY OFFICIAL PHOTO
are incorporated in vital protective
equipment serving an alert convoy system speeding vital materials
over vast and dangerous distances.
And AMPEREX, now building for battle, is working steadfastly to
produce electronic tube designs with highly important military
significance. Coincidentally, we are contributing, in these same
wartime engineering advancements, to the myriad of practical
industrial applications which are already evident
... for tomorrow.
AMPEREX ELECTRONIC PRODUCTS
79 WASHINGTON
STREET
www.americanradiohistory.com
BROOKLYN, N. Y.
electronics
DECEMBER
1942
Cover
DOUGLAS "DAUNTLESS" DIVE -BOMBERS
ELECTRON TUBE TERMINOLOGY, by W. C. White
42
Some early history and remarks on the nomenclature, popular and scientific, to be used in naming
new members of the vacuum -tube family are included in this article
AIRCRAFT ANTENNA CHARACTERISTICS, by Paul J. Holmes
46
permit the reactance and radiation resistance of a fixed aircraft antenna to be estimated following measurement of length, facilitating design of dummy antennas
Two charts
PRECISION TIME CONTROL
49
Tuning -fork used as power supply source for NBC synchronous clocks
second per day
is
accurate within one -third
RADIO IN THE U. S. ARMY
50
Signal Corps photographs show methods of installing, maintaining and operating modern military
communications equipment
GRAPHICAL DETERMINATION OF POWER AMPLIFIER PERFORMANCE, by R. I. Sarbacher
52
simple two -piece plastic calculator, used with static curves of power tubes, the complete performance of Class B and Class C amplifiers can be rapidly determined
By means
of
a
CIRCUIT ELEMENTS IN ELECTRICAL REMOTE CONTROL, PART II, by C. J. Dorr and L. N. Galton
57
Fundamental circuits using relays to provide time -delay, generate impulses, handle interlock problems
and perform selection functions
SIMPLE HARMONIC WAVE ANALYZER, by R. F. Thomson
61
Second and third harmonic distortion can be read directly in percentage of the fundamental frequency
through use of simple amplifier -filter- rectifier device designed to speed up test and inspection of audio
ENERGY STORAGE WELDING CONTROLS, PART V, by G. L. Rogers
63
Magnetic and electrostatic energy storage systems described reduce the demand upon power lines
and provide precise control needed when working with non -ferrous metals
AN EXPERIMENTAL TELEVISION SYSTEM, by Robert Mautner and Frank Somers
68
A description of a I4 -Mc television video transmitter and associated receiving equipment, with particular emphasis upon the practical problems involved in the design, construction and operation of
I
ELECTRONICS IN INDUSTRIAL TEMPERATURE INSTRUMENTATION, by M. F. Behar
72
Pointing out the unreailzed opportunities for the application of electron tubes to the measurement
and control of temperature, the author shows the difficulties and the most favorable fields of application
IMPEDANCE OF SOME SIMPLE ELECTRICAL CIRCUITS, by Beverly Dudley
Admittance and magnitude and phase of impedance of simple electrical circuits
in
75
graphical form
AVOIDING PATENT PITFALLS, by Rudolf F. Wild
78
Suggestions are given for avoiding the numerous pitfalls confronting the uninformed when seeking
a
patent
ANNUAL INDEX, VOLUME 15
181
KEITH HENNEY, Editor; Beverly Dudley, Managing Editor; Donald G. Fink (on
leave); Craig Walsh (on leave); W. W. MacDonald, Associate Editor; M. L.
Mattey, Assistant Editor; J. M. Heron, Assistant Editor; Harry Phillips, Art Director
H. W. MATEER, Publisher; J. E. Blackburn, Jr., Director of Circulation Electronics;
Wallace B. Blood, Sales Manager
DISTRICT MANAGERS, D. H. Miller, New York; R. H. Flynn, New England;
F. P. Coyle, Philadelphia; L. P. Canty, Cleveland; C. D. Wardner, Chicago
Contents Copyright,
1942,
by McGraw -Hill Publishing Company, Inc.
McGRAW -HILL PUBLISHING COMPANY, INCORPORATED
JAMES H. McGRAW, Founder and Honorary Chairman
Publication Office 99 -129 North Broadway, Albany, N. Y., U. S. A.
EDITORIAL AND EXECUTIVE OFFICES 330 West 42nd St., New York, N. Y., U. S. A.
James H. McGraw, Jr., President; Howard Ehrlich, Executive Vice President; Mason Britton,
Vice President; B. R. Putnam, Treasurer; Joseph A. Gerard!, Secretary. Cable Address:
MCGRAWHILL, New York. Member A. B. P. Member A. B. C.
ELECTRONICS. December, 1942, Vol. 15: No. 12. Published monthly. price 50c a copy. Allow at
least ten days for change of address. All communications about subscriptions should be addressed
the Director of Circulation, 330 West 42nd Street, New York. N. Y.
Subscription rates -United States and possessions, Mexico, Central and South American countries,
$5.00 a year. $8.09 for two years, $10.00 for three years. Canada (Canadian funds accepted) $5.50
a year, $9.00 for two years. $11.00 for three years. Great Britain and British possessions 36 shillings
for one year, 72 shillings for three years. All other countries, $6.00 for one year. $12.00 for three
years. Entered as Second Class matter, August 29. 1936. at Post Offioe, Albany, New York. under
Use Act of March 3. 1879. BRANCH OFFICES: 520 North Michigan Avenue. Chicago: 68 Post Street,
San Francisco; Aldwych House. Aldwych, London, W. C. 2; Washington; Philadelphia; Cleveland;
Detroit; St. Louis: Boston; Atlanta, Ga.
A McGRAW-HILL
®
PUBLICATION
DEPARTMENTS
Crosstalk
Reference Sheet
Tubes at Work
Electron Art
News of the Industry
New Products
New Books
Annual Index
Index to Advertisers
75
79
90
116
136
176
181
184
CHANGE OF ADDRESS
McGRAW -HILL PUBLISHING COMPANY
330 West 42nd Street, New York, N. Y.
Director of Circulation:
Please change my address on Electronics
From
To
Signed
www.americanradiohistory.com
41
U. S. NAVY OFFICIAL PHOTO
"Adolph, did you mean it?
Ihe gateway to
Çjermafll
airnetwork of railroads,New
w
at
M ER ICA'S great
terminates
lead
lines and highways
fan'es
air
the sea and
York. Çrom here
a road to Germany.
Every one is
across the Adantic.
Less than four short years ago you
inserted the travel ad at the left in
one of our finest magazines:
Remember it? You actually invited
us. Now, take a good look at that convoy on one of the sea lanes, crossing
the Atlantic
to Germany. The air
lanes are open, too.
...
And we, Adolph, are doing our utmost to produce a sufficient amount of
materiel*, so that our "travellers" will not disappoint you.
Typical users of UTC materiel are
... RCA, GE, Western Electric, W estinghouse,
150 VARICK STREET
EXPORT
DIVISION:
00
VARICK STREET
Bendix, Farnsworth, IBM, Philco, etc.
NEW YORK, N.
www.americanradiohistory.com
Y.
.
.
.
CABLES: "ARLAB"
Here is a tracing cloth that holds erasure scars at
a minimum -that won't show water marks or perspiration stains. Now you can have clean tracings,
in pencil or ink, free from these untidy "ghosts"
that reproduce on blueprints!
For PHOENIX is ghost -proofed by a remarkable
new process that defies moisture and gives you an
unusually, durable working surface. You can use
harder pencils with this improved cloth and get
sharper lines with less tendency to smudge. Even
GH lines show clearly, and reproduce sharply!
Erasing does not mar the drawing surface; erased
PHOENIX LESSENS
SMUDGE GHOSTS
ERASURE GHOSTS
Perspiration and water splashes
on ordinary tracing cloth create
"ghosts" which reproduce on
blueprints. PHOENIX Tracing
Cloth withstands actual immersion in water for fully 10 minutes at a time! Perspiration and
water marks will not stain ill
The new improved surface of
PHOENIX Tracing Cloth permits you to use harder pencils
Ordinary tracing cloths be
VW
EST. 1867
KEUFFEL & ESSER CO.
HOBOKEN, N. J.
NEW YORK
CHICAGO
ST. LOWS
SAN FRANCISCO
LOS ANGELES
DETROIT
MONTREAL
PHOENIX REDUCES
PHOENIX DEFIES
MOISTURE GHOSTS
(5H and 6H) and to get
sharper lines with less ten-
come scarred when erased...
erased spots produce ghosts
on blueprints.
PHOENIX has a durable
drawing surface that reduces
blueprints.
working
dency to smudge.
Result: Cleaner tracings and
areas take pencil smoothly -and ink without
feathering. Its new white color and increased
transparency give you excellent drawing contrast
and produce strong blueprints.
Let PHOENIX prove its virtues on your own
drawing board. See your K &E dealer, or write
for a generous working sample and an illustrated
brochure.
scars to
a
minimum.
www.americanradiohistory.com
REG. U.S
PAT. OFF.
TRACING CLOTH
for pencil and ink
Centtalab nowServesltselfatrdtfie
11K/usi?;
C
wi1hgTTATITF
ENTRALAB has added a new plant of large capacity for
the production of glazed and unglazed STEATITE.
This highly critical, strategic material is an important factor in
the operation of ultra high frequency equipment.
Centralab's STEATITE plant is in a position to furnish coil forms
up to 5 inches diameter and pressed pieces to approximately
6 inches square. The same high standards of excellence will
be maintained in this department that have characterized every
other Centralab product during the past decades. The Centralab
Ceramic department that has been in existence since 1930 has
built up an extensive engineering, production and laboratory
background to ensure a product of the highest quality that fully
meets military specifications.
STEATITE is an extremely dense non -porous ceramic of high
mechanical strength with low loss factor and low dielectric
constant. It can be fabricated in various cylindrical and flat
shapes by extrusion or pressing. Centralab is also equipped
to engineer and manufacture other grades of ceramics.
CENTRALAB
1930 Centralab
\%
-
Division of Globe -Union Inc., Milwaukee, Wis.
pioneered
a
fixed resistor of "hard-asstone" ceramic material.
1936 Centralab
added a temper-
ature compensating fixed condenser of ceramic material.
1940 Centralab
added a trimmer
condenser with temperature
compensating characteristics
2
19
a
Centralab addedown
its
care of
take
to
STEATITE plant
industry.
of the
those
needs and
4
December 1942
www.americanradiohistory.com
ELECTRONICS
THESE PHOTOGRAPHIC REPRODUCTIONS ARE THREE -QUARTER SIZE
M4p,4._&l2,_..
FREQUENCY
a
.o +o..:
Zar
SIMPLE
INSTALLATION
DIAGRAMS
MODEL 437-JP
Model 437
-J
P
Model 372
The Triplett Combat Line
Maximum Service in Minimum Space
TR11'LETT
wilt- INSTRUMENTS
New Answers to specialized needs of War: Production Speed -up and Standardization; Performance
under the Stress and Vibrations of Combat Service.
rectangular line of meters to meet
Model 437 J P
dimensions shown (see diagram). Wide -open scale for
maximum readability. Complete coverage AC -DC
Voltmeters, Ammeters and Wattmeters. Magnetic or
static shielding provided on order. Molded Plastic
Case for maximum protection in high voltage circuits.
Pivots, Jewels and other component parts designed to
meet severe vibration requirements.
Model 372 Frequency Meter -"All- American make"
Vibrating Reed Frequency Meter. Maximum readability by grouping of Reeds. Range- Frequency -Voltage
to meet specific requirements. Protected against excessive panel vibration. In standard 3 inch mounting
or on special order in any cataloged Triplett Case.
-A
-
Precision performance by new thin instrument with
standard Triplett movement housed in either metal
or molded case. No projecting base; wider shroud
to strengthen face; simplified zero adjustment;
balanced bridge support; metal bridges at both
ends; doubly supported core. For "Precision in
limited space" write for Triplett Thin Line Bulletin.
A WORD ABOUT DELIVERIES
Naturally deliveriés are subject to necessary priority
regulations. We urge prompt filing of orders for delivery as may be consistent with America's War effort.
TRIPLETT ELECTRICAL INSTRUMENT CO.
BLUFFTON. OHIO
ELECTRONICS
-
\tlFIiLET
5
December 1942
www.americanradiohistory.com
RCA ENLISTS THE ELECTRON TO
OPEN NEW
DOORS OF RESEARCH!
An example of how RCA electronic research is
leading to new progress in science and industry
The RCA Electron Microscope is one of the hundreds
of practical tools for progress that RCA electronic
research has developed. Using electrons instead of
rays of light, and electro- magnetic fields instead of
lenses, the RCA Eléctron Microscope enables man to
peer deeper into the hidden, sub -microscopic world
than ever seemed possible before. Magnification as
high as 100,000 diameters can be easily obtained
fifty times greater than is possible with the best optical oil- immersion mícroscópe.
For industry it has meant closer insight into many
processes, a better understanding of the methods for
making, treating, and preserving materials.
For chemistry it has meant the opportunity to
-
study, for the first time, details of molecular design
and structure, so that there can be a continued advance in the creation of such products as nylon, rayon,
synthetic rubber, and plastics.
For medical science it will mean the opportunity to
observe, for the first time, how the body fights bacterial and virus diseases -such as infantile
paralysis, smallpox, influenza, the com- FVICTORY
. BUY
mon cold and many others.
For all America -and when peace returns, for all the world, -this product of
RCA electronic research will lead the
way to a richer and fuller life.
WAR
BONDS
STAAIVS
v.-re
Vt.
Micrograph showing Vinylite in one of its many stages of polymerization. The study of plastics is aided by the RCA Electron
Microscope, which enables observation of the polymerization
process, typical of the plastics.
Tobacco mosaic virus, seen for the first
through the RCA Electron Microscope.
large protein molecule, very injurious to
tions may lead to the development of
antibody.
time by the human eye
The virus represents a
tobacco. These observaan anti -virus serum or
Micrograph of Pearlite steel, a carbon steel formed by controlled
annealing. By using very thin replicas of the surface, the structure
of practically all metals can be studied with the RCA Electron
Microscope.
Micrograph of staphylococcus bacteria, -pus producing organisms
which can attack any part of the body and cause painful and dangerous infections. The RCA Electron Microscope enables scientists to observe their actual structure, thus leading to important
work in protecting man against this bacteria.
RCA LEADS THE WAY
IN RADIO
- IN
ELECTRONICS
- IN TELEVISION
RCA Manufacturing Co., Inc., Camden, N.
www.americanradiohistory.com
J.
USE
(94ze
REG. U.5. PAT. OEE.
FOR MICA CONDENSER
REPLACEMENTS
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CERAMICONS
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RATLINE COEFFICIENT OF CAPACITY X
(N330IS-.000330M ME/ MMF/°C)
NO
THE scarcity of high grade mica makes it essential for manufacturers
of electronic equipment to switch to other types of condensers.
The dependability of the silvered- ceramic construction of Erie
Ceramicons has been definitely proved by their use in many types of
installations over 6 years.
In using Ceramicons for mica replacements, the function of
capacitor in question should be considered in selecting the properthe
type.
When practically no change of capacity with temperature is permissible, zero coefficient (type NPO) should be specified. Where moderate
variations are allowable, maximum negative coefficient (type N750) or
some intermediate value should be used to take advantage of the
smaller size of Ceramicons available in the higher negative coefficients.
Where rather large variations are allowable, and where power
factor is not critical, a new series of high dielectric constant Ceram icons, which will be available shortly, should be specified, since very
high capacities will be available in this type of unit.
The chart reproduced above shows the range of standard Ceram icons. The new high dielectric constant Ceramicons will be available
up to approximately 5,600MMF in the insulated style and to approximately 16,000MMF in the non -insulated style.
Write for literature that fully describes the operating characteristics of standard Erie Ceramicons.
ERIE RESISTOR CORP., ERIE, PA.
LONDON, ENGLAND
8
TORONTO, CANADA.
December 1942
www.americanradiohistory.com
-
ELECTRONICS
:
I\'ITEI)" electronic power tubes cannot
be spun out on
swift, automatic assembly lines. The Painstaking manufaeturing of these sensitive devices requires the skill of
Yunnan hands.
I Jere at the "United" Plant, incredibly accurate hands
Ircriorm tinder a system of personal supervision by electronic
engin,crs. One by one, the steps of forming and fitting the
,,t, at,. !cads, plies, grids, wires and rods combine to produce
r.u!,:rn,t ing tubes of such flawless precision that they con ,I, trot ç in top rating for performance. Never before were
t
i
I
i
i
),,t iis,u,is
"l.nit
vv
f
craftsmen and the brains of scientists so superbly
in advancing the scope and purpose of electronics.
Consistent technical advances in tubes, now required for
war. some day will be more readily available to you for
radio ttou»nunication, physiotherapy and industrial elecrani('- Remember to Took for "United" ón the t ilk'''.
i
UNITED ELECTRONICS COMPANY
NEWARK, NEW
www.americanradiohistory.com
J
E R S E Y
SMOOTH AC'l'IO\
Over-sized bearings provide smooth action
HAMMARLUND variable condensers are noted
for their smooth action. Superior mechanical design has made them the first choice of engineers
who demand precise mechanical and electrical
performance.
THE HAMMARLUND MANUFACTURING CO., INC.
460 West 34th Street, New York, N. Y.
www.americanradiohistory.com
VITAL
AGAINST ELECTRICAL INSULATION PROBLEMS
TURBO PRODUCTS
CHECK THESE
N
:;
`';,,.
EACH
TO
SPECIFIC
HAS
OBTAIN
HIGHEST
ADVANTAGES
OPERATING
REQUIRED
EFFICIENCY
There's the whole story behind the extensive use of TURBO flexible
the essential attributes to meet the urgent demand for
tubing
an insulation that can keep coming back for more'.
-all
F:exible Varnished Oil Tubing- meeting the all- purpose requirements of
insulation to stand guard against breakdown, moisture absorption, etc.
a
sleeve
Varnished Glass Tubing -for those applications where extremely high heat resistance
is a prerequisite.
Extruded Tubing -where extreme sub -zero temperature resistance to any effects of
embrittlement becomes the important consideration.
Wire Identification
Corps specifications
Markers -when
is necessary.
Various Insulation Materials
sheets, etc., are needed.
-for
strict compliance with Army, Navy and Air
the diversity of requirements in which tapes, cloths,
For proof, ask for samples of each. Specimen board
and list of sizes will be sent promptly without obligation.
WILLIAM BRAND & COMPANY
276 FOURTH AVE., NEW YORK, N.
ELECTRONICS
Y.
_
QFf
-
G11 D:s"
325 W. HURON ST., CHICAGO, ILL.
December 1942
11
www.americanradiohistory.com
the Sky Buddy
was goo&..but
THOUS. \\us. of Hallicrafters Sky Buddies gave
faithful service .
years of excellent performance!
Sky Buddy owners will be amazed at how far -reaching
the progress of research and new electronic development has been, even in the past year.
When Hallicrafters are again permitted to sell communications receivers for civilian use your new Sky
Buddy will have so many improvements, comparison
with the old models will be a difficult accomplishment.
Illustration (top) partial view of Hallicrafters Signal
Corps communications
.
.
equipment.
the
kaIlirraffrsi co_
CHICAGO, U.
S.
A.
keep communications open !
December 1942
12
www.americanradiohistory.com
-
ELECTRONICS
WHEN THE BLUEPRINT CALLS FOR CAPACITORS
give your equipment maximum reliability by using C -D Capacitors
Capacitors may look alike but C -Ds are engineered
and manufactured by specialists who have made them
their lifework. The combined, accumulated experience of 32 years' concentration on capacitors excluis translated into the significant extra
sively
component that gives C -Ds their extra measure of
stamina and longer life. C-D means "capacitors dependability"-a very good reason why there are more
Cornell -Dubilier Capacitors in use today than any
when
other make. Isn't that worth remembering
the blueprint calls for capacitors?
-
...
As the materials used in the manufacture of capacitors are
under control, we are permitted to produce only against
those orders carrying the necessary Preference Rating Extensions. Should you-be unable to enjoy the finer performance
of C-Ds now, we do look forward to serving you once again
when Victory has been wen.
C
-D
HIGH
ie
CAPACITORS
VOLTAGE DYKANOL
TK
These capacitors are universally accepted as the finest ever
offered in larger capacity and higher voltage for filter
service. Because of their compact construction the design
engineer will find them suitable where space limitations are
a problem.
Typical features of these outstanding capacitors are:
Impregnated and filled with non -inflammable, non -explosive
Dykanol, the impregnant noted for its high dielectric constant and stability under all operating conditions.
Hermetically sealed and therefore not affected by moisture,
time or temperature up to 93 °C.
Dried, impregnated and filled under continuous vacuum resulting in lower equivalent series resistance, longer life.
Conservatively rated -will safely operate continuously at
10% above rated voltage.
Encased in sturdy, arc -welded steel case, painted with a
special blue -gray weather- proof, non- corrosive lacquer.
Supplied with heavy -duty wet -process glazed porcelain insulator. These insulators are pressure- sealed resulting in
leakproof joints and high dielectric strength.
For further details write for Catalogue No. 160T
Cornell -Dubilier Electric Corporation
South Plainfield, N. J.
more in vse today than any other make
Cornell 1À6i/ier
capacitors
ELECTRONICS
-
_..
Paper
Dykanol
Wet
.3
Dry Electrolytic Capacitors
13
December 1942
www.americanradiohistory.com
SEALED VARIABLE RESISTORS
TO MEET HIGHLY HUMID OR DUSTY CONDITIONS
Stackpole engineering scores again!
MOLDED RARE
METAL CONTACTS
...also carbon, graphite
and composition types
CARBON PRODUCTS
Brushes (for all rotating machines)
-Anodes-Electrodes-Brazing Blocks -Bearings- Welding
Rods, Electrodes and Plates
Pipe- Packing,
-
-
Piston and
Seal Rings
Rheostat Plates
and Discs -Brake Lining, etc.
Sold to manufacturers
only -Catalog and
samples upon request
Two new Stackpole closed- cover, sealed variable resistors for volume or
sensitivity use, meet today's demand for units which will perform faithfully
anywhere from the world's wettest, most humid places to its dustiest, sandiest
spots -and in either standard radio or high frequency equipment.
The Type MG Variable Resistor is designed for extremely humid or salt
spray conditions and for use in equipment where internal and external leakage
must be held to a minimum. Actually, its leakage resistance is on the order of
300 meg. after 48 hours in 95% humidity at 40° C.
The famous Stackpole Type LP Variable Resistor is now furnished with a
dust -proof cover and effectively sealed with a special compound to the point
where resistivity from current carrying parts after 48 hours of 95% relative
humidity at 40° C. is five times that of the previous open construction resistors.
STACKPOLE CARBON COMPANY, ST. MARYS, PENNA.
E
SWITCHES Slide operated (either indexed or momentary contact type) -Rotary Index and Toggle types.
14
RESISTORS (fixed or variable) Carbon
composition resistors, fixed types up to
4 watts. Variables in 4 different types.
IRON CORES Molded from powders
in a variety of grades and sizes and for
use at frequencies to 150.175 meg.
December 1942
-
ELECTRONICS
Seres More Good News About
Insulating
Material
Leadless
rTHE INSULATOR
Trade Mark Reg. U.S. Paf. Off.
A
PRICE REDUCTION
is put into immediate effect by
MYCALEX CORPORATION OF AMERICA
Ltd.
Exclusive Licensee under all patents of "MYCALEX" (PARENT) Co.,
Applicable to full sheets in
HOWMUCH?
new price list,
7
of the
9
thicknesses
As much as 18% reduction in price of some sizes.
effective Nov. 2, 1942.
Phone, wire or write for
production facilities
After a decade of unchanged prices, we now find that our accelerated
available as cheaply
made
be
should
materials
war
vital
that
feel
We
costs.
in
lower
result
applications.
wider
even
encourage
to
users,
to
all
as possible
that THE
Last month we stated in various trade and technical publicationsMYCALEX
Leadless
of
full
sheets
supply
can
We
BROKEN.
BOTTLE -NECK HAS BEEN
or substitute
Insulating Material in large quantities, immediately. If you are using make -shift
materials, change to Leadless MYCALEX Insulating Material.
WHY?
DELIVERIES?
SOME FACTS ABOUT MYCALEX INSULATING MATERIAL
Leadless MYCALEX Insulating Mate'The most nearly perfect electrical insulator known today" is what leading engineers say about
electrical properties, as determined
-loss
low
and
rial. It is a ceramic, possessing the following characteristics of mechanical strength
by an independent laboratory:
CHARACTERISTICS:
64
*Dielectric constant
*Poteer factor
*Loss factor
0 0023
1
49
Dielectric strength
Specific gravity
Transverse strength
640 volts per nil!.
25
13,000 lbs. per sq. in.
to Navy Specification RE- 13A -317F.
*Measured at 300 kilocycles after 96 hours in distilled water according
Your own mechanics can machine
MYCALEX Insulating Material to
accurate dimensions. Or, send us
your specifications
and let us quote
on machined parts
fabricated in our
machine shop at
our new plant in
Clifton, N. J.
Leadless
MYCALEX
Insulating
Material
is
MACHINEABLE
Write for our free illustrated booklet describing
uses, machining technique, etc.
Address:
MYCALEX CORPORATION OF AMERICA
60
ELECTRONICS
-
CLIFTON
BOULEVARD,
December 1942
Dept.
2M,
CLIFTON,
N.
J.
15
THE T£ values of AlSiMag ceramic compositions are among
the many physical characteristics given in Property Chart
No. 416.
Frequently it is very difficult for the designing engineer to
get information as to detailed characteristics of an insulating material which he wishes to employ in his design. Therefore, American Lava Corporation took great pains in an
effort to furnish such information in Property Chart No. 416.
A Copy of this chart will be sent free on your request. It
is conveniently arranged for filing, hanging on the wall or
placing under desk glass. It takes only a moment to request
AlSiMag Property Chart No. 416. It might save you many
hours or days of laboratory experiment.
oC
AlSiMag Property Chart No. 416
Gives Complete Physical Characteristics
of the Most Frequently Used AlSiMag
Compositions. Free on Request.
-
AWARDED JULY 27, 1942
AAAAA
16
I]
1011.1111.
EA
December 1942
ELECTRONICS
FU(PV ICTt)RY
BUY
WAR
itom)s
si:rs
...where they'll do
the most good
Latest Jefferson- Travis two -way radio communication equip-
ments are limited to the Armies and the Navies of the United
Nations. Only the men in combat units or in the most vital
services have them. They are where they'll do the most good.
JEFFERSON -TRAVIS RADIO MFG. CORP.
41anuáactutQti
at 4itctatt, /Maine and /lfobi/¢ nado
NEW YORK, N. Y.
N:I,E(:'l'KllNl(:S
--
(1
1
P,rf¿1`
Communication
WASHINGTON,
December 1942
www.americanradiohistory.com
D. C.
f
tilamont
HARDWICK, HINDLE
BUILT
TO TAKE
HARDWICK, HINDLE, Inc.
Newark,
I8
N.
J., U.S.A.
1
This special 4 gang assembly of 50 watt rheostats is exceptionally rugged and compact. It's a fine example of the great
adaptability to unusual conditions of our metal base design.
It is gear operated for equipment in important combat units;
and it is standing up under terrific use. This special assembly
has withstood a 2000 foot -pound shock giving an acceleration
to the unit of 300 G.
As in all Hardwick Hindle rheostats of this type the exclusive
features assure you of 25% more capacity for handling possible
overloads -and consequently more heat dissipation -less temperature rise without taking up more space. Our deeper winding
forni gives more wire, more surface area.
We offer many other types of rheostats and resistors with
important exclusive advantages.
Please consult us-
December 1942
ELECTRONICS
NEW
THIN
as in so many
others, the new conditions imposed by war have
led to intensified research which has developed
new products and new qualities that are certain to
be valuable after the war.
Formica, with the assistance of customers and
suppliers, has had a share in this progress. Some
of the new things: laminated plastic name plates,
glass cloth base insulating material to serve some
of the uses of ceramics; arc resistant insulation,
"Pregwood ", a light, strong, impregnated wood
that serves many mechanical uses, and fluorescent
instrument panels visible in the dark.
When the war is over let us tell you about the
new things in Formica that might serve you better.
IN lamina
THE FORMICA
ELECTRONICS
. plastic materials,
INSULATION COMPANY, 4661 SPRING GROVE AVE., CINCINNATI, OHIO
-
December 1942
19
Are you choosing your resistors with wartime care?
LET THIS
"GLOBAR" CHART GUIDE YOU!
LOBAR" Ceramic Resistors are non -inductive
and have excellent radio frequency characteristics. They are rugged, have liberal overload capacity.
Standard terminals consist of metallized ends; permitting neat, orderly assembly in fuse clips or other
types of mountings. "Globar" Resistors are available
in many shapes and sizes in the types whose characteristics are briefly outlined below. "Globar" Resistors
are available in three tolerances on specified resistance:
5 %, 10% and 20 %. In designing or ordering please
do not specify 5% tolerance when 10% will do the
job, or 10% when 20% will suffice. The closer
tolerances slow up production. To conserve your time
and to assist you in selecting the resistor best suited
to your purpose our long experience in specialized
resistor manufacture is at your service. Send us full
details of your requirements and your problem will
have our immediate consideration.
GLOBAR BRAND CERAMIC RESISTOR CONDENSED SPECIFICATIONS
Type
Length
Diameter
Resistance
Per Inch
Of Length
*Overall
Watt
Rating
*Normal
Rating
Watts Per
Sq. Inch Of
Radiating
Surface
Min.
Max.
Min.
Max. Min.
Max.
Min.
Max.
"A"
I
/4"
18"
%e"
1"
25
15
1/4
54
ohms megohms watt watts
"B"
1/4"
18"
!16"
1"
5
15
1/4
54
ohms megohms watt watts
"CX"
1/4"
18"
jÌ6"
1"
1
ohm
1000
ohms
Maximum
Volts Per
Inch Of
Length
1/4
150
watt watts
1
watt
400
1
watt
400
21/2
watts
See
Note
*These ratings may be substantially increased by artificial cooling.
1. Type "A" has comparatively Straight Line Temperature- Resistance and
Voltage- Resistance Characteristics.
2. Type "B" has Negative Temperature- Resistance and Voltage- Resistance
Characteristics.
"CX" has a slightly Positive Temperature- Resistance Characteristic.
4. Other resistor types are available for specialized applications.
5. Globar Brand Resistors are usually furnished with plain metallized ends
for fuse clip mounting, but may also be supplied with wire leads if desired.
6. NOTE: Type "CX" Resistors have a low specific resistance and cannot
be subjected to voltage stresses permissible with Types "A" and "B ". The
maximum allowable voltage is that voltage required to yield the maximum wattage rating for this type of resistor.
3. Type
44h2
ERAr:J
Globar Division
CERAMIC RESISTORS
THE CARBORUNDUM COMPANY
Niagara Falls, N.
Y,
(Carborundum and Globar are registered trade -marks of and indieate ma nufaet ure by The Carborundum Company)
21)
December 1942
-
ELECTRONICS
orking as we are today on new developments . .. especially on the design of
special Electronic tubes, our engineers are
experiencing a wealth of knowledge for
future use in industrial applications.
Our engineers and scientists are constantly keeping ahead of today's fast moving pace in the field of electronics . .
when we again return to a peacetime basis
this knowledge gained will be an all important factor in the production of the latest
developments in equipment and tubes.
Lor military reasons, the tube illustrated is not a new
development.
Raytheon Manufacturing
Company
WALTHAM AND NEWTON, MASSACHUSETTS
ik
ELECTRONICS
-
DEVOTED TO RESEARCH AND THE MANUFACTURE OF TUBES
If.4 FOR THE NEW ERA OF ELECTRONICS
December 1942
21
Weston Model 633
A -C CLAMP AMMETER
-a real time -saver, which tests without
disturbing circuits or interrupting work.
The clamping jaws are simply placed
over the conductor or switch blade for
current reading.
Industry's production figures bear testimony to the outstanding contribution electrical ccntractors and plant maintenance
men are making to war-plant efficiency. Despite obstacles
such as materials scarcities and limited manpower, electrical
equipment -old and new -is being kept constantly fit for full
scale output.
As part of the efficient maintenance combat team the WESTON
test instruments illustrated -and others -are playing an important role. For in addition to their trustworthy indications on
which maintenance has long learned to depend -they also provide features which greatly simplify preventative maintenance
procedure. In less time -at far lower cost- industry's electrical
equipment is being kept fit with dependable WESTONS.
Weston Model 785
INDUSTRIAL CIRCUIT TESTER
A highly versatile tester for trouble
shooting. Provides voltage, current and
resistance ranges for checking motor
and control circuits, lighting circuits,
sensitive relay circuits, electronic circuits, etc. (D -C sensitivity 20,000 ohms
per volt.)
Weston Model 430
Weston Model 703
TEST INSTRUMENTS
DIRECT READING
The universal favorites for active
maintenance ... compact, rugged
and with enduring precision. Large
scale openings with hand calibrated mirror scales assure quick,
accurate readings. Available in
A -C and D -C instruments and
single phase wattmeters.
ILLUMINATION METER
- measures
all types of lighting
direct, without correction factors
fluorescent, mercury vapor, incandescent, neon, daylight, etc. Made
in models and ranges for shop and
laboratory needs.
-
Weston Electrical Instrument Corporation, 618 Frelinghuysen Avenue, Newark, New Jersey
22
December 1942
-
ELECTRONICS
IRA
and
humidity
Defeat hea t p robems
Extreme
THERMADOR transformers are "THERMATITE"
Aviation Audio Transformer
(Thermatite treated)
treated. THERMATITE is a
process of accurate heat controlled vacuum impregnation, using the best grade of materials.
This process has been developed and improved
by ten years of daily use by the same personnel
and supervision.
THE THERMADOR TRANSFORMER LINE
Included in the Thermodor Transformer line are
audio, auto, geophysical, bias supply, bridging,
cathode modulation, coupling, driver, field supply, filament, high fidelity audio, input, midget
plug -in audio, mixing and matching, modulobon, output, plate, power (combined plate and
filament), television, and tube -to -line transformers. Also manufactured are filters, chokes, and
reactors (audio and equalizing).
1
ELECTRONICS
-
THERMATITE
impregnated transformers will
therefore stand extreme conditions of climatic
change. This is very important with their wide
use all over the world.
EXPERIENCED ENGINEERS AT YOUR SERVICE
May we be of assistance in engineering and
producing transformers to meet your specific
requirements
?
TH E RMADOR
4A',
T)-{Esktrl:T1T
TRAh15VRIIAERS
THERMADOR ELECTRICAL MANUFACTURING CO.
5119 S. Riverside Drive, Los Angeles, Calif.
REPRESENTATIVES - Les Logan, 530 Gough St., San Francisco, Calif. Verner O. Jensen, 2607 Second Avenue, Seattle,
Washington M. J. Klicpera, P.O. Box 3113, Houston, Texas.
23
December 1942
www.americanradiohistory.com
Which is Your Choice
...to Keep
JIGGLING JERRY
If your product is subject to
vibration, Jiggling Jerry is not
your man. Stay -put Phil, the one
with the Phillips recessed head,
is your best choice for a dependable grip. It can be set up tighter,
and it will stay tight, despite
vibration.
Then, too, the Phillips Recessed Head Screw gives you
savings in assembly cost. The
screw clings to the driver the
-
OR
a Fastening TIGHT?
STAY -PUT PHIL?
driver is self- centering in the
recess so the assembly man,
with one hand free to hold the
product, can work faster. He
drives straight and sure however awkward the position.
Power drivers can be freely
used where, with slotted screws,
it would be necessary to
drive tiresomely by hand in
order to avoid screwdriver
accidents.
-
-
Phillips
.,And remember:...
Screws are t-better-lookaerwelldas more ecoing,
nomical to
Added up, this often means an average 50% SAVING IN ASSEMBLY COSTS
C
07' *78/ bsemóeg
LoeLsse/
WOOD SCREWS
Phillips
MACHINE SCREWS
SPECIAL THREAD -CUTTING SCREWS
RECESSED
HEAD
Screws
SHEET METAL SCREWS
STOVE BOLTS
SCREWS WITH LOCK WASHERS
Order stronger, cost -cutting Phillips from any of these sources
American Screw Co., Providence, R. I.
The Bristol Co., Waterbury, Conn.
New England Screw Co., Keene, N.H.
The Charles Parker Co., Meriden, Conn.
Central Screw Co., Chicago, III.
Parker -Kalov Corp., New York, N.Y.
Chandler Products Corp., Cleveland, Ohio
Pawtucket Screw Co., Pawtucket, R.I.
Continental Screw Co., New Bedford, Mass.
Pheoll Manufacturing Co., Chicago, Ill.
The Corbin Screw Corp., New Britain, Conn.
Russell, Burdsall & Ward Bolt & Nut Co., Port Chester, N.Y.
International Screw Co., Detroit, Mich.
Scovill Manufacturing Co., Waterbury, Conn.
The Lamson & Sessions Co., Cleveland, Ohio
Shakeproof Inc., Chicago, Ill.
The National Screw & Mtg. Co., Cleveland, Ohio The Southington Hardware Mfg. Co., Southington,
Conn.
Whitney Screw Corp., Nashua, N.H.
December 1942
www.americanradiohistory.com
-
ELECTRONICS
...
Somewhere in Africa
or Iran,
India, China . . . an American
bomber returns to its base. Tomorrow, it will fly again
provided
essential repairs are made tonight.
For this and numerous other such
situations, BENDIX -RADIO Service
Men are ever alert. Stationed at such
...
Products of BENDIX -RADIO
are important members of
"The Invisible Crew
the
precision instruments and
equipment which 25 Bendsx
plants from Coast to Coast
are speeding to our fighting
crews on World Battle Front:.
"...
ELECTRONICS
-
THE
centers as Cairo, Karachi and Kunming, within reach of advance bases
of United Nations forces, these
trained engineers are available at
all times to render expert service.
Here on the home front, too, men
and women of BENDIX -RADIO are
doing their bit towards victory.
/NV/S/BLE
CREW
Precision
Equipmenrbr
December 1942
25
www.americanradiohistory.com
OFFICIAL U. S. NAVY PHOTO
Serving with the
Navy of the Sky
..
.
American planes are writing V for Victory in the skies. And
with the Fleet Air Arm, as with other branches of the
service which require direct current from an A. C. source;
I. T. & T. Selenium Rectifiers are on the job.
-I.
Remarkably light in weight- compact
T. & T. Selenium
Rectifiers are particularly suitable for aircraft use. They have
no moving parts to wear out or cause failure at crucial
moments. They operate over a wide temperature range and
can be employed at extremely high altitudes.
Consulting engineering services available for specific requirements. Address Rectifier Division for descriptive bulletins.
,Selenium RECTIFIERS
IT
federal klephone and Radio Corporation
Formerly INTERNATIONAL TELEPHONE
i
RA010 MANUFACTURING
G
CORPORATION
December 1942
26
www.americanradiohistory.com
I
Offices
: 1000
Passaic Aye.
East Newark, New Jersey
ELECTRONICS
Pressed for time
AND TIME SAVED BY PRESSING
Acustomer needed a large quantity o t ese
in a hurry. The normal
71/2 -inch coil forms
cutting -off,
for
extruding,
called
processing
-
threading, drilling and other machining that
would have made "on time" delivery impossible as all equipment necessary for these processes was tied up for months ahead.
We could have thrown up our hands and said "Sorry"
We could have found plenty of alibis. But that is not
our way.
Our Engineering Department went to work. "What
about pressing ?" asked someone. Pressing? A piece 71/2
inches long with 52 holes and eight flutes and 52 threads
on each flute? A stiff problem. It had not, to our knowledge, been done before.
-
To make a long story, short we did it, and, pardon us
for saying so, we are rather proud of this achievement.
If you have any special steatite problems, we would like
to have a shot at them.
GENERAL CERAMICS AND
STEATITE CORPORATION
KEASBEY, NEW JERSEY
"All right, let's try it!"
The die was probably the most complicated one that
ever came out of our tool shop.
ELECTRONICS
-
December 1942
27
yr
700%
600%
G
THE AXIS
1
TIMES HARDER
//o.iming.
"NATION'S 8 MOST CRITICAL MONTHS
JANUARY. 1942
100%
JAN
FEB
EQUALS 100 °0
MAR
APR
MAY
HYTRON CORP.,
JUNE
JUL
OCT
NOV
DEC
Salem and Newburyport, Mass.
',lanufarturers of Radio Tubes Since 1921
28
SEPT
AUG
.
.
.
December 1942
-
ELECTRONICS
qehe wad tle
U. S. military gas mask lenses must be pear -shaped, dimensioned
accurately to 1/64 ", curved to meet exact specifications. Center
panel thickness -.100" minus .020" plus nothing. Outer %" wide
edge thickness -.090" minus .010" plus nothing. 5 Lumarith Plastic
lenses to a sprue -no finishing necessary.
Would you have turned to the eeivam
To manufacturers new to plastics, the most amazing thing about
custom molders is that in one operation they convert raw material
into a finished product. Modern production calls for fullest use of
the important work of custom molders. Yet many manufacturers
don't know how to avail themselves of this work, quickly and
without confusion.
So as founder of the plastics industry, we undertake this program, in the hope it will help you find the right custom molder to
and to speed your
execute any plastic part you may seek
production from start to finished product. Here is what you do:
-
1. Tell us what qualities you want in the molded part
impact strength; resistance to water, acids or solvents;
b
EG
.
U. 5
dielectric strength, etc., etc. We recommend the Lumarith
Plastic that fits your specifications.
2. We put you in touch with the available custom molders
best equipped to mold the piece.
3. The custom molder gives you a quotation.
4. We work with the molder in furnishing the formulation
of the Lumarith Plastic selected, that suits all factors
in relation to dies, heat, presof production technique
sure, etc.
...
We welcome your inquiries and questions.
GAT. OFF.
Lumarith Molding Powders
Noteler?
(Cellulose Acetate)
CELANESE CELLULOID CORPORATION, a division
of Celanese Corporation of America, 180 Madison Avenue,
New York City. Representatives: Dayton, Chicago, St. Louis,
Detroit, San Francisco, Los Angeles, Washington, D. C.,
Leominster, Montreal, Toronto.
Lumarith E. C. Molding Powders (Ethyl Cellulose)
CELANESE CELLULOID CORPORATION
ELECTRONICS
-
the ftia nepme
òtht_
29
December 1942
www.americanradiohistory.com
PIONEERS...in
OUR NAVY PIONEERED
CARRIER
THE AIRCRAFT
on the
Curtiss tiplane
war and peace
'
a
landed
Bay
Eugene B. Ely
in San Francisco and
Pennsylvania
took off
he
old U. S. S.
later
An hour
the
early in 1911.
Field, thus heraldingwar.
returned to Selfridge
important in this
carrier
modern plane
so
.
..:
GAMMATRON BUILT THE FIRST
TANTALUM TUBE
HK -1054
MAXIMUM POWER
Heintz and Kaufman engineers designed the first tantalum tube in 1928 to provide the ruggedness and
reliability needed in marine transmitters. Today nearly
30 Gammatron types, with power ratings from 50 to
5000 watts, are engaged in handling America's wartime communications.
By now tantalum is recognized as the ideal element for
plates and grids. It has the lowest gas content of all
metals, gives up this gas readily during the pumping
process, and then acts as a powerful absorbent for any
gas released during operation.
Tantalum construction explains the remarkable ability
of Gammatron transmitting tubes to withstand tremendous overloads without producing free gas which would
cause filament emission failure.
Our electronic engineers are now pioneering remarkable new types of tantalum tubes for the service of
America at war ... and some day for the world at peace.
3000
GAMMATRON
SALES REPRESENTATIVES
MARSH AGENCIES
M. B. PATTERSON & CO.
104 Battery Street
Seattle, Washington
W.
F.
434 Allen Building
Dallas, Texas
SEEMAN
W.
505 Franklin St.
KENNEDY SALES CO.
2362 University Ave.
St. Paul, Minnesota
E.
E.
McFADDEN
915 Montrose Ave.,
Bexley
Columbus, Ohio
Buffalo, New York
W. B. SWANK
610 Blaine Avenue
Detroit, Michigan
P. DEMAREST
1630 South Flower St.
Angeles, California
PAUL R. STURGEON
H. A. ROES
Boston, Massachusetts
HOLLINGSWORTH
Los
2017 Grand Avenue
Kansas City, Missouri
RALPH M. HILL
GORDEN GREY
25 Huntington Avenue
& STILL
Norris Bldg., Atlanta, Ga.
North Crawford Ave.
Chicago, Illinois
1
S. K.
MACDONALD
1343 Arch Street
Philadelphia, Pa.
D. R. BITTAN SALES CO.
53 Park Place
New York City, N.
NEINT2
GAMMATRONS...oF
30
OUTPUT
WATTS
j .-.-
....o ,
Y.
KAUFMAN
COURSE!
December 1942
ELECTRONICS
Yes! We have plenty of banana pins in many types and sizes.
And they are available for prompt delivery. As made by
Ucinite these pins protect vital radio connections against the
jolts, jars and jounces of mobile connections in tanks, jeeps,
walkie- talkies, field sets, etc. etc. You can count on them to
keep contact!
THE 459UCINITE
COMPANY
Newtonville,
Watertown
Street,
Mass.
DIVISION OF UNITED -CARR FASTENER CORP.
ELECTRONICS
December 1942
31
www.americanradiohistory.com
1
Ami,.?t
aeade,,e
MEN AND WOMEN OF
TO THE
CONNECTICUT TELEPHONE
M
F
O
R
D O
I
N G
E
T
R
I
H
D E N
E
I
&
**
O
R
D
We, the men and women of "Connecticut'', shall fly our burgee
and wear our "E" pins with a deep sense of pride. We have
done what it is every American's duty to do: our all -out best. The
"E" will be an inspiration to find ways of doing still better. The
ELECTRIC CORPORATION
CONNECTICUT
*
U T Y
A
S
T
H
E
Y
S
A W
I
T
communications equipment and precision electrical products we
are privileged to manufacture have direct and important military
assignments. We undertake that our output shall not be less
by a single unit than the maximum of which we are capable.
32
December 1942
www.americanradiohistory.com
-
ELECTRONICS
The SPRING that WINDS ITS TAIL on ITS BODY
sions, notably -stress is lower, or force is
greater, or deflection is greater-assuming
that the other two of the three factors are
fixed in value. Then again, the double coil
inspires a variety of pin locations to avoid
interference.... Why do we point all this
out? Simply to indicate the complexities of
spring design and specification. There is
only ONE right spring for the job -the one
made possible by science in springs.
TIMES only a torsion spring will do.
And only a unique torsion spring at
that
such as one of the "double- coil"
torsion springs below. You see, to achieve
proper spring length where the retaining
pin or shaft is short, these double springs
are coiled over themselves like thread on
a spool. Their advantages? Well, apart
from their suitability to close quarters, they
have other advantages over single -coil tortseiT
...
A BOOK HITLER WOULD LIKE TO SUPPRESS
.
Yours for the asking
40 pages
SCIENCE IN SPRINGS
f
...
about springs, carefully culled from
our master data. Design procedures
for springs, the "spring chart" for
determining the load and deflection
required to produce a basic stress,
spring specifications, spring calculations and formulas, tables and harts.
Write for it on company letterin ul.
IN THE ARMY NOW ...Springs have gone to the front in a number of ways Hitlerito and his Nipponazis would like to know. If
you need springs for fighting equipment, our men will be only too glad to make them or design and make them. Just say when
ti
pr
ed
e
.
C
Customer
Sa 14d
T
oíSpnnB_----
..lpS;catiot+__
__
HUNTER PRESSED STEEL COMPANY, LANSDALE, PENNA.
www.americanradiohistory.com
cet (goo.,rs
._-----' Mstasi._-
`
Sicetion---'"`.---
?,
Tes< Sya
yyyíìr
Toward Tomorrow's "Peace on Earth"
Today a single purpose motivates the people of Sylvania. That
is to help win the war.
At this season we must pause to
express appreciation for your patriotic understanding and sacrifice.
The experience of serving you in
the past prepared us for war. Our
war service will help you win the
peace.
ress. Tremendous strides are being
made in secret naval navigation
and military communications projects in our laboratories and plants.
Radio and electronic tubes, perfected for war production, will
open a new era of radio and tele-
s Y LVA N A
I
vision in the peace to come.
while our minds and hands
work only toward victory, our
hearts and eyes look ahead to
brighter days toward Tomorrow's "Peace on Earth."
So
-
ELECTRIC
PRODUCTS
INC.
Formerly Hygrade Sylvania Corporation
For war serves to sharpen scientific
vision and speed engineering prog-
34
EMPORIUM,
PA.
Incandescent Lamps, Fluorescent Lamps and Fixtures, Radio Tubes,
Electronic Devices
December 1942
-
ELECTRONICS
FOR
HIGH -FREQUENCY
POWER SOURCES
LAPP GAS -FILLED
CONDENSERS
In any electronic circuit, wherever lump capacitance
is needed, Lapp condensers will save space, save
power and save trouble. Available for duty at almost
any conceivably -useable voltage rating and capacitance, they bring to any application notable mechanical and electrical advantages: practically zero loss,
smallest space requirement, non -failing, puncture proof design, constant capacitance under temperature variations. Shown, at left, Unit No. 25934, rated at
200 amp., 6500 volts, capacitance variable 4300 mmf. to
"woo mmf.; right, Unit No. 23722, rated at 5o amp.,
7500 volts, capacitance 45 mmf. to 75 mmf.
STANDOFF, BOWL,
ENTRANCE INSULATORS
Standoff, bowl, entrance and other special - purpose
insulators are available in wide range as standard
Lapp catalog items. Other insulators of special design are easily produced by Lapp methods, either in
porcelain or steatite. The wide choice of such insulators available from Lapp simplifies the design of
high-frequency equipment. Also, Lapp is equipped
for production of many special assemblies, of porcelain or steatite, and the associated metal parts.
LAPP PORCELAIN
WATER COILS
For cooling of high -frequency tubes in radio transmitters and other electronic power sources, Lapp porcelain water coils have been widely used. With nothing about the porcelain to deteriorate, sludging is
eliminated, and with it the need for cleaning and
water changes. Porcelain pipe and fittings in any
needed size are also available as catalog items. We
welcome inquiry on any Lapp equipment for experimental or industrial electronic application.
www.americanradiohistory.com
ENGINEERED ESPECIALLY FOR QUARTZ
FAST, COOL CUTTING
Rimlocks consistently outperform in speed. They cut
faster and freer because thousands of diamonds are
held in radial position -presenting their sharpest
edges to the quartz piece.
LONG LIFE
Rimlocks are designed specifically for quartz cutting
by selecting the proper diamond size and controlling
the width of kerf. Choice of a hard, fast action or a
softer, more feathery touch may be hcd simply by
specifying Steel Rimlock or Copper Rimlock. Each
has its advantages depending upon the type of cutting preferred.
SURFACE CHARACTERISTICS
Rimlocks last longer because a full measure of diamonds is tightly locked in the wheel rim without
crushing. Crushing causes eventual movement and
loss, with consequent lowered life. This special bonding process* is exclusive to Rimlocks and is the latest
Dl -MET development in diamond cut -off wheels.
Rimlock's superior stiffness, uniform diamond size,
rigid bonding and extremely fast, free and cool
cutting all combine to produce an excellent, smooth
surface finish of high accuracy and parallelism. This
is particularly true when used on the Felker Dl -MET
Quartz Cutting Machine with Hydraulic Retardant.
UNIFORMITY
Rimlocks are uniform in quality and cutting ability.
An identical quantity of carefully graded diamond
grit is individually weighed and hand loaded into
each wheel. Diamonds are firmly packed to the very
bottom of every notch, then bonded by the new
Rimlock process.
PATENT APPLIED
FELKER
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December 1942
36
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ELECTRONICS
Every
few minutes, 24 hours a day, another DeJur
Meter, another DeJur Potentiometer, another DeJur
Rheostat
is
on its way to join up with America's
fighting forces on land and sea and in the air.
Here is as thrilling a story as any that American
industry has recorded so far. A dramatic merger
of men, mind and materials ... an overnight swing
from peacetime pursuits to wartime speed -up, and
not a single minute lost
. .
.
a transition from
normal working habits in a small Connecticut
town to never -ending production which is reflected
wherever the flag flies.
Out of all this
-
with your help and ours
-
Ptecedeo.
will
come final victory. Equally important, will come
new developments, new discoveries that will far
METERS
.
RHEOSTATS
POTENTIOMETERS
transcend anything in the past.
ZfJzcte, eubte on Also.ce tr°'z ?2eas eatalog 1-61 ,
Dot, Cf
Ru MEN
MSG
SS
eoi,
ech
Manufacturers
«fit
TION
Potentiometers of Meters Rheostats,
and Other
precision
Electrical
Instruments
DeJur Potentiometer
DeJur Milliammeter
Type 270
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ELECTRONICS
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BUY WAR BONDS
December 1942
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MASTER MULTITESTER
A. C. & D. C. VOLTMETER
D. C. AMMETER
The original engineering design features of this
precision Master Multi- tester makes it ideal for a
large variety of tests in both the laboratory and
factory. Incorporates the exclusive R.C.P. system
of A.C. measurements eliminating the troublesome copper oxide rectifier. Rectifier used is
rugged, extremely sensitive and easily replaced.
A.C. scales are practically linear and coincide
with D.C. scales. Capacity measurements are
direct reading. Ohmmeter has self -contained
power supply. Meter sensitivity. 2000 ohms per
volt. D.C. voltmeter range: 0-5-50- 250-25005000. A.C. voltmeter range: 0-10- 100 -500 -10005000. D.C. milliampere range: 0- 10 -50- 250 -1000.
D.C. ammeter range: 0- 1 -5 -25. Capacity meter
CAPACITY & INDUCTANCE METER
range: 0- .03 -.3- 3-30 -300 mfd. Low ohm scale:
0 -100. Center ohmmeter scale range: 0- 15,000150,000. Megohm scale: 0-.1-.5-15. Inductance
.25 - 100 - 1,000meter: .25 -1000 millihenries
10,000 henries. Meter and power line completely
fused. Supplied in handsome, black crackle wear resistant steel case. Operates on 105 -135 AC.
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Model 414 V -7 ready for operation
-
...
Other instruments in the complete line of R.C.P.
electronic and electrical test instruments described in
catalog No. 126. If you have an unusual test problem
either for production line or laboratory work
our engineers will be happy to cooperate in finding
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38
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ELECTRONICS
"Taking it". . . together
Communications...are key factors
in every movement and action
of the tank in combat. Orders
stuff" to stand up under
all the shocks and hard treatment sustained in battle action.
must be received and sent
To make RAULAND com-
" the
right through a tortuous mixture of mechanical noise and
artillery thunder
and these
orders must get through ! Time,
at such moments is precious as
life and RAULAND shortwave equipment is Electroneered
to meet Uncle Sam's demand
that communications for tanks
be as "tough and dependable as
the tank itself." They must have
munication transmitters
even more dependable, only
RAULAND Electroneered tun-
...
Buy War Bonds and Stamps!... Raular
ELECTRONICS
-
ing condensers are used. They
are designed and built to minutely controlled variations and
a fine degree of tuning ... and
this is maintained through the
roughest periods of tank maneuvers and battle operations.
Electroneering is our business
R ADIO
The
.t.tu>_SOUND_Ann_ COMMUNICATIONS
Rauland Corporation
.
.
.
Chicago, Illinois
d
employees are all doing their part as members of the 10% savings club.
December 1942
39
www.americanradiohistory.com
NATION-WIDE
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DISTRIBUTORS
, FFIC'!AL
PHOTOGRAPH,
U.S. ARMY AIR CORPS
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When he pulls down the hood of this Link Instrument & Radio Pilot Trainer, the flier
at the controls acts just as if he were in actual flight over fog -bound or blacked -out
terrain. He has to rely on a panel of flight instruments and on his radio earphones to
guide him to his "objective" ... at 300 miles an hour sitting still!
To keep Uncle Sam's airmen learning in Link Trainers, several Mallory precision products are used. Potentiometers to control the volume of simulated radio signals -themselves selected by Mallory selector switches. Rheostats for cockpit lights; pilot light
assemblies; and push button switches to control signal lights. Phone plugs and jacks
for both instructor's and student's microphones and head phones. Thus the communications and navigation of a Link Trainer
just like similar systems in actual fighting
planes ... depend on Mallory parts.
...
Perhaps you are in the market for precision parts for some device You plan to manufacture. Maybe you need a replacement part for present plant equipment ... or an
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December 1942
ELECTRONICS
Ill
www.americanradiohistory.com
Electronics-Secret Weapon of War
Presager of a New Scientific and Industrial Era
THE END of World War
a
I left scientists with
new
a
plaything. They did not know it at the
time but they had their hands on a revolution.
Within two years the world had radio broadcasting.
Within ten years the whole art of motion pictures
had been transformed as talking pictures replaced
silent movies. Within twenty years television was
born and people were seeing pictures in motion
by radio.
The fulcrum of this revolution is the electron
tube, a new tool of illimitable possibilities. One
form of the electron tube is the familiar radio tube;
the much publicized electric eye is another. There
are many other forms, each having distinct capacities
for saving time, saving energy, saving money, protecting life, limb and property.
The electron tube puts the electron to work-and
the electron is the basic building-block of the
universe.
Electronics is the new art, the new science of
putting the electron to work. Radio and sound pictures and television are aspects of electronics; but
there arc many other facets of this revolution which
have been brewing since the last war.
The electron tube has a typical American family
tree. Edison made the basic discovery of the "Edison
effect" sonic sixty years ago. This was followed by
the invention of the "Fleming valve" and the "de
Forest grid ". Then Armstrong contributed his share,
and hundreds of engineers in garret and cellar workshops and in the great university and industrial
laboratories went to work on the tubes which
employ electrons. The tube was a plaything before
the last war but the world conflict brought it out of
the toy stage and made it a practical, powerful tool.
Today the electron tube is guiding the destinies
of the greatest armies and fleets ever engaged in
the history of the world.
It is a part of the nerve center of the battleship,
directing its course, finding its adversaries, broadcasting running accounts of air battles to its crews,
directing gun fire and determining ocean depth.
In the air it is the means of locating and identifying enemy planes, piloting planes automatically,
giving communication from plane to plane and to
shore. It is even operating the controls of the plane.
In the maneuvering tank, in the officer's car, on
the back of a foot soldier it transmits and receives
vocal messages from every unit of the fighting
forces.
Along our borders, and those of our Allies is an
electronic screen which counts, follows and identifies enemy planes a hundred miles away through
darkness and through fog.
In industrial plants there are electronic counters
that enumerate passing articles faster than the eye
can see; automatic sorters which discard defective,
oversize, undersize, off -color articles; automatic cutters; devices which inspect the inside of things
which the eye cannot see; controls which protect
workers; controls of temperature; smoke eliminators; intruder alarms; automatic controls for whole
batteries of machines.
In its October progress report on American industry, the War Production Board points out that
the radio business is five times greater than a year
ago. From 20 million dollars a month last fall, it
has increased to well over 100 million dollars a
month. Unfilled war orders are in excess of 4
billion dollars.
From such vast growth will emerge a new engineering of products which will immeasurably
improve our peace-time living.
After the war broadcasting will be infinitely more
satisfactory: radio receivers will perform with a new
fidelity which will amaze us. Television reception
will be as flawless as the motion picture. Present
secret war developments will readily be convertible
to peace -time devices that will improve our standard of living.
No longer will ships collide with other ships,
with icebergs or the shore. No longer will trains
collide and aircraft crash in flight.
Garage doors will open as we approach and automatically close themselves. Electric lights will automatically go on and off according to our wants and
needs. Furnaces and boilers will be controlled and
smokestacks will cease to belch wasteful smoke. Air
will be made dust free and germ free. Food contamination will be checked, meat made tender.
Grade crossings will be made safe and auto
traffic will be automatically controlled.
www.americanradiohistory.com
Medical science secs new wonders ahead. Already
is meeting the exacting demands made upon it.
it is possible to see "whiskers" on germs, germs
Never before was electronic equipment called
which heretofore had been but a blur when viewed
upon to withstand temperatures ranging from 75
through the strongest optical equipment available.
degrees below to 150 degrees above zero FahrenToday so much secret development is going on in
heit. Never before did radios and transmitters have
the ultra -high -frequency field that little can be said
to withstand the shaking and abuse to which they
of its great future. But, without divulging military
are being subjected today.
secrets, it can be said that ply -wood is being dried
War demands have called for much redesign,
electronically in minutes instead of hours. Ultramuch change of materials and a new conception of
high-frequency welding (not to be confused with
operating to tolerances never dreamed of in peaceflame welding controlled electronically) is being
time material. As a result, electronic parts and
done dramatically and efficiently.
equipment makers are building better devices.
-highfrequency
heating
promises
Ultra
to revoUniversities and colleges are working at top speed
lutionize the baking into produce electronic endustry-it may even heat
gineers, for every radio
our homes.
operator in a plane, every
This is the sixth of a series of editorials
What is this miracle
radio man in the ground
appearing monthly in all McGraw-Hill
working tube that can see,
forces and on ships, every
publications, reaching more than one
hear, taste, feel and smell
man operating radar
and one -half million readers, and in
a thousand times more
equipment or electronic
daily newspapers in New York, Chisensitively than was poscontrol devices in ordcago and Washington, D. C. They are
sible heretofore?
nance . . and there are
dedicated to the purpose of telling the
What is the electron?
many thousands of them
part that each industry is playing in the
No one knows, not even
must be a trained
.
.
.
war effort and of informing the public
the scientists who know
technician.
on the magnificent war-production achow to employ it. ElecThe wall of military
complishments of America's industries.
trons cannot be seen or
censorship is high but it
felt; but if 61/4 million
is no secret that one of
million million electrons
Britain's best weapons
are pushed through a 100 -watt electric lamp per
that keeps the Luftwaffe from exterminating Lonsecond, it will light up to full brilliance. For elecdon is a radio locator, a device that gives alarm of
tric current merely is a mass movement of electrons.
approaching planes long before they can be seen
Each electron carries its share of electricity, and
with telescopes. Scanning the horizon constantly
since the electron has so little weight it can be movthe locator warns of the enemy's approach. In the
ed easily and quickly. Therefore, electricity transnose of a night fighter, the locator informs pilot
ported by electrons can be turned on or off with
and gunner when the enemy is within range.
great ease and speed. The electron tube merely is a
Neither is it a military secret that gunfire can be
device that controls the flow of electricity. It is an
controlled by electronics, and that electronics is
amplifier of power which can be made to do wonhaving a big share in training our new armies.
drous things. The sound of a termite gnawing inside
Necessity draws a veil over the most dramatic
of a log can be amplified a million times
to a
uses of electronics in warfare, but among those
roar that can be heard over great distances.
who know there is nothing secret about the fact
Colors can be classified and matched to a degree
that many of today's wartime applications will revonot possible by any other means.
lutionize our peace-time lives. Electronics will inChemical or vitamin consistency can be recogvade every industry with totally new devices and
nized by counting radio activity within the subject
machines. The future of the electronics industry is
being analyzed.
limited only by man's imagination.
There is no industry in which electronic circuits
Such is electronics, and its destiny!
cannot be used to speed up production, to increase
accuracy, to do heretofore impossible tasks of
calibration and measuring.
The opportunities afforded the engineers who are
developing this new "electronic age" are limitless.
.
...
Today the electronic industry
is 100M
at war. It
President, McGraw-Hill Publishing Company, Inc.
www.americanradiohistory.com
ELECTRONICS....KEITH HENNEY Editor....DECEMBER,
1
942
CROSS
TALK
PRP . . . OWI WPB states that during the peak
activity of processing fourth quarter Production
Requirements Plan applications, some 1300 people were
employed on a three shift basis on clerical work alone.
This is not nearly all the people, just in Washington,
who worked on this job.
PRP may be sickening in Washington, but to get
an idea of the great national headache it is, multiply
these clerks by the number of plants working under
the Plan, 30,000. All the aspirin in the nation cannot
cope with this situation. The truth is that PRP is
becoming hopeless. It is driving everyone nuts.
Priorities started off pretty well. So long as full
production was not attained, there was enough raw
material to go round. Then things got tough. A new
letterology had to be devised; Al jobs became Al A
jobs. Now if it makes a manufacturer any happier to
get no raw materials under an Al rating than to get
no raw materials under an A2 rating, some psychological benefit has been secured, but that seems to be
about all that has been accomplished.
The system creaks and groans. Under allocations,
a man may need two items to make up a gadget, but
one item is scarcer than the other although both are
critical. So he gets allotted to himself, 80 percent of
one item, 50 percent of the other. His production is
reduced thereby to 50 percent and is he going to refuse
to take the extra 30 percent of the item he cannot
use? Don't be silly!
The fact is there is no longer enough material to go
round. Critical materials must soon be allotted on a
technological basis and not upon a statistical basis.
PRP must soon be on the way out.
The new Controlled Materials Plan (CMP) deals at
the outset only with aluminum, copper and steel.
ELECTRONICS
...
Some time ago the editors
became interested in the appli-
TEMPERATURE
of
cation of electron tubes to the measurement and
control of temperature. The result of this sudden,
and perhaps temporary, interest was the article by
Craig Walsh in October. At the time the article was
edited, it was decided to send it to our fellow editor,
M. F. Behar of Instruments, who has spent so much
of his life in a crusade for better instrumentation
of certain variable industrial factors, including temperature. We wanted a foreword to point the article
up.
At the time Mr. Behar was busy, and then he went
away somewhere, and when he came back and was
not so busy and wrote the foreword, the article was
on the press and subsequently appeared under its
own steam without the benefit of Mr. Behar's
foreword.
Later on the foreword arrived. Mr. Behar had
really gone to town with the idea when he got
around to it. It seems that electronic engineers
have a golden opportunity in the measurement and
control of temperature ; but that the ground is only
scratched so far. The foreword, appearing in this
issue, is really an essay on the whole subject of
temperature control, telling us where to start, and
what the problems are. It is, therefore, published
after Mr. Walsh's article and not before it but we do
not believe either article suffers from this strange
editorial behavior.
Anyone having a yen to hitch a vacuum tube to a
thermometer will do well to scan Table I of this
present article. This table should re- direct the
efforts of electronic engineers into channels most
likely to produce success; it should stimulate invention and development of automatic temperature control systems combining precision and speed; it
should serve to stop the waste of energy of so many
engineers who have been intermarrying the most
incompatible mechanical and electronic devices.
www.americanradiohistory.com
A modern transmitting tube, repre-
senting three and one -half decades
of progress since the first three element tube was built
Title page and paragraph of Stoney
article in which the word "electron"
first appeared
ELECTRON
nection with his method of resolution
into plane wave fronts. This facility
in suggesting suitable terms proved
most useful when serving on the
now famous committee of the British Association which devised our
present system of electrical units,
and of which he was one of the early
members?'
WHAT is believed to be the first
published record of the word
"electron" occurs in the Scientific
Transactions of the Royal Dublin
Society for July 1891, in an article
by George Johnstone Stoney, M.A.,
D.Sc., F.R.S. A reproduction of the
original printing of the article title
page as well as the paragraph in
which the word `electron' was proposed and first appeared, is attached.
It is interesting to note that italics
were used in this original printing of
the word, thus giving it emphasis.
Stoney was born in Ireland in
1826. His whole life was devoted to
academic and government service.
His interests were wide -spread as
indicated by the fact that he published papers on astronomy, educa-
42
tion, physical optics, kinetic theory
of gases, and music. Many of his
ideas were somewhat ahead of his
time and he is a recognized contributor to the beginnings of our
modern physical concepts.
In connection with the origin of
the word `electron,' it is interesting
to note what was said of Stoney in
a biographical note' at the time of
his death in 1911:
"Stoney invariably invented a nomenclature for the quantities he was
dealing with, where none already existed. Such new terms are continually to be met with in his writings.
Many of them have been found by
others to be most convenient, and
have consequently taken root in science, as, for example, his term wavelet, employed advantageously in his
papers on microscopic vision, in con-
It is apparent, therefore, that the
origin of the suffix "tron" is not in
any way tainted with recent commercialism but, on the contrary, is
more than 50 years old and has a
thorough academic origin and background.
Professor Millikan's book "The
Electron "' devotes a portion of a
chapter to the origin of the word and
both the early and later conceptions
of its proper use and definition.
This new word, however, did not
come into common use to any great
extent in the years immediately following its initial publication. This is
indicated by the fact that the second
edition of J. J. Thompson's book
"Conduction of Electricity Through
Gases,' does not appear to use the
word anywhere in the text. This
book was used widely and considered
one of the standard works on the
subject by scientists and engineers
in the field at that time. In looking
over the text of this book, it is interesting to note the manner in which
the author discusses at length such
December 1942
-
ELECTRONICS
s
A discussion of such terms as "electron ", "electronic ", and "electronics "; some history
dealing with the early tube names and some suggestions for proper naming of electron
tubes by one who has been closely associated with vacuum tube engineering since the
beginning and is familiar with its communication and industrial applications.
By W.
C. WHITE
Electronics Laboratory
General Electric Company,
sehenectady, N. Y.
TUBE TERMINOLOGY
subjects as ionization by incandescent solids, photoelectric effects, determination of the value of a /m, discharges through gases at low pressures, cathode -rays, all without the
use of the word `electron.'
Another book used by all radio engineers during the early years of the
century was "The Principles of Electric Wave Telegraphy and Telephony" by J. A. Fleming.' The
second edition, published in 1910,
although not showing the word 'electron' in the index, does use it in describing the use of the Fleming
valve and does contain the phrase
"the electron emission from the
tungsten...
Use
."
of Terms "Electron Tube," "Vacuum
Tube," "Electronic Tube"
It will be noted that in this article the names "vacuum tube" and
"electron tube" are both used. "Electronic tube" is also sometimes encountered in publications. The recently issued (1942) American
Standard Definitions of Electrical
Terms (ASA Standards C42, published by the A.I.E.E.) under Group
70- Electronics, gives in Section 10
the following broad definition :
"Vacuum Tube
A vacuum tube is a device consisting
of an evacuated enclosure containing a number of electrodes between
two or more of which conduction of
ELECTRONICS
-
electricity through the vacuum or
contained gas may take place."
Use
of the Words "Electron," "Electronic," and "Electronics"
There appears to be some confusion in the use of the word `electron'
and its derivatives `electronic,' and
`electronics.'
Electron. The word `electron' is a
noun. It is popularly defined as "an
element of electric charge," or "the
elementary charge of negative electricity." The ASA (American Standards Associatioh) defines it as follows: "An electron is the natural,
elementary quantity of negative elec-
tricity."
In most cases this word is used in
modifying another noun and thus is
a noun used as an adjective. For
instance, it is correct to speak of an
"electron tube," "electron camera,"
"electron discharge," "electron gun,"
"electron lens," "electron microscope," "electron emission," "electron multiplier," "electron bombardment," etc. As regards "electronic
tube" versus "electron tube," the
latter is analagous to steam engine,
water tank, and vacuum pump, where
the meaning of the qualifying substantive is : operated by, containing,
or producing. It is true that we
speak of an electric motor, but this
is because the noun "electricity" is
All modern tendency
awkward.
December 1942
is toward
using the substantive
rather than the adjective in such
cases. It is apparent from the grammatical viewpoint, therefore, that
"electron tube" is preferable to.
"electronic tube."
Thus, it is correct to say "Electron
Tube Department," "Electron Tube
Engineering Department," "Electron
Tube Product Committee," and
"Electron Microscope Sales Engineer."
Electronic. This word is an adjective and is used only as an adjective. It is defined as "of or pertaining to an electron or electrons."
The suffix "ic" signifies "of the nature of, consisting of, characterized
by, of or belonging to, after the manner of, characteristic of, resembling,
connected or dealing with." Therefore, on this basis, the following
terms should incorporate this word :
"electronic formula," "electronic device," "electronic research," "electronic phenomena," "electronic engineering," "electronic equipment,"
"electronic regulator," "electronic
instrument," "electronic motor control," "electronic rectifier," and "electronic telemetering."
Electronics. This word is a noun
and is defined as "the science which
deals with the behavior of electrons."
The ASA defines it as follows : "Electronics is that branch of science and
43
TABLE
Generic
Term
Output
Energy
Character
of Space
1- Classification of Electron
Control
Means
-`Pc
,r_
Cathode
Tubes
Definitions
1
Thermionic
Reno tr on
A kenotron is a high- vacuum thermionic tube in which no means
provided for controlling the unidirectional current flow.
Phototube}
A phototube is a vacuum tube in which electron emission is produced
directly by radiation falling upon an electrode. A high- vacuum
phototube is one which is evacuated to such a degree that its electrical
characteristics are essentially unaffected by gaseous ionization.
Pliotron
A pliotron is a high- vacuum thermionic tube in which one or more
electrodes are employed to control the unidirectional current flow.
Magnetron
A magnetron is a high- vacuum thermionic tube in which a magnetic
is employed to control the unidirectional current flow.
is
one
Photoelectric
High- Vacuum
Electrostatic
Thermionic
Electromagnetic
Thermionic
Thermionic
Cold
Electrical
Phanotron
Glow
'Done
Pool
Tube
See phototube definition under "High -Vacuum Tubes ".
A gas phototube
is one into which a quantity of gas has been introduced, usually for
the purpose of increasing its sensitivity.
thyratron is a hot -cathode, gas -discharge tube in which one or more
electrodes are employed to control electrostatically the starting of
the unidirectional current flow.
Cold
Grid -Glowe
Tube
A grid -glow tube is a cold -cathode, gas- discharge tube in which one
or more electrodes are employed to control electrostatically the
starting of the unidirectional current flow.
Pool
Grid -Pool
Tube
A grid -pool tube (or tank) is a gas -discharge tube (or tank) with a
pool -type cathode (liquid or solid) in which one or more electrodes
are provided for controlling electrostatically the starting of the
unidirectional current flow.
Pool
la
A
(or tank)
Ignition
Electrode
A glow tube is a cold- cathode, gas -discharge tube in which no means
provided for controlling the unidirectional current flow.
Phototubet
Thyratron
Electronic
Tubes
(or Tanks)
is
A pool tube (or tank) is a gas -discharge tube (or tank) with a pool type cathode (liquid or solid) in which no means is provided for
controlling the unidirectional current flow.
Thermlonlc
lectrostati
Electrode
phanotron is a hot -cathode, gas -discharge tube in which no means
provided for controlling the unidirectional current flow.
A
Pool Tube"
(or Tank)
Photoelectric
Gas -Filled
field
Ignitron
Electromagnetic
An ignitron is a gas -discharge tube (or tank) with a pool -type
cathode (liquid .or solid) in which an ignition electrode is employed
to control the starting of the unidirectional current flow in each
operative cycle.
(Not used at present)
Light
Ultra- Violet
MIA
Standard
R -Rey
t
IRE Standard
Cathode -Ray
technology which relates to the conduction of electricity through gases
or in vacuo." Thus, we speak of the
"science of electronics," "experience
in electronics," and "teacher of electronics." Again, as in the case of
the word "electron," it is frequently
used to modify another noun, and
thus act as a noun used as an adjective. Therefore, it is also correctly
used in such expressions as "Electronics Department of the Cornpany," "Electronics Laboratory,"
"Electronics Engineering Department," and "Electronics Committee."
Early Tube Names
It is generally agreed that Dr. Lee
deForest was the first to apply a
new and special word to a vacuum
tube. This he did in calling his wireless detector an "Audion." In the
Transactions American Institute
Electrical Engineers for October,
1906, Dr. deForest, in his discussion
following this paper, said "Dr.
Pupin's opening remarks may serve
as an argument why the study of
Greek and Latin should be thoroughly introduced into our engineering schools. My knowledge of Greek
is almost nil ; I knew, however, that
and was of Latin and ion of Greek
derivation. But they are both expressive. Where we use a term one
hundred times a day, it is necessary
to have something brief ; we could
not expect the wireless telegraph
operators to use a long technical description of the apparatus in speaking of it, and when several types are
in use it is necessary clearly and
briefly to distinguish them ".
Dr. Pupin's remarks referred to
read as follows:
If there must
be a new name for each new detector
new name for everything that
comes up in the course of the development of the electrical art -pretty
soon the science of electrotechnics
"....
-a
44
will be a maze of new names ; and the
learning of the names will be much
more difficult than the learning of
the facts connected with the art. For
that reason I am oppoosed to new
names. Although Dr. deForest is
very enthusiastic about the elegance
of the name audion, I must say that
I am not very much impressed by it.
It is a mongrel. It is a Latin word
with a Greek ending. If he had said
acouion or acousticon it might have
been better, but more difficult to pronounce."
It is clear, therefore, that from
the very beginning there has been an
urge to create new names for new
electron tubes and, on the other
hand, the studied opinion that such
artificial words are not proper or
needed. Remarks of these two pioneers in radio sum up pretty well
the arguments that are still used
today for and against new names for
electron tubes.
December 1942
www.americanradiohistory.com
-
ELECTRONICS
Probably the first vacuum tube
names containing the suffix "tron"
were suggested by Dr. Irving Lang muir more than twenty -five years
ago in an article entitled "The Pure
Electron Discharge ".' Dr. Langmuir
introduced the name "kenotron" in
the following paragraph : "In order
to distinguish these devices from
those containing gas and in most
cases depending upon gas for their
operation, the name `kenotron' has
been adopted. This word is derived
from the Greek kenos, signifying
empty space (vacuum), and the ending, tron, used by the Greeks to denote an `instrument'." By usage the
name `kenotron' has been applied
only to the two-electrode, highvacuum tube.
Dr. Langmuir introduced the
name "pliotron" as follows: "The
term `pliotron' has been adopted to
designate a kenotron in which a
third electrode has been added for
the purpose of controlling the current flowing between the anode and
cathode. This word is derived from
the Greek pleion signifying `more'.
A pliotron is thus an `instrument for
giving more' or an amplifier. A similar use of the prefix 'plio' occurs in
the geological term 'pliocene'."
In these times when proof of citizenship is such an important factor,
it is improbable that any other electron tube can show as clear and undisputed a birth certificate as these
TABLE 2
Number of Times Word
Name
Appears in 10 Dictionaries
3 General 7 Technical
Dictionaries Dictionaries
Kenotron
Phototube
Pliotron
Magnetron
Phanotron
Glow Tube
Tank
Thyratron
Grid -Glow
Tube
Ignitron
1
3
0
3
3
2
2
4
0
1
1
2
0
0
1
4
1
3
1
1
In the years that have intervened
since the early use of special tube
names, some have been more or less
frequently employed in publications.
In other cases, the adaptation of special names has been slow. This is
easily accounted for. For instance,
the word `pliotron' was not used to a
great extent for many years because
practically the only form in which
this tube type could be purchased
and used was under the tradename
"Radiotron." On the other hand, the
words thyratron' and ignitron' came
into quite general use as soon as the
devices themselves became known
and used because they were such a
simple, one-word description of detwo.
Probably the next two electron - vices that otherwise had to be
tube names to appear were "dyna- described by several words.
tron" and "pliodynatron.fó It is inClassification of Tubes
teresting to note that although these
In classifying devices such as electwo later names are very infretubes, certain fundamental detron
quently used and the tubes which
must be made. One of these
cisions
they describe are not commonly emthe name of the tube is
is
whether
ployed, the two names themselves
based
on the way it is used or
be
to
are among the "trons" most frein which it is built. In
manner
on
the
quently included in technical dicthe naming be
words,
should
other
tionaries.
or de'dynatron',
functional,
such
as
These beginnings are what orgin-
ated the phrase "Graeco Schenectady," the creation of which is probably correctly accredited to Dr. Lee
deForest. Following these early
names, many tube and device names
were created. Some of these were
registered as trade marks. Some,
such as "Radiotron," "Tungar," and
"Rectigon," still are registered trade
marks. However, in the year 1937, the
General Electric and Westinghouse
Companies relinquished trade-mark
rights on ` ignitron', `pliotron', 'kenotron', and ` thyratron'.
ELECTRONICS
-
December 1942
`
`
TABLE
Name
3
Number of Times Word
Appears in 10 Dictionaries
3 General 7 Technical
Dictionaries Dictionaries
Dynatron
Klystron
Negatron
Pliodynatron
Radiotron
1
4
0
2
1
4
0
3
2
3
scriptive, such as `triode'? It would
appear that the descriptive term is
best because electron tubes are used
in so many fields and in so many different ways that much duplication
and confusion would result if the application were the basis of naming it.
Of course, there are bound to be
some border -line cases, and exceptions will quickly come to mind. For
instance, the term "cathode -ray
tube" is only partly descriptive. Also
"magnetron" is simply a high vacuum, hot -cathode diode and thus
is similar to a kenotron. In this latter case, however, structurally these
two tubes will always be very different.
Another fundamental is in a broad
classification into which tubes are
grouped. Here again, it can be descriptive of the tubes themselves.
Such a classification contains four
variables : (1) Number of electrodes;
(2) the bulb content; (3) the nature of the cathode ; (4) special features, such as control methods or
other unique items.
The words to describe this grouping of variables are pretty well established.
(1) The number of electrodes is
covered by the words `diode,' `triode,'
`pentode,' `tetrode,' etc.
(2) The content of the bulb may
be high- vacuum, gas, or mercury vapor.
(3) The cathode may be thermionic, pool, photoelectric, etc.
(4) The special features of a tube
may involve specific methods of control, such as the ignitor, or special
features such as the fluoresc-ent
screen, or the use of a pump to maintain vacuum.
By keeping the above group of
variables in mind, it is easy to describe practically all of the tubes in
existence at the present time. Thus
we have a gas- content, hot- cathode
triode, or a mercury-vapor, pool cathode triode with an ignitor.
It is very apparent, therefore, why
special words have come into accepted use for specific classes of
tubes. For instance, the word 'thyratron' is much easier to use than
the phrase `gas- content, hot -cathode
triode' mentioned in the last paragraph. In a similar way, 'ignitron' is
preferable to the cumbersome 'mercury-vapor, pool- cathode triode with
ignitron starting.' It is undoubtedly
(Continued on page 154)
45
AIRCRAFT ANTENNA
Pratt & Whitney -powered Vought seaplane designed for use as a
scout bomber and normally catapulted from the decks of battle-
ships and cruisers. Characteristics of this particular ship's radio
antenna, from cockpit mast to tail -fin, are readily estimated
E ACCOMPANYING CHARTS
By PAUL J. HOLMES
provide a simple means of deChief Engineer
Stoddart Aircraft Radio Co.
termining the approximate electriHollywood, Calif.
cal characteristics of fixed aircraft
antennas by measuring their length, largely upon the physical size of the
making some slight allowance (dic- airplane as compared to the length
tated by experience) for their prox- of the antenna. The upper dashed
imity to the fuselage or for the size line on the right side of the chart
of the ship.
is representative of a small airplane
Data obtained through the use of and the solid line represents a large
the charts facilitates actual measure- airplane.
ment of antenna characteristics and
The variation shown on the left of
is, ordinarily, sufficiently accurate to the vertical dotted line (lengths
permit design of dummy antennas under 45 ft.) depends largely upon
needed when bench-testing aircraft the proximity of short antennas to
radio equipment.
the metal fuselage of the airplane.
The solid line on the left side of the
Quarter -Wave Resonance
chart is representative of an anChart 1 is used in determining the tenna reasonably distant from the
approximate length of fixed aircraft fuselage, such as one running from
antenna for quarter-wave resonance. a wing-tip to the aft portion of the
The intersection points of the verti- fuselage. The dashed line immedical lines (measured length of an- ately below the solid line on the left
tenna) and the horizontal lines side of the chart represents a short
(quarter -wave frequency) with the antenna close to the fuselage, such
plotted angular lines indicate the as one run from a short mast near
quarter-wave resonance frequency the cockpit directly aft over the
for any length between 10 and 100 fuselage to the fin of the plane.
The following example illustrates
ft.
The variation of the angular lines the use of Chart 1: Assume a meason the right of the vertical dotted ured length of antenna as 47 ft.
line (lengths over 45 ft.) depends From the chart, the quarter -wave
resonance frequency is seen to be approximately 5 Mc. If the plane is
small, the resonant frequency will
be greater than 5 Mc, if large it will
be less than 5 Mc.
Inductance, Capacity. Resistance
Chart 2 is used in determining
the equivalent electrical components
of an antenna at various operating
frequencies. In addition to determining such characteristics at the quarter-wave resonance frequency the
equivalent capacitive or inductive reactance and radiation resistance at
operating frequencies above or below quarter-wave resonance may be
readily determined.
As an example, the equivalent
electrical components of the 47 ft.,
5 Mc quarter -wave antenna discussed
above may be determined for an operating frequency of 3 Mc.
The vertical lines marked across
the bottom of the chart from 0.1 to
3.0 represent the ratio of the selected operating frequency to quarter -wave resonant frequency, the latter being determined by use of Chart
1, i.e.
selected operating frequency
quarter-wave resonant frequency
December 1942
46
www.americanradiohistory.com
-
ELECTRONICS
CHARACTERISTICS
By measuring the length of a fixed aircraft antenna, making some empirical allowance for
its proximity to the fuselage or the size of the ship, reactance and radiation resistance may
be estimated with sufficient accuracy to permit the design of a dummy antenna
The horizontal lines marked on the lowing the vertical 0.6 line to the
zontal line as read on the left.
The lower, solid angular lines
right of the chart represent the an- point where it intersects the dashed
tenna's reactance in ohms. Those rectance curve and then proceeding mark in terms of capacity values
below the center or zero line to the right, the reactance is seen to which, when multiplied by a factor
indicate negative or capacitive reactance (operating frequency less
than quarter- wave). Those above
the zero line indicate positive or inductive reactance (operating frequency greater than quarter- wave).
The common intersection point of
the horizontal lines with the dashed
reactance curve and the vertical
lines indicates the reactance of the
antenna at the selected operating
frequency.
Assume the quarter-wave resonant
frequency as 5 Mc (measured length
47 ft.) . The reactance of this antenna at an operating frequency .of
3 Mc is found as follows: Divide the
3 Mc operating frequency by the 5
Mc quarter -wave resonant frequency.
The quotient is seen to be 0.6. Fol-
be about
- 325 ohms.
Referring again to the chart, the
upper horizontal lines are marked on
the left. These numbers at the left
represent the radiation resistance in
shown on the chart, produce a capacitive reactance equal to that of
the antenna. For example, the effective value of capacitance of a 47
ft. 5 Mc quarter-wave antenna at an
operating frequency of 3 Mc is
found as follows: The vertical 0.6
line intersects the reactance curve
ohms of the antenna. The common
intersection point of these horizontal lines with the solid resistance
curve and the vertical lines (ratio at a point just slightly higher than
of operating frequency to quarter- that of the 75 µµf capacity line, inwave resonant frequency) indicates dicating a value of capacity greater
the radiation resistance of the an- than 75 µµf or approximately 80
tenna
the particular operating µµf. This value of 80 µµf, when
frequency chosen. Thus, the radia- multiplied by the 10Mc /5Mc is 160
tion resistance of the 47 ft., 5 Mc µµf, which is the effective capacity
quarter -wave antenna at an operat- of the 5 Mc antenna under discussion
ing frequency of 3 Mc is seen to be when operated at 3 Mc.
The upper, solid angular lines
approximately 1.9 ohms as the 0.6
vertical line intersects with the re- mark in terms of inductance values
sistance curve and the 1.9 ohm hori- which, when multiplied by a factor
la
CHART 1-Approximate
lengths of fixed aircraft antennas for quarter -wave resonance are shown graphically.
pirical variations caused by proximity of the antenna to the fuselage and the physical size of the ship are indicated
Variation Depends
upon Proximity
of Antenna to
Fuselage,4
C
0
v
}
'
20
l'
Á
Center Fed
V' Antenna
OFF Center Fed
V "Antenna
°
B
14`.
Off Center Fed End Fed
Single Wire Single Wire
Antenna
15
Antenna
Measured Length =A +B\
A = Feeder
> 12
B=
Em-
-
Antenna
Variation Depends =
upon Physical Size of Plane
,....Center Fed
"Vu Antenna
2
10
12.5
15
17.5
20
25
30
35
40 45 50
Measured Length of Antenna
in
Feet
60
70
80 90
100
antenna at various operating frequencies may, then, be readily dequency of 5 Mc. At an operating termined by the following procedure:
frequency of 3 Mc it is found to
(a) Measure the length of the anhave a capacitive reactance of
325
tenna from the antenna insulaohms and a radiation resistance of
tor on the skin of the fuselage to
its -farthest point. If the an1.9 ohms. The value of reactance is
tenna is an off center fed "V ",
equivalent to a capacitance of 160
do not include the short side.
µµf. Thus, a good grade air dielecMeasure the length of lead to
tric capacitor having a capacitance
the "V" plus the length of the
longest side of the antenna
of 160 µµf, in series with a non proper to determine the measinductive resistance of approxiured length of the antenna.
mately 2.0 ohms would simulate a
47 ft. antenna at a frequency of 3
(b) From Chart 1, determine the
freresonant
quarter -wave
Mc. This would constitute a suitinto consideration
quency,
taking
able dummy antenna for the bench
the size of the airplane if the
testing of aircraft radio equipment
antenna is long or the proximity
to be installed in an airplane having
of the antenna to the fuselage
if the antenna is short.
an antenna 47 ft. long and operated
on a frequency of 3 Mc.
(c) Determine the ratio of selected
The characteristics of an aircraft
operating frequency to the
quarter -wave resonant frequency
47 ft. aircraft antenna is found to
be quarter-wave resonant at a fre-
shown on the chart, produce the
equivalent inductance of the antenna
at the particular operating frequency chosen. The inductance value
is found the same way as capacitance, outlined above, using the
angular inductance lines instead of
the angular capacitance lines.
(It is important to note when using
the chart that the capacitance lines
are used only when the antenna has
capacitive reactance at the operating
frequency, i.e less than quarterwave frequency. The inductance
lines are used only when the antenna
is inductive, i.e. greater than quarter -wave frequency.)
-
Estimating Procedure
To review the examples illustrated,
by the use of the antenna charts a
-
1,000
'
i
10,000
1111110111111111111
1
OIIIIII1boha!
li%t
MOI--...IMM.I
100
.
t
15
Inductance
.
--...
ll
----.
/ii
!
ts......
.t....
am=
Ma
1\
O.4N==
11111il!;itlIINN
Zµñ
10
l
h
_.ar
1
11!LJ
5,rh,
Resistance
100
11!:ílllf11111Nm
I!!HII!HI
ma
on
-
ih
'l
111111111111
1114i:i
f Ml
=
DAIDr
INI
iOM
f
ANIMU......Li:
15111511. °_.H
wIlIr111i:
MI111its11U
E
0
Mut tipl y
capacitance
by
IO Mc
Ì
.
w11cílni
tr. .EINE--------ti
-----/]/.---........-....
0.
0.5
0.3
c
+
CY
i!4 Freq. in Mc
eactance 11A`//%l1IM111INIMIC ReactanceIMMIMMIIIIMILIIIMIMPOIIIIIMIIIIMM2111
MNIMIIIIIIIIMMI11111111111111/211
t....... ti.l..... ti tin,
0.1
10
o
10
MIMNIII
t
i
v-
211=111111
.
Reactance
(d) Determine the reactance by the
common intersection of the applicable vertical line, the dashed
reactance curve and the nearest
horizontal line, reading the reactance value on the right side
of Chart 2.
(e) Determine the effective capacitance or inductance by multiplying the value of capacitance or
inductance found on the solid,
angular line intersecting the
point on the reactance curve obtained in connection with (d)
above, by the factor shown on
the chart.
1,00 0
,%
!iÌf:1
10
Ó 0.79
0.8 .0
1
.5
I
2 .0
100
the radiation resistance by the intersection of
the vertical line obtained in (c)
with the resistance curve and
the nearest horizontal line, reading the value on the left.
Both charts were compiled empirically and are the average of the characteristics of a number of antennas
of different lengths and types on
various types of airplanes.
(f) Determine
m
u
a
a
U
1,000
5,000
3.0
1.0t
Operating Frequency
Resonant Frequency
1/4
by dividing the operating frequency by the previously noted
quarter -wave frequency. This
numerical value coincides with
the numerical value of one of
the vertical lines on Chart 2.
www.americanradiohistory.com
CHART
2-
Approximate electrical
characteristics of a fixed aircraft antenna
operated above or below the quarter -wave
resonant frequency may be determined by
using the chart as outlined in this text
Amplified tuning -fork output power supply avoids synchronous clock variations caused by wartime overloading of a -c mains. Accurate to one -third second per day
Precision
TIME CONTROL
time -keeping
power supply system is now
in operation in National Broadcasting Company studios and control
rooms at New York. Synchronous
electric clocks connected to this precision system do not vary more than
one-third second a day. Similar installations are being made at divisional headquarters in Chicago, Hollywood, San Francisco, Washington,
Cleveland and Denver. Affiliated stations on the network may compare
their own clocks with the precision
system by listening to the NBC time
signal, transmitted twice daily from
Radio City.
Wartime conditions created the
need for this time system. Most electrical power distributing systems
throughout the country have been
affected by the heavy demands of
war industries. As a result, many
network operating divisions have
encountered deviations in the frequency of a -c supply lines to which
electric clocks are ordinarily connected. As far as the public is concerned, these deviations are not imAHIGHLY ACCURATE
portant since they are small in magnitude. In network operation however, seconds count and any lack of
synchronization between stations
may confuse the switching operations of an entire coast -to -coast network.
Special Tuning Fork
The precision clock control system,
perfected under the direction of O.
B. Hanson, NBC vice president in
charge of engineering, is based
fundamentally on the use of a special
tuning fork operating in a vacuum
chamber. The output of this fork,
vibrating at a natural rate of 60
cps, is amplified by vacuum tube
sufficient
equipment generating
power to operate 200 synchronous
clocks.
As a check on the absolute accuracy of the system, the master
clock in each divisional headquarters
will eventually be compared daily
with the time signals transmitted
by radio from the U. S. Naval
Observatory.
Since reliable and continued op-
Simplified diagram of precision clock control system.
a -c generator, driven by an a-c motor powered from
mains, drives a 60 cps tuning -fork unit and the amplified
put of the fork operates the synchronous clocks. Should
An
the
out-
the
65 cps
Secondary Forres
'1
55cps
eration of a time control system depends upon the unfailing continuity
of its power source, precaution was
taken during design to prevent interruptions due to power line failures. The equipment provides for
such contingencies. Normally, the
apparatus draws power with which
to drive the tuning forks and energize the amplifiers from city power
mains. If this source fails, automatic devices connect the clock control equipment to a reserve power
source derived from storage bat (Continued on page 156)
mains fail, the a -c generator is immediately driven by a
d -c motor operated from storage batteries. To speed up or
slow down the clocks. a 65 cps or 55 cps fork is substituted
for the 60 cps fork
-
Tuning
fork unit
60cps
To
NBC's O. B. Hanson adjusts a control on
one of the four panels comprising the
Radio City precision clock control system
,Au/v. correction
con t
H
Amp. I--
-i
A
clocks
ó Holdup
1p
nStudio
e coil
booth clocks
H Amp. F-.
power mains
T
K No/dupc01/-"o
/
J,
e
32v. d.c.
1770t:
Stor.
-_-- >-
110v.
3
mot,,
1
74Common
-l!0.<u.c.
IICn.
shaft
bat
www.americanradiohistory.com
Power factor
corr.
RADIO in
A woman civilian checks up on the com-
munications equipment of a tank
New "guidon" radio, a combination transmitter- receiver. (right) Reminiscent of the
lance carried by mounted knights and,
more recently. of cavalry pennons, it may
be spiked into the ground
Electrical noise affecting radio reception is
suppressed
points
at
s ix
in Army
vehicles
rep- in close contact with each other.
resenting the last word in techEquipment used by the Infantry,
nical design is essential in modern Artillery, Cavalry, Motorized Diviwarfare and the Signal Corps is see- sions and the Air Force is as reliable
ing to it, with the help of the nation's as loving care in construction by
electronic equipment makers, that home -front workers with a growing
American Army men have the best appreciation of the importance of
there is.
their labor can make it. Installation
Telephone, telegraph and other and maintenance in the field must be
wire-connected devices are playing a handled with equal efficiency and it
vital part in the winning of the war is here that the Signal Corps can
but upon radio and closely allied "air- use all the technical skill that men or,
borne" services falls the exacting for that matter, women with elecburden of keeping highly mobile units tronic experience offer.
COMMUNICATIONS EQUIPMENT
December 1942
www.americanradiohistory.com
-
ELECTRONICS
the
U. S. ARMY
Command car gear includes 'phone and icw. Radio
apparatus installed in these galloping gas -buggies must
be built to "take it"
Stepping a base -loaded antenna on a tank (left) röquires considerable gymnastic ability as well as a
thorough knowledge of what the equipment itself is all
about
Signal Corps men erect a rotary beam antenna.
Some of the arrays now required for military purposes exceed commercial varieties in complexity
Two feminine workers from the General Development Lab release a transmitter equipped meteorological balloon. More and more women are being trained
for such work
www.americanradiohistory.com
Graphical Determination
of Power Amplifier Performance
Complete performance of Class B and C power amplifiers may be obtained graphically
from static characteristics of tube, through use of plastic calculating device. Results
obtained quickly from routine schedule involving only arithmetic operations
By
ROBERT
I.
Illinois Institute
SARBACHER
Technology
Chicago, Ill.
of
WHEN it is desired to obtain
the complete dynamic characteristics of a power tube, it is often
more convenient to employ a method
of graphical analysis to obtain this
information, than to test the tube nates chosen depend upon how comdirectly. A number of such methods plete it is desired to make the analyof analysis have been developed sis and will, in general, be different
for a five -point analysis than for a
which involve graphical integrations
of the current waveform, obtained seven, nine, or eleven -point analysis.
from the static characteristic curves For an analysis of any number of
of the tube. The calculating device points, the proper selection of ordinates may be determined from the
to be described here may be adapted
method outlined in Dr. Chaffee's arto these various graphical analyses.
By its use the calculating process ticle, but a detailed understanding
of this article is not necessary for
may be simplified and the time required to make the calculations ap- the present application.
preciably reduced.
Design of Calculator
In the example prepared in the
following discussion the harmonic
The calculating device consists of
analysis, developed by E. L. Chaffee, a sheet of clear acetate -base plastic,
has been employed. This method of having a thickness of thirty or forty
analysis, which has been discussed thousandths of an inch. Its over -all
elsewhere,' is exceptionally accurate size depends upon the size of the
and is easily adapted to the calculat- sheet upon which the static characing device. It is based upon the deter- teristic curves of the tube to be
mination of selected ordinates along analyzed are plotted. The device is
a cosinoidal voltage axis, and the ad- especially adapted for use on the
on Fig.
1 have been found convenient. Lines which are marked A, B,
C, D, E, F, are drawn or scratched
with a sharp metal object on the surface of the plastic sheet. These lines
are spaced in such a way as to divide
a straight line passing through Q
and any point on the curve A in a
definite proportion, depending on the
type of analysis used. The proportion required by the Chaffee analysis
is indicated in the figure. A small
strip of plastic about
inch wide
and 12 inches long, with a straight
line ruled down its center, is pivoted
to the plastic sheet at Q, as shown
in the figure, in such a way that the
line on the strip passes through the
point Q. This strip is designated
G in the figure. A hollow rivet is
used in order that a thumb tack or
glass push pin may be inserted
through the device at this point. The
hole in the rivet should be of the
proper diameter to provide a close
fit with the shaft of the push pin.
The curves A through F, shown in
Fig. 1, may represent any convenient
vantages and simplicity of this plate voltage -grid voltage character- spiral such as r = a° 1 or r = AO
method of harmonic analysis lie in istics of the tube. These characteris- in polar form. The data for these
the fortuitous selection of these tics are often referred to as the spirals may be calculated from tables
ordinates. In general the ordinates e, - plane of the tube. When this available in a standard handbook.
are not equally spaced, nor are they plane is not available, it may be used In the construction of the series of
erected at equal intervals along the in a manner to be described later. If spirals shown in the figure, the folvoltage axis, although both of these the static characteristics of the tube lowing procedure was used. The
conditions may be true in certain are plotted on conventional 84 by 11 curve A was first plotted carefully
special cases. Moreover, the ordi- inch paper, the dimensions indicated according to the equation R = a° 1,
-
ee
-
52
December 1942
www.americanradiohistory.com
- ELECTRONICS
12.5"
1
p
G
STRIP OF ACETATE-BASE
PLASTIC
--
--
AT
0.5"
--
i-
LONG
ED U NE
CUT
FROM ACETATEDOT-BASE PLASTIC
--- - - --y
SHEET
}
i--
/
CURVE A IN POLAR.
/FORM IS. R =A -1
WHERE a = 1;66
`N\ \\
\
\
.n
\
/
i
/i
ui
Alb i
I
1
l'
1
e
A
I
C
CALCULATING DEVICE
FOR CLASS B
AND
C
OPERATION OF POWER TUBES
IAV.= 0.0833 0.5A +B +C +D +E +F(
II
= 0.0833 A+I.93B +1.73C +1.41D +E +0.52F1
= 0.0833
= 0.0833
I4 = O.0833
15 = 0.0833
16 = 0.0833
I2
I3
(
QA
A +1,736 +C-
E- 1.73F)
A +141 B- 1.41D- 2E- 1.41F)
A +B- C -2D -E+ F)
A +0.52 B- 1.73C- 1.4ID +E- 1.93F)
A- 2C +2E)
QB =0.966R
= 1.000R
--
E
D
USE
F
RIVET
ON.ep --eg PLANE ONLY
19
= 0.0833( A- 0.528- I.73C +1.41D +E-1.93FI
= 0.0833( A- B- C +20 -E -F
= O.O833(A- 1.418 +1.41D- 2E +1.41F)
110
=0.0633(
111
= 0.0833(
AA-
112
=0.0 833(
A
LIS
= 0.0833(
17
IS
QC= 0.866R
-
1.938 +1.730- 1.41D +E-052F(
1.938+ 1.730 -1.41 D +E- 0.52F(
O.SA- B +C- 0+E -F1
Fig. I --Calculating device for power tube analysis in Class B and C operation consists of two
=0.707R
0,E= 05001R
tube plotted on the e, -e, plane are
shown in this figure. The first step
in the process of obtaining information for the dynamic characteristics
of the tube is to locate a desirable
quiescent point on this diagram.
This follows from the pre -selection
of the polarizing potentials to be applied to the tube. This will, of course,
be done in accordance with the particular conditions and requirements
of the problem. The next step is to
select several likely positions for the
end point of the path of operation.
Let point A of Fig. 2 represent one
such end point. Then insert a glass
push pin through Q on the calculator
at the quiescent point, so that the
calculator is hinged at this point. Adjust curve A to pass through the
end point of the path of operation.
Application of Calculator
Join this point and A with the line
on arm G. Record both plate and
An example is shown in Fig. 2 of grid currents under the intersection
the way the calculator is used. Repre- of the line G and the curves A
sentative characteristics of a power through F. These values may be sub-
-
WITH LINE ON ARM G RECORD CURRENTS
AT INTERSECTION OF LINE G AND CURVES
ATHROUGH E. EQUATIONS GIVE AVERAGE
AND MAX. CURRENTS
Q.
1
1
I
1
:
0.2598
pieces of plastic, marked as shown and fastened together at Q by means of hollow rivet
where a = 1.68 for values of O in
steps of 10 deg. from O = 0 to B =
270 deg. Radial lines were drawn
from Q spaced 10 deg. apart to facilitate the plotting. The length of
these radial lines lying between the
curve A and the point Q were then
divided proportionately, in accordance with the schedule given in the
figure. The remaining curves B
through F were then drawn in as
shown. The plastic plate was placed
over the drawing, and the curves
traced on the plate with a sharp
pointed scriber.
The scratched
grooves were filled with black ink.
When the thin strip G with the
straight line drawn on it is riveted
to the plastic plate, as mentioned
above, the calculator is ready to use.
ELECTRONICS
I
PLACE GLASS PUSH PIN THROUGH Q AT
QUIESCENT POINT. ADJUST CURVE A TO
PASS THROUGH END POINT OF PATH OF
OPERATION. JOIN THIS POINT AND Q
1.738 +C- E +1.73F1
12.5
Q
December 1942
stituted in the equations of Chaffee,
as illustrated in the following
example.
Examples of Use
With the plate polarizing potential
= 2000 volts, and the grid polarizing potential E,.. _ -160 volts,
(twice cutoff) the quiescent point Q
is located as shown in Fig. 2. An
arbitrary end point A* for the path
of operation is located as shown in
this diagram. It was chosen in this
case to be at the intersection of the
line e, = e,= 240 volts and the line
of constant plate current, 700 ma.
For this end point the maximum
grid excitation voltage eT = 240
(
160) = 400 volts and the maximum alternating voltage across the
plate tank circuit is ED, = 2,000
Ebb
- -
-
At this point the total instantaneous current is 4a + G = 700 + 235 = 935 ma.
Since the total emission of the filament for
this tube is 400 ma., the choice of this Operating point represents a factor of safety for
the filament of more than 4.
53
www.americanradiohistory.com
THROUGH
OINSERT
PUSH -PIN
RIVET AT QUIESCENT POINT
eb
IL
t
OIL
o 4,?,
-
(VOLTS)
o
Ç
IJ
P
h
2 -The plastic calculating device superimposed upon the er, -e characteristic of the power
tube. The calculator is
placed on the graph with
its pivot at the quiescent
operating point, Q, and
is then adjusted so curve
A and strip G intersect at
the end point of operation
at A. Important electrical
Fig.
TYPICAL
CHARACTERISTIC
CURVES OF A TR IODE
STATIC
/p
_--
Q
,
\
CONSTANT PLATE
LINES OF
ó
2.000
O
LIN ES
611
Ia
o
CONSTANT
CURRall
values are read off from
the tube characteristic at
points where the straight
line of strip G intersects
the various spirals
a
\ i,;
i '
lu
o
CURRENT
;
X
``
/
111
;
'
%AIL
ADJUST CURVE A TO PASS
THROUGH END POINT OF PATH
OF
OPERATION.
0
ó
I
L
ADJUST
ARM G SO THAT UNE ON IT PASSES
END POINT OF PATH OF OPERATION, A.
THROUGH
Eg1 Tri
RECORD CURRENTS AT INTERSECTION OF
CURVES
A, El.
CD,E,AND
F
= 1,760 volts, peak value.
The currents recorded at the intersection of the curves A, B, C,
D, E, and F, and the line G for the
case shown in Fig. 2 are
240
Plate Circuit
A = 700 ma
B = 675 ma
C = 575 ma
I) = 400 ma
E = 165 ma
F = 2 ma
Grid Circuit
A = 235 ma
B = 200 ma
C = 120 ma
D= 40 ma
E= 11 ma
F = Oma
Equations for the currents given by
the Chaffee thirteen point analysis
are as follows:
54
I,,, = 0.0833 (0.5A + B + C + I) + E
(1)
+ F)
I, = 0.0833 (A + 1.93B + 1.73C + 1.41D
(2)
-+ E + 0.52F)
E
I2 = 0.0833 (A + 1.73B + C
(3)
1.73F)
2E
1.41D
13 = 0.0833 (A + 1. 41
(4)
1.41F)
B-
-
-
74=0.0833(A+B-C-2D-E+F)
+
-
1.73C
0.52B
+ E + 1.93F)
2C + 2E)
16 = 0.0833 (A
1.73C
I, = 0.0833 (A
0.52B
+ E 1.93F)
Is = 0.0833 (A
-
-
(5)
1.41D
(6)
(7)
+ 1.41D
(8)
78=0.0833(A-B-C+2D-E-F)(9)
Is = 0.0833 (A - 1.41B + 1.41D - 2E +
(10)
1.41F)
ho = 0.0833 (A - 1.73B + C - E +
(11)
1.73F)
Ill = 0.0833 (A - 1.93B + 1.73C - 1.41D
(12)
+ E - 0.52F)
= 0.0833 (0.5A - B + C - D + E
(13)
- F)
I12
Where
represents the average
current,
I, represents the fundamental current,
IA represents the loth harmonic current.
I,,,.
By inserting in Eq. (1), the plate
current values read from the graph
and tabulated above, we obtain the
average plate current: I. = 0.0833
(0.5 X 700 + 675 + 575 + 400 +
165 + 2) = 180.6 ma. From Eq. (2)
we may obtain the maximum value
of the fundamental plate current by
similarly inserting the appropriate
December 1942
-
ELECTRONICS
1000
Fig.
3
-A
set
of
z000 ,-I
static
750
1500
1
11,
1
I
I
4-Static
curves in
the e,, -e, plane, constructed from Fig. 3, with
calculator superimposed.
Note the arrows, radiating
from point A, indicating
means for improving certain types of performance
of power tubes
s0o
/
STATIC
ATIC
,00
CHARACTERISTIC
OF A
CURVES
TRIODE.
370
1--41,
-
no
1..
E50
200
,
-e5= 400
Iso
fr!pci:IEs0
1'/
Dy
.f
11
--
0
0
woos.
'@iN.
i11
2,U
250
s
41110
11{
500 1000
Fig.
'
ec=500
characteristics in the iG -e,,
and i, -er, planes corresponding to the eve,'
curves of Fig. 2. This
type of characteristic can
be used with the calcu'ator by converting them to
the curves of Fig. 4
i
__
-
........
500
1000
VOLT.
100
_
------- E00
--
Is o
_
o
2000
1500
eb
D
2500
.a.TS.
=
recorded above I.
0.0833 (700 + 1.93 X 675 + 1.73 X
575 + 1.41 X 400 + 165 + 0.52 X 2)
= 310.5 ma.
From Eqs. (3) through (13) we may
obtain in a similar manner the maxi-
current
eb
cP0OVOLTS
ERO
-
PLATE
CURRENT
mum value of any of the harmonics
flowing in the plate circuit.
In the grid circuit the average
2000
^-
PATH OF
LINE OF CONSTANT
OPERATION
,so.
7
CURVES iROY
CALOV.ATO-
looD
766
--
_-
grid current is obtained through a
similar procedure to give: LA =
0.0833 (0.5 X 235 + 200 + 120 +
40 + 11 + 0) = 25.3 ma, and the
maximum value of the fundamental
grid current is IPI, = 0.0833 (235 +
1.93 x 200 + 1.73 X 120 + 1.41 X
40 + 11 + 0.52 X 0) = 117 ma.
Similarly the harmonic amplitudes
in the grid circuit may be calculated.
With this information, the operating characteristics of the amplifier
may be calculated as follows: The
power output is given by
P, = %EPt=I
=%X 1760X0.3105--
CURRENT
Ili
1550
1120
-
PLATE
CORREEPONDIN. TO APPROX. THREE
TINES THE AVERAGE PLATE CURRI T
ALLOMA---
-
-
IINTANTANEOVS
pI,i j/
OIL
=-L40
I
I08_
,;
_
0
/
S
-e
o
o
8
Il
1
ELECTRONICS
O
O
273 watts
, Cc
j(',b'
0
I
O
p
;!í/
The d.c. power input to the amplifier
P
is
361.2
=
E551,,..
= 2000
X
0.1806
=
watts.
The apparent ** plate dissipation is
ISf
,
%///
.... //.(('%?
-1\1 Pi..
< ,,,///
300
_._
__
(a)
e_ee_I,wI
e
st
-
,
.,,
,
INCREASES PLAT
DISSIPATION
AVERAGE PL. TE CURRENT
ANO
P= Pn -P5= 361.2 INCREASES
POWER
OUTPUT
e
G
273
=88.2
watts.
This value is well within that specified by the manufacturer as the
maximum allowable plate dissipation. The plate efficiency is then
1
-
INCREASES PLATE¡ EFFICIENCY AND
EQUIVALENT FIATE RESISTANCE
December 1942
INCREASES MID
DISSIPATION AND
DRIVING POWER.
273 X100=75.6
77,=Pa8X100= 361.3
percent
55
R,,
The equivalent load resistance,
may also be calculated as follows:
L.,,
CR.,,
5680 ohms
RL
ED.N,
1760
I,,,,
310.5
X 1000 =
This relation together with that
of the effective selectivity
( Q.!,
= COL'') and the frequency de-
R.,r/
sired enables us to calculate the constants for the tank circuit.
In the grid circuit, the driving
power is given by
Pd= 3/Egi,NIGiN,= 3/X400X0.117 =234
watts.
The power supplied to the grid resistance to maintain the grid bias,
or the power delivered to the grid
polarizing source is
PD = EG,IG, = 160 x 0.0253 = 4.05
watts.
If a grid resistance is used to supply the grid bias, its value is
Ro,
=
163
6320 ohms.
0.0253
The apparent power dissipated at
PG = 23.40
the grid is P,, = PG
4.05
=
-
-
1935 watts.
Other assumed positions of the
end point of the path of operation
may be investigated in a similar
manner. When the results of these
calculations are collected, it is possiThe true plate dissipation may differ
from the apparent plate dissipation because
of the existence of secondary emission or ion
currents in the tube.
RATE
CORNENT
REGION
Lb' o
RESTRICTED
DUE
TO
PLATE
REGION
EXCESSIVE
DISSIPATION
5- Regions of
normally restricted
operation due to
limitations of tube
rating
Fig.
!%/r,,,,,,
(ATEO REGION
YOST DEaRULE NESION
FOR END POINT OF PATH
Of OPERATION
ANo C
IN
DUE
TO
RATE
CLASS
OPERATION.
EXCESSIVE
AND
SRC
DISSIPATION.
+e
ED
REGION
DUE
TO EXCESSIVE
GRID DISSIPATION.
56
ble to select the conditions which
will best meet the requirements of
the problem on hand, while keeping
within the manufacturer's tube ratings. If complete dynamic characteristics are desired, they may be obtained by calculating the performance data for a number of paths of
operation whose end points are
evenly spaced over the entire characteristic surface. These data may
be prepared as suggested by Chaffee in his discussion of the operating
characteristics 6f power tubes.' One
will then have available all of the information concerning the possibilities of the tube for the given polarizing potentials chosen.
An example of how the calculator
may be used when the static characteristics are not available on the
e,, -e, plane, but are available on the
i,, -e, and i0 -eb planes will be given.
For convenience characteristics for
the same tube are used. Naturally
the same final results are obtained.
Suppose it is desired to determine
the performance of a tube, operating
as a Class C amplifier, whose static
characteristics are shown in Fig. 3.
The maximum variations in grid
voltage shown in this figure are from
e, = -100 volts to e, = +500 volts,
and the plate voltage variations are
from eb = 0 to eb = 2500 volts. Construct the e,, -e, axes shown on Fig.
4 on suitable graph paper. The voltage scales for these axes are selected to include at least the maximum voltage variation mentioned
above. It is convenient to draw on
Fig. 4 the line of zero plate current.
This is approximately a straight line
passing through the origin of the
e5-e, plane, having a slope equal to
the negative of the amplification factor of the tube. Now the manufacturer's specifications for a tube
usually give the maximum plate voltage that is permissible in this class
of service. Using this value of voltage which is consistent with the requirements of maximum power output and efficiency for the tube, we
may now select the grid polarization
to be used. This voltage may be
chosen as twice the cut -off value.1This establishes the quiescent point,
as indicated in Fig. 4. Construct a
line, OAK, on the eb -e, plane for
e,, =e,,. On this line indicate the point
at which the instantaneous plate current is approximately three times the
maximum average plate current allowable. This point will now be used
as the end point of the path of operation as is indicated in Fig. 4. A
numerical example will be carried
through for this end point. If sim-
ilar calculations are carried through
for others in the neighborhood of
this one, the conditions of operation
which are best suited to the design
requirements and which are within
the manufacturer's limitations specified for safe operating conditions,
may be found. If the above procedure
is followed, the operating conditions
which will be obtained will be very
nearly the correct conditions for the
tube. If, instead of using the line
eL =eA, we use a line eb= 0.8e0, it is
possible that the power output and
efficiency may be slightly better than
in the former case.
After adjusting the calculating device as indicated in the previous example, we may tabulate the voltages,
both plate and grid, which lie under
the intersection of the arm G and
the curves A through F as follows:
A
ib
i.
240
240
B
300
225
C
Dl
E
F
475
755
1550
185
120
1120
40
-60
At the points indicated in the ib -eb
diagram, Fig. 3, we may read the instantaneous plate current that exists
at these points. Similarly, on the
iC -e, diagram we may read the instantaneous grid currents.ft For the
case illustrated they are
A
ib
io
700
235
BC DE
675
200
575
120
F
400
165
2
40
11
0
substitute these instantaneous values of current in the
equation given previously and proceed with the calculations in a similar manner to that done in the first
We may now
example.
The arrow directions shown in
Fig. 4 indicate the general way the
operating conditions vary as the
end point of the path of operation is
moved within the region enclosed by
the dotted lines. If, for example,
efficiency is a primary consideration,
we may choose to move A in the direction (d). This will increase the
efficiency and equivalent plate resistance required, but will reduce the
power output. There will be but
t The value of twice cut -off, although
widely used is not an optimum. Experience
with a variety of tubes indicates that l.ti
tithes cut -off voltage is more nearly correct.
tt Yote that these values do not form a
straight line when plotted in Fig. 3. The difference is. of course, due to the harmonic
currents which flow.
(Continued on page 158)
December 1942
-
ELECTRONICS
CIRCUIT ELEMENTS IN
Electrical Remote Control
PART 2
Relays are used to solve many industrial and communications problems. They are capable
of providing time delay, generating impulses, handling interlock requirements and performing selection functions. Methods of utilizing quick -acting, slow- operating, slow- releasing, polarized, double -wound and rotary- switch types for these purposes are discussed here
THE UNINITIATED, circuit
diagrams of electrical remote
control apparatus such as the automatic or dial telephone may appear
to be extremely complex. Yet all
such remote control apparatus consists of combinations of more or less
standard circuit elements which are
in themselves simple.
Circuit elements, in the main,
break down into four distinct classifications. These are : time delay, impulse, interlock and selection.
TO
Time Delay Methods
Time delay has as its function the
performance of circuit switching operations in proper sequence. In a
radio transmitter, for example, it is
frequently necessary that tube cathode voltages be applied before anode
voltages. While there are many different types of mechanical, electrical and electronic timers, it is often
desirable to use relatively simple
telephone type relays to achieve time
delay.
Figure lA shows a scheme in
which quick-acting relay A, equipped
with an adjustable- weight armature
spring and used in conjunction with
slow- operate relay B, provides operate delays up to approximately 2 sec.
When the initiator key is closed relay A is energized by a battery or
other power supply and its armature
spring pulls up but the weight on
the armature causes the spring to
ELECTRONICS
-
Since windings x and y produce opposite flux, the relay will not operate
and
until the capacitor has approached
full charge, when current flow
L. N. GALTON
through winding y ceases. The relay
is then operated by the current flowAmerican Automatic Electric Sales Co.
ing through winding x. On opening
vibrate and make and break contact the control circuit, the capacitor dis1
for some time before it settles charges through windings x and y
down in the pulled -up condition. As in a series -aiding direction, holding
the armature vibrates, increasingly the relay operated until the capacilonger current pulses flow through tor approaches a discharged condirelay B. As soon as the length of tion.
the impulse transmitted exceeds the
Impulse Generators
pick -up time of B, the latter operRemote control selection is freates and closes or opens circuits to
quently accomplished by transmisother equipment.
A similar arrangement, shown in sion of current impulses. ConseFig. 1B, is available for release de- quently, impulse generators play a
lays of from 1 to 15 sec. Energizing very important role. The ordinary
of relay A closes contact 1 and oper- telephone dial is a mechanical imates relay B. Then, when the circuit pulse generator. The capacitor -relay
to A is opened, the weighted arma- combination shown in Fig. 1C may
ture spring vibrates between springs have its control circuit wired through
2 and 3, transmitting decreasingly a break contact and thus become an
shorter impulses to B through con- electrical impulse generator, operattact 4 of B, which temporarily re- ing in very much the same manner
mains closed as B is a slow- release as does an electric bell or buzzer.
type relay. B drops out when the Such a contact is shown at 1 in Fig.
length of the impulse becomes less 2A. Time delay features similar to
that of Fig. 1C provide, in this inthan its release time.
Figure 1C illustrates a combina- stance, control of impulse timing
tion slow- operate and slow -release rate. The length of the impulses
arrangement using a large capacitor may, for example, be varied by
Z. Voltage from the control circuit changing the size of the capacitor.
Figure 2B shows a chain of redivides and part of it goes through
winding x while the rest goes lays, wherein relay A is operated
through the capacitor and winding y. from a control circuit. Relay A op-
December 1942
By C. J. DORR
57
TIME DELAY CIRCUITS
Quick
acting
(IA)
re/ay;
Initiator
/key
1
Iy
r
Weighted
armature
spring
(B)
Battery
(to ground)
Slowoperating
re/ay
ii
S .o.
0
Contact1
o
o
ext.
circ.
Slow-re/easing
re/ay
S.R.
2- o
Double-wound
re/ay
Capacitor Z
(IC)
FIG.
1-
(IA) Slow operating combination. (1B) Slow releasing combination.
(1C) Time delay circuit using capacitor
and double -wound relay
erates relay B and relay B operates
relay C and C opens the circuit to A.
Relays A, B and C then release successively and the cycle is repeated,
thus generating impulses on C at a
rate dependent upon the number of
relays in the chain and the operate
and release time characteristics of
the individual relays. Such an impulse generator may be used in conjunction with a rotary switch, as
shown, to successively step the rotary switch wiper. One specific application is the case of an airplane
engine under test, where thermocouple leads are progressively connected to a pyrometer.
In telephone and telegraph practice the character of an impulse may
become so altered by line resistance
and capacity that the impulse at the
remote end is incapable of reliably
operating the final equipment. Some
means must then be used to restore
the character of the received impulse. A relay combination which
accomplishes this is shown in Fig.
2C. The received impulse operates
fast -operate relay A, which locks itself, by closing contact 1, to contact
2 on B. Operation of relay A also
energizes slow- operate relay B by
closing contact 3 and simultaneously
closes local repeated impulse circuit
p. As soon as B operates, it opens
the locking circuit to A, thus allowing A to release. The repeated impulse then is equal to the operate
time of relay B plus the release
time of A, regardless of the length
of the received impulse, provided the
impulse is at least long enough to
operate A and no longer than the
operate time of A plus B. If there is
a possibility that the received impulse will be longer than the operate
time of A plus B then repeated impulse circuit q may be employed, in
which case the repeated circuit is
opened as soon as B operates.
If a received impulse is always of
the same length but this length is
too short to reliably operate local
equipment, then the simple pulse lengthening circuit shown in Fig. 2D
may be used. In this case, A is a
fast-operate type relay which functions satisfactorily on a short impulse, but is slightly slow -release in
character because of its parallel non inductive resistor shunt. Thus the
repeated impulse is lengthened by
the amount by which - the release
time of A is longer than its operate
time.
functions to be performed, the selection switch cannot be allowed to remain on the selected contacts for
the full time that it is desired to
keep the power function in operation. Remote control of radio transmitters, where one of several
transmitters must be turned on by
dialing a number and then one of
several frequencies must be selected
by dialing a second number, is an
example. In a case of this kind,
several A selection relays may be
locked to one B release relay and all
selections released at once by dialing
the release number.
A variation of this same kind of
circuit, but using a single relay instead of two relays, is shown in
Fig. 3B. Closing the "on" pushbutton operates the relay through winding x and the relay locks itself operIMPULSE CIRCUITS
Initiator
--1
rkey
-Double-wound
re/ay
Capacitor
Battery
to ground)
( 2A)
'F-1'
I
1
Rotary
switch,
El
0
(2B)
o
,I,-1
Interlock cireì' its may be broadly
classified as simple interlock and
lockout- interlock types.
In the simple interlock circuit of
Fig. 3A, when relay A is energized
from a pushbutton it locks itself
operated by closing contact 1. Operating the second key operates
relay B and releases A by opening
contact 2. A circuit of this kind may
be used wherever it is necessary to
rc...cmplish a power function by the
mcmentary closure of a pushbutton
and then to discontinue that function by the momentary closure of
another pushbutton. It is often used
in conjunction with selection equipment wherein the pushbuttons are
specific contacts (dialed numbers,
for example) on the selection switch
and where, because of various other
2
S.O.
I
0
Rep.
imp. circ.p,
(2C)
o
Rep.
imp. circ
(2D)
Non- inductive
shunt resistor
Repeated impulse
I
FIG. 2
(2A) Capacitor and double wound relay combination. (2B) Impulse
generator operating rotary switch. (2C)
Impulse regenerator. (2D) Impulse repeater
December 1942
www.americanradiohistory.com
ext. cire.
Slow -re/easing relays;
Interlock Devices
58
To
-
ELECTRONICS
ated by closing contact 1. Contact 2,
included to prevent accidental operation of the relay by operation of the
"off" button, is simultaneously
closed. When winding x has first
been energized, closing the "off" button energizes winding y in opposition to winding x and causes the
relay to release.
Another variation of the interlock relay is shown in Fig. 3C. The
first time the pushbutton is operated,
relay A operates on winding y and
locks itself operated by closing contact 1. Contact 2 is opened. Relay
B windings x' and y' are energized
but, since these windings are in opposition, relay B does not operate.
When the initiating pushbutton is
released, winding x' of relay B is
de- energized and consequently relay
B operates, opening contact 3 and
closing contact 4. When the pushbutton is again closed, winding x
of relay A is energized through contact 4 of relay B. Since winding x is
connected in opposition to winding
y, relay A releases and contact 2
closes. Winding y' of relay B remains energized, at first through
contact 1 of relay A and, after A
releases, through contact 2 of relay
A and the pushbutton. When the
pushbutton is released, winding y'
of relay B is de- energized and relay
B releases, opening contact 4 and
closing contact 3 to restore the original circuit condition. In brief,
then, relay A operates at the beginning of every other closure of the
initiating key and B operates at the
end of every other closure. Relays
INTERLOCK CIRCUITS
To
`-!
ext,
I1
circle
©
Battery
(to ground
fInitiator
keys
.1-E
y
lXA
t
re/ay
3
>off
(3B)
-`-J
-
o-E
Y
Y
Double-wound
_
(3A)
-il
2
,
_
2
B
yX"
o
yB
-
1
T
#
(3D)
(3C)
o
o
g.
l
0--T 2
at the beginning
and end, respectively, of the intermediate operations of the key. A
circuit of this nature is useful when
it is desired to perform two
functions over a single line, without
the necessity of having current flowing in the line after the selections
have been made.
A variation of this same scheme is
shown in Fig. 3D. The first closure
of the initiating key' connects the
negative terminal of the energizing
battery or power supply to B through
contact 1 and contact 2, thus operating B. As soon as B operates, it
prepares a circuit for A through
contact 3 but, since relay A is effectively short- circuited inasmuch as
both ends of the coil are connected
to the negative power supply terminal, A does not operate. As soon
as the initiating key is opened relay
A is no longer short-circuited and
operates in series with B. Operation
of A changes the polarity of voltage
appearing at the contacts of the
initiating key from negative to positive and also closes contact 4. The
next time the key is closed, relay A
is held operated through contact 3
and relay B releases because it is
effectively short-circuited. Opening
the key again allows A to release.
As in Fig. 3C, one relay operates at
the beginning of every other closure
and the other relay at the end of
every other closure. The circuit of
Fig. 3D is slightly slower in operation than that of Fig. 3C because of
the shunting method of operation but
has the advantage of utilizing single wound relays. The fact that both
battery or power supply legs are
connected to one set of springs on
relay A introduces a possible source
of trouble from short -circuits at this
point under improper conditions of
relay adjustment and, consequently,
it is desirable to introduce a slight
amount of resistance into the power
circuit to limit any such shorting
A and B release
current.
A lockout- interlock relay arrangement is shown in Fig. 3E. This type
B
ir
FFI F19
¡Key
¡Key
b
Q
jKey
b
(3F)
(3E)
FIG.
jKey
3-
¡Key
=re
-
Release
(3B) Interlock using one double (3A) Simple interlock circuit.
wound relay. (3C) Alternate on- and -off interlock. (3D) Another alternate onand -off interlock scheme. (3E) Lockout -interlock system. (3F) Lockout -interlock
system using self-locking relays
ELECTRONICS
-
December 1942
of circuit prohibits interference by
the operation of a second key while
a selection is in progress from a first
key. For example, if key a is operated, relay A is energized through
its contact 1, similar contacts on
relays B and N, contact 2'and connection through a resistor to the battery. Contact 3 is arranged to close
before contacts 1 and 2 open, thus
59
relay A remains energized through
contact 3 after it initially operates.
As soon as relay A operates, however, it is impossible to operate the
other relays because the battery circuit has been opened at contact 1.
If two keys are operated simultaneously, then the relay nearest the battery (in this case relay A) remains
operated while the other relay operates momentarily and immediately
releases. A circuit of this nature
might be used on a radio transmitter which has to be operated alternately from two or more separate
sources of modulation, where regulations require protection against
simultaneous connection of several
speech amplifiers to the transmitter.
Another lockout -interlock arrangement is shown in Fig. 3F. Operation
of, for example, key b energizes
winding x of relay B and operates
relay B through a chain circuit
starting at contact 1 and running
through similar contacts of all other
relays in series to the battery at the
end of the chain. As soon as relay
B operates, the battery is connected
through contact 2, winding y of relay B, to ground at the release key.
Winding y of relay 3 is thus energized so relay B is held operative.
The x winding circuits for all relays
is simultaneously opened at contact
3 of relay B. If two keys are depressed simultaneously and the associated relays operate simultaneously, the relay nearest the battery
end of the chain will remain operated while the other relays will operate momentarily but quickly
restore. This circuit provides for
the locking of any selection until it
CIRCUITS
SELECTION
To
To
Quick-act ng
re /ay,
ext cire.
14.1141
Initiator
Battery
(to ground)
ext circ.
key
Pivot
Q
ext17b
=-circ.
.
Po /arizéd
(4B)
To
(4C)
To
Dial ,--2
Rotation
Operate
1
switch
Y
o
0
o-0
leve/ o
"4-CNo./ °
A
of
\oÿ
o
position
o
Re /ease
ext. /..o'b-t.
f--.-. Normal
°o
ext 7c/rc.
tire.;
S.R.
magnet Rotary
/
flr
1_.--r-Slr
re/ay
AA)
i
Cam"
0
magnet-
''--Off- norn/a/
s Re /ease
spring
(Levels No. /
No. 2
and
mechanica//y
Interrupt.
springs
Level
No.2
ganged)
(4D)
(4 E )
Home
Receiving
Sending
Operate
position
Ke
ly
0.3.
o
os-p
0
j
Release
ó
, keys
To
o
\ °J other
o °- relays
Line
itlotor- driven
(4G)
synchronized brushes'
4-
FIG.
(4A) Simple direct selection scheme. (4B) Direct selection using
polarized relay. (4C) Coded selection method. (4D) Simple step -by -step selection system using switch with separate rotation and release magnets. (4E) Another step -by -step selection method. (4F) Relay "counting chain." (4G) Elemental
time -relation selection system
60
cally non-locking selection keys are
used. It is used when a selection
once made must not be interfered
with by the operation of other initiating keys until the first selection
function is concluded. It is obvious
that the release key could be replaced by a break contact on a release relay, which could be automatically operated after some sequence
of events initiated by the selection
had been completed.
Selection Circuits
Selection circuit elements are
probably the most basic of all electrical remote control tools. They are
the design starting point, insofar
as desired end -actions are concerned,
when it is desired to perform one
of several functions at a distance
over a small number of wires. Many
applications require such wiring
simplification. In a general way, selection circuits are divided into four
basic groups. These are: direct, step,
time -relation and continuous types.
Direct selection is that type of control involved in closing a single
switch to perform a single function,
as in Fig. 4A. The insertion of a relay between the switch and the load
permits the control of a large amount
of power at a distance without the
necessity for a heavy -duty switch
and heavy inter -connecting wiring.
By employing a polarized relay,
either one of two selections may be
made over a single wire, as illustrated in Fig. 4B. Throwing the key
to the right operates the polarized
relay in one direction, while throwing the key to the left operates the
polarized relay in the other direction.
A somewhat more elaborate means
of direct selection is the "coded"
method shown in Fig. 4C. Selection
is accomplished by actuating one or
more of the initiating keys, to energize one of several circuit paths. The
number of possibilities is equal to
2"
1, where n equals the number of
relays. This is true since the condition applying when none of the relays
are energized is not generally considered a selection.
Figure 4D represents perhaps the
simplest of step -by-step selection
schemes, utilizing a type of rotary
switch having both rotary and release magnets. Successive closures
of the operate key advance the rotary
-
To
o-* other
o-.ß
is released by the operation of the
release key, even though mechani-
(Continued on page 167)
December 1942
-
ELECTRONICS
2KC Fili-er?
Harmonic
analyzer
4 K Filter
o--
o
o-
_0
I
Sine
Oscillator
Isolating
Amplifier
Device
Under
Wave
0O
9
Test
o
6 KC
Voltage
1
Filtero--+
Amplifier
I
Rectifier
M
o
I'
J
L
1-Functional block diagram illustrating the application of
the harmonic wave analyzer and its essential component circuits.
Photograph of completed instrument, from rear, shown below
Fig.
Simple HARMONIC
WAVE ANALYZER
By R. F. THOMSON
Cambridge, Mess.
Speed of testing and inspection of audio frequency devices is facilitated through use of a
simple amplifier -filter- rectifier instrument, designed to read directly the amount of second
and third harmonic distortion
THE primary requisites of any
audio amplifier are uniform frequency response and freedom from
distortion. The frequency response
can readily be found by point to
point measurements with relatively
inexpensive equipment. The harmonic distortion is a difficult problem to solve, since it is done by analysis of the wave shape, which is a
tedious job, or by means of a wave
analyzer which involves an expensive piece of apparatus.
A simple and relatively inexpensive harmonic wave analyzer has
been designed and constructed which
provides a means for determining
the second and third harmonic content of an amplifier or similar piece
of apparatus operating in the audio
frequency range.
Fundamentally
the method is based on the assumption that the harmonic content of
the equipment under discussion is
reasonably independent of frequency. This assumption is fulfilled
ELECTRONICS
-
quite well in audio amplifiers so
long as the output load is a pure
resistance. The instrument for
making these harmonic measurements operates on the same principle
as that of a wave analyzer. An adjustable sinusoidal voltage of fixed
frequency is applied to the equipment under test and a variable gain
amplifier incorporated as part of the
wave analyzer is adjusted until the
output meter, fed through a filter
of fundamental frequency, reads
100 percent. The reading is also obtained for the magnitudes of the second and third harmonics, respectively, by noting the meter reading
when the appropriate filter is
switched into the circuit.
As shown in the block diagram of
Fig. 1, the fundamental parts of
this instrument are an isolating
amplifier, band -pass filters, a voltage
amplifier, a rectifier and meter. The
first amplifier is used to isolate the
instrument from the circuit under
December 1942
test. The band -pass filters are tuned
to pass only the desired fundamental, second or third harmonic
frequencies. Following the filters is
a two -stage audio amplifier feeding
a diode rectifier which in turn actuates a milliammeter having a range
of
0 -1
ma.
A schematic wiring diagram of the
wave analyzer, complete with power
supply is shown in Fig. 2. A type
6J7 connected as a triode, and transformer- coupled to the filter, is used
in the first stage. This stage must
be free from harmonics and must be
capable of feeding sufficient voltage
into the filter. Several methods of
feeding the filter without a transformer were tried but none were
satisfactory due to the low impedance of the filter. The matching
transformer T, has a turns ratio of
3.6 to 1 and is a universal plate-toline transformer of good quality.
This reflects a load of approximately
7,500 ohms back to the plate. The
61
www.americanradiohistory.com
Rx
_
0.11.1.f
f
2C
atn
aawaas_;
L1/2
6J7
6
2C,
F--.
t
Lp
C¢
Si
L,
8C5
0.01
µf
75
2
-IF2c
2cß
E, T2
TC
2C;'
n
I
Meg
2c,
A'
600
25µf
C
500
IµfT
0 -104a
2500
R,
n--11
0.1
f
2500
`
1
µf
EliOV
80
a-
s,
QOO
250
Y
° 2sov
%
0.1
5V
q
Meg
46.3V
Fig.
2
-Schematic wiring diagram
filters provide a reactive load at frequencies removed from the pass frequency so this stage has to be
matched near the point of maximum
power transfer.
the harmonic analyzer
of
Filter Constants
L1/2
Filter Considerations
The band -pass filters used in this
Lz
instrument were of the conventional
constant K prototype T section type.
The input or characteristic impedance of this filter was 600 ohms and
the bandwidth 500 cps. As the input and output inductances, iL1, are
independent of the frequency and a
function of only the characteristic
impedance and bandwith, they were
connected directly into the circuit
ahead of the band switch. The inductance used in this part was a
telephone retardation coil with the
iron core removed. These coils have
an inductance of 0.191 henry and a
comparatively high Q. The coils L2
2,000 cps
Oscil Iator
2000 cps
Band
No.
Pass
I
2C1
ó\--{
--(
Arm
ELI
L2
2C1,
I
L1
/2
---r óóÒ áóòo ti-
Cz
Resonant Frequency of Filters
2,000 cps 4,000 cps 6,000 cps
0.191 h
0.191 h
0.191 h
5.96mh 1.49mh 0.662mh
µ
1.06
1.06µf
1.06 µf
0.03321.0 0.0083µf 0.003791.0
Zo
600 ohms 600 Ohms 600 Ohms
Band Width 500 cps
500 cps
500 cps
C2
2C1
3- Diagram of band pass filters, with
circuit constants for filters for fundamental,
second harmonic and third harmonic
frequencies
Fig.
were receiving type radio frequency
choke coils with sufficient turns removed to give the desired inductance. These inductances were measured by resonating them at the desired frequency with laboratory
standard condensers. The filter condensers were chosen by again resonating them, with the corresponding
inductance, at the desired frequency.
This procedure was followed with
each of the three arms of each filter.
It is essential that the coils of the
filters be of a relatively high Q to
lessen the losses throughout the pass
band. For this reason available
iron -core coils were not feasible. The
Q of these coils is about 10 which
provides an attenuation of about 16
db over the pass band. Values for
the various parameters of the filters
are given in Fig. 3. These filters
gave approximately 71 db attenuation at the unwanted frequencies.
Because the voltage output of the
filters is very small (a maximum of
0.07 volts), two additional stages of
amplification are necessary to raise
this voltage to a reasonable amount.
This is accomplished by means of a
605 connected as a conventional voltage amplifier, and resistance coupled
to the succeeding stage. Distortion
in this stage is of no consequence as
the change of wave shape would only
tend to cause a slight change of the
meter reading which would automatically be compensated for in the
calibration.
The signal is then amplified by
the triode portion of a type 75 and
is then fed into the diode section of
the tube which acts as a full wave
rectifier. The rectified current is
read from the 0 -1 milliammeter.
This type of metering circuit was
(Continued on page 155)
50
too
45
40
t 90
E
50%
s0
35 ° 70
2,000 cps
Sinusoidal Voltage
Analyzer
30
+60
25
50
20
340
>
.s
'100
IO %
15 'E 30
4000 or
6,000 cps
Fig.
l0
E
20
Oscillator
5
z
10
N o. 2
0
4- Circuit
connections used in calibrating the harmonic
analyzer
0
0
al 02 03 04 OS 0.6 0.7 08 09
Output Current in Ma.
f.0
5-
Typical calibration curve for analyzer. The harmonic
content in percent is directly readable from meter indication
Fig.
62
December 1942
www.americanradiohistory.com
-
ELECTRONICS
Energy Storage
WELDING CONTROLS
...Part
5
Resistance welding of nonferrous m et al s requires
larger currents of shorter
duration. This greatly increases the peak power demand upon an industrial
plant's a -c line. Magnetic
and electrostatic energy storage systems described here
reduce the burden
By
G.
L.
ROGERS
I:lrrl,vrRiP$ A'er'IiUlt
Industrial l'ohhrol Fiql. Dept.
Gehoral h:lrrh'ic Co.
Sch Uhl r'lrul!1
OF
THE MANY methods devised
by man for attaching one piece
of metal to another, resistance welding is one of the most important to-
day. Machines and techniques have
been developed to the point where it
is possible to resistance -weld most
of the available metals and alloys.
Capacitor discharge control applied to a stored energy type welder which handles
The welding of non -ferrous metals
up to two thicknesses of 0.081 -in. 24 ST Alclad
welding
increased
that
required
has
currents be used and that control be
secondary, as
more and more precise. The reason on the power supply system for a with the transformer
welding
spot
for this greater demand on welding very short time, with relatively long in a conventional
equipment and controls is that when waits between. To reduce the bur- machine.
The transformer is, however, difheated, most non-ferrous metals pass den on power supply systems two
have
storage"
from those used in convenferent
of
"energy
quickly from the solid to the fluid methods
the
It has a relatively
to
applied
welders.
been
tional
time
some
for
is
there
state. During the transition
only a very narrow temperature welding of non -ferrous metals, par- large cross section and air gap and
range within which they exhibit a ticularly aluminum and its alloys. exhibits a highly inductive charplastic tendency. Consequently, in These two energy storage methods acteristic, with consequent ability to
welding them satisfactorily a con- are magnetic storage and electro- store considerable energy in its
magnetic field. The primary is
siderable amount of concentrated static storage.
energized by d -c voltage instead of
heat must be applied and the rate
the a -c voltage used by conventional
of heating must be carefully conMagnetic Energy Storage
welders. Current that builds up
trolled.
Magnetic energy storage makes through the primary rises along an
Through extensive research, welding machine manufacturers have use of the ability of a magnetic field exponential curve characteristic of
been able to develop machines and to store electrical energy. The ele- circuits containing inductance and
techniques for welding non -ferrous ments of the system require a weld- resistance and is ultimately limited
alloys with conventional a -c welders. ing transformer having the usual by the resistance of the winding. As
The desired result has often been primary, excited from a source of the primary current increases, some
obtained, however, at the expense of power, and a low- voltage secondary. voltage is induced in the secondary.
large single -phase peak line demands. Work to be welded is introduced be- But, since the rate of change of
That is, heavy demands are made tween suitable electrodes in series primary current is relatively slow,
ELECTRONICS
-
63
December 1942
www.americanradiohistory.com
insufficient current flows in the sec ondary to heat the work appreciably
during this energy storage phase.
When the primary current has
reached a value sufficient to store
enough energy in the transformer to
weld the particular metal being
worked, the primary circuit is
opened. Stored energy is released
and, since it cannot dissipate itself
in the opened primary circuit, a high
current at low voltage is developed
in the secondary circuit. This produces sufficient heat to weld the
material between the electrodes.
Welding current in such a system is
characterized by a rapid rise to the
maximum value and a somewhat
slower decay. It may be seen that
by controlling the current value at
which the primary circuit is opened
a wide range of controlled secondary
circuit currents may be obtained.
The circuit elements are illustrated
in Fig. 1A. Fig. 1B depicts the
primary and secondary currents in
the welding transformer. The primary interrupting means, shown
simply as a switch in Fig. 1A, is
actually a series of contractors so
arranged that they may be progressively and automatically operated to
introduce series resistors until operation of the last contactor completely opens the circuit. The contactors are actuated by a series current relay which may be adjusted
over a wide range to govern the
energy stored for the weld.
Power Supply Considerations
While magnetic energy storage
welders may be operated from any
d -c source of suitable voltage and
current capacity (usually 130 to 170
volts at a peak current of from 200
to 1500 amp), they are almost invariably supplied through rectifiers.
Very few industrial plants have d -c
systems of sufficient capacity and the
use of rectifiers also provides additional refinements of control. The
basic rectifier is three -phase, half wave in character, using ignitrons
anode fired through phanotrons
Weld
Switch
trans.
Electrode
D-C
Work
'-E /ectrode
Weld mach.
source
(IA)
Sec. loop
Pri, cur.
(IB)
Sec. Cur.
-'
1-
Fig.
Schematic illustrating basic elements of magnetic energy storage spot
welder circuit and curves showing currents obtained in the associated trans-
former
2- Elementary diagram of three
phase, half -wave ignitron power certifier
for magnetic energy storage spot welder
Fig.
-
3-
Circuit showing a method of phase controlling the output voltage of a single
tube ignitron rectifier and graphical analysis of the resulting relationship between
grid and anode voltages. Three such circuits would be used to control the rectifier of Fig. 2, one in each leg, with the
control rheostats ganged
Fig.
4 -Block diagram of elemental electrostatic energy storage spot welder circuit
Fig.
Disch. cont.
3
phase
Supply
Weld trans
Work
Inversé volt. limit
64
.
(high- vacuum diodes).
phanotrons providing an unidirectional current pulse to the ignitor at
the beginning of each positive half
wave to ionize the ignitron and permit it to pass current. The rectifying action of the phanotrons prevents
reverse current through the ignitors
during negative half cycles. This type
of rectifier is capable of passing very
high current of short duration, using relatively small tubes. On a duty cycle basis the tubes may be operated
at ratings similar to those used for
a -c welders with the exception that
peak current ratings are based on
the capabilities of a single tube and
average ratings on three tubes in
parallel.
Voltage Control Method
For operation of larger welders of
the magnetic energy storage type,
an adjustable rectifier d -c output voltage becomes desirable. Large welders may be called upon to weld the
metals for which the energy stored
in the welding transformer must be
relatively small compared to the
available maximum. In attempting to
control precisely the current at which
the primary circuit is opened, at low
values of current, the rate of rise is
rapid and any variation in relay operating time takes on increasing importance. By lowering the applied
d -c voltage, the entire current -time
curve is flattened and the same order
of control may be obtained at low
currents as is possible at high currents.
A simple phase control which may
be applied to rectifiers to obtain an
adjustable output voltage, is illustrated in Fig. 3A. This figure illustrates the control applied to a single
tube. In practice a similar circuit is
used for each ignitron, with the voltage control rheostats ganged on a
single shaft. The operation of the
circuit is as follows : The rheostat
R, and capacitor C, act as a delay
circuit to hold the grid of the thyratron negative during a portion of
the positive half cycle, thereby reducing the conduction angle of the
ignitron and, consequently, the d -c
December 1942
www.americanradiohistory.com
An anode
transformer suitable for the supply
voltage and frequency and the output
voltage required is provided along
with necessary protective devices.
The basic rectifier is illustrated schematically in Fig. 2. The ignitrons are
operated in the usual maner, with
-
ELECTRONICS
R,
JJvWJ
Tube
Tube 2
l
From 3-phase power source
Tube 3
T,
02Ó00Q,
(sec)
L3
L2
L1
(prl)
T3
Tl
T3
(sec)
Tube
R3
R4
Cl
C3
T6 (sec)
Ts Om)
C4
Rs
Tube
7
oa
R.
le
T2 (Pri)
-
Tube 8
woo
Cs-
CR,
r1
T8 (sec)
e
To (sec.)
.
0000
Tube
10
Rn
B
Cs
Tube
=CL
Cy
Te
8
(sec)
p,
2.
C8
111'.
Tube
L
ú ,Ç
M
R13
t
44
áN3
E
Fig.
to
(pri)
L2
W
(sec)
T4
Ts
(pri )
t'.1)
°
Il
T6
a
M 6
C
R14
t
(pri.)
R16
Re.
R1
a
L3
5- Schematic
of
typical electrostatic energy storage spot welder charging rectifier. Component parts unof the operating principle are omitted for the sake of simplicity
necessary for an understanding
output voltage of the rectifier. With
no resistance at R2, the thyratron
grid becomes positive at the same
time as the anode and full output is
obtained. As resistance is inserted
at R2, the voltage across C, lags behind the anode voltage to reduce the
output. This action is illustrated
for a single tube in Fig. 3B. When
applied to all three phases with an
inductive load, the wave shapes of
Fig. 3B are modified by commutation
from one phase to the next and by
the highly inductive load. The end
result is the same, however, and the
more complex wave shapes involved
are omitted for the sake of simplicity.
In practice three-phase rectifiers
such as the one described are usually
used to operate two welding machines. Interlocking circuits are provided to prevent operation of both
machines at one time and selection
of the proper voltage for each machine is automatically made by the
use of two separate voltage adjusting rheostats and interlocking relays. The usual cathode protective
time delay relays, as well as overload
and loss -of -water protection, are
provided.
Electrostatic Energy Storags
Electrostatic energy storage makes
use of the ability of a capacitor to
store electrical energy. Reduced to
bare essentials, such a system re-
ELECTRONICS
-
quires that a capacitor bank be
charged to a predetermined voltage
and then discharged through the
metal to be welded. The total capacitance, the voltage to which it is
charged and the inductance and resistance of the discharge path determine the amount of available energy
and the rate at which it is delivered
to the weld.
capacitors
Because
enormous
would be required in the welding
transformer secondary circuit in
view of the very low- voltages available there, electrostatic energy storage welders usually incorporate capacitors in the primary circuit. Primary circuit capacitances range from
120 tsf upward, charged to between
1000 and 3000 volts. The principal
elements of one typical capacitor discharge welder control to be described
are : a three -phase, full -wave, grid controlled rectifier for charging the
welding capacitors to an adjustable
voltage between 1000 and 3000 volts
and a series- and -shunt ignitron system for discharging the capacitors
into the welding transformer primary. A block diagram of the system is illustrated in Fig. 4.
The rectifier and voltage control
amplifier shown schematically in Fig.
5 consists of three phanotron tubes
1, 2 and 3 and three thyratron tubes
4, 5 and 6, in a conventional three phase, full -wave arrangement fed
from the three -phase transformer
bank Ti, T and T,. Since an energy
December 1942
storage capacitor of the size used
acts as a virtual short circuit, sufficient reactance is included in the
anode transformers to limit initial
charging current to a reasonable
value. In this particular control, the
anode transformers deliver 3800
volts line -to-line and limit the short
circuit current to approximately 15
amp d.c.
Analysis of Typiccl Circuit
Control of the output voltage is
obtained by grid -controlling the
three thyratrons. It may be seen
that if these tubes are completely
cut off all return paths for d -c are
blocked and, consequently, full con trol of the output may be obtained
by controlling these three tubes.
Since each thyratron operates in
conjunction with first one and then a
PUBLISHED
Spot Welding Controls
(August, page 36)
Seam and Pulsation Welding
(September, page 55)
Special Welding Controls
(October, page
62)
Timers for Welding Control
(November, page
65)
SCHEDULED
Checking Welding Controls
65
second phanotron and has two successive return paths as long as its
anode is positive with respect to
either cathode, the possible angle
over which it may conduct is 240 deg.
instead of the 180 deg. or less associated with half -wave rectifiers.
Therefore, in order to obtain full
control over the entire conduction
angle, a grid phase control voltage
differing somewhat from the conventional displaced sine wave must
be used.
In order to obtain 240 deg. control, each thyratron grid is supplied
with a saw -tooth wave obtained as
follows Taking the grid circuit of
tube 4 as an example, grid transformer T, supplies a sine wave voltage which is so displaced that its
maximum negative value is reached
as the anode of tube 4 starts positive. This voltage is rectified by one
half of tube 7 and is used to charge
capacitor C,. During the time that
the voltage of T, (sec.) is less negative than the voltage across C, the
capacitor charge bleeds off through
resistor R,. The resultant grid voltage is the saw -tooth wave illustrated in Fig. 6 in conjunction with
the anode and exaggerated grid characteristics of tube 4. Examination of
Fig. 6 shows that by applying a d -c
voltage in series with the voltage
across C the voltage applied to the
grid of tube 4 may be made to cut
the grid characteristic at a point determined by the value of d -c voltage
applied. Thus the conduction of this
tube may be varied by a variable
d -c voltage. Tubes 5 and 6 are similarly controlled.
Since the output of the grid cir:
Closed and open front views of an ignitron rectifier unit for magnetic energy storage
spot welders
would be progressively cut off until 9 and achieves complete cut -off. As
is passed only sufficient current to the voltage across CL increases, the
maintain the capacitor voltage total voltage across
and R inagainst leakage and bleeder current. creases ; consequently the drop across
However, in order that more accur- R,,, which subtracts from the standate voltage control may be obtained, ard, increases. When the load caan amplifier tube 9, and a voltage - pacitor voltage reaches a value such
standard tube 11 (along with the that for a given setting of P, the
necessary power supply from trans- potential applied to the grid of tube
former
tube 10 and filter capaci- 9 reaches zero, a slight further intors C, and C,,,) is provided.
crease of CL voltage drives this grid
positive. Thus it will be seen that as
Refinements in Control
the load capacitor voltage increases
tube 9 is cut -off until nearly the deConsidering first the grid circuit sired voltage is reached. Upon furof tube 9, the standard voltage across ther load capacitor voltage increase,
tube 11 in series with any voltage ap- the tube is driven to saturation.
pearing from the slider of P, to the
The voltage applied to point B
positive output line is applied across in Fig. 5 consists of two combined
cuit networks is essentially negative, the two equal resistors
and R. voltages, one voltage between points
the second half of tube 8, in connec- With zero voltage on the load CL, the
C and D and the other the drop
tion with the secondary of T, and standard voltage is divided equally
filter capacitor C;, is used to furnish and one half is applied to the grid across tube 9. Remembering that
tube 9 remains cutoff until nearly
a constant d -c bias to displace the of tube 9. This voltage is negative
zero line to a more convenient posi- with respect to the cathode of tube the desired output voltage is reached,
at the beginning of the charge point
tion. This displacement
R
T
R
brings the
zero line to a position more nearly
at the average zero of the a -c component of grid voltage. It is now
possible to obtain control of the
rectifier by displacing point B in Fig.
5 both positive and negative from
the cathode potential of the thyratrons. Connection of point B to the
slider of potentiometer P, would provide one possible method of voltage
regulation by proper selection of the
fixed bias across R. If this was done,
as the voltage across the load capacitor C, increased the rectifier
+
E
(points
BtoO)
a
°
Fig.
6
-Anode voltage and phase
111SIM
E
(points C+oD)
Tube
9,Saturated
con-
trolled grid voltage waveforms, illustrating
the operation of tube 4 in Fig. 5
Region of
Stabilization
7-
Output vs. input voltage of regulating amplifier for electrostatic energy
storage spot welder charging rectifier
Fig.
Output Voltage)
December 1942
66
www.americanradiohistory.com
-
ELECTRONICS
ciently to require two or three cycles
for the rectifier to reach a "full -on"
condition. The second function of
Cs is to drive the junction of R9 and
R10 and the grids of tubes 4, 5 and 6
negative with a rapid rise in output
voltage. The magnitude of this effect is proportional to the rate of
rise of output voltage and holds down
the charging rate of small load capacitors.
Undervoltage Indicatine
Device
When it is necessary to operate an
energy storage type welding machine
at very high speeds, it is possible to
attempt to weld before the system
has been completely charged to the
desired voltage. A low capacitor
voltage, for example, may result in
a defective weld.
To forestall faulty operation, an
indicating device is inundervoltage
Closed and open front views of a capacitor discharge welder control. Capacitor
is shown scheIt's
circuit
cluded.
may
be
adjustments
and
"hold"
timer
tap -switch, voltage control and "squeeze'
matically in Fig. 8. Tube 12 is a
locked behind the small door
small thyratron and points C and D
are those similarly identified in Fig.
B is practically at Cs potential so the variation of voltage between points
5. Operating in a manner similar to
grids of the thyratrons are positive B and D is shown in Fig. 7.
that of tube 9, the grid of tube 12 is
A contact of relay CR, controls the
and these tubes are fully conducting.
(Continued on page 174)
As the capacitor charge proceeds, rectifier during periods in which the
the voltage between points C and D capacitor CL is discharged for weldincreases, substracting from the pos- ing. When this contact is closed, the
----- Weld trans. pri. vo /f
itive voltage applied to the thyratron rectifier is effectively blocked by
We /d trans. pri. cur.
grids. So long as tube 9 is in a non- driving the thyratron grids negative
conducting state this action is not to C10 potential. Capacitor C8 serves
Time
sufficient to affect the rectifier out- a dual purpose. It prevents transient
Effect
of
Reducing
(A)
put. However, as the output voltage loads at the beginning of the chargCapacitor Vol +age
approaches the desired value tube 9 ing cycle and serves to "watch" the
vo/t
begins to conduct and reduce the rate of output voltage rise, prevent-Pr,. cur
positive component of control vol- ing "overshooting" when charging
tage. Thus, over a small range of small values of capacitance. For the
output voltage the grids of the thy- first function of C, R and Rro are so
(B) Effect of Reducing Capacitance
ratrons swing from a positive po- selected that with CR1 contact closed
.Pri. volt
tential to a negative potential. At their junction is just sufficiently
-Pri cur.
of
conduction
prevent
negative
to
some point along this curve, depending upon leakage and bleeder cur- the thyratrons. Upon opening CR1
rents, the thyratrons reach a con- contact to release the rectifier, potenduction angle just sufficient to fur- tial at point B snaps to that at the
(C) Effec+ of Reducing Inductance
nish these currents, and the circuit junction of R. and R10. Capacitor C8
stabilizes at that output voltage, as then delays further change of potenPri. cur.
,
determined by the setting of P1. The tial in the positive direction suffi-
1
Pri.
volt.
(D)
-
\a.
Effect of Reducing Resistance
Discharge wave
of components
for a given set
wave as one corn
--- Discharge
ponent is changed
8- Undervoltage indicating circuit for
electrostatic energy storage spot welder
shown in elemental form
Fig.
ELECTRONICS
-
9-
Discharge and shunt -tube oscillaFig.
tion suppression circuits of electrostatic
energy storage spot welder
10- Effects of changing constants in
discharge circuit of electrostatic energy
storage spot welder
Fig.
67
December .1942
www.americanradiohistory.com
An Experimental Television
Successfully operated in the 114 Mc band just before the war, the inexpensive
video equipment described is semi -portable and susceptible to adjustment without elaborate test equipment. It should, therefore, be of immediate practical value to educators
and of interest to men storing up knowledge of the art for future commercial application
a source of most of the waveforms
peculiar to video transmission. In
An iconoscope camera and a mono scope are provided for producing
certain instances, study of such
waveforms may be efficious in the
wartime personnel- training program.
While the following text includes
a brief overall picture of the entire
system it deals particularly with the
design and construction of mono scope test equipment, the radio frequency portion of the video transmitter, the video modulator and the
receiver converter unit. Some data
concerning other units and circuits
is included, particularly where designs previously described in the literature have been simplified, but
readers interested in details concerning such units are liberally referred to published material. Sync signal generators have, for example,
been described by Wilder and Brustman" and the design of receiving
equipment has been described by
Television camera and monitor, complete with pre-amplifier
CONSTRUCTED just before the
war and operated for several
months in the 114 Mc band, the television system to be described provided the authors with supplemental
data on video technique which should
be invaluable when the art assumes
major commercial significance. Low
in cost, semi -portable and susceptible
to adjustment without elaborate test
instruments, much of the equipment
will be of immediate practical interest to educators since it provides
visual images, the camera being
equipped with a 2 -inch cathode -ray
tube monitor. Both image producing
units use the same timer and shaper
units, but each has its own preamplifier. Either the iconoscope or
the monoscope can be fed individually to the line amplifier. The modulator pre -amplifier and the modulator are fed from a common 400 v
power supply. A crystal -controlled
oscillator -doubler and two additional
frequency-doublers form the radio
frequency generating equipment of
the transmitter. The output of the
last doubler is fed into a driver
amplifier. The output of the driver
amplifier is link-coupled to the modulated r -f amplifier, which is cathode modulated and produces a carrier in
the 114 Mc band. A 500 v power supply provides plate power for all r -f
stages of the transmitter.
Fink".
The receiver consists of a 114 Mc
converter, the 12.75 Mc output of
Overall Video System
which is fed to the first i -f amplifier
Throughout the design and con- of a commercial television receiver.
struction of the transmitter, an atThe Monoscope
tempt was made to build video equipment which would conform to the
A type 1899 monoscope tube prooriginal RMA standards for tele- vides a video signal for testing exvision transmission. The equipment ternal equipment and is useful in
was thus originally designed for 441 checking the operation of the scanlines but it is a simple matter to ning generator and auxiliary equipadapt it to the standard of 525 lines ment used with the transmitter. The
promulgated by the NTSC. Some monoscope pre -amplifier consists of
limitation on the quality of the re- five tubes and is similar to that used
ceived picture results from the use for the conventional iconoscope
of an amateur -type 2 -inch icono- camera, except for the fact that a
scope in the telecamera, but other- high frequency peaking stage comwise the transmitter has features pensates for the decreased high freequivalent to those possessed by quency response resulting from
modern commercial equipment.
the method of coupling to the mono A block diagram of the elements scope. The peaking adjustment is
of the video transmitter and re- made by means of a variable resistor
ceiver- converter is given in Fig. 1 in the third stage of the pre -ampli-
68
December 1942
www.americanradiohistory.com
-
ELECTRONICS
System
ROBERT
By
MAUTNER
SOMERS
FRANK
and
screen end of the tube a clearance of
two inches in every direction is
maintained to avoid capacitance bypass of the higher video frequencies.
Size, positioning, linearity and peaking controls are brought out to the
top of the monoscope front panel.
Other details involved in the design
adjusted.
To maintain perfect synchroniza- and construction of the mono tion with the generator sync -signal, scope pre -amplifier are discussed by
control circuits were employed to Barco"
permit the sync pulses to generate
Timer and Pulse Generator
the sawtooth waves necessary for
The timer and pulse unit used is
scanning. This constitutes direct
drive of monoscope deflection. similar to equipment developed by
While it is possible to use a conven- H. B. Deal of the RCA License
tional blocking oscillator or gas Laboratories and described by Fink.
tubes for scanning, use of such This unit was built for the original
methods results in more elaborate RMA standard of 441 lines. Adjustcircuits and the necessity for fre- ment to conform with the NTSC
quent readjustment of the speed standard of 525 lines would necessitate increasing the oscillator frecontrol.
The output of the monoscope pre- quency from 13,230 to 15,750 cps
amplifier is cathode -coupled to a (which can be achieved by merely
transmission line and is then fed to resetting the tuning of the oscillator
the line amplifier. No gain control is condenser) and resetting the divider
necessary on the pre -amplifier but ratios.
The frequency dividers used in the
shielding of the monoscope is important for stable operation. At the shaper unit are similar to those al-
fier and can be set correctly by observing the reproduced pattern in a
kinescope. A sharp following edge
on all vertical lines in the reproduced pattern and the absence of
"smearing" or "tails' is obtained
when the control is properly
Line
Amp.
Iconoscope
Mono scope
Pre -Amp,
Pre -Amp
Camera
and Tcono.
DeFI. (1847)
Shaper
Unit
Mono scope
-Mod.
Mod.
-+ Pro:Amp -n (2-807)
(1852)
v
R-F
Mod.
RFAmp 0- Oriver
(829)
(815)
400 volt
Power Supply
(2 -83 )
e
XTAL
Osc.
(6L6G)
(83)
Timer
and DeFI.
(1899)
Converter
114 MC to
(902)
1
Doub
(61_60
-1- 7--
Power Supply
Monitor
Fig.
Doub.
(6V6G)
.-
12.75 MC)
-Block diagram
ELECTRONICS
-
of
Tele.
Rcvr
I-Fcirc.
complete television video transmitter and associated receiving equipment
December 1942
Alk *7.
Front and back views of the
mitter r -f section
trans-
ready described elsewhere. Further
information, including notes on the
adjustment of the various parts of
the circuit, may be found in a series
of articles published in 1940n. Some
modifications to permit operation of
the frequency divider on the 525 line
standard will be necessary. Using
the former standard of 441 lines, the
ratios of frequency division were 7,
7, 3, 3. If it is desired to use the
same series of four multivibrators
a dividing sequence of 7, 5, 5, 3 can
be used for 525 line operation. It is
quite probable that adjustment can
be made on the second and third
multivibrators to accomplish this
without employing new circuit constants. In any new equipment, however, it will probably be desirable to
employ counter circuits rather than
multivibrators for the appropriate
frequency division. Counter circuits
are somewhat less critical in their
adjustment and have the additional
advantage of maintaining the required frequency division over wide
limits of voltage. Brief discussion
of a suitable counter circuit has been
published by Bedford=.
69
www.americanradiohistory.com
To hoc
def. p/te
o
6J5
r7/
6SJ7
65.17
Nor and vertb /anking
for Icon.-
0.05
:Nor driving
>Vert. driving
o/
4000
>Drivingpu/ses
return
200000
}
6J5
From
shaping
unit
°-!
To vert
6d5 deep/ate
0.25
6SJ7.
"Er
0.25
ó
0
025=
m
/0,000
2
400,9
202 000
80,ÓD0
0.25
ó
H
o
8
Power cable
Fig.
2- Circuit
showing method of adapting driving pulses for unbalanced electrostatic deflection of 902 monitor tube and 1847 iconoscope camera tube
ground. In an effort to reduce
capacitance to a minimum the
mount for the iconoscope was rebuilt and two additional stages of
iconoscope with the expectation that amplification were added to the prea tube of this type might be substi- amplifier. When these changes had
been effected it was possible to adtuted at some future date.
vance the gain well into the noise
Camera
level. To remove all traces of hum
A considerable amount of time was pattern, it was found desirable to
spent in investigating the action of use direct current on the heaters of
the 1847 in the camera circuit. At the pre -amplifier tubes. Careful adthe full gain of the original pre- justment of the bias on the iconoamplifier and line amplifier it was scope then produced a satisfactory
impossible to obtain sufficient ampli- image on the kinescope. Adjustment
fication to produce a satisfactory of the bias to permit higher beam
iconoscope signal. Part of the diffi- current and greater iconoscope outculty appeared to be due to excessive put produced excessive "dark spot"
capacitance between iconoscope and voltages, while lower beam current
A two -inch iconoscope (type 1847)
was employed in the camera unit.
All of the deflecting circuits (Fig.
2) were designed for a larger type
//4 mc
6L6G
/t
L5
815
Cis
caused the signal to be lost in the
Adjustment was
noise voltage.
sufficiently critical to indicate the
desirability of incorporating a shading- voltage generator, and the construction of a suitable unit has begun. Methods of developing such
voltages are discussed in Part III
of the series of papers by Wilder
and Brustman" and in a paper by
Sherman''. If no shading voltages are
used it is desirable to use a lens
whose maximum aperture is f/2 or
larger and to have the scene brilliantly illuminated.
Care must be taken to avoid internal light deflection within the
camera tube itself. In one experiment, a 16 mm moving picture projector was focused directly on the
iconoscope mosaic, providing a high
intensity light source. While a considerable output voltage was obtained, light reflected from internal
portions of the gun structure produced an excessive dark spot. It is
also necessary to position the raster
so that no portion of the scanning
field or image touches a section of
the wire used to support the mosaic
at the end of the iconoscope tube.
Failure to observe this produces erratic operation.
The mechanical construction of
the camera pre -amplifier is such that
it can be easily adapted to a large
iconoscope if and when desired.
Horizontal and vertical blanking
voltages are available from the shaping unit. The vertical blanking voltage has been found most useful
when operating the iconoscope.
//4 mc.
N.
L6
/14mc.
L7
/50
000
829
;
d.%a. plates
áin.
on machine screws
//4mc.
RFC3
/4mc.
--I 060
-Cw
OÁ)2
L,
0002
fT
-
ó
0 00J/
ÓRFCZ
/S,000
500
/0
/50
RFC
-E6' 002
0 002
0.001
0.002
0-200 ma
0 -/00
+200
a-c
-c
CI Card. ZU75AS
C5 Card. ZR5OAS
C6
Nat. M -30
C10
Card. ZR25AS
Nat. M -30
CII
+400
6.3 v
Fig.
C14
C16
C20
C21
Card.
Card.
Cord.
Card.
ZR25AS
ET15AD
ET15AD
ET30
3- Schematic
diagram
,0
-íY1C
mo
/35 v
(Ad ús
ma
a-c
Lt 8t., 1-in.i.d.,1-in. long No.l4
5/8-in. i.d., 1-in. long No.14
L3 23/4 t., 3/4-in. i.d., 11/2-in. long No.14
L4 31/2 t.,7/8-in. i.d., I1/2-in. long No.14
L5 3t., 11/2-in. id., 1-in.long No.14
L6 2 t., I-in. i.d., 1-in. long No.14
L2
0.002
Mod.
6.3v.
of r -f
O
0.002T
+
6.3 v.
6.3 v
bar
ma
00005.8
8
Shorting
0-/0
0.000
0.001
0.100 ma.
L
3,000
(IOW)
500
(/0W)
0-100
ma.
(/0)
'v
(/0 W)
+400
11:c7r6-7/
L7 3t. (c.+J., l -in. i.d., 1-in. long No.14
L8 2pcs. 3/8 -in. dia. solid copper rod 21/32 -in.
c to c spacing
RFC Nat. RI00
RFC2 25 t., No.24 en.,
RFC3 Ohmite Z1
1/4
-in. dia.
section of the television video transmitter discussed in the text
December 1942
70
www.americanradiohistory.com
-
ELECTRONICS
A two -inch kinescope was originally built into the camera unit for
focusing and to serve as a check on
the size of the scanning raster.
However, the better resolution obtained with the 9 -inch kinescope in
the receiver provided somewhat
greater ease in focusing and was
therefore used for this purpose. The
smaller kinescope was then used only
as an indicator of scanning raster
size and position.
Sawtooth scanning voltages required by the 1847 tube are
obtained from the line and field
pulses produced by the shaping
unit in a manner similar to
that outlined in connection with the
monoscope and, consequently, there
are no frequency adjustments in
the scanning circuit. Power supply and positioning circuits were
adapted from those recommended by
Sherman ". The circuit employed to
adapt driving pulses for electrostatic
deflection of the 902 and 1847 tubes
is shown in Fig. 2.
The
Transmitter
The transmitter proper consists
of two units
(1) the r -f driver
stages and modulated radio frequency amplifier and (2) the modulator unit.
The radio frequency section contains five tubes. The first tube is a
6L6G crystal -controlled oscillator and
frequency multiplier, followed by a
6L6G multiplier stage and another
frequency multiplier using a 6V6G
tube. The output of the 6V6G multiplier feeds into the grid circuit of
a driver amplifier using an 815 tube,
which drives the final (modulated)
amplifier utilizing a type 829 tube.
Controls on the front panel of the
transmitter include those for oscillator plate circuit tuning, tuning for
the 6L6G and 6V6G multipliers and
tuning for the grid circuit of the
final amplifier. Tuning controls for
the driver amplifier grid and plate
circuits are on the back of the transmitter. Final amplifier plate circuit
tuning is accomplished right at the
plate line.
The transmitter was designed for
114 Mc, double sideband, transmission using the RMA standard of 441
lines and 30 frames per second, or
60 fields per second. It has, however,
been used at various frame frequencies from 15 to 30 per second
and at many other numbers of lines
per frame.
Front and back views of the monoscope and signal generator unit. Panels, from
top down, contain the monoscope and associated circuits, video mixing amplifier,
pulse generator, timer. Regulated power supplies are on the bottom shelf
:
ELECTRONICS
-
The schematic wiring diagram of
the transmitter is shown in Fig. 3.
The crystal has a fundamental frequency of 14.251 Mc. The output of
the "tri -tet" oscillator is tuned to
the second harmonic of the crystal.
The succeeding 6L6G doubles and
the 6V6G doubles again so the output frequency in the plate of 6V6G
tube is 114.008 Mc. The 6V6G stage
is coupled to the input of the 815
driver -amplifier by means of a link
circuit.
Mc comparable with those obtained
at lower frequencies and it will freouently be found when ordinary
lumped circuits are used that the
plate current of an unloaded stage
doubling to this frequency is close
to rated load value. So- called "series"
tuning (actually not series-tuning
but a method of trimming the tank
inductance to resonate with tube and
stray capacities) is sometimes helpful and may be used as in the 6V6G
plate circuit. It should be noted
that the inductance used when series
R -F Driving Unit
tuning should be very slightly
It is usually quite difficult to ob- greater than that necessary to
(Continued on page 170)
tain tank circuit impedances at 112
December 1942
2
To
Video
-807'5
1852
line
amplifier
20
-r T 0.002
1
7s
0.160
irr T/ T20
00002
a;0.0002
a0004
To
90
8BFig.
4-Schematic
829 cathodes
B+400
B+ 300
diagram of pre -amplifier and modulator unit suitable for cathodemodulating the transmitter diagrammed in Fig. 3
71
Opportunities for Electronics in
INDUSTRIAL TEMPERATURE
INSTRUMENTATION_
measurement mometers and pyrometers -the types
and varieties which were developed
before the advent of electronic devices. As a result there are excellent
opportunities for the application of
electronic principles to the measurement and control of temperature in
industry.
Of all measurable magnitudes
there are only a few which are ubiquitous.
Such magnitudes are
weight, length, time, and temperature. Of all measurable magnitudes,
however, temperature is the most
variable both in time and space. It
is the one whose effects are most
likely to play havoc with mankind's
intentions, from going out for a walk
to building a huge synthetic- rubber
manufacturing plant.
Only a century ago, temperature
was one of a scant score of known
magnitudes; today it is one of hundreds. But the unique thing about
temperature is that it affects the
measurement of nearly all of these
hundreds of known measurables.
Ambient temperatures, conductor
temperatures and various local temperatures affect nearly all the thousands of distinct methods of measuring these athermal conditions and
properties. Consequently, almost
every time a new method is devised
for determining a physical or chemical value, the temperature coefficient
must be taken into account.
Often, a dreaded "temperature
error" became a respectable temperature measurement method. Today
the classes, types and varieties of
temperature measurement methods
are innumerable, as is indicated in
Table I. Even if the Bureau of
Standards or a richly- endowed institute succeeded in counting all known
methods today, the published count
would probably be out -of -date
For some background relative to this article tomorrow.
the reader is invited to read an item labelled
The author recognizes the neces"Temperature" in Crosstalk, this issue.
TEMPERATURE
and control* is one of twentyodd major fields of industrial instrumentation among which may also
be listed the measurement and control of: (1) humidity, (2) pressure
(and vacuum), (3) chemical processing conditions, (4) electrical processing conditions, (5) liquid level
(and position), (6) speed (and acceleration), (7) processing time and
schedules, (8) fluid flow, (9) physical properties of materials, (10)
chemical properties of materials,
(11) radiant energy (light, infrared, ultraviolet, x-ray irradiation,
etc.), (12) dimensions, and (13)
quantities (i.e., traffic count, etc.)
In considering the widely different
rates at which electronic developments have penetrated these major
fields of industrial instrumentation
during the last decade, the writer
was astonished to discover that it is
in the field of industrial temperature
measurement and control that the
science of electronics has made the
least relative progress in relation to
the possibilities in the field of temperature. A smaller percentage of
the practicable methods of measuring and controlling temperature has
been "electronized" than has been
the case with the practicable methods of measuring and controlling
pressure, pH, position, plasticity,
porosity, packing or power.
Three important reasons for this
state of things are as follows: (1)
The number of ways of measuring
temperature is beyond reliable count
and is still growing, (2) the great
majority of inventors and development engineers in the field of electronics are unaware of the rich possibilities, and (3) consequently, they
devote their energies to electronizing the best -known forms of ther-
sity of "working with what you've
got." Admirable solutions of difficult problems have been achieved in
this way, and their commercial embodiments are worth their weight in
gold. Such problems come up where
the nature of the equipment (furnace, still, or vulcanizer) and the
nature of the process (normalizing
of steel, curing of rubber, or fractional distillation of petroleum) are
both such that a non -electronic primary element has been found most
acceptable and is firmly entrenched.
Likewise the electronic engineer has
usually found the final elements of
the automatic -control system already
selected for him -for example a particular type and make of valve with
the desired lift -flow characteristic,
operated by a particular type and
make of electric motor with the desired speed-torque or other characteristic. On a large job he may even
find that the electrical engineer has
already specified a particular type
and make of motor controller.
Problems of Temperature Specialist
In some extreme cases the electronic engineer would find that he
was only called in because the insurance underwriters, with explosive
atmospheres to reckon with, had
specified the elimination of ordinary
relays and contactors from a temperature control system which in all
other respects was considered entirely satisfactory. He would stick
in an oscillator tube here, a power
tube there, perhaps a pair of thyratrons-and that was that!
This sort of work is not altogether
a waste of effort. It is decidedly useful. But it is not the penetration of
electronics into the field of industrial
temperature measurement.
An analogy may drive home the
point. Imagine that the field of industrial illumination control has
December 1942
72
www.americanradiohistory.com
-
ELECTRONICS
Table
I
CLASSIFICATION OF METHODS OF MEASURING
TEMPERATURE *
By
Editor, Instruments; founder and director,
The In8truntentation Manual Project:
Pi Waugh, Pa.
1.
2.
3.
4.
5.
1.
never been penetrated by modern
electronics. You
modern electronic engineer-are called to a certain factory where the illumination
level from a battery of arc lights
above a conveyor belt has to be maintained at a certain value in order to
process the sheet material passing
under the lights. The control is
manual : an old- fashioned seleniumresistance primary element is connected to a large switchboard milliammeter in front of the operator
whose duty it is to operate an oldfashioned water rheostat by a block and- tackle arrangement. You are
acked to automatize this installation
by electronizing it. Now then, how
would you solve this problem?
First of all, since light must be
controlled automatically, it will be
necessary to employ a light- sensitive
primary element at the initial or
starting point. But will you scrap
the 1910 model selenium -resistance
element and substitute a more modern blocking layer photocell or caesium -oxide phototube? Not necessarily The old selenium cell is itself
an electronic device and should not
be discarded too hastily. Its spectral
response curve may more closely
match the spectral sensitivity curve
of the photo-chemical process under
control than the response of the latest blocking -layer cells or caesium oxide tubes. The chances are, of
course, that from the rich variety
-a
Control One Must First Measure
Here then is the first point! The
author laid down as one of the cornerstones of instrumentation seventeen years ago the dictum that before a condition can be controlled it
ELECTRONICS
-
Il. Methods Employing Continuous Effects
Properties of bodies
a. Thermal expansion, expansivity, expansibility
(1) of gases '
Instruments are classified by utilized coeffi(2) of liquids
cient (linear, cubical); also as cathetometric,
(3) of solids
extensometric, volumetric, etc.
b. Electrical conductivity or resistivity
(1) metals, of alloys
(Resistance measurement methods
(2) other solids
jI classifiable by type of circuit, by type
I
(3) electrolytes
of instrument (deflection, self -bal(4) ionized gases, etc.J
lancing, etc.) and in other ways
c. Viscosity, fluidity
d. Refractivity
e. Vapor pressure
f. Magnetic susceptibility
g. Sound velocity
h. Dielectric " constant "
i. Elasticity
j. Rotatory polarization
k. Color of transmitted light
1.
Color of reflected light
m. Hydrogen -ion concentration
(.
n. Specific heat
Compressibility
etc., etc.
Effects between bodies
a. Simple differences of properties
(1) Expansivities
(a) Bimetallic
b. Effects at interfaces or junctions
Instruments classified also by utiliza(1) Solid vs solid
(2) Solid vs liquid
i tion of effects, modes of conversion of
l energy: thermo -electricity, etc.
(3) Liquid vs liquid
c. Effects at a distance (radiometry)
(1) Methods utilizing Stefan -Boltzmann fourth -power law
(2) Methods utilizing displacement of maximum energy density.
(Color temperatures, of stars, etc.)
(3) Methods utilizing selected band or effective wavelength
(a) Measurement of the monochromatic energy by visual
o.
2.
matching
Measurement by " extinction " methods
(c) Combinations of (a) and (b)
(d) Selection by filtration as in use of red glass
(b)
Selection by special curve of receiver; phototube or
photocell, plate emulsion, etc.,
Methods utilizing ratio of energy at two effective wavelengths
Spectroscopic, spectrographic or spectrometric methods
(e)
(4)
(5)
etc.
Ill. Methods Utilizing Irreversible Effects
of new models of photocells and
To
Color
Etc.
.
!
phototubes on the market, you will
find one whose output is a better indication of the particular variable
to be measured and controlled.
Methods Utilizing Discontinuous Reversible Effects
Freezing point
A line must be drawn (both meanings)
Boiling point
between equilibrium temperature effects which include the International
Molecular transformation Standards,
and all others.
point
Solubility
1.
MAJOR M. F. BEBAR
Fusion
Color change
etc.
1.
2.
IV. Combination Methods
Methods using a temperature coefficient of an entire assembly
" Calorimetric pyrometers," " aspiration pyrometers " and other
devices requiring transport or transfer or manipulation of the body
or of a continuous sample
Methods requiring the introduction of an " indicator " as in line reversal method
1.
2.
3.
Behar, M. F., in Temperature Symposium of American Institute of Physics. Reinhold
New York, 1941. Page 350.
December 1942
Publ. Corp.,
73
www.americanradiohistory.com
must first be measured. In entering
the field of industrial temperature
control, the electronic engineer must
always keep in mind the importance
of the primary element. He should
always think of it as a measuring
element. Its output (whether a current or a mechanical displacement
or other effect) is the indication of
the measured value of the temperature. A classification of industrial
temperature measuring devices
which may be suitable for the measuring element is given in Table II.
The final elements of a temperature control system likewise deserve
careful study. Returning to our illumination- control problem, you
probably will not hesitate to scrap
the whole rope-lift water rheostat.
There are four good reasons for so
doing : (1) The muscular control of
the operator can be replaced by a
simple automatic device free from
fatigue and the "human element,"
(2) the unnecessary slowness of the
corrective action may be eliminated
through the use of well -known current- regulating means, some of
which are devoid of mechanical moving parts; (3) the difficulty of obtaining precise control through
manual operation may be overcome
through the use of electronic control
devices with the negative feed back
whereby a precision of 0.01 of 1 percent is not uncommon ; (4) the possibility of reducing or of eliminating
Table Il
CLASSIFICATION OF INDUSTRIAL TEMPERATURE
INSTRUMENTS
I.
1.
Mechanical Effects
Liquid -in -Glass (Visible Column)
(a) Mercury ( -38 to +640 deg. C)
(1) Etched stem (laboratory or chemical)
(2)
(3)
Industrial
Miscellaneous (pocket, wall, etc.)
Spirit (Typical ranges: pentane, 180 to +20 deg. C; alcohol
70 to +120 deg. C)
(1) Etched Stem
(2) Industrial
(3) Miscellaneous (pocket, wall, etc.)
(c) Gallium -in- quartz (+31 to -I 1000 deg. C)
Pressure Spring
(a) Mercury ( 38 to +538 deg. C)
(1) Ncn- compensated (tube length, 25 ft.)
(2) Head -compensated (tube length, 35 ft.)
(3) Fully- compensated (tube length, 150 ft.)
(b) Non - mercurial Liquid Expansion ( 40 to +400 deg. C)
(c) Vapor Pressure (Range limits, 30 to +370 deg. C)
(1) Progressive Scale
tube length, 150 ft.
(2) Uniform Scale
(d) Gas ( -130 to +538 deg. C) (tube length depends on bulb
(b)
2.
3.
volume)
Solid Expansion
4.
Fusion (pyrometric cones)
1.
2.
(a) Bimetallic (upper limit about 550 deg. C)
(b) Metal and Refractory (upper limit for Monel
4.
650 deg. C)
II. Electrical Effects
Electrical Resistance
(a) Platinum ( -180 to +1000 deg. C)
(b) Nickel, etc. ( -180 to +200 deg. C)
Thermoelectric. Note dual classification
(a) Galvanometric
(a) Rare - metals (to 1600 deg. C)
(b) Special alloys (to 1300 deg. C)
(b) Deflection and semi-
potentiometric
3.
about
(c) C -SiC (to 1800 deg. C)
Total- radiation (lower limit 400 deg. C)
(a) Hand
(b) Autometric and autographic
Selective- radiation (lower limit 660 deg. C)
(a) Photometric
(b) Disappearing filament f (a) Visual
L
r (b) Autometric and autographic
(c) Flux extinction
(d) Color ratio
J
flicker through the use of highly -developed electronic control schemes
such as the now-common automatic
volume control. These four considerations sometimes play a part in
electronizing the final elements of
industrial temperature control system, but they do not and cannot
dominate the decision as they would
in the control of illumination or ir-
radiation.
The reason for this is commonly
referred to as application lag.
Every industrial temperature control application is characterized by
a time interval between the moment
that the automatic controller has
completed a corrective function and
the moment that its primary element
can begin to feel the effect of the corrective action. There never is any
definite delay, but always a sort of
wave -and not like any of the mathematically-definable waves of electrical phenomena but a complex wave
a ragged ocean breaker.
Some of the keenest brains in the
field of temperature instrumentation
have striven to express application
lag mathematically but their equations are so over-simplified that they
do not truly represent the hard
physical realities and seldom help to
solve the inherently difficult problems. One inherently difficult problem, for example, is the soaking pit
vertical furnace into which a
huge ingot is lowered and subjected
to the soaking process. This process
is officially defined by the American
Society for Metals as "holding steel
at an elevated temperature for the
attainment of uniform temperature
throughout the piece." The author
has impishly italicized three words
which, in the present state of the art,
represent wishful thinking: the
reality in a soaking pit is not one
temperature but an exasperating set
of temperature gradients that chase
one another too fast to be plotted and
too slowly to give an "averaging"
effect of near -uniformity.
Electronic engineers may help to
make furnaces, ovens, stills and
other applications more controllable
but their greatest opportunities lie
in electronizing the primary or measuring elements of industrial temperature instruments in order to improve the measuring properties of
these elements. In so doing it is important to give consideration to the
industrially important measuring
-
-a
(Continued on page 163)
December 1942
74
www.americanradiohistory.com
-
ELECTRONICS
of
IMPEDANCE
Some Simple Electrical Circuits
The impedance and admittance of simple circuit elements, connected in series and in
parallel, is presented as a means for simplifying and aiding in the analysis of complicated
electrical circuits for communication or industrial applications
IN circuit analysis it
is frequently
convenient to have available in
convenient form the impedance functions of the more common types of
simple electrical circuits. This is
particularly true for those design
applications where simple combinations of common circuit elements are
frequently used, and where time is a
consideration in design.
In this Reference Sheet* are compiled the expressions for the impedance and admittance functions of
the simplest types of two-terminal
circuits composed of lumped values
of L, R, and C. The circuit elements
By
BEVERLY DUDLEY
1Iamilliuu Ed
are considered to be ideal in that
they conform fully to the mathematical expression for their behavior and have no losses. Unless
otherwise indicated, it is assumed
that there is no coupling between the
various elements of the circuit. For
convenience, the impedance data is
divided into two sections, one on
series connected circuit elements,
and the other on parallel connected
circuit elements.
In each tabulation, the schematic
diagram of the circuit is shown in
the first major column. The second
column gives the impedance of the
circuit in Cartesian co- ordinates involving real and quadrature terms,
the impedance being given in the
form, Z = R
jX. The third column tabulates the absolute value or
the magnitude of the impedance
from the real and quadrature terms,
using the familiar expression, Z =
V R° -{- X2. The fourth column gives
the phase angle of the impedance in
TABLE OF IMPEDANCE OPERATIONS
OPERATION
Addition
Z= ZZ +z2= (Ri +JX) +(R2 -JX2)
Subtraction
Z= Z,- Z2= (Ri +JXi) -(R2 JX2)
= (Ri- R2)- J(X1 +X2)
_(R1 +R2) +J(XX -X2)
Multiplication
* The
tabular material in this Reference Sheet is taken
from a forthcoming
"Introduction
book.
to Radio Engineering". with permission
of the publisher.
RESULT
Z= ZZZ2= (IZilA)(IzaI /e?)-
z=
=
Z2
Raising to nth power
Extracting nth root
I
ZI
L-e
IZiz21
)Division
(IZ2I /e2)
_I z2I
Z =Z "= Z n/ne
I
I
Z = ÇÍ =Z ^_IZ
ELECTRONICS REFERENCE SHEET
^/en
/e,+e2
e,-e2
IMPEDANCE OF SERIES CONNECTED CIRCUIT ELEMENTS
CIRCUIT
PTO.
IMPEDANCE
Z=R+jX(ohrns)
MAGNITUDE OF IMPEDANCE
R
R
IZI=[R2+X2] V2(ohms)
R
1
2
jwL
-J6ÖÒ6ÒN
PHASE ANGLE
9= tan '
-?-:-(z.
R,
R2
+
wt..
1
1
wC
wC
R,+
4--,
-rifar-/b00`
R
1
2
-w
n
jwC
-
2
R,+ R2
R2
ADMITTANCE
Y=1/Z(mhos)
0
C
J
(radians)
I
O
R+ R2
M
L,
s
jw(L+L2±2M)
i-
-1
j
t
w
(
-wvOO6-
R+
$
JWVV
R-j
}
--R-C
L
R
1tì
C
C
C+C 22
l)
rC
1
\
w
L
C
Ì-
i
jwL
l
C
w L+L
,
z +2M )
n
/
C,C2
r
Rz+w2L21
L
J
w
2
w
I
1
L
1
wC /
R+(`'L
\\
1/2
\l
/
/
`wL
tañ
z
C C,
l
Cz /
t
1
J
[R2±(L_)jzl
z J
R+wL
z
R
tañ'- wRC
+
wCR+I
wC
i wzLC-
7T
2
/2
tan'
and impedance are measured in
ohms, admittance is expressed in
mhos, frequency in cycles per second. Inductance and capacitance are
expressed in henries and farads, respectively. The phase angle is expressed in radians in the equations
given in the tables. The phase angle
may be expressed in degrees by multiplying by 57.2958; that is, 1 radian
= 57.2958 degrees, or, 1 degree =
0.0174533 radian.
(L- wC )
R
R
-j (L - wCz)
¡
Rz+\wL
wC
Circuit analysis often calls for
the addition, subtraction, multiplication, division, raising to a power, or
extracting a root of one or more
impedances. These operations are
facilitated by providing expressions
for impedance in both the rectangular and the polar forms. The
rectangular form is most useful in
those instances involving the addition and subtraction of impedances,
in which case the real and quadra-
ELECTRONICS REFERENCE SHEET
www.americanradiohistory.com
2
wzCZR-2wC
1
J
wC
R- wL
wL
I
/z
[ wzC2R2+11
1
wC
( wL
radians, calculated from the magnitude of the real and quadrature
terms. In general this phase angle is
given by = tan -1 (X /R), where X
is the reactance and R is the resistance of the circuit. From these two
columns, the impedance, in polar
form, is readily obtained since Z =
1Z1 /B. The last column tabulates the
admittance for each circuit in rectangular co- ordinates.
In all cases resistance, reactance,
O
+ 2
C2
C,
%
w(L,+L2±2M)
L2
IMPEDANCE OF PARALLEL CONNECTED CIRCUIT ELEMENTS
No.
CIRCUIT
M PEDANCE
I
Il
Z= R+j
X(ohms)
IZI
=[R
X2[
+
ADMITTANCE
PHASE ANGLE
MAGNITUDEOFIMPEDAN[E
1(ohms)O=
Y= I/Z (mhos)
R(radians)
ton-
RI
11
RI + R2
0
+R,
R
RI+R2
R2
RI
R2
L1
lI
+w [LiLI+L2+2M
L2_M2J
12
[Li
rL+L +2M1
L2
[L,L2_M2
]
M2
LI, L2 I
-jW
+ 2
L1
IÌCI
n
C2
I
-j
13
I
w(Cl2)
+j
2
w(
CI
+CZ)
IIC2
-
wL-jR
-w RC
R+
R
w2L2R+jwLIll
wLR
w2L2+R2
w2L2+R2 ]%
14
/111111
R
tna
wL
1
wLR
L
15
-i
R
--Wvvvvvw-_
tan
R
2
[I -1:6/2
R1+w2 R2C1
w
C
1T-
,
L
16
wL
wL
J
I-w1LC
\
x
+
-
11-
(1-w2LCl/
2
6.,L
G
R
17
1
R
18
rRllj2(wC- 1¡¡)l
R+) (wC-L)
[R)
11
L
R2
R
w
z
C
2
R +
C
wC
L
I
R
(wC-a)1
R
-j
(wC-WL \l
L\RI +(wC-wLl ]
+ dc--,+_,L).2]
z J[
tan-I
l
+-(wL---l1
C\ wC
Z +[
r(
R
w
C
2
R2 L
wC
+-(mL
C
)2
I
2
mC
C
R+'J w R2C-L+w2
\wL-wCl]
R
\
ïC2
tan
R2+(wL- wC
(WL-wC)2
I`
L/
R
[wC+
RZ+w2
L2
]
C
L2
2
RI
111
Ri
L
/
l
(RI +R2)2+(wL-wC)2
\
19
R2
2
w R2L-wICC
RR2 (RI +Rÿ+w1L2R2+
R2(RI+R2)+w2L1R2+C2
RC
t
(
wLR12-/ C(wL-ruCl2
(RI+R2)2+(wL-C2
tin
wC
+
C
w
I
1
11
+J
(R1+uL2)(w1RiC1+I)
[wLR2-R12 L(wL-J
/
2
(wL C)
RI+w2RIR2C2(RI+Rí+w'L1C1R1
l
(RI
CRI
w[R¡C L+w2LCCLRiC)]
R1(RI+RZ,+w2L2R1w J
(RI+R1+1wL-\ )2
+1
(R?+wl L1)(w1 RiC+1)
ture components are treated sepa- other form. The impedance may be If the resistance and reactance are
rately. The polar form is most con- expressed in the alternative rec- both given, the magnitude of the imvenient for the remaining types of tangular and polar form, respec- pedance is
operations, in which cases the mag- tively, as follows:
Z= RfjX= IZI/LB
nitudes and phase angles are dealt
with separately. The manner of car- Having given the magnitude and
rying out these various types of op- phase angle in polar form, the resiserations is indicated in the accom- tance and reactance components in
panying table.
rectangular form are given by the
It is also convenient to have on expressions,
hand means of converting from one
cos O
R =
form of expressing impedance to anX = IZI sin
O
IZI
=
+ X2
11R2
and the phase angle is
tañ (X /R)
The use of these simple circuits
results in a saving of time and aids
in the analysis of more complicated
electrical circuits employed in electronic applications.
ELECTRONICS REFERENCE SHEET
O
=
1
Avoiding Patent Pitfalls
PATENTS are granted for "new
and useful" inventions. Much
has been written on the subject of
what constitutes a "patentable invention", because it is not always
easy to draw a boundary line separating patentable from non- patentable matter. This subject is particularly important since the majority of all inventions does not
relate to basically new devices, structures, and methods, but relates to
improvements in known and existing ones.
A patent attorney may advise
against filing a patent application,
or the Patent Office or the courts
may refuse to grant a patent for a
newly developed device or method
because it does not "amount to invention" or "merely involves mechanical skill ". These seemingly disparaging remarks should not dishearten the inventor, because they
refer only to the patentability of the
device or method and are no measure
of its usefulness or commercial
success.
Since no exact definition of a patentable invention is possible, which
could readily be applied in all cases,
considerable controversy has arisen
at times over this question, and the
concept of a "patentable invention"
tends to vary.
The following considerations may
be helpful in an attempt to determine the patentability of an invention in doubtful cases.
If the device, structure, or method
under consideration, which for the
sake of brevity shall be termed the
"invention ", relates to a combination of elements or method steps in
which one or more elements or steps
have been added to a known combination so that the new combination
operates in a new manner to produce
an improved or different result, the
invention is patentable, provided, of
course, that it is new.
If the invention relates to a combination of elements, methods, or steps
differing from a known combination
only by substitution of one or more
78
By RUDOLF F. WILD
Philadelphia, Pa.
of the elements or steps by their
known equivalents, the invention is
not patentable, unless the result obtained by this substitution is such
that it would not be expected by a
person skilled in the art. The unexpected result may lie in a vast improvement of performance or efficiency, considerable reduction in
space requirements or cost, or a
great increase in the ease of manufacturing.
The same is true if the invention
relates to a combination of elements
or method steps which differs from
a known combination only by the
size, position, or degree of one or
more elements or steps.
In the last two cases it is particularly important to convince the Patent Office that the invention represents an advancement of the art.
The above outline is rather crude
but it is beyond the scope of this
discussion to enter more deeply into
this matter.
tion, if feasible, of an embodiment
in such detail that it enables others
skilled in the art to make and use
this embodiment without the exercise of further inventive skill.
Abstract ideas relating to inventions of non -complex nature can
often readily be translated into an
embodiment. In cases of complex
nature, however, the process of
translating the idea into an embodiment may be a weary one. It may
happen then, that a record is made
of the idea, perhaps conveyed to a
patent attorney, whereafter all activity ceases. In this case no invention has been conceived, because the
abstract idea was not translated
into an embodiment. From a patent
viewpoint, therefore, the abstract
idea alone is worthless, because it
cannot form the basis for a patent.
It may be assumed and relied upon
in some cases, that the patent attorney is sufficiently familiar with
the art to be able to translate the
abstract idea into an embodiment.
While this may be the case, the inventor, or rather the originator of
the abstract idea, would not be able
Embodiment of the invention
to prove inventorship if called upon
Patents are not granted on ab- to do so in interference proceedings,
stract ideas without the showing of as will be discussed below. It is esan embodiment thereof, which con- sential, therefore, that the inventor
sists in a description and illustra(Continued on page 159)
arid PAT
This article
rácle co
E11JTs
will be helpful nta'
various suggestions
their inventions. to inventors
ill securing
which
knownjnventïans.
suggestions patents on
ernployesehavin
rriay
be well
be unknown to 9 Patent departments.,
or to individual
inventors inventors
to follow
smoll firms,
the
who have
Potent Laws
requirements
occasion
upaasan
pPlicit for imposed bY the
cr patent.d
Y
n
December 1942
-
ELECTRONICS
TUBES AT WORK
logarithm (to the base 10) of the ratio
of the incident light to the light transmitted by the emulsion grains, thus:
d
A Photoelectric Densitometer
79
Thorium Detector
82
Device for Blind Cashiers
82
Control for One -Way Tunnel
82
Hammered Iron Tips Last Longer
84
Photoelectric -Controlled Coal Larry
84
R -F
Heating Aids Tin -Can Makers
86
Commercial Aircraft Aids
of microamperes or fractions thereof,
it is necessary to amplify the output of
the phototube considerably in order to
Photoelectric
Densitometer
A
By CARL C. SMITH
THE DEVICE to be described was de-
signed for the purpose of obtaining
consistent densities in the production
of separation negatives, comprising
one phase of the color- separation process of making natural color photo-
graphic prints from Kodachrome
transparencies. When used as recommended, the device is sufficiently accurate to insure uniformity of the
gray -scale densities of negatives obtained through each of the tri -color
filters used in this process.
Design Considerations
The essential elements comprising a
densitometer include a source of light,
a lens to concentrate and direct the
light, an aperture to limit the area of
the film to be examined and some
means of determining the amount of
light transmitted through the film area
under consideration.
In order to maintain consistent accuracy of measurement, there are a
number of variables which must be
confined within prescribed limits. For
example, the obstruction presented to
the passage of light by the silver grains
in the film emulsion is a function of
the scattering and absorption of the
light and both of these factors vary
with the wavelength of the light beam
used. If an incandescent source of
light is used, as in the instrument described, it is essential that the filament
voltage of the lightsource be closely
regulated since the spectral distribution of the light varies greatly with
small changes in filament temperature.
When a phototube is used as the
measuring element, an additional reason for close maintenance of spectral
quality is introduced, since all known
photosensitive surfaces possess spectral
selectivity in that they are not equally
sensitive to equal intensities of radiant
energy of various spectral regions.
Since the output currents of photo emissive tubes are usually of the order
ELECTRONICS
86
-
facilitate measurement of the photo tube current variations on commer-
available deflection types of
meters of the order of one milliampere
full -scale deflection. (Such a meter is
definitely desirable in an instrument
for use in the dark room, as compared
to galvanometers or electrometers, as
it is considerably more rugged.) A
stable amplifier is therefore another
necessary element.
Variable negative size and other considerations require limitation of the
portion of the film under measurement
and the necessity of using a small aperture in the measuring beam path imposes further problems in the design of
the amplifier, in that its sensitivity
must be sufficient for the range of
densities which it is desirable to include. The density of a photographic
emulsion may be expressed as the
cially
= log,o
Í
wherein d is the density and I and I'
are, respectively, the incident light
and the transmitted light. This expression is equivalent to the logarithm
of the reciprocal of the transmission:
d
= logio
1
7,
wherein d is the density, as before,
and T is the transmission factor of
the emulsion. From these considerations it is apparent that a densitometer designed to cover the range of
density of the device described, 0.1 to
2.0, must be capable of measuring light
intensity ratios of approximately 100
to 1.
Electronic System
The electronic system incorporated
in the instrument includes a voltage doubler type a -c power supply and a
single high -mu amplifier tube. Voltage
delivered to the phototube is well regulated by the VR 150-30 connected
across the variable portion of the
power supply load resistor. Amplifier
plate voltage is regulated to some extent by the same VR 150-30. Amplifier plate current is measured by a
zero-to-one milliammeter and increases
with decreases in the amount of light
incident upon the phototube surface.
The complete densitometer circuit is
shown in the accompanying schematic
diagram.
Since simplicity was an essential requirement in this device, the light source consists of a small lamp which
has an integral condensing lens cast
with the glass envelope. The lamp is
Simple photoelectric densitometer designed to insure consistent densities in
color -photography separation negatives. It functions as a comparator. a photographic step-wedge rather than direct calibration being used in the process
79
December 1942
www.americanradiohistory.com
This new antenna by G. E., with circular bays, eliminates the usual complex, costly structure, yet
radiates energy uniformly. It is on example of General Electric engineering leadership in FM equipment.
D.E.
WENT TO THEM AND FOUND OUT!
AMONG owners of frequency -modulation receivers, a large majority like the quality of FM
reception. For example, 85 per cent say it is
better than regular broadcast reception, and 91
per cent would recommend it to their friends!
These are facts and figures taken directly from
a survey made for General Electric in 14 cities
by an independent research organization. Among
owners of General Electric FM receivers, the
approval registered was even greater.
FM Receivers
NO OTHER
80
December 1942
- ELECTRONICS
Today G. E. is building FM transmitting and
receiving equipment for war purposes only, with
the same precision and skill that characterize
all of its electronic devices. When peace comes,
General Electric FM equipment will be more
For
than ever the best that money can buy
detailed information on the FM survey. write
for booklet, entitled "What the Consumer Thinks
of FM," to Radio, Television, and Electronics
Department, General Electric, Schenectady, N.Y.
The research organization went directly to
private homes for its findings. It sought and
obtained answers from both FM and non -FM
owners of high, medium, and low cost sets. The
answers took on a pattern of telling significance.
Seventy-eight per cent of the non -FM owners
rated virtual freedom from static and better
tone quality as the outstanding FM advantages.
Eighty per cent of FM owners emphasized these
same advantages also.
FM Broadcast Apparatus
MANUFACTURER
ELECTRONICS
-
!
FM Broadcasting
OFFERS
SO
FM Police Radio
MUCH
GENERAL
FM
FM
...
Military Radio
EXPERIENCE
ELECTRIC
December 1942
I60- F2.6918
M
81
www.americanradiohistory.com
mounted directly above the measuring
aperture immediately below which the
phototube is mounted. The lamp is
battery- operated to obtain constancy
of output during measurement and a
switch is provided for opening the lamp
circuit when measurements are not
being made. This feature is desirable
since it permits the amplifier tubes to
remain at operating temperature while
other photographic work is in progress
and thereby contributes to the stability of the amplifier_ since there is always some degree of drift in a d -c
amplifier until operating temperature
is reached.
Method of Use
The method of using this densitometer is quite simple. The amplifier tubes
are energized and allowed to attain
normal operating temperature with the
lamp dark. After a five minute warm up time the milliammeter reading is
adjusted to full -scale deflection by adjustment of the variable arm of the
50,000 ohm phototube voltage control.
When the lamp is turned on, the meter
deflection automatically falls to about
5 percent of full -scale deflection. The
portion or portions of the film to be
measured are then placed over the
aperture and the meter reading carefully noted. A photographic step -wedge
of the desired range is next passed
over the aperture until the meter again
reaches the deflection noted from the
film measurement. The density is then
read directly from the calibration of
the step-wedge.
It is possible, of course, to make the
device direct -reading by expressing the
meter readings as a function of density
and preparing a curve. Due to such
variable factors as lamp blackening,
amplifier tube changes and battery
voltage variation over long periods,
direct calibration of a simple densitometer of this nature is not considered desirable. Little or no inconvenience is experienced when using a calibrated wedge and a great deal more
accuracy is obtained since the known
Device for "Blind Cashiers"
Canadian George A.
Lafleur has invented a portable machine which detects the denomination
of United States paper currency. It
buzzes once on dollar bills, twice on
fives, three times on tens and four
times on twenties.
In operation, the device requires that
the bill to be examined be placed in a
metal "billfold" compartment, where
it is scanned by a light -beam. Light reflected from one of the four denomination-determining numbers in a corner
of the bill is reflected into a phototube
and the output of the phototube actuates the signalling mechanism.
According to J. O. Kleber, chief engineer for the American Foundation
for the Blind, under whose auspices the
device was recently demonstrated, the Salt Lake County electrician Carlquist
operating principle could be readily checks operation of the one -way tunnel
traffic-control unit
adapted to detection of different cloth
textures. He thinks the bill detector
would probably cost about $25 to tunnel at each end constitute the sysmanufacture.
tem's automatic traffic "cop ", cars
cutting light beams as they enter and
again as they leave. Traffic lights remain set for traffic flow in one direction
only until the number of cars counted
exit equals the number counted
Control for One -Way Tunnel at the
at the entrance. In the absence of
BINGHAM, Utah boasts a 6,000 -ft. ve- traffic in either direction, a convenhicular tunnel through which cars may tional timing apparatus switches the
pass in either direction but not at the traffic lights every three minutes. Ensame time. G-E automatic electronic try of a car from either direction
controls set entrance traffic-lights so causes the photoelectric system to asthat traffic may flow in one direction sume control.
only for three minutes, make sure that
In addition to controlling traffic,
precisely the same number of cars electronic equipment insures proper
come out as went in, then switches the tunnel ventilation, turning on a blower
lights in the other direction. If the when the carbon monoxide content of
tunnel is not completely cleared within the air within the tunnel rises above a
five minutes after traffic starts to flow pre- determined value and turning the
through it a signal sounds and a patrol- blower off again when the air is satisman goes in to determine the cause of factorily cleared. Traffic is automatthe jam, manually re- setting the sys- ically prohibited from entering the
tem after he has the jam cleared.
tunnel while the carbon monoxide is
Photoelectric relays just inside the being cleared.
BLIND 29 -year old
and unknown readings are taken within
a short interval of time.
ORIYERS...,.{mut
.
2fßS9Yt tKN'
sIGNAL4
Thorium Detector
INCREASED PRODUCTION
of high -power
radio tubes being built at the Westinghouse Lamp Division has been made
possible by the development of a detector that automatically sorts filament
wire to determine whether it is made
of pure tungsten or contains thorium.
The detection process consists of introducing a sample of filament wire
into an electric carbon arc. As the
wire burns completely, visible results
are observed by means of a spectroscope. Two lines appear in the observed
spectrum if the wire is pure tungsten
while four lines appear if the wire contains thorium.
PEOCSTOfANS
Net ALLOWtO
IN
.0 THE
PIT
ROADWAY
ust 3;.AIY
DRIYERE
tiT SIGNALS
Traffic signals at the tunnel portals consist of one green and three
red lights. Two of the red lights are in parallel to guard against burning out of a lamp. The other red light is connected to batteries through
a throw -over relay, stops tunnel traffic in the event of a power failure
December 1942
82
www.americanradiohistory.com
-
ELECTRONICS
IN THERE
woalr.r -aee Ae M*1e
You don't need to look to know that in
the first line of communications, you're
sure to find CINCH parts, performing as
they are expected to
... on the past
tation of a quarter of
a
faction where the utmost
repu-
century of satisis
demanded
...
CINCH
sockets, terminal strips,
lugs and
con-
nectors are sure to be "in there working
all the time ".
Photo by
Army
Signal Corps
U. S.
MANUFACTURING
INCH
CORPORATION
2335 WEST VAN
BUREN
STREET
CHICAGO, ILL.
SUBSIDIARY: UNITED-CARR FASTENER. CORP., CAMBRIDGE, MASS.
ELECTRONICS
December 10
12
83
Hammered Iron Tips
Last Longer
IN ORDER to save tin the percentage of
this metal used in solder employed by
many firms in the electronic equipment
manufacturing field has been reduced.
Solder containing less than the prewar amount of tin appears to be satisfactory for most purposes but it requires the application of more heat to
make it flow properly. The resulting
use of hotter soldering irons has, in
some instances, materially shortened
the life of copper soldering -iron tips
and copper, too, is a metal which must
MIGHTY IN THE PINCHES
be conserved.
From Bill Schall, chief inspector of
one of the Stromberg- Carlson Telephone Mfg. Co. plants, comes word
CLARE TYPE K
help
RELAY
D C
CALLITE CONTACTS
CLARE MIDGET RELAYS
that filing of soldering-iron tips hastens
their demise. It is better, says Bill, to
hammer them back into the required
shape, and better still to have such
hammering and the required re -tinning done by a few experts for the
entire plant. S -C has standardized on
three soldering -iron tip shapes to facilitate such wholesale re- conditioning.
do a giant's job
War intensifies the engineer's constant fight
against weight and space. Every ounce, every inch, meets the toughest
kind of "squeeze play" In assisting the C. P. Clare & Co. solve
the problem of designing a midget relay that would do a giant's job,
CaRite produced silver contacts of small size, of precision uniformity,
and extraordinary abuse- resistÌ'ng. stamina. Today, Callite- equipped
Clare Relays are vital fighting parts of planes, corvettes, tanks and
other powerful weapons.
When similar contact problems confront you, Callite will gladly
assist in finding an efficient solution. Catalog No. 152 describing
C -T screw, rivet and welding -type contacts is now available.
C A
L L
I
T
E
T U N G S T
E
N
544 -39th St., Union City, New Jersey
C O
R P
O
R
A T
I
Photoelectric -Controlled
Coal Larry
AT THE Adolph Coors Company plant
in Golden, Colorado, G-E photoelectric
relays play an important role in effectively controlling the movements of
a "Larry" or movable coal-bin which
evenly distributes fuel to a sectional
hopper feeding a chaingrate boiler.
The relays were installed to replace
limit switches, eliminating mechanical
wear, and are used in conjunction with
an electronic time -delay relay which
permits the larry to be brought to a
smoother stop than is ordinarily pos-
O N
Branches: Chicago, Cleveland
-
SPECIALISTS in the manufacture of electrical contacts and formed parts for all
electronic applications in standard or special shapes
of tungsten, molybdenum,
silver, platinum, palladium and alloy combinations of these metals.
use materials under priority control, preference rating
extensions and end use data must be supplied with all orders.
As Callite Tungsten products
KEEP
'EM ROLLING WITH
CALCITE
CONTACTS
CALLITE
TUNGSTEN
Trade Mark Reg.
U. S. Patent Off.
Fuel is evenly distributed by this movable
coal -bin traveling on an overhead track.
One of two control units, comprising a
lightsource and a phototube, may be seen
in the upper right corner. immediately
beneath the wheel
December 1942
84
www.americanradiohistory.com
-
ELECTRONICS
FOR
Ferip RESULTS
USE TUBES
WITH
GENERAL CERAMICS
STEATITE INSULATORS
a
.
t
,e4
tbe
htte
t9 c
.
aeQ
tJb e
S
e0
4t
.
SC$4.
Qe
E
ALT
te
Two major advantages over ordinary commercial
steatites are:
Low surface conductivity and contamination.
2. Good insulating quality at high operating
1.
temperatures.
As vacuum tubes increase in power, more and better
insulation becomes necessary. Glass insulation is unsatisfactory at high temperatures and high frequencies.
Natural lava from Sicily has the essential insulating
qualities but is unobtainable.
General Ceramics has succeeded in producing a
steatite that, as an insulator, is equal to natural lava,
but requires no expensive Carboloy tools for machining. In addition, these insulators are made of domestic
materials and therefore are available in quantities.
Outstanding electronic tube manufacturers have
tested General Ceramic's Steatite Insulators and are
using them with marked success. These insulators can
be supplied in pressed or extruded shapes for every
type of vacuum tube requirement.
GENERAL CERAMICS AND
STEATITE CORPORATION
GENERAL
ICI
...
ITUOTIT! CIN/OYT11111
11i
RI
/NI( :s
Pervmhrr
85
19 12
www.americanradiohistory.com
sible when a driving motor is plugged.
Attached to both lower rear corners
of the larry are units comprising a
lightsource and a phototube. As the
larry oscillates slowly back and forth
on an overhead track in front of the
BOTH ARE
JEFFERSON ELECTRIC
TRANSFORMERS
small 1.6 ounce transformer is as accurately
made
give as precise performance as the largest
transformers.-Both are Jefferson Electric in correctness
of design and accuracy of manufacture.
The line of Jefferson Electric Transformers for all
radio and communication systems incorporates correct
basic engineering resulting from a lifetime of transformer specialization. They include a wide range of
sizes and are made to withstand the climatic conditions
anywhere, -from the Tropics to the Arctic.
In the manufacture of millions of transformers, skilled
craftsmanship has been developed which with modern
equipment and 250,000 square feet of plant space
make possible large output of dependably uniform quality.
To aid you in saving time, our engineers will be glad
to make recommendations
JEFFERSON ELECTRIC
COMPANY, Bellwood, (Suburb of Chicago) Illinois,
Canadian Factory: 60 -64 Osler Ave., W. Toronto, Ont.
hopper, vertical metal strips suspended
from the rear rail intercept a beam
and stop the larry at corresponding
hopper sections. Use of a photoelectric
relay unit at each rear corner of the
larry insures operation regardless of
the direction in which the larry is
travelling. The metal strips intercepting the light beam are hinged, so
that they may be thrown up out of the
way if a particular hopper section is to
be skipped.
Photoelectric relays also control the
movement of the larry when it requires re- filling. An end upright is
swung up out of the way, permitting
the larry to run a distance of thirty
feet to the coal supply, where a similar
upright intercepts the light beam and
stops the larry so that it can be filled.
THE
-to
...
JEFFERSON
ELECTRIC
TRANSFORMERS
PROOF
TROPICAL
RAINS
AGAINST
AND ARCTIC ICE
R-F Heating
Aids Tin -Can Makers
TIN PLATING on many of the cans in
which food is shipped to United Na-
tion's fighters everywhere will shortly
be less than thirty millionths of an
inch thick, one pound of the precious
metal doing a job that formerly required three.
Instead of dipping strip steel used in
the manufacture of cans into molten
tin, engineers have devised a means of
depositing the tin by electrolysis. After
electroplating, the tinplate must be
heated so that the tin will flow and
cover the plate without flaws. The
heating is accomplished during the electrolysis process, without physical contact between the plate and the heating
equipment, by induction. Thus danger
of arcing or burning is minimized and
the steel strip may run continuously
through the "flow zone ".
Equipment with which to test the
practicability of the new electroplating
process was originally set up by
Westinghouse engineers in a radio
manufacturing plant. Tubes designed
for broadcasting service supplied the
required high frequency current and,
curiously, a clothes -wringer pulled the
test strip through the heating unit.
.
Commercial Aircraft
Aids
FROM THE Civil
Aeronautics Adminis-
tration comes word of several electronic
communications and navigation inno-
vations which will aid American commercial aviation:
A new uhf two- course radio range
system has been developed to the point
where initial installations can be made.
Pilots will have visual indication of
86
December 1942
-
ELECTRONICS
-\?
SERVE ALL FRONTS!
BY GUARDIAN
*
Yuletide joys of '42 will not include the many electrical gifts which
brought us cheer, and ease, and comfort in other years. Relays by Guardian
have marched on from peacetime industry to the firing lines of war. Doing
war jobs in many ways ... in planes ... in tanks ... in communications
in bomb releases and gun controls. Wartime jobs which Guardian anticipated
and planned long before "Pearl Harbor ".
,
...
But, while thinking, building, and engineering the tools of war today,
Guardian again is looking ahead to peacetime applications of Relays, Solenoids, Electrical Controls of all kinds. If you are making plans for "after it's- over ", ask our engineers to plan with you. Write to Guardian. Our wartime experience can help you build better products for the future.
GUARDIAN
1
6 2 5 W
E
S T
A
ELECTRONICS
W A
L
N U
COMPLETE
T
S T R
LINE
OF
RELAYS
t;
1{
CONTROLS FOR ANY PURPOSE...ranging
from tiny
from 150 watts to 1000 amps
...
relays weighing less than an ounce
big, rugged two -pound contactors.
... to
ELECTRIC
C H
E T
E
)
x?
SERVING AMERICAN
December 1942
www.americanradiohistory.com
WAR
I
C
A G O
,
I
L
L
I
N O
I
S
INDUSTRY
K
HOW OPTICS SERVED
A CHEMICAL PLANT
Atroublesome operation in a
well known chemical plant was the reading of inaccessible gauges. Every twenty minutes an employee would
climb a fifty -foot ladder and call successive readings down
to the control board below. Today all these measurements are
taken instantly by the engineer on duty, without leaving his chair
and with far greater accuracy. Control has been greatly improved; unnecessary time and labor eliminated ...This improvement
the sector in which they are flying.
Voice communication, when required,
will over -ride the range signals, on
the same frequency.
Simple and inexpensive monitors for
radio airport boundary markers have
been developed and are ready for widespread installation. The monitors are
small receivers placed halfway between markers and airport. They actuate a siren if for any reason the
marker transmissions fail, bringing repairmen in a hurry.
Unattended weather -reporting and
traffic- control transmitters located at
many isolated spots, such as on mountain -tops or islands, will henceforth
be controlled by frequency modulated
radio signals. This saves wire by
avoiding the necessity for cabling between such stations and their remote
control points, still permits them to be
turned off at an instant's notice at the
approach of any enemy. Small radio
transmitters are being used as "obstruction markers." Installed atop high
towers or buildings, they give approaching planes a distinctive warning.
Warning signals come through to the
pilot's earphones over regular aircraft
radio communications channels and, in
some instances, also actuate a warning
light on the instrument panel.
Under development is a radio range
monitor which not only warns CAA
airways workers when a range transmitter drifts as little as three deg. off
its proper compass points but also
sends a distinctive warning to approaching planes, indicating when
something is out of whack in the
ground equipment.
was an accomplishment of advanced optical design and manufacturing, a typical example of how Perkin -Elmer engineers
can improve industrial efficiency. Frequently the amazing science
of optics can "team up" with chemical, mechanical or electronic
methods to provide the answer to otherwise insoluble problems.
Despite the fact that The Perkin Elmer Corporation facilities are
I00,000,000-VOLT
ELECTRONS
and will be devoted entirely
to the war effort for the duration, we shall welcome your let-
ter describing present problems
or future plans. If we can be of
service now or in the future, we
shall be glad of the opportunity.
THE PERKIN-ELMER CORPORATION
GLENBROOK, CONNECTICUT
Charlton (right) and W. F.
Westendorp examine coils of a new 100,000,000 -volt "induction electron accelerator, which will, among other things, permit x -ray studies beyond the 8 -inch armor
plate depth achieved by present -day
1,000,000 volt machines
G -E's Dr. E. E.
MANUFACTURERS OF PRECISION LENSES
PRISMS
and MIRRORS
OPTICAL DESIGN AND CONSULTATION
88
December 1942
www.americanradiohistory.com
-
ELECTRONICS
The high regard in which I R C
Resistors are held by Engineers and Executives of
America's leading electronic industries is clearly attested
by the voluntary remarks quoted at the right. These are
taken from among returns to a nation -wide marketing
study recently made by a wholly independent research
organization. This survey was completely unbiased,
with no company name or product disclosed.
P
lIEF EffilE
D
"We require quality, uniformity, service-and I R C have
proven without a doubt definitely reliable."
"1R C seems to be choice of
engineers in the government
radio research job I'm in."
"Most complete engineering
data."
"Most stable as determined,,,y
laboratory tests over two -year
period."
"...
In my business, Aircraft
ElectricalEngineering,I always
specify I R C."
"Fine people to do business
PERFOR1IACE
with."
"We handle only one line of
resistors and of course that
must be the best namely
R C."
-
I
FIXED AND VARIABLE
"To us, in the
Company, the 1R C mark on
a resistance is the equivalent
to a hallmark on sterling."
RESISTORS
INTERNATIONAL
IRC flies the
flog of the Army
-
Navy Production Award
for "high achievement."
RESISTANCE COMPANY
403 NORTH BROAD STREET
PHILADELPHIA, PA.
ELECTRONICS
-
December 1942
89
www.americanradiohistory.com
THE ELECTRON ART
Graphic Solutions of Parallel Circuits
Ignitron Rectifier in Industry
The Mass Spectrometer
Atmospheric Propagation of Sound
Telephone for Hard -of-Hearing
Amplification Factor with Square Mesh Grids
Measurements of Very Short Wave3
Extending Range of Meters
B
90
100
102
102
106
106
108
114
c
Fig.
Some Graphic Solutions
of Parallel Circuits
ROBERT C. DAINE
SOLUTIONS of series circuits
are familiar to every electrical student
but solutions of parallel circuits are
not so well known. This is probably
because electrical properties of circuit elements are given on the basis
of resistance, reactance, and impedance. Solutions of parallel circuits
convert these values to conductance,
susceptance and admittance for combining them and then convert back
again for obtaining the answer usually
required.
Some graphic solutions of parallel
circuits are presented here which depend on the theorem in geometry which
states that, "The perpendicular from
the vertex of the right angle to the
hypotenuse of a right triangle is a
mean proportional between the segments of the hypotenuse." This theorem
enables us to find the reciprocal of a
number graphically.
In Fig. 1, a right triangle is shown
in which, according to the above
theorem, DB /AB = AB /BC or BC=
ABVDB. If AB = 1 in the scale used,
then BC is the reciprocal of DB. DB
can represent the absolute value of
GRAPHIC
OZ,
3 -Two impedances of opposite sign,
and OZ when connected in parallel
produce the net impedance OZ
which equals the combined impedance,
Z. If, due to the scale of the perpendicular, AB, the sum of 1 /Z, + 1 /Z, ...
is changed by a factor such as 100 as in
the illustration above, this error will
be compensated for when finding the
reciprocal of the sum by the same
method. Therefore the perpendicular
can be of any convenient value, but
for greatest accuracy it should be
about the length of the average impedance of the problem.
The general case of two impedances
Fig. 2- Diagram illustrating the general
in parallel OZ, and OZ, is shown in
case of the combination of two impedances
Fig. 2. A circular arc is drawn about
connected in parallel, the resultant of the point O with any convenient radius.
OZ, and OZ_ being OZ
On OZ, a perpendicular OA is erected.
Its intersection with the arc at A is
used to form the vertex of a right
can be used in the formula for parallel triangle, one side of which is formed
impedance, Z =1/ (1 /Z, -+ 1 /Z_ + ...) . by the line AZ, and the other by the
1 /Z, .. .
We find the reciprocals, 1
line AB drawn at right angles to AZ,.
graphically, add these values vector - Then OB = k (1 /OZ,). In the same
ially and find the reciprocal of the sum way OC is drawn equal to k(1 /OZ,).
/Z
X-RAYS SPEED WAR PRODUCTION
the impedance, Z, and BC will equal
1 /Z.
If AB equals some other value
than 1, such as 10, then BC = 102 /DB
or 100 times the true reciprocal.
This method of finding reciprocals
1-Triangle illustrating that the vertical line, AB is the geometric mean of the
two segments of the base, DB and BC
Fig.
This 300,000 -volt x -ray machine is in everyday use inspecting welded joints.
It inspects steel up to 4 inches in thickness.
Note the photographic plate
inside the pipe at the portion of the weld being inspected
December 1942
90
www.americanradiohistory.com
-
ELECTRONICS
I
,LE ,r,¡¡
anin
d,.
ww
www.americanradiohistory.com
U
OB and OC are then added in the parallelogram, OBDC, to form OD, equals
k (1/OZ,-- 1 /022). On 0D a perpendicular OF is erected and a right
triangle drawn as before, the segment
of its hypotenuse OZ equals k X
1 /k(1 /OZ, -1- 1 /OZ0.
This is the combined impedance desired and is shown
in the correct phase relation to the
given impedances, OZ, and OZ.,. Three
or more impedances can be combined
in a similar way, adding two at a time.
The combination of two impedances
CONNECTORS
TO GUARD THE
ULTRA -HIGH
Z2
FREQUENCIES
THE
coaxial fittings shown
here are known as Type TQ
Connectors and are one of the
many styles of Cannon Plugs used in radio and television work.
Designed to keep the unruly high frequencies under control, the
TQ Fittings provide continuous shielding with constant impedence
thereby maintaining the shielded circuit through any connection
point. The body of both plug and receptacle is machined from
A
Fig. 4-The vector OZ represents the parallel combination of a pure resistance, OZ,
combined with a pure reactance, OZ_
solid brass rod and is cadmium plated. Isolantite washers are used
for insulation. A skirt at the back of the fitting provides for easy
soldering of the cable shielding to the shell of the contact.
xp
CANNON SERVES MANY INDUSTRIES
The sound engineering back of the TQ Connector and the features
designed to aid the user are typical of the care given every construction detail in all types of Cannon Plugs which are used by many
industries -wherever dependable electrical connections are needed.
pp
Fig. 5 -A section of Fig. 4 illustrating that
Z is the geometric mean of R, and X connected in parallel
of opposite sign, as in resonant circuits
is shown in Fig. 3. In this case unless
the Q of the circuit is quite low the
figure becomes impractically large.
The case of a resistance OZ, and pure
Diagram shows how removab e doors permit easy access to
terminals for wiring. A tapered skirt makes it easy to solder
shielding of cable to the connector. The outer shell on the
plug protects both the wiring and shielding.
reactance OZ, is indicated graphically
in Fig. 4. In this special case the com-
CANNON ELECTRIC
Cannon Electric Development Company, Los Angeles, California
Canadian Factory and Engineering Office: Cannon Electric Company, Lim ted, Toronto, Canadr.
bined impedance OZ is seen to be
equal to the perpendicular from the
vertex to the hypotenuse of the right
triangle OZ,Z2. This construction is redrawn in Fig. 5 to show a simple
method of combining resistance and
December 1942
www.americanradiohistory.com
-
ELECTRONICS
Night Patrol
structural
T BOAT ?No, she's an American this acids, salts and water;
lLJ one, prowling for the Japs ... off strength, light weight, excellent elecZamboanga...in the Gulf of Papua... trical insulating properties and ease
of machining.
or on the Timor Sea.
Keep abreast of the developments
The advantages of Synthane for subnaval
not
semarine equipment are
in the field of technical plastics through
crets. Synthane is simply valued for Synthane folders. We'll gladly send
the same properties that were so desir- them at your request.
able in peace time applications, namely SYNTHANE CORPORATION, OAKS, PENNA.
resistance to corrosion from solvents, 1Or.Jor War Bonds - Treasury Department Honor Roll
Plan your present and future with plasfies
A- Airbrake
piston -drilled, turned and
grooved on lathe, milled.
B- Insulator- bandsawed, turned, deified.
and counterbored.
SYNTHANE TECHNICAL PLASTICS
SHEETSRODSTUBESFABRICATED PARTS
SYN_ANE_
flake.
www.americanradiohistory.com
tarrrfnared
SILENT STABILIZED
GEAR
MATERiAI.
Coupled to the War Effort
in a hundred ways,
Cardwell k also tied into almost every type of communication
use of Cardwell Flexible and Rigid Insulated
Couplings to isolate radio frequency controls.
When the type "A" Coupling was first designed, even though we believed it to be "tops ",
we hardly expected the tremendous acceptance it
now enjoys. Since it seems minute in comparison
to the larger units, we have "blown up" a separate view of this most popular of all the Cardwell
Couplings, to better indicate its construction.
Type "FNF" is the most widely used of the rigid
types, while type "C" and "E" are the standard
flexible units for higher voltage and torque. Type
"D" and "F" are spe:ial and not so readily
obtained.
Iequipment through the extensive
pure reactance in parallel. This method
for the parallel combination corresponds to the well known impedance triangle for series circuits. The proof of
Fig. 5 is as follows: By similar triangles, we have proportion Z, /R = X1,/
81R,2 -f- X,, or Z, = R, X,/ VR2
X,2.
This is the mathematical formula for a
resistance and reactance in parallel as
given in many textbooks.
If it is not required to find the phase
angle but only the absolute value of
parallel impedances, another theorem
of geometry can be used. This theorem
states that in any triangle a line
drawn parallel to the base divides the
sides proportionally. Thus in Fig. 6,
AB /AC = AD /AE, or AD = AB X
CNE
RIGID
6-
Diagram which may be used to
.ind the absolute value but not the phase
ol two paralleled impedance; AD is the
resultant of AB and AE
Fig.
\
--
Zr
z,
- -(z
+Z21 \
[z, +Z21
7- Application of Fig. 6 to two impedances, OZ, and OZ whose resultant
when connected in parallel, is OZ
Fig.
FNF
RIG ID
B
AB
A
Z
Manufactured of critical materials, including phosphor bronze springs, brass
hubs, Alsimag ±196 insulation, case hardened cup point steel set screws, etc.,
highest priorities are required to insure delivery of these small items, so vital,
however, to communications equipment and therefore of priceless importance.
CARDWELL
THE ALLEN
9
D.
CONDENSERS
CARDWELL MANUFACTURING CORPORATION
BROOKLYN, NEW YORK
f
AE /AC. If AB =
AE = Z,, AC =
Z, -}- Z_, and AD = Z, this equation
becomes the well known formula for
parallel impedance, Z= Z,Z,/ (Z, + Z2).
The application of this method to two
impedances, OZ, and 0Z2 is shown in
Fig. 7. OZ, and OZ, in correct phase
relation are added graphically to form
O(Z, + Z2). This sum is then transferred by compass to the same line as
OZ,. OZ,,, may then be redrawn in any
convenient position, as O (Z2) to open
up the angle between OZ, and OZ, for
greater accuracy, ordinarily at about
GO deg. with OZ,. A line is drawn
from
(Z, + Z2) to (Z,,), then a line through
Z, drawn parallel to this line intersects 0(Z,) at Z and OZ is the re-
December 1942
www.americanradiohistory.com
-
ELECTRONICS
From Guadalcanal
to
Murmansk.
.
Shure "Fighting Microphones" Get The
Message Through in the hot, humid jungles
of the Tropics
... on the icy tundras
of the Arctic. Microphones must function
under extreme conditions. Neither heat
nor cold, neither moisture, impact or blast
can imperil vital information! Shure Micro -
phones-on every crucial battle front
in
the world -are made to meet every test of
widely varying conditions. From Guadalcanal to Murmansk
... from Libya
to the
Caucasus, they will Get The Message Through!
Fighting Microphones by
Designers and Manufacturers of Microphones and Acoustic Devices
225 W. HURON STREET, CHICAGO, ILLINOIS
ELECTRONICS
-
95
December 1942
www.americanradiohistory.com
quired value of the combined impedances. However, in this case the
absolute value only of OZ is shown, and
its angular position is meaningless.
Figure 8 shows a combination of
two impedances of opposite sign in
which the combined impedance OZ is
greater than either of its components.
In this case for greater convenience
OZ, has been transferred to the line of
O;Z,
Z
22
MODERN BAND -CHANGERS
Faster -More Convenient -More Efficient
Actually, over 90% of our inquiries on band -switching problems can be
solved by B & W Turret Coils-better and more efficiently than by any other
means.
In performance, B & W Turret Coils meet most exacting specifications. Their
ruggedness assures this performance even when the going is toughest. Their
manufacture-pioneered by B & W engineers on a quantity. line production
basis -is fast being developed to meet vastly increased wartime demands "on
the nose."
For greatest efficiency in the selection and use of Turret Coils, we suggest
that you consult B & W engineers on your basic equipment design. A wealth
of specialized engineering experience is freely at your disposal.
Literature upon request. Inquiries invited.
VARIABLE CONDENSERS FOR HIGH POWER USES
Shorter than conventional units and having built -in
neutralizers and built-in coil mounting feature, B 6 W
Variable Air Condensers meet the highest performance
standards. Other features include perfect electrical symmetry; Alsimag 196 insulation throughout; low distributed inductance; low minimum capacities; and many
more desirable characteristics. Technical data sheet
upon request.
8-
Combination of two impedances of
opposite sign in which the combined impedance, OZ, is greater than either of its
components
Fig.
The construction for two impedances
of the same phase angle, AB and .BC
is presented in Fig. 9. These impedances are added linearly to equal AC.
By a construction similar to Fig. 7
their combined impedance is found
equal to AZ. If the lines AC and AE
are drawn at 60 deg. with each other
and another line, AF, equal to BC is
drawn at 60 deg. to AE, a line from
F to B will intersect AE at Z and also
F
F\ - \
--
\
\
\
\
Z1+Z2
A
BARKER
&
WILLIAMSON, Radio Manufacturing Engineers
235 Fairfield Avenue, Upper Darby, Pa.
96
B
C
9-
Impedance triangle constructed for
Fig.
two impedances of the some phase angle
December 1942
www.americanradiohistory.com
(Z2)
-
ELECTRONICS
SPECIAL ceramic parts like these can now be
delivered by Isolantite Inc. with unusual promptness for these unusual times. Production of many
shapes-formerly requiring special machining operations or partial molding on hydraulic equipment
-has been greatly speeded by automatic molding.
Isolantite Inc. now has additional capacity available
for the production of very small automatic pressed
parts. Delivery cycle has also been materially reduced on the larger automatic pressed parts where
tools are available.
The more efficient service that installation of
automatic presses makes possible is but one of many
advantages offered users of Isolantite* insulation.
Isolantite's manufacturing processes, for example,
permit extremely close dimensional tolerances compared with general ceramic requirements. This facilitates equipment assembly, since critical dimensions
can be held within close limits.
Contributing to dependable equipment performance is a unique combination of advantages which
Isolantite incorporates in a single ceramic body
uniformity of product, high mechanical strength,
electrical efficiency and non -absorption of moisture
-each an outstanding feature in itself.
Isolantite Inc. invites inquiries from manufacturers concerning production of small pressed parts
for war applications.
-
ELECTRONICS
-
CERAMIC INSULATORS
ISOLANTITE INC., BELLEVILLE, NEW JERSEY
*Registered trade-name for the products
December 1942
of Isolantite Inc.
97
www.americanradiohistory.com
Fig. 10 -Same diagram as Fig. 9. but par
:ially redrawn to provide linear scale on
each arm
determine the combined impedance AZ.
The proof of this statement is as follows: FE = AE (both are sides of an
equilateral triangle), then FE = BC.
FE is also parallel to BC. Therefore
FB is parallel to EC and must intersect
AE at Z. So it is seen that the combined impedance AZ can be determined
by the lines AB, AE, AF, and FB only.
Figure 10 shows Fig. 9 partially redrawn with a linear scale on each arm.
This forms a chart sometimes used for
parallel resistances. To use this chart
place a straight edge across the lines,
intersecting AC and AF at the values
for two resistances añd their combined
value can be read on AE. More than
two resistors can be combined by combining the sum of the first two with
the third and so on. This chart can
also be used for parallel impedances if
they have the same phase angle. It is
also used for series condensers, using
the scale to indicate capacity instead
of impedance. This is possible because
the formula for effective capacity,
{
inaudagraph speakers, Inc.
3911
"e/V49
98
S.
o
Michigan Ave., Chicago
Dine 9/#ea
iC
auk in a,CLate 94941d
11-Diagram showing method of converting series circuit in its equivalent
parallel circuit or vice versa
Fig.
December 1942
-
ELECTRONICS
W /M1OTL5
Rhe stets, Resistors
in Electrical Anaß yzer for Aircraft
--.0111...)11h
Analyzer Saves TIME for Republic Aircraft
The electrical analyzer, devised in the testing laboratories of the
Republic Aviation Corp., was designed primarily to speed up aircraft
testing and locate trouble without disconnecting any wiring. It also
enables making adjustments on all electrical equipment prior to final
assembly, for it is able to duplicate any missing circuits or loads. It
also enables a direct analysis of any error in wiring assembly, indicating the exact location of circuits in error. Wide variation of power
output makes it adaptable to any type of service or testing.
The use of Ohmite resistance units in this aircraft electrical analyzer
is another indication of how Ohmite products help speed war production -how they help test planes as well as fly them.
Write on company letterhead for
helpful 96page Industrial Catalog
and Engineering Manual No.
40.
OHMITE MANUFACTURING COMPANY
ELECTRONICS
-
4818 Flournoy
Street
December 1942
Chicago, U.
S. A.
99
www.americanradiohistory.com
DEPEND ON
,
IRV -O -LITE
INSULATING TUBING
TO DO THESE
1.
-
C,C2 /(C, -I- C,), is similar to the
formula for parallel impedance.
A convenient means of converting a
series circuit into an equivalent parallel
circuit or vice versa is shown in Fig. 11.
The familiar vector diagram for a
series circuit, R.,, X, and Z, is here
combined with the diagram for a parallel circuit R
X and Z previously
shown in Fig. 5. Since the combined
impedances Z, and Z for the respective figures are equal in phase and
magnitude, Il and X, for the series circuit is equivalent to R and X of the
parallel circuit.
In all of these figures, all lines designation vectors in correct phase relation
are indicated by arrows.
C
FOUR JOBS
Insulate wiring systems
2. Prevent accidental terminal shorts
3. Act as protective conduit
4. Guard external cables
Over 25,000,000 feet of this Fibronized tubing now protect
the wiring of electrical apparatus. This fact proves that
IRV- O -LITE meets manufacturers' requirements. Here's
why they buy it.
Ignitron Rectifier in Industry
AN ARTICLE under the above title by
J. H. Cox and G. F. Jones appears in
the October, 1942 issue of Electrical
The DeWalt Products Corporation utilizes IRV -O -LITE XTE -30
to provide ample insulation and
protection for the cabes of their
electric saw.
Engineering.
Although the first application of ignitrons was in transportation service
in mines and railroads, the applications
of these important electronic devices
have been accepted by other industries,
notably that of electrochemistry. At
the present time more than 2,000,030
kilowatts of ignitron rectifier units
have been purchased by that indust -y
Short lengths of IRV -O -LITE
alone.
The article discusses primarily the
installation and operation of the ignitron rectifiers for large power concentration and indicates the manner in
which individual ignitron rectifier
units may be combined to increase the
power output.
XTE -30 are applied as terminal
insulation on condensers that are
made by the Wells Manufacturing
Corporation.
FOR WIRE INSULATION: Because IRV -O-LITE has high dielectric
strength, it provides good insulation protection and takes but a minimum amount of space. This thin-walled tubing, therefore, is especially
adapted for use on intricate wiring placed in confined areas. For easy
identification of circuits, IRV -O -LITE is furnished in six standard
colors: black, green, white, yellow, red and blue.
Short lengths of IRV-O -LITE act as
insulating sleeves to prevent short circuits between adjacent terminals
and metal parts. Ample protection at these places is provided by the
high dielectric strength of the tubing. Identifying symbols may be
marked on these short lengths. creating a combination wire marker
and lug insulator.
FOR CONDUIT AND EXTERNAL CABLE INSULATION: Many manufacturers use IRV -O -LITE as both conduit and external cable covering
because of its excellent physical characteristics. The tubing is tough.
offers high resistance to tearing and abrasion, and provides additional
insulation for the wires covered. It resists heat, concentrated acids and
alkalies, denatured alcohol, and petroleum solvents, including gasoline.
FOR TERMINAL INSULATION:
CANADIAN ARMY RADIO
TECHNICAL INFORMATION ON IRV -O -LITE
This tubing is extruded in two types, XTE -30 and XTE -100. Under
ordinary conditions, XTE -30 is recommended. XTE -100 is better fitted
for installations where higher dielectric and tensile strengths are
required and higher temperatures are encountered.
Dry Dielectric Strength
Wet Dielectric Strength
Tensile Strength, Ib. per sq. in.
Elongation
Life at 105 Deg.
XTE -30
750 VPM
350 VPM
2150
250%
C.
400 hrs.
XTE -100
1000 VPM
1000 VPM
3700
200%
450 hrs.
additional information on the properties of IRV- O -LITE, sizes
available, prices and for samples to be used in testing, write
Dept. 106. giving details about application.
For
IRVINGTON
0M0RD
Plants at IRVINGTON, N. J. & HAMILTON, ONT., CAN.
Representatives in 20 Principal Cities
100
ada's eastern seaboard depends upon the
network of communications built and maintained by the "Linemen in Khaki. Men
of the Royal Canadian Corps of Signals
work behind the scenes of the barriers
Of flit_
WOR[G
VARNISH & INSULATOR CO.
IRVINGTON, N. J., U.S.A.
The vast system of defense set up on Can-
TRAM
.,
u
,,o MARK
Canada has erected against any enemy
who might approach from the East. This
photo shows a radio receiving and transmitting room. Shore batteries, naval stations and airdromes are linked together by
an intricate set of electrical "nerves"
December 1942
-
ELECTRONICS
/
f
Tlll:
90505 Secondary Frequency Standard
Precision Frequency Standard for both laboratory and production uses. Designed around the
GE G-18 and G18 -A crystal, having a frequency
temperature coefficient of less than 1 cycle /Mc/C °.
The crystal is sealed in Helium in a standard metal
tube envelope. Adjustable output provided at intervals, of 10, 25, 100, and 1000 KC with magnitude useful to 50 MC. Harmonic amplifier with
tuned plate circuit and panel range switch. 800
cycle modulator, with panel control swtich. Panel
plate supply control switch. In addition to Oscillators, Multi -vibrators, Modulators, and Amplifiers, a
A
JAMES MILLEN
°
MAIN OFFICE
built -in Detector with 'phone jack and gain control on the panel is incorporated. Easily adjusted
to WWV. Self-contained AC power supply with
VR 150 -30 voltage regulator. Used in quantity by
Signal Corps, Navy, FCC, British and all large government prime contractors such as GE, RCA, Western Electric, Sperry, Westinghouse, etc. Cabinet
size 9" x 95/8" x 101/2 ", weight 20 lbs. Compact,
dependable, stable, trouble -free. Price complete
with GE crystal and tubes $135 net, f.o.b., Malden
for 115 V. 60 cycle model. Available for the duration, of course, only on proper priority.
M
MFG. CO., INC.
AND FACTORY.
MALDEN, MASSACHUSETTS, U. S. A.
ELECTRONICS
-
101
December 1942
www.americanradiohistory.com
The Mass Spectrometer
THIS cutaway view you have the
inside story of Utah wirewound
controls -the reasons behind their
ruggedness and dependability. You
can see how high -quality, resistant
wire is evenly wound on a substantial
core. The resistant element can never
loosen, being clamped in place over
its entire length.
Utah Carter Rheostats are available
in six stock sizes, from 3 to 25 watts.
Type 4 P, for instance, dissipates 4
watts over the entire resistance ele-
IN
ment. The treated Bakelite strip on
which the resistance wire is wound is
tightly clamped and enclosed in an
all -steel housing. The movable arm
and the resistance element are elec-
trically insulated from the housing,
mounting bushing, and shaft. The
diameter of the housing is 17í"
smaller than Bakelite controls of
equal wattage.
Write for complete data on this and
other Utah Carter Rheostats, Potentiometers, Resistors, Attenuators.
-
UTAH VITREOUS ENAMEL RESISTORS -From 5 to 200 watts, they are
available either as fixed, tapped or adjustable. Also non- inductive types.
UTAH JACK SWITCHES -Long and Short Frame and
to meet the circuit and space requirements you need.
"Imp"
Type Switches
UTAH PHONE PLUGS -Two or three conductor types -for practically every
type of application.
UTAH TRANSFORMERS are fully guaranteed. Able to meet the requirements
in choke, input, output and smaller capacity power transformers.
UTAH JACKS -Short and Long Jacks and "Imp" Jacks to meet your requirements. Special Utah Jacks to meet Navy and Signal Corps specifications.
WRITE FOR FULL DETAILS
UTAH RADIO PRODUCTS COMPANY
General Offices and Factory
8i7
ORLEANS STREET
CHICAGO, ILLINOIS
PROVIDING A CONVENIENT source of reference material, between two covers,
the September, 1942, issue of the
Journal of Applied POrlpies is devoted
to mass spectrometry. The mass spectrometer is "essentiaLy a high vacuum
tube in which the gas studied is admitted to a pressure of the or.ler of
10 ' mm of mercury. The molecules of
the gas are ionized by electrons of
controlled energy from a thermionic
filament and acceleratrng grid. Ions of
many different types are formed even
in a pure gas corresponding to varioiu
modes of breaking down of molecule
accompanied by ionization. The ions
so formed are then drawn out of the
ionizing chamber by an applied electric field and are caused to move to a
combination of electric and magnetic
fields designed so as to sort out the
ions according to their ?n /e or mass to
charge ratio."
Although still largely a laboratory
device and not yet commonly applied
in industrial analyses, the mass spectrometer may well become an important
tool for industrial research as well as
routine testing. One application of
mass spectrometry recorded in this
issue of the Journal is in the field of
gas analysis, an application which appears to have important significance
at the present time. It is hoped that
additional information on this subject
may be recorded in an early issue of
ELECTRONICS.
The articles in this special issue on
Mass Spectrometry are as follows:
Mass Spectrometer As An Industrial
(editorial).
Short History of Isotopes and the
Measurement of Their Abundance, by
E. Jordan and Louis E. Young.
Measurements of Relative Abundance with the Mass Spectrometer, by
E. Jordan and M. A. Coggeshell.
Gas Analysis with the Mass Spectrometer, by John A. Hipple.
Some Applications of Mass Spectrometric Analysis to Chemistry, by D.
Rittenberg.
The remaining articles in this issue,
representing contributed articles on original research, deal with a diffraction
adapter for the electron microscope,
axial aberration of electron lenses and
reflections of electromagnetic waves
from a parabolic ionized layer.
Tool
Atmospheric Propagation
of Sound
NEW PUBLICATIONS devoted to the advancement of science tend to be decreasing in numbers rather than increasing during the present crisis. Already a number of journals have been
forced to change their editorial content
or to modify the frequency of their appearance. Therefore, it comes as a
rather refreshing note to record the appearance of a new quarterly review de-
December 1942
102
www.americanradiohistory.com
-
ELECTRONICS
A date with Destiny
These two modern weapons of battle
...the electronic tube and the bombing plane ... have an important date
with post -war industry. In the days
to come Eimac tubes, like the airplane, will help achieve the better
way of life for the common man.
"First in Peace, First in
War," First in the important new developments in the field of
electronics.
OFFICIAL PHOTO U. S. NAVY
EITEL- McCULLOUGH, INC.
For high achievement in the production of
war material ... the joint Army -Navy "E"
awarded September 4, 1942.
SAN BRUNO
CALIFORNIA
U.S.A.
Export Agents: FRAZAR & CO., LTD.
201 Front Street, San Francisco, California, U. S. A.
www.americanradiohistory.com
Muke a note of these
WILEY BOOKS
-outstanding in the
Electronics Field!
FUNDAMENTALS OF ELECTRIC WAVES
By
Hugh Hfldreth Ski!Iiva. Prof, ss'or of lilcetrieal En O,or, ring, Stanford University. 186 pages,
9, 67 illustration.., s..7.J.
6 .r
i
Professor Skilling's book discusses the principles of wave action, with particular emphasis on the basic ideas of Maxwell's equations and repeated use in
simple examples. Stress is placed on physical concepts, with full attention to
mathematical rigor, and with concrete application to engineering practice.
COMMUNICATION CIRCUITS
Ily
i
I.:nncnre A. Ware. 9ssocrair
f,...v, of Elcelvirnl Engineering;
n
'l,1,
it, of IS,
fosìng,
1
F:n
and Henry B. (teed,
I' nlr, rs-Os of Iowa. (in press).
ha, rt,
0,,
b
Pro -
The theory of communication circuits is presented in this thoroughly comprehensive volume. The basic principles of communication transmission lines
and their associated networks are presented, covering the frequency range
from voice frequencies through the ultra -high frequencies.
HIGH -FREQUENCY ALTERNATING CURRENTS
By I:w,c SIrlh.aiu. .L.nriet i'n. 1, o.-. ,rod
1:. Ora
seho,I of Eh
illustrut ion..,
tl,ind
L
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Fh,rrl a,n Ing,
9, $6.0o,
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Assistant Professor; both of the Moore
PcnnsylrwNa, Second Edition, 530 pages. 226
i
Cnir,rríty
of
Presupposing a knowledge of calculus and differential equations, this book
gives a thorough and detailed mathematical analysis of the fundamental principles of electric communication, underlying telephony, sound reproduction,
radio, facsimile, and television.
PRINCIPLES OF RADIO
By
Keith Denney, Editor, "El, '(conies ". Fourth Edition. 549 paw's, JIG illustrations,
6
z 9, .$3.5(1.
An elementary book which combines both the theory and practice of radio.
Treats technical matters so simply and is so complete that it contains all the
information which the technician, experimenter, or operator needs. The recommended textbook of the pre -service radio technician course sponsored by the
U. S. Signal Corps.
RADIO- FREQUENCY MEASUREMENTS BY
BRIDGE AND RESONANCE METHODS
By L.
i
Hartshorn. 265 pagos, 99 itiustrations,
6
signed to record the progress of the
sciences in the service of mankind, under the name Endeavour, published by
Nobel House, Buckingham Gate, London, S. W.
The first issue of this publication to
come to our attention is marked Volume
1, No. 3 and dated July, 1942. It contains approximately 40 pages, one of
which is in full color. Page size is 8x11
inches and no advertising is carried.
Articles in the July issue include the
following: The Scientist's Responsibility, The Red and Blue Coloring
Matters of Plants, by Robert Robin son, The Substance of Heredity, by E.
D. Darlington, Some 18th Century
Chemical Societies, by James Kendall,
Plastics and Their Application, by Edward Appleton, Disease Resistant
Plants by F. T. Brooks, The Propagation of Sound in the Atmosphere, by E.
G. Richardson, and finally, Progress
in Bacterial Chemotherapy, by L. E.
Garrod.
The article by Dr. Richardson, "The
Propagation of Sound in the Atmosphere," will probably be of most interest to readers of ELECTRONICS. This
4 -page article, containing eight references, gives a survey of past researches.
It is shown that the transmission of
sound in the air shows many peculiarities, frequently of a very surprising
kind. Explosions and gunfire are often
inaudible in regions comparatively close
at hand, while distinctly audible at
greater distances. Echoes of a fog horn
may sometimes be heard for as long as
15 seconds after the original sound has
been cut off. The article by Dr. Richardson provides an interesting account
of recent investigations carried out on
this subject by various workers in
acoustics.
x 9, $4.50.
The subject is treated from the most elementary aspects up to the more complex. This is the first systematic treatment of radio -frequency bridge methods
and stationary wave methods.
ELECTRICAL ENGINEERS' HANDBOOK
-
NEW TELEWONDER
COMMUNICATION AND ELECTRONICS
By
Harold Pender, Editor -in -Chief and Knox SleIlwain, Associate Editor -in- Chief, and 47 contributors. Third Edition, 1022 pages, 981 illustrations, 5% by 8%, $5.00.
This volume covers the whole field of communication as a unit; it includes
telegraphy, telephony, radio broadcasting, point -to -point radio telephony,
facsimile transmission and reception, public address systems, sound motion
pictures, aviation radio, and television. Every phase of electric communication
and electronics receives extensive handbook treatment by a staff of specialists.
ELECTRICAL COMMUNICATION
By
Arthur A. Albert. Professor of Conuuunication Engineering, Oregon State College. Second Edition, 534 pages, 398 illustrations, 6 z 9, $5.00.
A well -prepared and exceptionally informative book on communication and
general electrical subjects which involve electron tubes, circuit theory, and
transmission theory. Contains excellent bibliographies as well as suggested
problems.
MATHEMATICS OF MODERN ENGINEERING
1 -By
Robert E. Doherty, President, Carnegie Institute of Technology. and Ernest
Keller, Consulting Engineer, Lockheed Aircraft Corporation. 314 pages, 82 illustrations. 6 a 9,
$3.50. Volume II -By Ernest G. Keller. 300 pages, illustrated, 6 x 9, $4.00.
Volume
In these two volumes and a third, now in preparation, those aspects of mathematics are presented which have been found to be most valuable to engineers.
Numerous problems of varying degrees of difficulty are given, with these
can be tested a knowledge of the mathematics involved.
JOHN WILEY & SONS, Inc.
440 Fourth Avenue
New York, N.
Y.
104
John Logie Baird has a new invention
called colored stereoscopic television.
which he claims will revolutionize entertainment after the war. Instead of seeing
a flat picture, as you do in the movies,
the new television reproduces an image in
color with the depth and appearance of
solidarity and reality. The apparatus is
also being developed to enable it to be
used as the television telephone
December 1942
www.americanradiohistory.com
-
ELECTRONICS
MORE WATT -OHMS
PER CUBIC INCH
...greater dependability.., easier mounting ... less weight
Yes, Mr.. Engineer, this is an odd, non -standard
technical term -but it is one easily understandable, and
certainly one that best explains the tremendous advantages obtained with Koolohm Resistor construction.
. For Koolohms provide the highest wattage ratings
and resistance values in a given volume, with safe resistance wire sizes.
. Moreover, Koolohms deliver their full wattage
ratings regardless of resistance values.
Koolohms can be mounted easier and quicker and
in less space -directly to the chassis or to grounded parts.
Koolohms give a big, extra measure of dependKOO LOH MS
CONVENTIONAL
ability on the high resistance values by using larger wire
(21/4 times the cross -sectional area of that used by other
manufacturers for these same values).
Koolohms are made with wire that is insulated before
it is wound. This insulation is a special ceramic material
having a dielectric strength of 350 volts per mil. at
400° C. It is heat -proof to 1000° C; fully moisture -proof,
and so flexible it can be wound on small forms, either in
short -proof layer- windings, or in high- density progressively-wound interleaved patterns.
Write today for the complete Sprague Koolohm Catalog and sample resistors.
SPRAGUE SPECIALTIES COMPANY
(Resistor Division) North Adams, Mass.
n
I
',--0
PHREN
l
SPRAGUE
Here is an actual comparison between a Sprague Koolohm resistor and
a
tional wirewound!
Mona!
C
2.5 mil. minimum
10 watts, 7500 ohms
414"
11/16.
40 grams
Must not come in
contact with chassis
or grounded parts
A
Specifications
Limiting Wire Size
Rating
Length
Diameter
Weight
Mounting
(see above
illustration)
Wire Wound Resistor
ELECTRONICS
-
Koolohm
2.5 mil. minimum
10 watts, 7500 ohms
127/32'
7/18
14 grams
Con be mounted flat
on chassis or to
grounded parts
Isn't Modern
UNLESS
WIRE- WOUND RESISTORS
It's
Wound
December 1942
with
CERAMIC INSULATED
WIRE!
103
www.americanradiohistory.com
Telephone Set for Hard
of Hearing
THE OCTOBER, 1942, issue of The Bell
Laboratories Record describes "A New
Telephone Set for the Hard of Hearing" in an article of this title by Alfred Herckmans. The telephone set is
similar in appearance to that usually
encountered in homes and offices, but
differs in that it is provided with a
three- position switch for determining
the volume output, and in the fact that
an additional amplifier is incorporated
in the base of the antenna. This amplifier consists of a granular -carbon
microphone whose dialjhragm is actuated by a bipolar receiver element using permanent magnets. When the
amplifier is in use, its receiver element
is connected in place of the regular
hand -set receiver, while the transmitter element is connected to the hand -set
receiver in series with a 41 -volt battery
which may be placed in any convenient
location and is connected to the set by
two wires. With this arrangement, the
hand -set receiver is operated by the
IWAS during the Coral Sea Battle
amplified speech from the transmitter
element of the amplifier.
The employment of the receiver transmitter mechanical amplifier provides an additional gain of 25 db and it
is estimated that persons with hearing deficiencies as much as 60 db loss
will receive adequate volume to conduct
satisfactory telephone conversation. It
is estimated that this type of instrument will be suitable for 90 percent of
those conscious of hearing impairment.
The gain provided by the amplified
element is sufficient to cause singing
under certain conditions although this
tendency is completely eliminated with
the ordinary telephone hand -set in normal use:
... the ship's
loudspeakers were tuned to the airplane circuits
and the conversation and commands of the pilots
could be heard. Suddenly came a strong call from
Lieutenant- Commander Bob Dixon, flying a scout
bomber: "Scratch one flat top!" Through the loud-
speakers Dixon's message re- echoed over the entire
ship and cheers rang out from stem to stern. Report
from Chicago Tribune. * * * Remler Company,
Ltd., one of the firms entrusted with important
Amplification Factor with
Square Mesh Grids
work for the United States Navy, helps to make
FROM TIME TO TIME
the sound systems which enable our fighting forces
to coördinate their operations through the main-
tenance of communications.
REMLER COMPANY, LTD.
2101 Bryant St.
San Francisco, Calif.
REMLER
-Onnounccny
Communication 4111/2m¢nt
ELECTRICAL PLUGS AND CONNECTORS
106
considerable effort
has been spent on the mathematical or
experimental evaluation of equations
for expressing the amplification factor
of multi -element tubes. A number of
theoretical and empirical equations are
already available expressing the amplification factor for tubes having grid
structures of parallel wires for either
plane or cylindrical structures. The analytical solutions available are mathematically complicated even though they
apply to the simplest physical cases.
In the October, 1942, issue of the Wireless Engineer, T. C. Eaglesfield offers
an article, "Triodes with Square Mesh
Grids- Calculating the Amplification
Factor." This article deals with the experimental determination of the amplification factor for grid structures consisting of grid wires with square mesh
openings. Because the theoretical approach is so complicated, experimental
verifications were obtained by setting
up a model of the triode and measuring
the electrostatic screening effect produced by the mesh grid. The results of
December 1942
-
ELECTRONICS
on
peaker
Mgkeror
Marl/ref
"Engineer a loud speaker for battleships!"
"Engineer a loud speaker to gc in training tanks!"
"Engineer a loud speaker for submarines!"
"Engineer a loud speaker for command cars!"
"Engineer a loud speaker for landing barges!"
Those are just a few of the instructions Jensen has
received since America decided to make war its business.
Unsurpassed design and production facilities have made
Jensen "Loud speaker maker for the armed forces."
In addition to the
great honor, it is invaluable experience.
enien
MANUFACTURING COMPANY
RADIO
6601 South Laramie, Chicago
ELECTRONICS
-
December 1942
107
www.americanradiohistory.com
this experimental determination are
given by the expression
u
4.55 x
p login coth 5 24
d/p
where x is the distance from grid to
anode, p is the mean distance between
grid wires from center to center, and d
is the diameter of the grid wire. This
equation is derived on the basis of
mesh grids having square openings so
that as far as the grid is concerned two
dimensional symmetry exists.
Measurements of Very Short
Wavelengths
THE INCREASING use and application of
frequencies corresponding to a wavelength of one meter or less gives added
importance to the article, "Wavelength
Measurements of Decimetric, Centimetric and Millimetric Waves ", by
A. C. Clavier in Electrical Comm noicati.on, Vol. 20, No. 4, 1942. Even though
the work reported by Mr. Clavier does
not record the most recent developments in frequency measurement it
does provide a survey of the state of the
art up to the time when war broke out.
Consideration is given to the following
method of frequency determination:
(1) Determination of frequency by
beating the unknown with a standard
frequency, (2) use of a tuned circuit
of lumped constants as a wavemeter
in accordance with the technique at
lower frequencies, (3) applications of
circuits with distributed constants, (4)
MORSE CODE TEACHER
VACUUM TUBE VOLTMETER
Top ranking engineers give this handy portable instrument
high priority for its ease of operation, extreme sensitivity
over wide frequency range and its ability to make accurate measurements
below 1 megacycle. Best of all, the -hp- Model 400 Vacuum Tube Voltmeter gives voltage indication that is proportional to the average value
of the full wave. This is a feature not found in the average voltmeter on
the market today. Get information now on this and other superior -hpinstruments. Give details of your problem so our engineers can be of
greatest help. No obligation, of course.
CHICAGO OFFICE:
ALFRED CROSSLEY
549 W. RANDOLPH ST.
CHICAGO, ILLINOIS
HOLLYWOOD OFFICE:
N. B. NEELY
5334 HOLLYWOOD BLVD.
HOLLYWOOD, CALIF.
HEWLETT
NEW YORK OFFICE:
BRUCE O. BURLINGAME A6SOC.
69 MURRAY ST.
NEW YORK, NEW YORK
PACKARD
COMPANY
BOX 135M
STATION A
PALO ALTO, CALIFORNIA
Dorothy Hall, amateur short-wave
operator who, in 1938 established corn munication with the isolated inhabitants of
Pitcairn Island in the South Pacific, will
teach Morse code operation at Washington Square College, New York University.
A class of 100 pupils, all potential Signal
Corps members started on September 22.
The course is open to all men and women
who have high school diplomas, including
two years of mathematics. She is shown
at the receiving set in her home
Mrs.
December .1942
108
www.americanradiohistory.com
-
ELECTRONICS
15 KVA for a BATTLESHIP
... or
15 VA
for
a
VACUUM TUB
... Sola engineers
Tra affitmers. They deliver constant, stable
will design the transformer that will stabilize
your power supply at peak efficiency 24
voltage on 2th®uur shifts even though line
voltages vary as mule s thirty percent.
hours per day.
Sola Constant Voltage rehstsformers are
fully automatic and instantaneous in opera-
You name the assignment
Even under normal conditions supply line
voltages are rarely constant. And now, with
power lines taxed beyond capacity by the
unprecedented demands of war production,
fluctuating voltages are a constant threat
to the safety of sensitive, precision instruments ... a constant handicap to the efficiency of production lines.
There are no assignments too vital . . .
none too small for Sola Constant Voltage
\
11
1
11
tion and self -protecting against short circuit.,
There are no moving parts.
.,
Compact, standard designs are available
in capacities ranging from 1SVA to 10 KVA,
or special units for special applications can
be built to your exact specifications.
Ask for Bulletin
DCV-74
SOLA ELECTRIC COMPANY
2525 Clybourn Ave., Chicago, Illinois
CONSTANT VOLTAGE TRANSFORMERS
ELECTRONICS
-
December 1942
I
www.americanradiohistory.com
09
use of the coaxial -line wavemeter, (5)
dielectric guide for the measurement
of centrimetric wavelengths.
It is shown that a very accurate and
convenient means of measuring frequency at the usual wavelengths is
to beat the unknown frequency with a
known frequency of high stability and
precision. This method is difficult to
apply as the frequency increases in
the ultrahigh frequency region because
it is difficult to generate short wave
oscillations of high stability whose frequency is precisely known. Quartz
crystals are not suitable at the high
frequencies because the thin crystals
which must be employed are rather
fragile. Furthermore, it is difficult to
have led to the use of circuits with
distributed constants, and particularly
to the use of transmission lines. A
two -wire parallel line type of transmission line, commonly known as a
Lecher wire system, lias been used for
this purpose for many years. If, as is
usually true in practice, the separation between the wires is long compared with the wavelength, radiation is
usually sufficiently small as to be
negligible. In this case the impedance
of the line will vary with distance from
the source to which it is coupled, and
this change of impedance along the
line may be used to determine resonance points and hence the wavelength.
In such application the distance he-
TELESCOPING
and
SECTIONAL
ANTENNAE
for
Fig.
4
MOBILE
PORTABLE
and
FIXED UNITS
'
for our
ARMED FORCES
Ward can help you with
your antenna problem
WARD PRODUCTS
CORPORATION
1523 East 45th Street
CLEVELAND, OHIO
1
- Wavemeter with coaxial lines
produce an amplified harmonic to a
satisfactorily high degree with the
types of tubes which were available
when this research was originally
undertaken.
Frequently the wavelength or frequency need not be known with a high
degree of precision and in such cases
tuned resonant circuits find considerable application, particularly in the
region of decimetric waves. A resonant circuit of lumped constants may
be used in this region and the technique is the same as that used in longer
wave measurements of frequency.
An examination of the selectivity of
such circuits and the different resistances present in the oscillating circuits show that this type of resonance
indicator may be considered satisfactory only for wavelengths of at least
30 centimeters or greater.
A single turn spiral or a toroidal inductance produces a satisfactorily high
value of Q in the desired frequency
spectrum, but in practice it is difficult
to attain the very low values of
capacitance necessary for tuning and
it is even more difficult to vary this
capacity. Furthermore, a device of this
sort is difficult to couple to the power
source in measuring.
The necessity of finding an easy
method of calibration in terms of
wavelength, and the difficulty encountered with circuits of lumped constants
110
tween two consecutive resonances is
not exactly equal to half the wavelength in air since the velocity of
propagation along the line is slightly
less than that in free space. The error
due to this cause is small on well constructed lines; usually much smaller
than the inherent error in reading the
distance between consecutive resonant
points.
Lecher wire wavemeters are in current use for the measurement of decimetric waves. However, they have the
following disadvantages:
(1) The
higher the frequency the more the line
radiates; (2) it is difficult to localize
the excitation at one point along the
line; (3) it is not easy to eliminate
effects due to surrounding objects and
movement of the operator. For these
reasons it is preferable to use coaxial
lines where this is possible.
A coaxial line wavemeter is illustrated
in diagrammatic form in Fig. 1. A
test line, BC, whose length is adjustable by means of a micrometer screw
M, is connected to the antenna, X and
to the thermocouple, T, through the
quarter wave line AB and CD. The
line in front of A toward the antenna
and behind D toward the thermocouple
presents impedances at A and B which
are pure resistances when the line is a
half wavelength long.
In models which were constructed
using this principle, it is possible to
December 1942
www.americanradiohistory.com
-
ELECTRONICS
46 YEARS AS MANUFACTURERS OF TELEPHONE EQUIPMENT
22 YEARS AS MANUFACTURERS OF RADIO COMPONENTS
Serving a greater field than ever before with the same high quality workmanship and
service That our old customers have been accustomed to for many years.
Now offering a greater line of products than ever before.
!9 VARIABLE RESISTORS -Carbon and
e SWITCHES- Separate
JACKS
Wire-
wound.
to KEY SWITCHES
and in
Combination
with Variable Resistors.
PUSH SWITCHES
PLUGS
TELEPHONE RINGERS AND GENERATORS
addition we are manufacturing several telephone and radio components and assemblies for special Government applications.
In
We earnestly
solicit your inquiries.
CHICAGO TELEPHONE SUPPLY CO.
ELKHART, INDIANA
Branch Office, 401 N. Broad St.
Philadelphia, Pennsylvania
ELECTRONICS
-
December 1942
measure wavelengths to an accuracy
of one part in two thousand. Just as
in the case of measurements made with
the Lecher wire system, the measurement is subject to an error resulting
from the phase velocity along the lines
being somewhat less than the propagation velocity in free space. However,
this error is small at the frequencies
for which the type of measurement is
most suitable. It has been found that
coaxial line wavemeters may be used
for measurement of wavelengths down
to the centimeter wave band. For wavelengths of a few centimeters, the influence of transverse dimensions of the
coaxial line causes trouble and coupling problems arise. For frequencies
higher than those corresponding to a
few centimeters, dielectric guides are
therefore necessary for the determination of wavelength.
The simplest dielectric guide consists merely of a metallic pipe without
an inside conductor. Theory and experiment show that electromagnetic
waves may be propagated through
them provided that the wavelength in
air is below the fixed limit which is of
the order of the diameter of the guide.
In making use of wave guides for the
measurement of wavelengths, it is
necessary to bear in mind that several
different wave structures may be
propagated along the lines, each one
of which gives different values of attenuation and wavelength.
To measure wavelength with dielectric guides, it is necessary to transform
the wavelength measured along the
guide into the corresponding wavelength in free space. Experiments indicate that it is possible, in the present
state of the art, and with transmitter
frequency stability available at the
present time, to rely on the theoretical
relation,hips established between these
wavelengths.
Very brief mention is made of the
... and we have earned
them the hard way too, majoring in
electrical research thruout our 47 years ... Thordarson Engineers have always been ahead of new developments ... that is
why you will find, both in military and civilian use, engineers
specifying Thordarson transformers for that vital job where
unfailing performance is paramount.
Submit your transformer problems to
Thordarson Engineers . . . they know how
to solve them.
RECORDING AN OPERA
THORDARSON
ELECTRIC MFG. CO.
CHICAGO, ILL., U.S.A.
500 WES'. HURON STREET
Ikptte,
714
112
s; e
The first full recording of Rossinï s opera,
fr
"The Barber of Seville ". ever done in this
country. was accomplished by the RCA
Victor Co. in New York's Lotos Club. The
machines at the upper right are used to
cut the records, while the opera is being
sung in the club's gallery
December 1942
-
ELECTRONICS
IN THIS ELECTRONIC AGE
* Knobs
Two batches of different
steel alloys became mixed.
They had to be sorted quickly, positively, economically.
This oscillograph pattern
served to identify one alloy
from the other.
manufacturer of ignition
equipment wanted to check
operating conditions. This is
what he saw when a defective condenser was across
breaker points.
A
are adjusted; a green dot gyrates to weave a weird
pattern; the operator is fascinated by the graphic story unfolding before his eyes. Truly crystal gazing, in this electronic
age. And dealing with the past, present and future of a host
of details encountered in research, production, servicing
scientifically.
A decade ago the cathode -ray oscillograph was a scientific
curiosity. A dozen or two such costly instruments existed in
this country, mainly in lavishly equipped laboratories. But
Allen B. DuMont pioneered the commercial cathode -ray tube
and oscillograph. With advanced engineering and economical production methods, he brought such equipment within
reach of everyone. Today DuMont equipment is standard
in laboratories, engineering departments, plants, maintenance
routine -and in military operations, of course.
Regardless what your job may be or what industry or war
effort you serve, it can be done better, quicker, cheaper, if you
resort to this electronic crystal gazing, with DuMont equipment.
-
Wrile for
Li
urI
.
.
A musical instrument man-
ufacturer wanted an "electronic blueprint" of good
tone. This oscillograph gave
him the wave form to be
matched for good-tone accordions.
ALLEN B. DU MONT
LABORATORIES, Inc.
Passaic
New Jersey
Cable Address. Wespexlin, New York
ELECTRONICS
-- December
1942
113
possibility of using the qua sioptical
properties of extremely high frequency
oscillations for the determination of
wavelengths through the use of inter pherometers and gratings, but the article does not treat any of the topics
in detail.
The article is concluded with a bibliography of twenty items, most of
which were published between 1935
and 1939.
Extending Range of Meters
Electronic
Engineering, carries an article in its
July issue which is particularly significant and useful in these days of heavy
demands for electrical measuring instruments. The article by B. Swift is
entitled "Universal Shunt for Multi range Meters -Some Factors Affecting
Their Design," which deals quite comprehensively, in two pages with such
matters as the effects of instrument resistance, temperature coefficient of the
shunt, effects of series resistance, examples of universal shunt, low resistance shunt and limitations of shunt
OUR BRITISH CONTEMPORARY,
values.
It is pointed out that in designing a
universal shunt for a meter, the following data must be obtained: (1)
The resistance of the instrument to be
shunted, and whether this is all copper
or part of it of material with a negligible temperature coefficient such as
Manganin. The proportion of each type
of material should be found as this is
required to determine the temperature
coefficient. (2) The accuracy required
for shunted instruments. This affects
the accuracy of the shunt adjustment,
and more important still determines
whether the temperature error of the
shunted instrument is to be less than a
specified value. (3) The current for
full -scale deflection of unshunted meter.
Ok
U. S. TRAINS CHINESE
SHALLCROSS SWITCHES
Are constructed of the finest materials
available. Many designs may be obtained
having solid, fine silver contacts, and ceramic or phenolic insulation. Where essential
War Production dictates the
use
of switches
MEMBER
that are rugged and dependable, send
your specifications to Shalicross, Dept. C 3
group of twenty Chinese have been
trained at Scott Field, Ill., so that they can
instruct fellow soldiers in China. These
cadets are shown operating a radio corn munications set in a ground station at the
U. S. Army Air Corps radio communication
school under the direction of Staff Sgt.
Herbert I. Tye
A
December 1942
114
www.americanradiohistory.com
-
ELECTRONICS
2am/rim every fastening job...
BOLTS, NUTS AND
LOCK WASHERS
Wherever You Can Use
P -K Self- tapping Screws You Can Save
Time -Consuming Operations!
It has never been claimed that Parker-Kalon Self- tapping Screws offer
the best means of making EVERY fastening under ALL conditions . . . BUT,
it is a fact that, for a very large percentage of metal and plastic fastening
jobs, these famous screws offer a combination of ease, speed and security
that no other fastening device or method can match!
How P -K Self- tapping Screws Simplify Fastening Jobs
...
One easy operation makes a fastening with P-K Self-tapping Screws . . .
merely drive the Screws into plain untapped holes. Such simplicity eliminates tapping and tap maintenance ... solves the problem of getting scarce
taps ... stops fumbling with bolts and nuts and placing of lock washers .
does away with inserts in plastics . .. cuts out riveting and welding in hard to- get -at places.
Start now ... question every fastening Be sure you can't employ the simple Self- tapping Screw method before you put up with a more difficult one.
Call in a P -K Assembly Engineer to check over
fastening jobs with you. He can show you how to
search out ALL opportunities to apply P-K Self -tapping Screws. And, he'll recommend them only when
they will do the job better and faster. If you prefer,
mail in assembly details for recommendations.
Change to Self- tapping Screws Over
Night...
No matter what material you're working with ...
light or heavy steel, cast iron, aluminum, brass,
plastics ... you can adopt P -K Self -tapping Screws
to advantage. And you can make the change -over
without interrupting production. No special tools
or skilled help are required. Parker-Kalon Corp.,
192 -194 Varick Street, New York, N. Y.
PARKER KAWN
!
S[j F-TA IPI.N 6 SCREWS
a
SELF- TAPPING SCREWS FOR EVERY METAL AND PLASTIC ASSEMBLY
Give the Green
i. ht:
, fto
War Assemblies
ably higher where music was used
than where it was not used. Increases
in production rates, resulting from the
introduction of music ranged from 1.3
percent to 11.1 percent. Further studies
indicated that the effect was not a
transient one. The production inDr. L. P. Wheeler, FCC, becomes Presicreases are even more surprising when
dent, Institute of Radio Engineers
it is considered that many of the groups
measured consisted of employees on
Fritz medal awarded to W. R.
1943 ;
piece work who were already producing
at what was considered top speed. In
Whitney; critical communications jobs
addition to increasing the production
rate, Monday morning ahsenteeism and
listed by Selective Service headquarters
early end -of- the -day departures decreased considerably.
The effect of a carefully selected and
planned musical program in a plant
already using music, but with indiscriminate selection, was studied and an
increase in the production rate of 6.8
percent was noted. This would seem to
comequipment; mechanic, radio
Selective Service Headquarters ing
munication office; production man, bear out the theory that while music
Determines Critical Jobs
bilingual; program- transmission sup- is better than no music, programming
radio operator; radio repair- will not be satisfactory until it is unervisor;
In Communications
man, broadcasting; recording engineer; dertaken on the basis of a careful
SELECTIVE SERVICE Headquarters has rigger, radio; station installer, station analysis of the results it gets. We have
notified local boards of 92 occupations repairman; traffic chief, radio com- to date only the showmanship and exwhich are to be considered "critical" munications, transformer repairman; perience of the programmers. More
when classifying men for the call to translator; transmission engineer; war statistical analysis of factory performance should teach us much. Proarms. The list was issued in accord- correspondent; wire chief.
gramming must ultimately be underance with certification by the War Mantaken for the factory, if not for the
power Commission that communication
specific operation. Fatigue curves vary
services are essential to the support of
in shape and amplitude and it is diffithe war effort.
cult to find one remedy for dips ocDraft deferment of men on this list Prof. Burris-Meyer Gives
curring at different times in different
continues to be at the discretion of the
operations. The remedy for this exlocal boards, Selective Service infor- Definite Figures on Effect of
ists and the technique for employing it
mation men emphasized. In general, Music on Production
is in hand.
deferment is determined by the answers
IN A PAPER DELIVERED to the American
In closing Prof. Burris -Meyer obto three questions:
Society of Mechanical Engineers re- served, "Little of the music used in the
1. Is the man in an essential service?
cently Prof. Harold Burris -Meyer pre- factory is germane to the endeavor it
2. Is his job essential to the funcsented the results of what is claimed to accompanies. The work song took not
tioning of that service?
be the first scientific, statistical in- only its rhythm but its mood and lyric
3. Is he irreplaceable in that job?
The new listing is designed to answer vestigation conducted in this country from the work operation. The transfor the purpose of evaluating the ef- cription carried something composed
questions 1 and 2.
of industrial music on employee for the concert hall, the stage or the
In classifying registrants employed fects
morale
and factory production. The night club. The leisure music is not in
in these activities, Selective Service Dishowed that in 75 percent of the the idiom of the modern industrial
rector Hershey said, consideration data
investigations production was consider- plant and yet the industrial audience
should be given to the following:
(a) The training, qualification, or
skill required for the proper discharge
of the duties involved in his occupation;
(b) the training, qualification, or
skill of the registrant to engage in his
occupation; and
(c) the availability of persons with
his qualifications or skill, or who can
be trained to his qualification, to replace the registrant and the time in
which such replacement can be made.
Here are the communications jobs
of interest to the radio industry which
are to be considered "critical."
Accountant, cost; carpenter, maintenance; control -room man; control supervisor, junior; control supervisor,
senior; director, international broadcasting; electrician (all around) ; engineer, professional and technical; foreign-language; announcer -translator;
foreign -language-news -or-script writer ;
NEWS OF THE INDUSTRY
for
John
foreman, electrical work; instrument
maker; machinist (all around) ; manager, employment and personnel;
manager, production; mechanic, electric maintenance; mechanic, maintenance; mechanic, mechanical tabulat116
When Uncle Sam drafted KALB's junior and his two male
successors, the station management drafted the Alexandria. La. high school
debating coach, Miss Dorothy Aden. With a few weeks of training Miss Aden
obtained her Third Class Operator's License and is well on her way to
getting the Second Class rating
DOUBLE DRAFT.
December 1942
-
ELECTRONICS
WALKERuTURNEP FLEXIBLE SHAFTING
...meets war's
hardest tests !
-
aircraft and other mechanical weapons where
requirements are unusually severe Walker- Turner
Flexible Shafting has thoroughly demonstrated exceptionally high quality of design and materials. As one
of the largest manufacturers of flexible shafting for
industry, Walker- Turner has gained wide experience
in design, production and application of flexible
shafting for remote control and power transmission.
In
-
Although it is one of the busiest departments of this
Company, we are always glad to help other concerns
who may wish to learn more regarding the possibility
of simplifying design through the use of flexible
shafting. Walker- Turner Flexible Shafting is available
today in products used for war purposes, in a wide
range of sizes and specifications.
WALKER- TURNER COMPANY, INC.
14122 Berckman Street
wa
Plainfield. N.
J.
er-
urne
company. Inc.
PLAIfFIELD. n.J.
U.S.A.
ELECTRONICS
-
FOR REMOTE CONTROL AND POWER TRANSMISSION
December 1942
117
at present rate soon be the largest
audience for the musician. No artist
undertakes a composition or performance without the consciousness of his
audience, and insofar as his art is
valid he undertakes to exercise emotional control over that audience.
When the composer starts to think of
his work as being first and oftenest
performed in a factory, before people
who are working while they listen, we
may well have a musical idiom which
is something new on the face of the
earth, and what industry can do for
music may be as important when the
record of this civilization is written, as
anything music can do for industry."
will
THE
NATION CALLS
WHEN
DURING
an emergency -building
morale
-
for our effectives
-providing entertainment
problems
-instruction on local defense
-dissemination of
Selling defense bonds
John Fritz Medal Asarded to
Willis Rodney Whittle.
news
WILLIS
-
MAXIMUM
YOUR STATION WANTS
DEFINED AREAS
COVERAGE IN YOUR
,
BLAW -KNOX VERTICAL
RADIATORS
listeners.
greater
experience covering
They are backed by
of radio.
the entire history
mean
coverage -more
BLAW-KNOX
V E R T
I
C A L
,..RADIATORsS
TOW
FM AND TELEVISION
BLAW -KNOX DIVISION
of Blaw -Knox CompanyPa.
Pittsburgh',,
Farmers Bank Building,
118
RODNEY WHITNEY, chan
engineer, inventor, author and educator, has been announced as the recipient of the 1943 John Fritz Medal, the
highest American engineering award.
The medal was first awarded in 1902 to
John Fritz, pioneer iron master and
engineer in whose honor the award established. It has been awarded annually since that time for "notable
scientific or industrial achievement,
without restriction on account of nationality or sex." It is conferred by a
hoard composed of representatives of
four national engineering societies, the
American Society of Civil Engineers,
The American Institute of Mining and
Metallurgical Engineers, the American
Society of Mechanical Engineers, and
the American Institute of Electrical
Engineers.
Dr. Whitney's most notable achievement was the creation and development
of the General Electric research laboratory, one of the earliest of its kind in
the United States. This laboratory,
pioneer in the application of science to
industry, has gained a world-wide reputation by the quality of its work and
the importance of its results. He became vice -president and director of
research of the General Electric Co.,
in 1928, and in 1932 vice -president in
charge of research.
Other recipients of the John Fritz
Medal are Lord Kelvin, George Westinghouse, Alexander Graham Bell,
Thomas Alva Edison, Charles T. Porter, Alfred Noble, Sir William H.
White, Robert W. Hunt, John E. Sweet,
James Douglas, Elihu Thomson, Henry
M. Howe, J. Waldo Smith, George W.
Goethals, Orville Wright, Sir Robert
A. Hadfield, Charles Prosper, Eugene
Schneider, Guglielmo Marconi, Ambrose Swasey, John Frank Stevens, Edward Dean Adams, Elmer Ambrose
Sperry, John Joseph Carty, Herbert
Hoover, Ralph Modjeski, David Watson
Taylor, Michael Idvorsky Pupin, Daniel
Cowan Jackling, John Ripley Freeman,
Frank Julian Sprague, William Frederick Durand, Arthur Newell Talbot,
Paul Dyer Merica, Frank Baldwin Jewett, Clarence Floyd Hirshfeld, Ralph
Budd, and Everette Lee De Golyer.
December 1942
,
-
ELECTRONICS
i
T
is not too much to say that
Pan American
Airways has
invented the technique of transoceanic air transport; a technique based on superb skill,
meticulous maintenance, and
thoroughly reliable equipment.
PHOTO COURTESY OF PAN AMERICAN AIRWAYS SYSTEM
National and Pan American
Airways have never been
strangers, but we are particularly proud that year by year
Pan American has turned increasingly to National communication Equipment.
Upper photo: Pan American Strato- Clippers.
Lower photo: A Pan American radio installation using
National Receivers.
ELECTRONICS
-
NATIONAL COMPANY, INC.
MALDEN, MASSACHUSETTS
December 1942
119
www.americanradiohistory.com
FCC Radio Intelligence
Meeting a pressing need
Division Proves to be
Invaluable in the War Effort
-for
defense communications improvement
-demanding extension of services, development
of refinements, more specially trained engineers
lifE RAIuII INTELLIGENCE Division of
the Federal Communications Commission has been rendering a service to
the nation in its war program which
has proved its worth many times over.
The demands of war have necessitated
an increase of personnel of this division
of about 50 percent to bring the total to
about 900 engineers, technicians and
cartographers. The work goes on 24
hours a day, 7 days a week to bring to
the attention of our military staffs all
possible information which is trans mitted by radio throughout the world.
The United States and its territories
are divided into twelve monitoring
areas in each of which is located
Prepare for specialization in this
important field
with the aid
of these books
a primary fixed
THIS LIBRARY was selected by radio
engineering specialists of the McGraw -Hill
publications to give a well- rounded view of
communications engineering theory, applications, and special techniques. From important tube and radio fundamentals to
special emphasis on high- frequency prob-
lems, the essentials of this field and its
complete modern background are grouped
here, for the aid of those who wish to prepare quickly for design and research work
in the vitally important and expanding
field of defense communications engineering.
..
The newly -assembled
.
DEFENSE COMMUNICATIONS LIBRARY
6 volumes, 3662 pages, 6 x 9, 2111
illustrations, many tables and charts
for comprehensive practical working knowledge of ultra -high frequencies
These books give the basis
gaged in ultra -high frequency phenomena, is
the material on radiation from antennas of
various types, effect of the earth on the
propagation of radio waves, and the refraction and reflection of waves. A "must" for
advanced workers engaged in wave propa-
Hund's PHENOMENA IN HIGH FREQUENCY SYSTEMS
A complete survey of theories, practices, and
equipment the high frequency communications engineer requires in design and development of ultra -high frequency systems. Chapters on High Frequency Generators, Electromagnetic Theory, Theory of the Ionized
Layer, Lines of Long and Short Electrical
Length, and on Directive Systems have particular application In the present emergency.
2. Hund's HIGH- FREQUENCY
MEAS1.
tube constants and characteristics, radiation,
and other high frequency electrical quantities. Of special timeliness is the material on
measurements of frequency and phase modulation, the discussion of the use of cathode
ray tubes in high- frequency measurements,
and the determination of radiation. directivity and other transmission phenomena.
3. Straffon's ELECTROMAGNETIC
THEORY
An advanced text on electromagnetic theory.
treated mathematically through the extensive application of vector analysis. The first
chapters deal with electrostatic and electromagnetic fields, and are followed by chapters on plane, cylindrical and spherical waves.
of particular interest to the engineer en-
Special low price
Easy terms
Bought singly, these 6 books would
cost you $31.00. Under this offer you
save $2.50 and in addition have the
privilege of paying in easy installments
beginning with $3.50 ten days after
receipt of the books. and continuing
at $5.00 monthly for 5 months.
No installment charge
These books assemble tor your convenience facts, standards, practice,
data, for the whole field of communications engineering, with emphasis on training in ultra -high fretuencies. Add them to sour library
now, under this advantageous offer.
120
throughout continental United States,
Hawaii, Alaska, and the West Indies.
To coordinate the activities of all these
stations Radio Intelligence Centers are
located at Washington, San Francisco,
and Honolulu which act as clearing
houses for the exchange of information.
The primary monitoring stations and
the three Intelligence Centers are connected to each other by radiotelegraph
and wire teletypewriter services.
In addition to its services in gathering information concerning the activ-
gation phenomena.
4. Reich's THEORY AND APPLICATION OF ELECTRON TUBES
A standard and authoritative text on electron tubes, the heart of modern communication system, giving thorough, coordinated
groundwork in tube and circuit theory, with
emphasis on fundamental principles and their
use in many applications in electronics, communications, power, and measurements.
5. Everiff's COMMUNICATION ENGINEERING
A standard and well -known text covering
communication practice at all usual frequencies. emphasis is on theorems which
apply fundamental similarities of simple networks to new complicated structures.
6. Glasgow's PRINCIPLES OF RADIO
ENGINEERING
A well -known text, relating theory of the
thermionic vacuum tube and its associated
circuits to communications without slighting necessary mathematical explanations.
Used in Government -sponsored defense communications courses.
UREMENTS
An authoritative treatise on measurements
of voltage, current, power frequency, L, C, R,
10 DAYS' FREE
monitoring station.
These stations are equipped for recording all high-speed code transmissions, direction finding, and general
monitoring work. In addition, there
are 96 secondary monitoring stations
and a number of mobile units located
EXAMINATION
EXAMINATION COUPON
McGraw -Hill Book Co., Inc., 330 W. 42nd St., New York
Send me Defense Communications Library for 10
days' examination on approval. In 10 days I will
send you $3.50, plus few cents postage, and $5.00
monthly till $28.50 is paid, or return books postpaid.
(We pay postage if you send first installment with
order.)
FIGHTING FOR HIS HOMELAND IN
Na nie
AMERICAN INDUSTRY.
Dr. Chao -Chen Wang is at work in the
Address
electronics
E & M
City and State
Position
Company
I
.
12 -42
laboratory
of
Westinghouse
Co. where his efforts are speeding
up the delivery of vital communications
equipment to China and other United Nations. He was sent here by the Chinese
government on a university scholarship
and his specialty is uhf.
December 1942
-
ELECTRONICS
.
,
.,
F",
_
-
=
t7---0
.:'`:*Lá.
3=L.;: :
Weight: Approximately
Should you be one of those engineers who is looking for a relay with plenty of guts,
you will be gratified to learn that Clare Type K. d. c. Relays, according to reports
by one of our large customers, withstand a "300 G" test. Here is a relay that not
only stands up under this extraordinary test, but also fits perfectly into designs where
inches and ounces count.
Only a product of character, constructed of the finest materials by skilled, painstaking craftsmen,
12/3
ounces
heelpiece is equipped with a split type lockwasher.
The coil is carefully wound to exact turns on precision machines. Coils can be supplied impregnated
with a special varnish. They are covered with a transparent acetate tape. Each coil shows data regarding
resistance and type number.
can function properly under such rapid acceleration. Materials making Clare Type K. d. c. relays
are the best procurable: contact springs of nickel silver, insulators of special heat- treated Bakelite,
and all metal parts plated by a special Clare process to withstand a 200 hour salt bath test.
As illustrated, it is extremely small, measuring only 1M" x 1h" x I ", and weighs approximately 1% ounces ... It can be furnished in the
contact forms shown above with any number of
springs, up to and including 12... Coil voltage
range is from 1.5 volts to 60 volts d. c.... Contacts of either 18 gauge silver, rated one ampere,
50 watts, or 18 gauge palladium, rated two amperes, 100 watts can be furnished.
The design is such that the relay itself is capable of withstanding severe vibration. Therefore. no anti -vibration springs are employed
... The screws by which the contact spring pileups are fastened to the heelpiece are tightened
under pressure and secured into the heelpiece
by a coating ofGlyptol as an added precaution.
The tiny size and featherweight of this relay
are a definite contribution to design problems.
Like all Clare Relays, it can be "custom- built"
to meet your specific requirements. Write us
regarding them. We will make suggestions. In
the meantime, send for the Clare catalog and
data book. C. P. Clare & Company, 4719 West
Sunnyside Ave., Chicago, Ill. Sales engineers in
all principal cities. Cable address: CLARELAY.
Spring insulators are
made from special
heat treated Bakelite
that permits punching without cracks
or checks and pos-
I .nifrm armature nwvcmcnt is assured by a hinge ut
"fatigueless" beryllium copper, heat treated and designed to provide a wide margin of safety, insuring
long life under vibration and permitting millions of
uniform operations.
sesses minimum
cold flow and low
moisture absorption
properties. Each Type K Relay is given
a. c. insulation breakdown test.
a
1000 volt
The armatureassembly, heelpiece and
coil core are made of
magnetic metal,carefully annealed. The
armature assembly is
available with either
single or double arm.
Contact springs are made of nickel silver to the manufacturer's specifications. The contacts are over -all
welded to these springs by a special process.
The small coil is
equipped with a front
spool head having a
flat side. This locks
the entire coil in
place against the
heelpiece, prevent-
ing it from turning
or becoming loose. The screw holding the coil in the
Spring bushings of Bakelite are designed, constructed
and attached to the springs so that the small springs
used on this relay are not weakened. Uniformity of relay operation and long service life are thereby assured.
CLARE RELAYS
"Custom -Built" Multiple Contact Relays for Electrical, Electronic and Industrial
ELECTRONICS
-
December 1942
Use
121
l
SAMPLE,
DETAILS
BELOW
A
SUPER AIRCRAFT RELAY
Below are specifications of a specific G -M type 27 relay for 14
volt D. C. operation. These characteristics can be varied over
a wide range to suit the requirements of different applications.
Vibration and acceleration -15 g; Altitude- 40,000 feet;
Contact pressure -50 grams (double make double break contacts I; Contact capacity 20 amperes at 30 volts d.c. (100
ampere inrush); 200 hour salt spray test; Pick up
volts
(.36 watt) at 20° C.; Nominal coil voltage -14 volts d.c.; Coil
wattage at 14 volts d. c.- 2.8 watts at 20° C.; Dimensions
11 s x 1 , x 1?;. inches high; Weight 5 oz.; Box frame construction for superior strength and sturdiness; Contacts protected
from damage and dirt by bakelite box design; Temperature
range -40 to ± 90° C. Write for further information.
-
FREE samples of the
above relay will be furnished relay users if re-
-5
quest is accompanied
by priority of AIK or
better. Request specification No. 12723.
Industrial Representatives
Attend Army Staff School
G-M LABORATORIES INC.
4313 NORTH KNOX AVENUE, CHICAGO,
U. S.
'GM
A.=
3G,4,4VY o.'
v./.
PNOTO
Coming through ..
Clear
... intelligible ... in
the heat and noise of battle
&ctk4-1;ce
... orders
are coming through
MICROPHONES
While we cannot discuss the actual developments embodied in many of our new
models, we can say that they have been designed specifically to limit background noises
and to allow speech to come through the bedlam of battle.
ELECTRO -VOICE MFG. CO., Inc.
1239 SOUTH BEND AVENUE
SOUTH BEND, INDIANA
Export Office: 100 YARICK STREET, NEW YORK, N. Y.
122
ities of our enemies, the Radio Intelligence Division also intercepts many
distress signals of ships at sea and airplanes forced down at sea and at isolated points, intercepts reports on submarine sightings by ships under attack, and with its direction finding
equipment many airplanes are guided
to safety, especially in the vicinity of
Hawaii. An outstanding example of its
interception of distress signals was the
picking up of the signal transmitted by
a Navy plane forced down in the South
Pacific near the Galapagos Islands
by a monitoring station in Pennsylvania. The information was passed on
to the Navy Department and the crew
rescued promptly.
The division also conducts research
and development work in new radio devices for use in its special field, especially in the tracking down of illicit
transmitters.
Advanced
training
schools for its personnel are operated
and recently, under the auspices of the
State Department and the Coordinator
of Inter -American Affairs, a number of
students from Latin America and Mexico have been enrolled.
A FOUR -WEEK ORIENTATION course in
Army organization and procedures is
being conducted at the Command and
General Staff School at Fort Leavenworth, Kansas for 83 industrial executives and representatives whose work
is closely associated with the war program. Of the 83 men attending the
school nine are from the communication industry. L. Myles Regottaz, export manager of the RCA Manufacturing Co., H. Leslie Atlass, vice -president
of the Columbia Broadcasting System,
and Henri C. Bohle, assistant vice president of the International Standard Electric Corp., manufacturing
subsidiary of the International Telephone and Telegraph Co. represent the
radio portion of the communication industry.
The course will consist of 146 hours
of instruction and will cover the general picture of the military forces of
the United States, their organization,
administration and operations; the
duties and responsibilities of the several divisions of the War Department
and of the governmental agencies connected with the war effort; the duties
and functions of the War Department's
field agencies and some general principles of tactics, strategy, supply and
administration.
Coast Guard Takes
Over Mackay Station
STATION WSL, the coastal radio telegraph marine station of the Mackay
Radio & Telegraph Co. located at
Amagansett, Long Island, has been
leased by the Coast Guard for the duration of the war.
December 1942
-
ELECTRONICS
L\J
.
Rising and falling with the waves ... men
on a rubber raft ... human lives snatched
from the sea... by a thin layer of inflated
rubber.
Important? Yes. It's important that
the thin sheets of rubber be kept free of
cracks and blisters, that the raft unfold
easily, that it be safe when it's needed.
That's why rubber life rafts are processed in special air conditioned rooms ...
to make the rubber tough and longlasting. /loom, temperature and humidity
- against
WATER
General Electric has already taken an
outstanding part in developing this new
kind of air conditioning for war industries. After the war, (di users of air conditioning will benefit from the lessons we
have learned in meeting these stringent
war requirements.
More people will enjoy air conditioning because it will be more compact
nuire economical. Cars will have it. Also
planes and boats. Small stores, as well
...
as large, will want it to increase sales,
to keep goods fresh. Factories will demand it as an aid to production.
Thus place to turn for this new equipment will be General Electric ... a logical
source of heating. refrigeration. air conditioning, and heat transfer equipment
of all kinds. '/'urn to G -E.
Air Conditioning and Commerical
/refrigeration Department, I)irision 4.7,
General Electric Co., Bloomfield, N. J.
are maintained more exactly than ever.
To do jolis like this, air conditioning
equipment must be more precise, more
flexible, more compact. Required "climates- must be reproduced faithfully ...
wherever and whenever wanted.
ELECTRONICS
-
December 1942
eogdereoger,
GENERAL
4
ELECTRIC
123
r THERMOSTATIC
\
III-METALS
ELECTRIC:IL CONTACTS
J
Percolators or Pursuit Planes
* Almost overnight,
whole industries have changed over
from peacetime to war production. *Yet, whether it's brooders or bombers, transformers or transports. percolators or
pursuit planes, the need for Wilco specialized thermostatic
bi- metals and electrical contacts remains unchanged. Resistance bi- metals (from 24 to 440 ohms. per sq. mil; ft.) and
high and low temperature thermostatic hi- metals are available in wide variety. *Also Wilco electrical contact alloys
(in Silver, Platinum, Gold. Tungsten. Metal Powder Groups).
The
H. A.yVILSON CO.
Branches: Chicago and Detroit
Signal Corps Deliveries
$3,000,000 worth of communications equipment is being delivered to and accepted by the Signal
Corps daily. This rate is twenty times
the rate of a year ago. This remarkable performance is the result of cooperation between the Signal Corps, the
WPB, and industry. The radio manufacturing industry had to be expanded
many fold in a very short time. The
telephone industry was in a little better
shape for adjustment to the vastly increased requirements for manufactured
MORE THAN
materials.
Even at the rate of $3,000,000 worth
of equipment daily, several years
would be required to complete delivery
of all equipment on order by the Signal
Corps which amounts to about six billion dollars. Thus, even more spectacular figures for production by the communications industry can be expected
in the near future.
St. Louis Utility Installs
F -M System
is THE latest city to have installed a two -way f -m radio system to
give instant communication during
emergency periods in a utility system.
The Union Electric Co. of Missouri has
recently put into service three f-m
transmitter- receiver units for emergency service. One unit is located on
the top floor of the Union Electric
building in the downtown area and
the other two are carried on trouble
shooting emergency trucks. The operating frequency is 39.6 Mc.
ST. LOUIS
Col. John Stilwell Elected
Director of American
Standards Association
ENAMELED
MAGNET WIRE
Much of the success of
Hudson Wire product is
due to a new coating method that gives
a smooth, permanently -adherent enameling. Mercury -process tests
guarantee perfect uniformity; great tensile strength assures perfect laying even at high winding speeds. Especially adaptable for
reduction in coil dimensions without sacrificing electrical values.
Our engineering and design facilities are of your
this
disposal-details and quotations on request.
H
DSON WIRE COMPANY
WINSTED
124
.III
%I
CONNECTICUT
COL. JOHN STILWELL has just been elected to serve a three -year term on the
board of directors of the American
Standards Association. He is now serving his third term as president of the
National Safety Council. He has also
served as president of the Greater New
York Safety Council and of the American Museum of Safety. As general superintendent of Transportation and
later vice -president of the Consolidated
Edison Co. of New York, Col. Stilwell
has had much to do with the safety
program of that company.
Denny Appointed FCC
General Counsel
has been appointed general counsel of the Federal
Communications Commission to succeed Telford Taylor who has been
commissioned a major in the Army.
Denny was an assistant general counsel of the FCC since February when he
transferred from the Justice Department.
CHARLES R. DENNY, JR.,
December 1942
-
ELECTRONICS
COMPANY
ENERAL RADIO
Y
A TO R
B O
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1laui
/r,lrrrs
.°c
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RA-D-10
nof
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ELECTRICA
FOUNDED
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APPARATUS
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STREETASSAGHUSETTS
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TO USERS
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RADIO
are
service,
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around
worked
is essential.
operation
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instrument o Prompt
months
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to handle
must be n0
and equipped
problems
is organized
department
p and
adjustments
importance
with
unprecedented experience
of the
today's
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and capably. long since convincedisusof
doubly necessary.
or
major
repairs have Today this service
for
kept on every
is
guaranteed
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file
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history
area
case
new.
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complete
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NOTES.
repair work
possible
AN D MAINTENANCE Radio customers
time, and
SERVICE
General
G
production
of
valuable
to savetheir equipment.
helped hundreds
q
repairs,
for
from
returns
NOTES,
service
MAINTENANCE
to get better
AND IZAL
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by type
your set
instruments
yGeneral
Radio
When requesting
list your nurobed.
please
please
serial
number and
Sincerely
Gentlemen:
Service
ELECTRONICS
-
December 1942
www.americanradiohistory.com
Manager
Alaskan Broadcast Station
Raises Power
KFAR AT Fairbanks, Alaska
has stepped up its power from 1000
watts to 5000 watts by permission of
the Federal Communications Commission and is prepared to increase it
further to 10,000 watts after the war,
or sooner if conditions warrant it.
Military considerations emphasized the
necessity for higher power broadcasting in Alaska because even on 1000
watts this station had been a distinct
aid to both Army and commercial aviation. Also, this station was the only
means by which military authorities
could reach the population with instructions in case of an emergency.
With these things in mind, the FCC
gave permission and the WPB granted
the necessary priorities to get the station operating at the higher power in
very short order.
STATION
Faster PLASTIC Deliveries!
* Branding
by Rogan on plastics after molding eliminates many time -consuming
mold- making operations, and permits you to use blank stock parts! Use only one
master die for interchangeable parts . . . Rogan will brand the markings for
different uses . . . FASTER!
APPROVED
AS THE EQUAL OF ENGRAVING
Rogan "deep- relief" branding on plastic parts meets rigid requirements. Has been OK'd as the equal of engraving now called
for in specifications.
ROGAN
BRANDING
CUTS
COST
Radio Club Hears deRosa on
Synthetic High Fidelity
.
Save expensive lettering and marking costs through the use of
simpler molds, fewer dies. Illustrated is a plastic shut -off branded
by Rogan, just one example of ability to handle any job. For
plastic parts large or small, flat, curved, round or conical, save
time and money by utilizing Rogan's exclusive branding process.
Send description of your requirements today!
ROGAN BROTHERS
hoc S.
AT THE DECEMBER 10 meeting, Radio
Club of America, L. A. deRosa will
Michigan Ave.,
Illinois
EASTERN PLANT-154 Lawrence St., Brooklyn, New York
STABILIZED A. C. VOLTAGE
UP TO 25 KVA
Varying Input Voltage
Constant
995 -130
115 VOLTS
VOLTS
r-
INSTANTANEOUS ACTION
When
Output Voltage
NO MOVING PARTS
precision electrical device or a critical process is powered from
a Raytheon Voltage Stabilizer will permanently eliminate
all of the detrimental effects caused by AC line voltage fluctuations.
Made for all commercial voltages and frequencies, single or three
an
a
AC line,
phase.
Raytheon's twelve years of experience in successfully applying the
Stabilizer to hundreds of perplexing voltage fluctuation problems is at
your service. It will pay you to take advantage of our engineering skill.
Write for Bulletin DL48 -7I
JE describing Raytheon Stabilizers.
RAYTHEON MANUFACTURING CO.
100
Ì
Willow Street
WALTHAM, Massachusetts
21
describe the work he has been doing
with improving auditory reception by
taking advantage of the fact that the
ear is fundamentally a distorting translating device. According to Mr. de
Rosa, an analysis of the operation of
the human hearing mechanism leads to
the conclusion that the ear supplies the
brain with signal patterns which are
highly distorted versions of the externally impressed acoustical energy.
By the cognizance of the general rules
governing the distortion characteristic
of the ear it is possible to supply the
hearing mechanism with sounds consisting entirely of externally generated extraneous products and yet produce natural and apparently distortion
free responses. The ear apparently
acts as a narrow band transducer and
by applying certain patterns of distortion lying only within the middle
range of audio frequencies, it is possible to simulate low and high frequency sensations; this, despite the absence of low and high frequency signals
in the sound conveyed to the ear.
One of the many applications of the
development is the reproduction of an
apparently high-fidelity signal from a
receiver having a poor bass and high
frequency response. The theory underlying the production of various effects
will be discussed at the meeting and a
practical demonstration will be given.
Blind Persons Used in
Precision Assembly
THE UNIVERSAL MICROPHONE CO. Of Inglewood, Calif. is using blind men and
women in certain types of precision assembly with very good results. These
workers are placed in normal working
positions with other workers at jobs in
which their blindness offers no handicap.
December 1942
www.americanradiohistory.com
-
ELECTRONICS
Serving America's War Work Now...
the better to serve all
American Industry later
AmerTran modulation
transformers and reoil immersed
actors,
type, for large broadcast transmitters.
-
Here in AmerTran's factories under the accelerated tempo
of war production, we are designing and building better
transformers that will help meet the competitive conditions of the general business upswing of the future.
Here in blueprint form, and in the shape of refined designs and improved construction, better AmerTran equipment is being produced to serve war -time America now
to serve peace -time industry later. Tomorrow these
improvements will be available to the whole of the communications field for general electronic and radio applications. The confidence you have placed in the
AmerTran pre -war products you are using today
confidence merited by 41 years of leadership-will be
many times justified when the splendid results of the
work AmerTran is doing today become generally available to a victorious American industry.
...
AmerTran RS plate
transformers and reactors, oil- immersed
type, for all large
-a
installations.
AmerTran W plate
transformers and reactors for all small
and medium installations.
AMERICAN TRANSFORMER COMPANY, 118
Manufactured Since
AmerTran transformers are manufactured to meet your
exact electrical and mechanical requirements.
ELECTRONICS
-
1901
Emmet St., Newark, N.J.
at Newark, N. J.
Ài ERTizAN
127
December 1942
www.americanradiohistory.com
I. T. & T. Merger
TWO
Gi
lifiG'lulp CTOR31,6T11126
Pe:: peat.
TiOVVIE,
ASSOCIATE
MANI'P. \CTURING Com-
panies of the International Telephone
and Telegraph Corp., the International
Telephone and Radio Manufacturing
Corp. and the Federal Telegraph Co.,
have been merged and the name of the
resulting corpóration is Federal Telephone and Radio located at Newark,
N. J. The new organization consists of
about 5500 persons and is devoted almost entirely to the production of communication and radio equipment for the
war program. A new factory is being
built in New Jersey and will be the
home of the new corporation. It is
planned that all laboratory and manufacturing operations associated with
I. T. & T. in the United States shall
eventually be centered there.
General Limitation Order
L -183
Aub 1943 Victory
for ur Country club
arY of
ur AYYío
GENERAL LIMITATION Order L -183, issued by the War Production Board on
September 18, and which became effective on October 3, has given rise to
numerous questions regarding its applicability and method, and the extent
to which various operators are affected by its terms. In order to clarify
the situation, the Radio and Radar
Branch of the War Production Board
has summarized the questions gleaned
KENYON TRANSFORMER CO., Inc.
840 BARRY STREET
NEW YORK, N. Y.
MANUFACTURING
COMPANY,
iNC.`.
SIGNAL GENERATORS - AUDIO OSCILLATORS - TEST EQUIPMENT
RAGIO RECEIVERS - TRANSMITTERS - ELECTRONIC DEVICES
L..
e a
o.
v .i
t, ,
It
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128
Interpreted
from its correspondence. The most
frequent questions and their answers
are given below:
Q. What apparatus is governed by
the Order?
A. The definition of electronic
equipment is interpreted very
broadly and includes within
its meaning anything and
everything in the electronic
field which is not specifically
exempted in Schedule A of the
Order.
Inter -communicating
equipment involving the use of
vacuum tubes is covered by
the Order.
Are
replacement and repair parts
Q.
covered by the Order?
A. Yes. Replacement and repair
parts in the hands of the
manufacturer may not be
transferred except on orders
bearing a preference rating of
A -3 or higher.
Q Are distributors affected by the
Order?
A. No.
Distributors are restricted only to the extent that
they must obtain preference
ratings before they may acquire any new supplies.
Does
L -183 apply to export sales?
Q.
A. Yes. The terms of the Order
are entirely general and apply to all transfers regardless
of conditions, destination or
purpose.
Q. What is the basic purpose of the
Order?
A. The purpose of the Order is
December 1942
www.americanradiohistory.com
-
ELECTRONICS
MOUNTING
Imo'
BONDED RUBBER
TO KEEP
HARMFUL VIBRATION
FROM
J,¡C DEVICE
EVERi
TYPICAL INSTALLATION
DOUBLE MOUNTING
SQUARE PLATE
TO keep mechanical and electrical equipment operating at peak
efficiency and also prolong its operating life are factors of prime
importance in today's program of high speed, precision production. Lord's contribution toward this end is the development of a
series of Shear Type Bonded Rubber Mountings, particularly
adaptable to electronic equipment.
Lord Mountings are made in two main types, Plate Form and
Tube Form, and in load capacities ranging from a few ounces up
to 1500 pounds. Due to the Lord method of bonding rubber to
metal, the rubber, when loaded on main axis, is stressed in free
shear. This design for free shear softness in the direction of the disturbing forces, results in an exceptional reduction in the natural
frequency of the mounted system. Where very delicate, sensitive
equipment is to be protected, the use of double or series mountings
is recommended, thereby doubling the axial softness, and increasing the lateral softness. Lateral softness may be varied by changing the length of connection between mounting units. Double
mountings give ideal protection where disturbing vibratory forces
emanate from more than one direction.
No intricate layout, no special tooling or close machining is
necessary to accommodate Lord Mountings. Properly installed,
they absorb sudden shock and undue stresses, isolate harmful
vibration and eliminate noise translated through solid conduction,
all of which prolong equipment life and keep it operating at maximum efficiency. Regardless of size or weight there is a Lord
Mounting for every electronic device. Send for Bulletins 103 and
104 on Lord Shear Type Mountings, or better still, call in a Lord
vibration engineer for consultation on your design problems.
There is no obligation.
i*G
TYPICAL INSTALLATION
HOLDER TYPE
V.
S. PLATE FORM
F
-
.
4
MOUNTINGS
f
PROLONG EQUIPMENT LIFE by isolating vibration, which reduces
metal fatigue, thereby preventing subsequent failure.
TUBE FORM
r
ROUND PLATE
INCREASE PRODUCTION by eliminating the necessity for close machining and precision alignment.
SAVE VITAL MATERIAL by reducing equipment weight; heavy inertia
masses of machinery bases can be eliminated.
9
INCREASE PERSONNEL EFFICIENCY by eliminating nerve wearing
noise and vibration, translated through solid conduction.
LOWER MAINTENANCE COSTS by protecting equipment against
sudden load shocks and stresses, thereby minimizing repair and replacement
operations.
DIAMOND PLATE
V. S. TUBE FORM
ORIGINATORS OF SHEAR TYPE BONDED RUBBER MOUNTINGS
LORD MANUFACTURING
COMPANY...
ERIE, PA.
LOR*
BONDED RUBBER
SHEAR TYPE
VIBRATION
-
TE
FORM MOUNTINGS
... NEW YORK, 280 Madison
TAKES RUBBER IN
SALES REPRESENTATIVES
IT
FRACTIONAL H.
MOUNTINGS
Ave.... CHICAGO, 520
SH
1!1!
TUBE FORM
N.' Michigan
MOUNTINGS
Ave....
FLEXIBLE
BURBANK, CAL., 245
E.
w ATI!w YT!'n"111,
www.americanradiohistory.com
P,
COUPLINGS
Olive Ave.
twofold: (1) To prevent the
consumption of new raw material and the manufacture of
non-essential apparatus; (2)
To distribute existing inventories on an equitable basis.
SPECIALISTS
IN
Electronic Control
Q.
Are dry batteries subject to the
Order?
A. No. The production of dry
batteries is controlled by Limitation Order L -71.
may parts for maintenance
and repair be obtained?
A. Maintenance and repair parts
will be available through normal channels. Distributors of
such parts may obtain preference ratings through the use
of PD -1X, the Distributor's
Application for Preference
Q. How
Rating.
Q. Are recording discs subject to the
Order?
A. Yes. Recording discs are subject to the restrictions of L -183
and may be obtained through
distributors who may apply
ENGINEERING
SERVICE
Our function in the service of the
electronics industry is twofold.
1. Engineering
of control circuits
for specific requirements involving use
of sensitive relays of all types.
2. Manufacturing of relays precisely matched to exacting specifications.
You are urged to consult us in detail
regarding all aspects of your electronic
control problem directly or indirectly
associated with the relay.
NEW
SIGMA
DEVELOPMENTS
A.C. Sensitive Relays for use on
small A.C. inputs from 60 to 2,000
cycles.
Super- Sensitive Polarized Relays
weighing slightly over 6 oz., and operating on a few microwatts.
Hermetically Sealed, Plug -In Relays for operation under severe environmental conditions.
Aircraft Service is a norm for which all
SIGMA Relays are designed.
SIGMA INSTRUMENTS, INC.
76 -78
BOSTON
Freeport Street
MASSACHUSETTS
for preference ratings on
Form PD -1X or the consumer
may apply on Form PD -1A
for his requirements.
Army Specialist Corps
and Officer Procurement
System Consolidated
testing officer procurement through the Army Specialist
Corps as a civilian agency of the War
Department, it has been found that
the purposes of the Corps could not be
accomplished to the best advantage in
the midst of the war because of the
civilian status of those appointed in
it to serve with the Army. In the interest of efficiency, uniformity of operations, discipline, and the avoidance
of duplication of effort, it is not deemed
advisable to have two uniformed services. Accordingly, the Army Specialist
Corps will cease to function as a separate organization, and the procurement of specially qualified persons required by the Army for service in other
than civilian positions will be accomplished by Specialist commissions in
the Army of the United States.
AFTER A PERIOD OF
F. R. Lack Appointed
Director of Army-Navy
Electronics Expediting Agency
vice president and
manager of the radio division of the
Western Electric Co., has been appointed director of the Army-Navy
Electronics Expediting Agency, a newly
created post. He will coordinate and
supervise all Army and Navy joint
activities in production expediting of
communications and radio apparatus
and equipment. Major General Roger
B. Colton, chief of the Signal Supply
Services, and Captain Jennings Dow,
in charge of the Radio and Sound
Branch of the Bureau of Ships, will
serve as associate directors.
FREDERICK R. LACK,
Van Dyck Announces I. R. E.
Officers for 1943
AT THE NEW YORK MEETING of the
Institute of Radio Engineers on November 4, Arthur F. Van Dyck, President of the I. R. E. for 1942, announced
the formation of the New York Sec-
tion. New York has always been a
stronghold for radio engineers and
meetings have been since the inception
of the Institute in 1912. With the formation of the New York Section, this
metropolitan area assumes the same
position as that of Institute sections in
other cities in this country and in
Canada. Programs for the New York
Section will be under the direction of
a locally elected group of officers. The
officers for the New York Section for
1943 were announced by Mr. Van Dyck
as follows: President, H. M. Lewis,
consulting engineer; Vice President,
Murray G. Crosby, RCA Communications; Secretary, Harry F. Dart, Westinghouse Lamp Division.
In addition to these local officers for
the newly created section, Mr. Van
Dyck also announced the results of
the election of national officers. Dr.
L. P. Wheeler, of the Federal Communications Commission has been
elected to the office of President, with
F. S. Barton, of the British Air Commission, in Washington, D. C., as Vice
President. The directors, elected by
the membership, to begin their term of
office on the Board of Directors include
Dr. W. L. Barrow of the Massachusetts
Institute of Technology, H. A. Wheeler,
of the Hazeltine Service Corporation,
and Dr. F. B. Llewellyn, of the Bell
Telephone Laboratories.
130
A. M. Hageman Appointed
General Engineering Manager
of Westinghouse Lamp Works
has been appointed
general engineering manager of the
Westinghouse Lamp Works at Bloomfield, N. J. He will be in charge of all
development and engineering activities
involved in the production of lamps
and electronic devices. He was formerly in charge of lamp engineering.
DR. A. M. HAGEMAN
Admiral Noyes Rescued
After Sinking of Aircraft
Carrier Wasp
Leigh Noyes, former
director of Naval Communications, was
among those rescued when the aircraft
carrier Wasp was sunk by Japanese
submarines off the Solomon Islands on
September 15. Admiral Noyes was
commander of the task force at the
time of the attack and was using the
REAR ADMIRAL
Wasp as his flagship.
December 1942
www.americanradiohistory.com
-
ELECTRONICS
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INTERNATIONAL TELEPHONE
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CORPORATION
RADIO MANUFACTURIN(;
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FEDERAL TELEGRAPH COMPANY
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Corporation
Federal Telephone and Radio
loeuteii at JPerr'ar./
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INTERNATIONAL TELEPHONE ANI) TELEGRAPH CORPORATION, h7 Brood Street, New York, N.Y.
ELECTRONICS
-
December 1942
131
WAAC's to Receive
Performance Counts
Radio Training
THE FIRST GROUP of WAAC's to replace
ENGINEERED FOR ENGINEERS
EMBY INSTRUMENT AND RELAY
RECTIFIERS are the product of
years of laboratory research.
They are manufactured in eight
standard sizes with outputs ranging from 8 to 120 milliamperes.
Due to special forming processes the Emby instrument and
relay rectifiers have been made
permanently stable and their life
is unlimited.
The unipolar conductivity of
the selenium -to -metal junction is
utilized for rectification purposes.
In addition, all Emby instru-
ment and relay rectifiers are
shock -proof and perform satis-
factorily in the temperature
range from -80 °C to -4-70 °C.
Convenient soldering lugs are
provided on all types thus elim-
inating additional assembly
parts. Detailed data sheet mailed
on request.
are of the
self- generating type and are manufactured in ten standard sizes and four
sensitivity ranges. Detailed bulletin
mailed on request.
EMRY PHOTOELECTRIC CELLS
ACTUAL SIZE SERIES
ACTUAL SIZE SERIES
S
L
RECTIFIERS
RECTIFIERS
SELENIUM RECTIFIERS
EMBY
PRODUCTS
1800 West Pico Blvd
3 .,
COMPANY,
Los Angeles,
INC.
California
in others, the six-hour minimum that
the Federal Communications Commission requires.
(2) The average FM program schedule is 73.2 percent non -duplicated in
contrast with AM service offered to
the same area. In other words, 73.2
percent of the programs are planned
for FM and heard only over FM stations. Percentages range from a minimum of 10 percent to a full 100 percent
non -duplication over eight others.
(3) At least 28 of the commercial
enlisted men as radio operators and
mechanics in Army Air Forces Headquarters Companies will begin training
on November 30 at the Midland Radio
and Television Schools, Inc., in Kansas
City, Mo. Additional groups will be
started in training at intervals of one
month until a sufficient number of
women radio specialists have been
stations maintain full or partial staffs,
trained.
aside from any personnel that also
works for an affiliated AM outlet. Six
FM outfits have no connection with
Gerard Swope to Receive
any AM interests and are operated as
independent ventures.
Hoover Medal
(4) Not a single one of all the opGERARD SWOPE, president of the Generating stations which returned the
eral Electric Co., has been selected as questionnaire reports any intention of
the sixth recipient of the Hoover Medal curtailing its
operating schedule.
with the following citation:
Three admit maybe it might be neces"Gerard Swope, engineer and dis- sary at some later date if no provision
tinguished leader of industry, ever could be made to replace transmitting
deeply interested in the welfare of tubes when they wear out. Rather than
his fellowmen, whose constructive go off the air entirely they'd prefer to
public service in the field of social, cut down on daily schedules and thus
civic and humanitarian effort has prolong the life of the tubes.
earned for him the Hoover Medal
(5) Nine FM broadcasters are unfor 1942."
able to serve their entire assigned area.
The medal will be presented to Mr. Today they're serving somewhat less
Swope during the Winter Convention than 60 percent of the territory they
of the American Institute of Electri- will eventually whenever full installacal Engineers (luring the week of Janu- tion of antennas and higher wattage
ary 25. 1942. Previous recipients of transmitters becomes possible. Only
the Hoover Medal were Herbert one of them expects this to happen beHoover, in whose honor the medal was fore the war's end; another says
named, Ambrose Swasey, John Frank "maybe."
Stevens, Gano Dunn, and D. Robert
Yarnell.
Mr. Swope was elected president of A. H. Phelps New Westingthe General Electric Co. for the second
time in September 1942 when his suc- house VP
cessor. Charles E. Wilson, was named ANDREW H. PHELPS has been named
vice chairman of the War Production vice president of Westinghouse ElecBoard.
tric & Mfg. Co. Before joining Westinghouse he was affiliated with
McGraw -Hill Co. as Sales Manager
and Director of Public Relations. At
Radio in Homes Figures
time he was also connected with
Released by Bureau of Census one
U. S. Chamber of Commerce having
THE METROPOLITAN area of Boston leads charge of all district offices and the
the country on the coverage of radio field forces. In 1919 he served as
in the home with receivers in 97 per- executive secretary of the International
cent of the homes according to figures Trade Conference at Washington.
just released by the Bureau of the
Census. The figures for other areas
are Chicago, 96.2 percent; Philadelphia, Technical Valuation Society
96.2 percent; Los Angeles, 95.8 percent; Pittsburgh, 95.2 percent; Grand to Hold Annual Forum
Rapids, Mich., 96 percent; Paterson, THE ANNUAL FORUM of The Technical
N. J., 94.8 percent, and Sacramento, Valuation Society will be held on DeCalif., 91.8 percent.
cember 12, 1942, at New York. The
morning session will be devoted to
prominent economists, appraiser and
valuation engineers who will present
FM Broadcasters Report
papers and direct discussion on many
IN SEPTEMBER THIS YEAR, FM Broad- pressing valuation problems, particucasters, Inc., questionnaired the FM larly in their relation to the war effort.
The afternoon session will consist
broadcast stations on various matters
of general interest to the cause. A re- of committee meetings and the annual
port has now been issued; the gist of business meeting of the Society.
Further information may be obwhich follows:
(1) The average length of the FM tained from W. C. Fisher, Technical
program day is 10z hours, ranging in Valuation Society, 33 W. 39th St., New
some areas from 24 -hour service to, York, N. Y.
December 1942
-
ELECTRONICS
It's the movement
that counts
IF you want to find out how accurately, and for
how long, an instrument will do its work, you've
got to examine the part that makes it work.
In every Simpson Instrument this basic operating
mechanism is a movement which incorporates both
full bridge construction and soft iron pole pieces.
There is nothing new about this type of design. It
has been recognized for many years that such a
movement is more accurate, more rugged, and more
but
expensive,
...
-
-there is something entirely new in the patented
Simpson expression of this design. For out of the
long experience in instrument -making on which the
Simpson organization is founded, there has been developed a movement which offers this better design
in its best form, and which permits substantial
economies through standardization and straight line
production.
If your need for instruments is vital enough to
give you the right to buy, it is vital enough to rate
the best. To those who have
searched out the facts, best
means
.
.
.
Simpson.
MODEL 260
High Sensitivity Tester
A typical example of Simpson
leadership. Ranges to 5,000 volts,
both AC and DC, at 20,000
ohms per volt DC, and 1,000
ohms per volt AC. Current readings from microampere to 500
milliamperes. Resistance readings from %2 ohm to 10 megohms. Five decibel ranges, -10
to +52 DB.
1
SIMPSON ELECTRIC CO.
5200 -5220 Kinzie St., Chicago, III.
O
ELECTRONICS
-
December 1942
133
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-
ALLEGHENY
Atlas Powder Company
has long used
Potter and Brumfield
CORP.
BELMONT RADIO CORP.
Chicago, Ill.
CLAROSTAT
MANUFACTURING
CO.
Brooklyn, N. Y.
CONNECTICUT TELEPHONE
FACTURING Co.
ót
MANU-
Meriden, Conn.
'9-t+tlw'8
"THE
LUDLUM STEEL
(Two plants)
Relays
Princeton
wtrrti.
FAIRCHILD AVIATION CORP.
Jamaica, N. Y.
RELAYS
FEDERAL MANUFACTURING & ENGINEER ING CORP.
POSITIVE ACTION RELAY"
Brooklyn, N. Y.
INTERNATIONAL NICKEL CO.
Huntington, West Virginia.
LAPP INSULATOR Co.
S11CKE
WORM
WAR are applied
never
dhesive backing,
EI.ECIRICAI
king, a
Use
smooth
trace.
magic °
LeRoy, N. Y.
THE PERKIN -ELMER CORP.
Glenbrook, Conn.
THE REAMER CO., LTD.
San Francisco, Cal.
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SPEEDS
labels. With adhere
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leaving d .. ever
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Dept. EI2. Sales 6 Distributors,
St
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Kum Klee
SUMMERILL TUBING CO.
Bridgeport, Pa.
C
i
SYLVANIA
ELECTRIC
PRODUCTS,
INC.,
Emporium, Penna.
1/û,Q/1
S. S. WHITE DENTAL MANUFACTURING
Co.
Hercules
Eleecoók rnbi.
Mfr
Staten Island, N. Y.
AC
aC
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2.2.2_2.2.2
CANADA
DISTRIBUY
BD
LTD
IN COMPANY
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DATE REMOVED
Rauland Corp. Acquires
American Rights to
British Patents
OF Chicago has acquired the American interests and
patents of the Gaumont- British Picture
Co. of America, Cinema-Television,
Ltd., and Baird Television and also the
American rights of all present and future patents of the Gaumont-British
Picture Corp., Ltd. of London in the
fields of television, electronic tubes,
and photoelectric devices. Rauland has
taken over in its entirety the laboratory
and engineering staff as well as the
equipment of the first -mentioned three
companies.
THE RAULAND CORP.
December 1942
-
ELECTRONICS
TESTING the stamina of materials and instru-
To make mechanical adjustment of the appa-
High Altitude
ratus under test, small rotating shafts are in-
ments in the "Tenneyzphere"
Chamber removes the last vestige of guesswork.
Standard
range of temperatures run from
-40° to 150° Fahrenheit. (Special
from -90° to 320° Fahrenheit.)
units test
interior
is
These are manually
turned from the
outside and studs extend through suitable packing to keep them airtight.
These cabinets meet the test requirements
Observation ports permitting full visibility are
sealed to prevent interior condensation.
stalled.
The
of
all U. S. Government Agencies: Army Signal
Corps, Navy Bureau of Aeronautics, National
Advisory Committee for Aeronautics.
scientifically air- conditioned.
Altitude Chambers, Constant and Variable Temperature Baths, Humidity Chambers, and All-Weather Rooms, with tables giving specifications for many important installations write Dept. E -12.
For illustrated booklet describing "Tenneyzphere" High
TENNEY ENGINEERING, INC.
8
ELECTRONICS
- December
1942
ELM STREET, MONTCLAIR, N. J.
135
2
PROVEN BY TWO YEARS UNDER THE FIRE OF EXPERIENCE
ACCEPTED FOR THEIR DEPENDABLE & UNWAVERING PERFORMANCE
and BJ power relays meét
every known requirement for
flight, firing and communication control.
BO
and BJ are Relay Veterans.
They have seen two years on the
firing line of experience ... on the
sea ... in the air ... and on land.
They have proven themselves durable and completely dependable.
BO and BJ have semi -balanced
armatures which require minimum
wattage to withstand shock and
vibration up to 12 G ... they operate at temperatures of 120 plus or
50 minus ... they are corrosion resistant beyond specifications ...
their weights are significantly low
... their dimensions are minute .. .
their double pole double throw
design permits abundant contact
arrangements ...
BO
Coil
Nominal
Number
Volts
28
29
30
32
33
34
35
36
38
42
5.0
6.0
7.8
13.2
15.4
20.
24.
32.
50.
112.
Amperes Resistance
.500
.422
.319
190
.162
.125
.106
.078
.049
.022
10.0
14.2
24.5
70.0
95.0
Watts
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
160.
230.
415.
1024.
5000.
7
The above coil
data is based on continuous duty at nominal operating
voltages. Coils are impregnated to withstand humidity and salt spray.
Bakelite parts are molded. Contact arrangement D.P.S.T. Double break
normally open or closed and D.P.D.T. Contact rating non -inductive 15
amperes for 12 and 24 volts D.C. and 110 volts A.C.
.. , and they are
INTERCHANGEABLE
... variations in the mounting base
can be made to make this relay widely
interchangeable
In Bakelite Mounting Model BIB
Nominal
Number
Volts
Coil
BJ are Accepted
and Approved RELAYS
BO
and
2
24
1.61
26
28
2.56
4.07
6.47
9.92
30
32
34
36
38
40
42
L LiED
Il TROL
15.0
25.4
39.5
59.6
86.3
Amperes
1.243
.8003
.4918
.3093
.2017
.1332
.0786
.0506
.0339
.0232
Resistance Watts
1.293
3.270
8.267
20.90
49.16
112.6
323.5
780.6
1738.
3725.
2
2
2
2
2
2
2
2
4
2
2
data is based on continuous duty at nominal operating
voltages. Coils are impregnated to withstand humidity and salt spray.
Bakelite parts are XXXP laminated wax impregnated. Contact arrangement D.P.S.T. Double break normally open or closed and D.P.D.T. Contact
rating non -inductive 5 amperes for 12 and 24 volts D.C. and 110 volts A.C.
The above coil
www.americanradiohistory.com
ilf
NEW YORK CITY
LOT:
sI
SIT
r'^CaO
PLa'TTs.1 ü
NEW PRODUCTS
Month after month, manufacturers develop new materials, new components,
new measuring equipment; issue new
technical bulletins, new catalogs. Each
month descriptions of these new items
will be found here
Garceau Velograph
THE GARCEAU VELOGRAPH is a direct
writing oscillograph for use in the
lower frequency range. Applications
of this instrument include the study of
vibration in airplanes, analysis of pressure in rotating and reciprocating machinery, seismography, oscillographic
analysis of welding and other electrical equipment operating on commercial
power line frequencies, and, in medicine, electrocardiography and electroencephalography.
The recording system utilizes an
electrically sensitive paper chart which
is marked upon by a charged stylus.
The trace is produced in a dry state
and is immediately visible and permanent, requiring no processing or developing. It does not blur even at high
speeds. Since no pens are used the
equipment is particularly adapted to
automatic remote control operation.
The instrument will operate in any
position and in the presence of excessive acceleration and vibration. The
charts can be marked only by the
electric current and therefore their
subsequent handling does not produce
unwanted scratches.
Garceau Velograph
The high speed forms of this instrument have a maximum trace amplitude,
peak -to-peak, of the order of an inch.
They respond in substantially linear
fashion to frequencies from zero to
the order of 100 cps, with 120 cps as
the present practical upper limit.
Chart speeds for these instruments are
ELECTRONICS
-
recommended in the range from 2.5 cm
per second to 30 cm.
The oscillograph elements operate on
an electro- magnetic principle. There
are no permanent magnets, piezoelectric crystals, nor moving coils. The
elements are designed for ruggedness
and are practically unbreakable and
fool -proof. The stylus arm is a solid
bar of aluminum $ inch in diameter
which cannot be accidentally bent or
broken. If it is forcibly pushed beyond its normal limit of travel a slipping clutch in the head prevents
destruction of the vibrating element.
The entire equipment operates on 115
volts 60 cps and requires anproximately
125 watts per channel. Power at 50
cps may be used but requires change
in the gearing to obtain correct chart
speeds. The input impedance is approximately one meghom. This may be
balanced to ground. With the usual
single-stage d -c amplifier, an input signal of approximately 30 volts peak -topeak is required for full scale
deflection. An additional built-in direct- coupled amplifier stage allows
maximum deflection with an input signal of approximately 0.5 volts. A
continuously adjustable gain control is
supplied.
These instruments are supplied for
multiple channel operation with up to
The single
20 recording elements.
channel tape width is 1 inches per
channel and a four channel instrument
uses a seven -inch tape. Prices for
single -speed Garceau Velogranhs are
$250 for the first channel nlus $225 for
each additional channel. The quintuplet instrument illustrated costs $1150.
Chronograph channels are added at $50
each. Gear shifts permitting two
speeds, are added at $150. Other devices such as remote control starting,
automatic time stamps, etc., are provided in special installations.
Electro- Medical Laboratory, 1505
Highland St., Holliston, Mass.
Water Detector Lock
AN ELECTRONIC WATER DETECTOR LOCK
(type P15NH) when used in conjunction with a unit called probe fitting
December 1942
(type H31) will indicate water seepage
in gasoline storage tanks. The probe
fitting unit is mounted in a standard
pipe fitting on the top surface of the
tank, with the probe rod projecting
down through the tank to the level at
which water seepage is to be detected
(about three inches from the bottom
of the tank). The water detector lock
is wired to the probe fitting unit and
is located at any point remote from the
tank. When water seepage rises to
contact the probe tip, an electrical circuit is completed and the water detector lock operates by turning off
pumping equipment and actuating an
alarm circuit. The water detector lock
operates on 115 or 230 volts, alternating current, and will handle output
loads up to 10 amps at 115 volts, alter-
nating current. It comes in a weatherproof, pressed -steel housing, although
an explosion -proof housing is available,
if desired. Probe fitting unit comes in
brass, stainless steel, and other metals.
Photoswitch Inc., 21 Chestnut St.,
Cambridge, Mass.
Ward Leonard Products
Ward Leonard
Electric Co., Mount Vernon, N. Y., include the following.
Vitrohm Strip Resistors are especially suited to applications in aviation,
radio, and installations where space
limitations and high unit space watt
ratings are important requirements.
These resistors employ a strong, flat
refractory core for the resistance wire
winding. Terminals are mechanically
banded and spot welded in position on
the core; the core and winding are then
sealed in a fused -on Vitrohm enamel.
THREE PRODUCTS FROM
Vitrohm
Strip
Resistors
Each unit is fitted with a self- sustained
mounting bracket and spacer. These
spacers and end brackets are riveted to
metal strips that extend through the
core providing additional heat radiating facilities. Several sizes of Vitrohm
strip resistors are available, ranging
from 11. to 6 inches in length with ratings of 30 to 75 watts. Bulletin 23,
available on request, gives dimensions,
ratings, ohmic values, and other information.
Bulletin 69 Pressed Steel Rheostats
meet the need for a small, sturdy,
power rheostat having a large number
of steps and ample current carrying
capacity. These rheostats are 4 inches
in diameter with as many as 43 steps
137
*
Pressed Steel Rheostats
Production
men will
fell
you that these compact units
meet the current widespread
demand for greater adaptability without sacrificing electrical characteristics. P r o duced by specialists in the
wire wound resistor field,
IN- RES -CO products include
fixed and variable resistors,
meter shunts, choke coils,
solenoids, etc.
If a special resistor is required to meet a critical application, IN- RES-CO engineers will collaborate in
solving the problem. Write
today for illustrated literature.
TYPE WL,
I
of control and are rated for 100 watts.
Spacings through air and creepage distances between parts of opposite polarity and between current carrying and
grounded parts meet the requirements
of AIEE, NEMA and the Underwriters' Laboratories for 300 volt service. In addition to these characteristics, Bulletin 69 Rheostats feature balanced contact arm, "dead" shaft construction, copper graphite contact
shoes and front or back-of-board
mounting in single and multiple assemblies.
watt, standard toler-
%, maximum resistance:
ohms, size 3/16" x I"
Mounting by terminals,
long.
.015" thick by 1/16"
type,
strap
ance
1
50,000
i
wide tinned copper. Special terminals can be supplied at any
angle desired.
type of full -wave, high- vacuum rectifier; 6AG5 is a heater -cathode type of
r -f pentode with a sharp cut -off characteristic and a high value of trans conductance; 6J6 is a miniature twin
triode having two grids and two plates
with a common cathode indirectly
heated; the 934 is a small high- vacuum
phototube intended primarily for use
in sound and facsimile equipment but
it is also suitable for light-operated
relays and light -measuring equipment;
the 935 is a high- vacuum phototube
possessing extraordinarily high sensitivity to radiant energy rich in blue
and near ultraviolet and will respond
in the region down to about 2000
Angstrom units.
Literature describing these tube
types more thoroughly is available
from the manufacturer, RCA Mfg. Co.,
Harrison, N. J.
Cut -off Blade
THIS
NEW DIAMOND ABRASIVE cut -Off
blade, designated Di -Met Rimlock, is
particularly efficient in cutting all
hard, brittle non -metallic materials,
such as quartz, glass porcelain, tile,
ceramics, clay products, etc. This
blade utilizes a special bonding process
which rigidly locks the diamonds in
the rim of the wheel without crushing.
Two Rimlock types are available. The
first is a hard steel bond that makes
an exceptionally stiff and fast cutting
blade, and the second is a copper bond
which, though not quite so fast or
stiff as the steel, operates with a softer
action and with some increase in life.
Felker Mfg. Co., Torrance, Cal.
Recording Disc Shipping
Container
Midget Metal Base Relays
"PACKARTON" IS THE name of a new
Bulletin 104 Relays are small compact remote control units adapted to
applications within their ratings where
space is limited. These relays are
available for operation on alternating
and direct current circuits. Standard
relays are of the open type, front connected solder type terminals, double
pole, double throw, silver -to- silver contacts. Contacts are rated: 4 amps up
to 24 volts alternating or direct current
and 4 amps alternating current; 1 ampere direct current from 25 to 115
volts. These relays are vibration resistant up to ten times gravity in the
energized position. The overall height
from base to armature is 1/ inches.
light- weight,
corrugated container
which is designed to safeguard the
shipment of delicate glass base records
via air, railway or truck. The con-
IMPORTANT
tS0tAC188 MAROS
UO NOT DELAY
rAEM1E PO nm
KEEP (ROM MEAT
New Tube Types
INSTRUMENT
RESISTORS COMPANY
25 AMITY ST., LITTLE FALLS,. N. J.
THE FOLLOWING TUBE types for use
in connection with WPB rated orders
are available to equipment manufacturers. Type 1C21 is a cold- cathode,
glow- discharge triode designed for use
primarily as a relay tube; 2AP1 is a
high-vacuum, cathode -ray tube similar
to type 902 except that it has separate
leads to all deflating electrodes and the
cathode; 5R4 -GY is a coated -filament
Shipping Container
struction of the container utilizes a suspension- cushioning principle whereby
the records are kept in position between
protective coverings. The container is
easy to handle, is dustproof and needs
no excelsior for packing.
Gould -Moody Co., 395 Broadway,
New York, N. Y.
December 1942
138
www.americanradiohistory.com
-
ELECTRONICS
We need a man
Who can Read and Write
QUALIFICATIONS:
He can read with intelligence, understanding and sympathy,
this and every issue of ELECTRONICS; he has an interest in
both the highly technical and the severely practical sides of
electronic engineering; he has a feeling for our objectives in
publishing quickly and accurately material on all phases of
design, production and use of radio, communication and indus-
trial applications of electron tubes.
He can
write as
of ELECTRONICS
he would like to be written to as a reader
- informatively and with
a
feeling for the
current (and future) needs of our 18,000 subscribers on subjects both theoretical and practical; subscribers for whom we
must expand our editorial department as a service to the rapid
expansion in this industry.
Such a man will realize that the publishing business can afford an unusual stability
through the readjustment period to come; that a job with ELECTRONICS offers
him an opportunity to serve in a broad capacity in the present emergency; to make
a name for himself in his chosen field; to work for a fine company as one of the
editors of ELECTRONICS. Are you built along these lines ? If so
-
PLEASE WRITE TO
Keith Henney, Editor
ELECTRONICS
330 W. 42nd St., New York, N. Y.
ELECTRONICS
-
December 1942
1
www.americanradiohistory.com
39
Stratosphere Chamber
parts of
aircraft and radio which are to be used
THIS UNIT TESTS mechanical
altitude work. The chamber
operates between the temperatures of
plus 200 deg. F and minus 75 deg. F
with an internal pressure variation
from ambient at the location of the
unit to 3 inches of mercury absolute.
Both the pressure and temperature
variations are controllable throughout
their ranges. Humidity control is from
25 percent to 95 percent, relative to
all temperatures above plus 40 deg. F,
or at a fixed bottom temperature of
plus 32 deg. F. Below this level, absolute humidity will correspond to the
air saturation at the coil temperature,
which will average 15 deg. to 20 deg.
lower than the chamber temperature.
in high
Automatic Precision Timers for
War-time Speed and Accuracy
The application of Industrial Electrical Timers to speed -up production,
decrease operating costs, eliminate waste and safeguard life is the accepted
method of modern science, business and industry. Precision time instruments of the INDUSTRIAL TIMER CORPORATION are built to meet
the most exacting requirements of war -time production. Right now they
are in use in some of the nation's largest plants. Write today for complete
descriptive bulletins.
New Tandem Timer shown above for laboratory, production and life testing.
Automatic Reset Timer
Time Totalizer
Time Delay
INDUSTRIAL TIMER CORPORATION
115 EDISON PLACE
Ta the
NEWARK, NEW JERSEY
diy,e Qj
Co
MaIe-Izaoh..
al.d MATCHLESS
IN QUALITY
-
Large size or small, the QUALI'T'Y
of Ferranti Transformers quality proved beyond all argument
never varies in its high standard. Today, expanded facilities
enable us to produce standard
and special transformer equipment and instruments of superb
QUALITY at quantity-production prices. Subcontracts solicited.
-
-
RUSH DELIVERIES
MODERATE PRICES
FERRANT
ELECTRIC, INC.
R.C.A. BLDG., NEW YORK, N.Y.
Heating equipment for higher temperatures is composed of strip heaters so
arranged that the forced convection
circulates air during the heat cycle.
Three indicating recorders are provided for continuous recording of temperature, pressure and humidity.
Twelve mechanical connector shafts
through the outer shell of the chamber
project inside the liner, permitting
the attachment of either a flexible
shaft, an angular rigid shaft, or a small
belt drive to any mechanical part that
may be mounted in test position in
the chamber. Eighteen electrical connections are provided. A separate machine compartment is located back of
the unit, but may be placed adjacent
to the end.
hold -Hold Mfg. Co., Lansing, Mich.
Rubber Substitute Material
for Strippings
A SUBSTITUTE FOR CRITICAL materials
formerly used in gaskets and strips is
a new strip material called Fel -Pre
Thiokol. This new strip material is
produced by the application (by special methods) of Thiokol to a specially
processed felt base. The result is a
spongy rubber cushioning effect. The
material is weather resistant and is
available, in quantity, in lengths over
six feet. It may be used in any applications which requires a spongy type
rubber strip.
Felt Products Mfg. Co., 1530 Carroll
Ave., Chicago, Ill.
December 1942
140
www.americanradiohistory.com
-
ELECTRONICS
>e
,.'.`.,.'_...
COMMUMCATIO1NS
J1
... directing anm of combat
[A
"Ye'
This battle drawing was prepared with
the aid of Army and Navy authorities.
fighting units may be many miles
apart. Yet every unit, every movement, is closely knit into
the whole scheme of combat through communications.
IN modern battle, our
-
Today much of this equipment is made by Western Electric,
for 60 years manufacturer for the Bell System.
Here are some examples of communications in action.
1 Field II.Q. guides the action through
field telephones, teletypewriters,
switchhoards,wire,eable,radio.Back of
it is G. H.Q., directing the larger strategy... also through electrical communications. The Signal Corps supplies
and maintains all of this equipment.
2 Air commander radios his squadron to bomb enemy beyond river.
3
On these transports, the command
rings out over battle announcing system, "Away landing force!"
.1 Swift PT boats get orders flashed
J
by radio to torpedo enemy cruiser.
5 From observation post goes the telephone message to artillery, "Last of
enemy tanks about to withdraw across
bridge
..."
6
Artillery officer telephones in
reply, "Battery will lay a S minute
concentration on bridge."
7 Tanks, followed by troops in personnel carriers, speed toward right on
a wide end -run to flank the enemy.
They get their orders and keep in con.
tact -by radio.
western Electricjai
ARSENAL OF COMMUNICATIONS
ELECTRONICS
-
141
December 1942
www.americanradiohistory.com
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,st
sionist
.
mo
How Sally used up a copper mine
elbow -rest
at the picture carefully. See that
under Sally's arm?
sermon on
significant. In fact, it's a humble
It is
war production.
arm -rest and you
Understand the existence of that
why, in less than
understand one of the basic reasons
American inseven months after war- conversion,
to provide more
dustry is hollering for Washington
copper and other basic raw materials.
she reached over to
Before Sally got her arm -rest,
for an airplane instrument
a box, picked up a tiny part
Now the supply box
and placed it in the machine
so that the parts flow
is tilted and constantly jiggled,
Sally saves a
motion
to her finger -tips. With each
of time.
a
second
half
fraction of an ounce of energy and
America's
Without such tiny savings of time and effdrt,
handihopelessly
would be
20, 000, 000 factory workers
with
work
at
capped in their race against the millions
Japan and Italy.
a head -start of years in Germany,
...
of our factoThe muscle- misers and second -savers
when splitting seconds
ries come in handy in this war,
it is in battle.
in production is as important as
arm- rests, jiggle
Who are the men that provide the
ceaseless hunt for
the supply -boxes, conduct the
human motion?
wasted half -seconds and needless
They
I. They are the "methods" men of industry.
managers, operations
have all sorts of titles: plant
efficiency engineers,
managers, methods engineers,
men and machines to
etc. But their job is "to manage
save time and materials."
core of the industrial
In peace, these men were the
highest living standsystem that gave you the world's
hours of work.
ard at the world's lowest cost in
managers," with the
In war, these same "methodsworkmen, are
intelligent cooperation of American
by splitting seconds
cutting years from our arming task
This example
from its millions of individual operations.
a plant
what
of
of time- saving is just an indicator
many other jobs,
operating man does. Such men have
maintenance, but
including the important job of plant
they are the
which
"second- splitting" is the field in
envy of the whole world.
is the product
The American Production Manager
Complex, loose of the American industrial system.
system may seem to
jointed and aimless though our
because it is
the theorist, it meets every challenge,
man for discovering,
the best system ever devised by
initiative.
developing and rewarding individual
available in handy booklet form.
Reprints of this advertisement are
COMPANY, Inc.
McGRAW-HILL PUBLISHING
W
3
3
0
W
E
S
T
4 2
N
D
S
T R E E T
www.americanradiohistory.com
N E
Y
O
R K
CO
.:.
çz 1,-
a
4i
ro..t
:
t.,*4
SALLY
'.4'
IS UP YOUR ALLEY!
WASHINGTON, and other large city
newspapers were used for the advertisement shown opposite, because government and
public need to understand the asset which America
has in its trained industrial staffs.
Read what we said about "methods management" in the advertisement, then ask yourself the
secret of American genius for production economies in men, materials and time.
One big advantage we have in this country
is the interchange of know -how between industries.
If an instrument maker reduces a fourth -class
hand motion to third -class, all other managers of
small part assembly can, and do, find out how it
was done.
By means of the articles and advertisements
in FACTORY,* a plant operations magazine,
tens of thousands of plant operating men keep
abreast of each new development in equipment
and technique.
The magazines of the McGraw -Hill Network
of Industrial Communication exist solely for swapping ideas. They are backed by the editors and
engineer- correspondents, who gather information
wherever it is developed, and funnel it out to the
fields where it is needed.
So valuable is this interchange of technical
information that many companies are surveying
their organizations to make sure that the supply
of Industrial Magazines is adequate.
If you would like suggestions as to how to
conduct such a survey, just write to Reading
Counselor Department, McGraw -Hill Publishing
Company, Inc., 330 West 42nd Street, New York.
THE McGRAW -HILL NETWORK
"war- news" from the
"war- production- front" through a staff of 153 editors
23 publications, which gather
and 725 engineer- correspondents ... More than 1,500,000
executives, designers, production men and distributors
use the editorial and advertising pages of these magazines to exchange ideas on war -production problems.
THE McGRAW -HILL BOOKS
Publishers of technical, engineering and business books
for colleges, schools, and for business and industrial use.
McGRAW -HILL PUBLISHING
330 WEST 42nd STREET
COMPANY, Inc.
NEW YORK
THE McGRAW -HILL NETWORK OF INDUSTRIAL COMMUNICATION :
*Factory Management
American Machinist
Aviation
Bus Transportation
Business Week
Chemical & Metallurgical
Engineering
&
Maintenance- SHOWS HOW TO
Coal Age
Construction Methods
Electrical Contracting
Electrical Merchandising
Electrical West
Electrical World
MANAGE MEN AND MACHINES TO SAVE TIME AND MATERIALS
Electronics
Engineering & Mining Journal
E. & M. J. Metal and Mineral Markets
Engineering News- Record
Food Industries
Mill Supplies
Power
Product Engineering
Textile World
Transit Journal
Wholesaler's Salesman
OF BUSINESS AND
ALSO AFFILIATED WITH BUSINESS PUBLISHERS INTERNATIONAL CORPORATION, PUBLISHERS
TECHNICAL MAGAZINES FOR OVERSEAS CIRCULATION
www.americanradiohistory.com
Miniature Tube Socket
Diamond Saws
designated
(Navy type designation
CEJ- 49401) is a new addition to the
line of "Viking" products of the manufacturer. The socket utilizes government grade G steatite insulation which
consists of glazed top and sides, with
the bottom wax impregnated. The
socket is designed for use with the
9000 series and miniature series tubes
including RCA 1S4, 1S5, 1T4, 1R5,
A MINIATURE TUBE SOCKET,
as
No. 267
are designed
for use in speeding up production and
in cutting manufacturing costs in the
production of piezo quartz crystals for
Army and Navy radio communication
systems. The machine utilizes a special rolling-in process which eliminates
hammering and makes a perfect flange
or bead. Other features of the machine
include a more uniform spacing and
depth of nicks; and a more even distribution of the diamond. Immediate
deliveries are subject to priority. Sizes
available are 6, 8, 10, 12, 14 and 16
.inch.
Vreeland Lapidary Mfg. Co., 2020
S. W. Jefferson St., Portland, Ore.
"VRECO" DIAMOND SAWS
Phone -Switch
defftat
TYPE SW-141 PHONE- SWITCH is a con-
f".141
1
YOU'VE GOT
NOTHING
TO LOSE!
etc. Contacts are phosphor bronze,
heavily silver plated, and are self aligning so that they receive the tube
prongs without danger of fracturing
the glass base of the tube. Other features include orientation of contacts for
minimum capacity effect and a center
shield for grounding to chassis. Folder
D and general products catalog 967D
give additional information as well as
prices and delivery on this item.
E. F. Johnson Co., Waseca, Minn.
necting link between air and ground
communications. It is a double circuit
microphone switch designed for use -by
an operator wearing heavy mittens, and
is so constructed as to permit easy on
and off switching. It remains in open
position normally and can be locked
into closed position. High impact
strength Tenite 11 is used in its con-
Choice: Medium weight or flexible glass.
Solder Pots
Both with two or four holes.
All glass
no fibre or foreign material
inserts to warp or fall out.
.
.
No metal gromets to
machined in glass.
"wow "; holes precision
Priced at less than other fine brands; imme-
diate delivery.
G11ARANEE!
HERE S
tr
-il
Older
SMALL CAPACITY SOLDER pots are available for continuous operation in radio,
motor and similar electrical equipment
plants where individual soldering melting pots are desired for each operator
or for small repair and homecraft
shops. The pots are sturdily constructed, consisting of a cast iron pot
which is mounted by a single screw
)04.1c
the unwed
return
nes
satisfied,
keep the toed pay
and
We'll
blarkr.our co,ttplintent.you're got
both ways.
freight
loge.
to
nothing
THE
G
COMPANY
BLANK DIVISION Y.
York, N.
RECORDING . New
395 groodwaY
...it
i
GOULD -MOODY
BLACK- SEAL''
GLASS BASE INSTANTANEOUS
RECORDING BLANKS
TURN IN YOUR SCRAP
UNCLE SAM NEEDS IT!
struction. The instrument is heavily
nickel plated, and uses Bakelite insulation. The switch is mounted on sturdy
brass brackets, with blades made of a
phosphor bronze material. Cordage
clamps for taking up cable strain are
provided as an integral part of the
housing. The device measures 4§i
inches in length, inches in thickness,
and 1.1, inches in width.
American Radio Hardware Co., 476
Broadway, New York, N. Y.
Gummed Labels
onto a plated steel stand. The pot is
heated by a single heat, porcelain
nickel-chrome heating element which
can be quickly and inexpensively re-
placed when necessary. These pots are
available in two capacities. The first is
Model No. 200 with a 1i lb capacity,
and the other is Model No. 250 which
has a 2 lb capacity.
Lectrohm, Inc., 5125 West 25th St.,
Cicero, Ill.
144
A NEW GUMMING which is called "stick to- metal" is available for either paper
or linen fabric stickers to be used on
tools, machines, etc. The stickers may
be used to carry inspection data, instructions, or warnings. Samples of
"stick -to- metal" gumming on either
paper or linen fabric for test purposes
are available from the manufacturer,
as well as a free booklet entitled "War
Production Labels."
Ever Ready Label Corp., 141 East
25th St., New York, N. Y.
December 1942
www.americanradiohistory.com
-
ELECTRONICS
A BETTERMENT ..
eltil Yrd4littrie
.
Has there been a substitution for the "Good Old Days"
Saturday night lavation?
No, the modern shower
is a BETTERMENT!
Romantic as we may be, few, if any of us, would
want to go back to the old tub bath in the stove- heated
kitchen (often the only heated room in the house).
Neither will many of you designers and engineers
now
want to go back to commonly used materials
these
replace
you
once
to
get
...
impossible
practically
...
materials, not with substitutes, but with materials
designed to do a better job for you.
Getting the right NON -metallic material need not
involve tedious delays for research and experiment.
The CONTINENTAL -DIAMOND Laboratory has been
doing experimental work of this nature for more than
27 years. Its files contain records of hundreds of
difficult material problems solved. C -D is not limited
to working with one or two NON -metallics, but manufactures FIVE distinctly different materials. One of these
may be the answer to your "What Material ?" problem.
so you won't have to
Avoid substitute materials
...
go back to the kitchen -tub bath.... Write us today
about your problems. . . . Send for Booklet GF- 13.
Gemirineard--- Rig/if/J(4a
Established 1895
ELECTRONICS
-
.
.
F
I
.
B
Manufacturers of Laminated Plastics since 1911
December 1942
R
-
E
C
O M
NEWARK
P
A
N
Y
'DELAWARE
15
Terminal Blocks
DEFENSE REQUIREMENTS
THESE BLOCKS ARE DESIGNED
with ample
clearance and leakage distances for use
in circuits up to 750 volts, and are
conservatively rated at 30 amps. The
dielectric strength at 60 cps (50 percent relative humidity) is approximately 373 volts per mil. All blocks are
tested at the factory at 2500 volts to
ground. The molded sectional design
of the blocks makes it possible to have
terminal blocks from one to fifty terminals, eliminating waste space and
saving time in mounting. The blocks
are equipped with white marker strips,
washer head terminal screws and large
section terminal strips held firmly in
ELECTRICAL
COIL WINDINGS
& TRANSFORMERS
Designed to meet specific requirements or to your specification.
COIL WINDINGS
ELECTROMAGNETS
SOLENOIDS
COIL ASSEMBLIES
PAPER INTER -LAYER SECTION
BOBBIN WOUND
FORM WOUND
The
"G.H.Q."
for Latest
Equipped for vacuum and pressure impregnation-varnish or
Stratosphere Data
For testing aircraft instruments
and parts under conditions
duplicating those found at
higher altitudes make KOLDHOLD your "General Headquarters" for stratosphere information. The KOLD -HOLD
Stratosphere shown here, reproduces actual flying temperatures and pressures at will . . .
controlled accurately when and
where you need them.
In addition, visibility is always excellent . . . you can
SEE the performance of instruments and devices with moving
parts through the large Thermopane glass panel. Where requirements demand, s t r o b oscopic beams may be directed
through the panel to slow
down the action and provide
lubricant viscosity tests at the
same time for charting and
recording.
KOLD
HOLD's engineering
service is ready to cooperate
. . . send your requirements
for complete recommendations.
-
-
NEW YORK-1819 Broadway- Circle 63092
CHICAGO
201 N. Wells
Randolph 3986
LOS ANGELES -1015 W. Second -Mich. 4989
KOLD -HOLD
-
MANUFACTURING CO.
446 N. Grand Ave., LANSING. MICH., U.S.A.
146
compound.
experienced organization at
your service prepared to assist in
design or cooperate on problems.
An
place. Steel mounting brackets are
provided with slotted mounting holes 35,;
inch long to accommodate a No. 10
screw, facilitating easy mounting.
To make ordering easier these blocks
are available in sets of unassembled
parts. The parts come in kits. The
CDM -100 kit contains 50 center barriers and terminals, while the CDM101 Kit contains five sets of end bar-
riers, mounting brackets, marking
strip, threaded through rod and other
necessary hardware. These kits come
in handy for use where terminal block
requirements are varied.
Curtis Development & Mfg. Co., 1
North Crawford Ave., Chicago, Ill.
DINION
P.O. BOX
COIL
COMPANY
CALEDONIA, N.
D
Y.
JONES 500 SERIES
PLUGS and SOCKETS
Forge Welder
"TEMP- A -TROL"
IS
THE
NAME
Of
a
forge welder which makes possible
combined automatic spot welding and
heat -treating of alloy steels and heavy
sections. It permits the employment of
relatively unskilled labor for spot
welding operations. In operation, the
weld itself automatically controls the
functioning of the machine. It isn't
necessary to change the machine controls since welds of exactly equal quality can be produced consecutively in
to A inch material, ik to t inch, in
A to g inch, or in three sections of A
inch material at the same time. The
welder can be used to automatically
heat -treat the weld in the same operation. This post -heat refines the grain
size of the weld and eliminates coarse
and brittle grain structures. In setting the control of the welder it is
necessary only to determine the temperatures which will produce the best
weld and heat-treat characteristics in
6
contact
Plug and
Socket
5000 volts and 25 amperes. Fulfills every
electrical and mechanical requirement.
Polarized to prevent incorrect connections. Easy to wire. Sizes: 2, 4, 6, 8, 10
and 12 contacts.
Thousands of uses.
Write for Bulletin 500 today.
HOWARD
B.
JONES
2300 WABANSIA AVENUE,
CHICAGO
December 1942
-
ILLINOIS
ELECTRONICS
11
CUT OU?
RRLED TALK
any given material. The basic element
of the control is a welding electrode of
a highly sensitive thermocouple which
shuts off the current when the correct
temperature is reached, and turns it
on again when the weld has been
cooled to the proper degree.
Bulletin No. 301 gives line drawings
of the thermocouple electrode, a typical
"Temp -A -Trol" cycle, comparisons of
grain structure, diagram of automatic
phase-shift heat control, etc., and is
available from the manufacturer, Progressive Welder Co., 3100 East Outer
Drive, Detroit, Mich.
A
twist of the switch gives
you 50 -200 -500 ohms or hiimpedance. U9 -S is a ruggedly constructed dynamic that
does the job of 4 mikes.
Adjustable to semi- or non directional operation, with a
level of --52DB at hi -im-
pedance. Response free from
peaks and holes from 40 to
9000 cycles.
TURNER
Microphones
Transceiver
"AIRPHONE" (MODEL BRT) is a simple
to install piece of equipment which is
TURNER U9 -S
OFFERS 4 IMPEDANCES
HAN -D
either dynamic or crystal,
Han -D gives exceptionally
clear voice reproduction without blasting from close speaking. Feedback is surprisingly
low. Fits the hand, can be
mounted on standard desk or
floor stand or hung by hook.
Positive contact slide switch
permits push -to -talk operaIn
Give Crystal -Clear Reproduction
designed for operation with aircraft
type microphones. It weighs eight
pounds and operates from self -contained standard batteries. Both the
transmitter and the receiver are crystal controlled. The receiver section is
manually operated and has automatic
volume control and automatic audio
TURNER
HAS LOW FEEDBACK
Where intelligible communications are a must,
Turner Microphones will do the job, clearly
and concisely. Constructed to withstand heavy
duty under all acoustic and climatic conditions,
you can be SURE with a Turner. Each Turner
Microphone is given an individual sound pressure test over the entire audio band before
your assurance of comleaving the factory
plete satisfaction.
tion.
-
TURNER NO. 101 CARDIOID
CUTS OUT BACKGROUND
NOISE
The 2- element generator offers true cardioid characteristics, with the best features of both dynamic and
velocity. Highly sensitive to sounds originating n hont
of the mike, it's dead in the rear. Available in Standard,
De Luxe and Broadcast models.
level control. The output impedance to
earphones is 500 ohms. The transmitter has an output of watt with push to -talk operation, and no stand -by
current drain. Both transmitter and
receiver operate on a frequency range
of 2000 to 8500 kcs. The transceiver
measures 4 x 3 x 8 inches. Orders for
Model BRT should specify the desired
operating frequency in kilocycles, and
the desired type of microphone jack.
Airphone Div., United Cinephone
Corp., Torrington, Conn.
IF YOU HAVE A PRIORITY RATING, we can help you
select the Turner Microphone best suited to your needs.
Ask, too, for information on how to make your present
Turner mike and equipment give you longer, better
service.
FREE
4
ELECTRONICS
-
for NEW Turner Microphone Catalog and Service Manual
Write
Crystals Licensed Under Patents of the Brush Development Co.
TURNER L -40 -3H
FREES
BOTH HANDS
Here's the unit for all call
systems, police cars, sports
announcing. "Third Hand"
holds the special L -40 mike
close to the mouth, giving
tremendous volume without
feedback. Third Hand is
light in weight and gooseneck adjusts to any position.
A low -cost efficient unit.
147
December 1942
www.americanradiohistory.com
Communication Sv stei With
I ntercelttor Control
te
THIS IMPROVED Executive- Monitor communication system consists of two or
PHOTO ELECTRIC CELLS
ANY
IN
..
eallacikt
ANY
EQUAL TO
.
more master stations connecting up to
nineteen remote stations in the system.
The executive and monitor stations can
talk to each other, or either can carry
on two -way amplified voice conversations with remote desk or trumpettype sub- stations in outlying departments. The interceptor -control feature
enables the assistant at the monitor
station to intercept all incoming calls
originating at the remote stations. Both
the executive and monitor stations are
equipped with busy signals to show
when other stations are in use. A pag-
USED TO
PRE -TEST
Btu Alois
SN
STRATOSPHERE
CHAMBERS
Luxtron Photo -Electric Cells in Strato-
ibvri.
or special
it
PHOTO ELECTRIC CELLS
BRADLEY LABORATORIES,
148
ST.
New York, N. Y.
"GLnsoH o'' IS A glass- insulated, low
power, flexible heating element which
is available in any length, by the inch,
foot or yard, and is particularly useful in very limited spaces. Its construction consists of a resistance wire
which is wound on a fibre-glass core
and is protected by a fibre -glass
braided covering. The% fibre -glass can
be readily bent and compacted to fit
snugly about parts to be heated, or
jammed into very tight spots. Wattage
ratings are from 1 to 4 watts per
body inch, depending on the application. Operating temperatures may he
as high as 750 deg. F.
Clarostat Mfg. Co., Inc., 285 North
6th Street, Brooklyn, N. Y.
-
complete
MEADOW
CO.
699 East 135th Street
Flexible Heating Element
technical data. We are at
your service for consultation on special problems.
4$2
POLYMET CONDENSER
ing button enables the user of any
master station to call all other stations
simultaneously, for paging- and locating
persons instantly, and for issuing emergency warnings or general announcements to the entire staff. High- powered
trumpet -type substations provide extra sound volume. All wiring lines are
connected to inconspicuous junction
boxes for neat and simplified installation. The unit utilizes 110 -120 volts,
alternating or direct current. Power
consumption for the entire system is
rated at 46 watts. This system is UL
approved and is licensed under A.T. &
Executone. Inc., 415 Lexington Ave..
New York. N. Y.
lustrateti lit -
with
POLYMET
T. patents.
sphere Chambers,
where pilots are pretested, have to meet
the most severe conditions of cold, humidity, vibration. The
fact that they satisfy
the Army and Navy
requirements is proof
that they can meet
the most particular
specifications of all
commercial and industrial applications.
rrature
oa
We are always at your
service in supplying you
fine condensers; we've
been making condensers
for the past twenty -one
years.
REQUIREMENTS
The widest range of scientific
and industrial requirements can be
met by Luxtron Cells -the Cells that
meet the stringent requirements of
the Army and Navy. For measurements, analysis, indication, metering, control, signal, inspection,
sound reproduction, etc. Luxtron
Units can also be produced to mset
special needs.
e$et$r
INC.
NEW HAVEN, CONN.
December 1942
-
ELECTRONICS
Inter- coznniunicating System
designated as the KS -60
Super Selective system and is made
up exclusively of master stations and
permits a number of two -way conversations to be held simultaneously without crosstalk. The master stations can
call one another regardless of whether
the station being called has power on
or not. Systems may be built up progressively beginning with two master
stations to any amount of stations desired. A feature of the unit is its use
of private earphones. When an earphone is used the "talk- listen" switch
does not have to be operated, and the
unit works exactly the same as a telephone. Volume for earphones is adjustable.
These units have an amplifier of
super sensitive design which delivers a
maximum output of 2A watts and permits operation with undiminished
power and efficiency with the units as
far as 3000 feet from one another. Systems consisting of 2 to 10, 20, 30, 40,
(iO, 80, etc., stations are available.
Talk -A -Phone Mfg. Co., 1219 W. Van
Burren St.. Chicago, Ill.
THIS SYSTEM is
Continuous -Flow Colorimeter
"LuMETRON'
(glum,
400 -S) is a con-
tinuous -flow colorimeter for immediate
and direct indication of the light transmission of a liquid flowing through the
instrument. It is suitable for continuous registration of concentration,
color or turbidity of solutions in chemical processes. The operating principle
of the instrument is similar to the one
of the usual type of photoelectric
colorimeters except that the liquid
under test passes through a glass tube
Official
Navy
photograph
U. S.
TRANSFORMERS
THAT GO TO SEA
Transformers designed to the rigid requirements of the
United States Navy have chcracteristics that enable them
to meet the most extreme conditions.
RA
rather than being contained in an absorption cell or a test tube. Once
calibrated by means of a solution of
known concentration, the instrument
indicates the concentration directly and
continuously, obviating the necessity
of taking samples and analyzing them
at regular intervals. The instrument
operates from 105 -125 volts, 50-60 cps
alternating current, and has a constant
voltage transformer and a built-in
color filter. The price of the instrument
is approximately $170.
Photovolt Corp., 95 Madison Ave.,
New York, N. Y.
ELECTRONICS
-
December 1942
O
o¡
u
-
Hermetically Sealed Transformers, built to
these specifications by the Chicago Transformer Corporation, not only pass the Navy Five Cycle Salt Water Immersion Test but also other severe operating, temperature
and pressure tests set up in our own laboratories.
Waterproof
-ú-1
CHICAGO TRANSFORMER
CORPORATION
3501 .WEST ADDISON STREET
CHICAGO
I
19
Literature
In Vital
Instruments of
WAR
COMMUNICATIONhotu
tourie
y
1Ialhícraftcrs, Inc.
KESTER CORED SOLDERS Won't Let Go!
-
In the communications equipment of a fighting
machine -built to "take it and dish it out"
Kester Cored Solder is worth its weight in gold!
Circuits sealed with Kester are permanently
trouble- free-as dependable as the tank, plane
or ship itself.
Kester Rosin -Core Solder, especially designed for
electrical use, contains a patented, plastic rosin
flux that does not cause corrosion or injure insulating material. Kester Acid -Core Solder, for
general applications, makes a tight, clean,
permanent union.
Kester Cored Solders are available in a wide
range of core and wire sizes, one of which
is exactly suited to any production requirement.
All are superior in quality-they resist bending,
vibration, shock, contraction and expansion.
Let Kester engineers assist you with any production problem solder
may help to solve. Write
fully -there's no obliga-
tion!
KESTER SOLDER COMPANY
4204
Wrightwood Avenue, Chicago, Illinois
Eastern Plant: Newark, N. J. Canadian Plant.: Brantford, Ont
BUY
UNITED
STATES
AVINGS
BONDS
AND STMT PS
Phenolite Handbook. This handbook
contains technical and descriptive data
on Phenolite, laminated Bakelite. The
handbook describes how Phenolite is
made, its general properties, various
sheets made, grades of paper base,
grades of fabric base, grades of asbestos base, how Phenolite tubing is
made, tubing grades, values and tolerances, tolerances of Phenolite rods and
the typical uses of all Phenolite. Also
included in this handbook, in chart
form, are the related Navy and Federal
specifications. This forty -four page
handbook available from National Vulcanized Fibre Co., Wilmington, Del.
Replacement Sheets. Several new sheets
are available for the following bulletins to bring them up -to -date: Bulletin
1- discounts and terms; Bulletin 23Vitrohm strip resistor; Bulletin 60AVitrohm and Ribohm field rheostats;
Bulletin 69-4 inch pressed steel rheostats; Bulletin 2721 -Type C motor disconnect switches; Bulletin 2722-motor
disconnect switches Type C; Bulletin
2751 -tumbler type motor starting
switches; Bulletin 4021
-c combination starters; Bulletin 4201 -c automatic motor starters; Bulletin 4221
automatic transfer switches; Bulletin
351 -thermal time delay relays. These
replacement sheets are available from
Ward Leonard Electric Co., Mount
Vernon, New York.
-a
r
I
tin.%'
_.
epens
on
COMMUNICATIONS
On America's far-flung battle fronts, radio communications are speeding the ultimate victory.
At home and abroad, wherever our combat units
are in training or in action, BUD Products
prove their dependability under all conditions.
BUD RADIO, Inc.
Cleveland, Ohio
150
-
Low Temperature Brazing. In a recent
issue of "Low Temperature Brazing
News" No. 19 a typical war application of Easy -Flo -Silver brazing alloy
is illustrated. It describes the problem
of brazing a 2 inch threaded flange into
a completely closed 20 gauge sheet steel
container. Issued by Handy & Harman, 82 Fulton St., New York, N. Y.
Color Code Resistor Card. This pocket
size color code resistor card shows
clearly the A, B, C and D color denotations of a resistor. It explains the resistor color code and gives examples.
On the reverse side of the card is Ohm's
Law. This card is free to all Sylvania
radio servicemen. Available through
Sylvania jobbers or from Sylvania
News, Emporium, Pa.
Screws. In this 20 page illustrated
booklet, on self- tapping screws, is described the quality routine; the functions and advantages of each type;
stock sizes and head styles; packing,
finishes and special screws. All types
of self- tapping screws are covered and
their typical applications. Booklet No.
475 available from Parker -Kalon Corp.,
200 Varick St., New York, N. Y.
December 1942
www.americanradiohistory.com
-a
-
ELECTRONICS
Colloidal Graphite. A 4 page bulletin,
No. 421 -T on the use of "dag" colloidal
graphite as a lubricant for running-in
internal combustion engines, compressors and other mechanical equipment is
obtainable from Acheson Colloids Corp.,
Port Huron, Mich.
Tube Base Data Connections and Chart.
In an 8 page folder the element connection and base layout of over 600 different types of radio tubes are given.
This folder permits rapid socket selection for practically any tube now in
commercial use. Tube base connections
diagrammatic
are illustrated by
sketches of the bottom view of the tube
bases. A tube base chart is included
which indicates the proper base to use
for any of the tubes listed. This folder
may be obtained from Weston Electrical Instrument Corp., Newark, N. J.
Selenium Rectifiers. Bulletin R -40 contains general information on selenium
rectifiers, including their assembly,
plate sizes, efficiency, input voltage,
stability, cooling, regulation, etc.
Illustrations and graphs covered by the
text matter are included in the bulletin.
Benwood Linze Co., 1815 Locust St., St.
Louis, Mo.
Frequency Assignment Chart. A chart
showing the frequency assignments in
the radio spectrum for stations in the
United States is available from ELECTRONICS Editorial Department at ten
cents per copy, payable when ordering.
This chart was compiled in September
1940 from data of the Federal Corn munications Commission, and includes
revisions above 30 Mc, adopted in May
and June 1940. The chart is printed on
heavy coated paper and is suitable for
framing since it is mailed unfolded.
ASA Price List for 1942. More than 550
American Standards are listed in the
price list for 1942 by the American
Standards Association, 71 of these
represent new and revised standards
approved since the last (Feb. 1942)
issue of the list. There is a separate
heading for standards developed specifically for the war effort. Another
section is devoted to safety standards.
Other standards include definitions of
technical terms, specifications for
metals and other materials, test methods for finished products, dimensions,
etc. Send requests to American Standards Association, 29 W. 39th St., New
York, N. Y.
Also available is the new standard
methods of testing and tolerances for
fabric tubular sleeving and braids.
This specifies permissible variations on
inside diameter and wall thickness of
sleevings and braids, also governs tolerances as to weight, number of carriers, ends on bobbin, yarn number and
Lafayette
is your COMPLETE source of supply, espe-
cially on those hard to find Electronic, Radio and Sound
no order too small or too large for
Equipment parts
our prompt attention. LAFAYETTE GIVES YOU IMMEDIATE ACTION on deliveries! .Lafayette personnel is
trained to work with your expediters.
If quick delivery of engineering samples, or production
quantities is your problem, write, wire or phone Lafayette.
...
pages indexed for
quick reference ... Get your copy now! Address Dept. 12G2, 901 W. Jackson Boulevard,
Chicago, Ill.
FREE Buyers Guide!-130
Fans- Photographic equipment at
lowest prices! Write for complete catalog.
Camera
LAFAYETTE RADIO CORP.
901 W. JACKSON
BLVD., CHICAGO, ILL.
265 PEACHTREE ST., ATLANTA, GA.
ezethe0-ea...
r
POWER
GENERATORS
GE
ER G
PIONEER
CONVERTERS
DVNAMOTORS
s
`POR
ooRESS:
WARREN
t--_" ALE:
PLANTS
«
GEN-E-R`oTORS
D.C.MOTORSóTOR
STREET.
ILLINOIS
SIM
aNT0.10E
NEW VORN
N. T.,
-
imperfections. Available from American Standards Association at the above
address.
ELECTRONICS
-
December 1942
151
Electrical Connectors. This 16 page illustrated condensed catalog supplement
covers the most popular types of electrical connectors. The catalog deals
briefly with the two leading types used
in aircraft applications and details more
complete information on connectors for
radio microphones, sound equipment,
power heavy -duty control circuits, public address systems and geophysical research, electronic low-level circuits and
small power applications. Obtainable
from Cannon Electric Development
Company, Los Angeles, Calif.
SPEED UP
ASSEMBLY
.
usiurr
Reg. U. S. Pat. Off.
Excellent Opportunity for
a
Project Mechanical Engineer
and
a
Project Electrical Engineer
Capable of taking full responsibility
for the development of any project
from the idea stage on.
WE ALSO HAVE OPENINGS FOR
28 Electronic Engineers
Television Engineers
Expert Radio Technicians
Licensed Aeronautical
Engine Mechanics
6 Mechanical Engineers
2 Electrical Engineers
2 Physicists
2 Certified Aeronautical
Sheet Metal Workers
(Skin Men)
1 Mathematician with
at least Master's Degree.
2
SOCKET CAP SCREWS
WITH KNURLED HEADS
House Organ. In the May 1942 issue
of The Aerovox Research Worker is
published the article "Taking Complete
A -F Amplifier Data ". This article describes the procedure for the routine inspection of audio amplifiers in maintenance and trouble shooting.
In the June 1942 issue is an article
"Amplitude Modulation ". This article
covers the use and advantages of complete modulation, side band generation
and amplitude modulation circuits.
"High-Efficiency R -f Amplifiers" are
described in the July 1942 issue. Class
B operation, the Doherty high -efficiency amplifier and Terman -Woodyard
amplifier are covered. Available from
Aerovox Corp., New Bedford, Mass.
2
2
Unexcelled opportunity with a vital defense industry. Duty may require flying
in military air craft. Flying instructions
given in some cases.
Write fully giving education, experience,
age, dependents, draft status, references
and enclose snapshots, if possible. Arrangements will be made for personal
interview. Address Director of Personnel.
AERO DIVISION
MINNEAPOLIS - HONEYWELL
REGULATOR COMPANY
Industrial Instruments. Catalog 95 -A
describes instruments for the measurement and control of industrial process
conditions. The bulletin is made up of
en sections: grouping and description
of all instruments, accessories and supplies appropriate to a particular field
of application, such as temperature,
flow, pressure, level, humidity, etc.,
combination instruments, valves, instrument panels and similar subjects.
Copies from The Foxboro Co., Publicity
MINNEAPOLIS, MINNESOTA
We are not interested in receiving applications
from those now employed in war work.
Dept., Foxboro, Mass.
Fingers gear right to the
knurling. This prevents slipping and lost motion and naturally saves time speeds
assembling. The knurling also
permits locking the screw
after countersinking. "UNBRAKO" Cap Screws have
unbelievable strength arc
accurately made. Deliveries
are better than average.
Sizes: No. 4 to 11" diameter.
Write for the "UNBRAKO"
Catalog -now.
Switches. This is a preliminary bulletin
which describes Type DX mu- switch,
designed especially for direct current.
The technical specifications and operating characteristics are included. MuSwitch Corp., Canton, Mass.
-
-
Knurling of Socket Screws originated
with "Unbrako" years ago
1
STANDARD
PRESSED
STEEL
JENKINTOWN, PENNA.
COX 596
152
CO.
Into Lingo designing
has gone the finest
engineering skill and
modern antenna enainecrirg. The re-
sult--"plus" performance combined with
low installation and
rnaintenanco costs.
House Organ. The October -November
issue of National Radio News contains
/99 ft. (above roof)
Radiator at WIBM,
Jackson. Mich. Another example
of
Lingo versatility to
meet every station
article "Electronics Promises Bright
l'uture ". This article, based on the
;eneral Electric Company's quarterly
eport to its stockholders, states that
lectronics is the new science for the
new world and the bright promise for
the future. Other interesting articles
.nt
I
covered in this issue are: How Recordings are Made, Thordarson 15 -watt
Amplifier, Interchangeability Chart for
Discontinued Tubes, Questions and Answers for Radio Operator Examinations. This is the official house organ
of the National Radio Institute Alumni
Assoc., 16th & You St., N. W., Washington, D. C.
need.
LINGO
VERTIG`A
ADIATORS
JOHN E. LINGO
á
December 1942
SON INC. CAMDEN N.
-
J:
ELECTRONICS
Thermocouple and Tube Data. A new
6 page bulletin which acts as a guide in
the selection of the most satisfactory
thermocouples, thermocouple protecting tubes and lead wire for a given
instrument application in line with restrictions placed upon certain critical
materials. It supplements the first
bulletin ever issued by an instrument
manufacturer to list thermocouples by
materials, rather than by trade names,
it gives recommendations on thermocouples, lead wire, protecting tubes,
plugs and sockets; information on
thermocouple checking; millivolt conversion tables and other useful data.
In the September 1942 issue of
Wheelco Comments appears an article
"Universal Controllers Offer Unusual
Approach to Temperature Control
Problems ". This article describes and
illustrates design features of the company's universal controllers.
obtainable from
Both releases
Wheelco Instruments Co., Harrison &
Peoria St., Chicago, Ill.
Maintenance and Operation Instruction.
"Keep 'Em Working" is the title of a
new book which aids owners of "Caterpillar" products in getting the most
out of their machines. It gives the
reasons behind the maintenance and
operation instructions, goes into detail
on the care of certain critical parts and
gives general information that is not
conveniently available elsewhere. Form
No. 7609 available from Caterpillar
Tractor Co., Peoria, Ill.
New Type Calendar. This calendar,
built on a War Week basis, with its 52
weekly sheets has an overall size of
152 x 24i inches. A section of technical
data for the engineer and draftsman is
included. This section contains charts
on wire and sheet metal gages, screw
threads, etc. Request should be written on business letterheads to Frederick Post Co., Box 803, Chicago, Ill.
Metal Shielded Wire. Bulletin 202 describes Precision metal shielded wire.
The bulletin describes the method of
protecting insulated wire enclosed in
either thin wall seamless aluminum,
copper or lead tubing. Bulletin 202
available from Precision Tube Co., 3824
Terrace St., Philadelphia, Pa.
Capacitors. Bulletin GEA -2027 describes a -c Pyranol capacitors for use
with motors, in control, fluorescent
lamp ballasts, luminous tube transformers and other a -c equipment. Bulletin GEA -2621 describes d-c Pyranol
capacitors for use with radio transmitters, electronic devices and various
d -c industrial applications. Bulletin
GEA -3966 describes Navy type capacitors for d -c filter applications. All three
bulletins from General Electric Co.,
Schenectady, N. Y.
ELECTRONICS
-
December .1942
Its like having a complete
plant laid on your desk,
when you -"Let Lewyt
Do It."
-
You get in "Packaged
Production" -the most upto -date facilities for Metal
Fabrications; Precision Machine Work; Electrical and
Mechanical Assemblies. In addition, you get 54 years of experience in precision manufacturing backed up by carefully
engineered methods and closely coordinated production
controls. You can, therefore, trust us with all the production
responsibilities on a single part or a complete product.
Just now, "Packaged Production" is ear -marked for war.
But if you, too, have a war-production manufacturing
problem, we'll gladly lend you a hand prior commitments permitting.
-
-
y
LEWYT METAL PRODUCTS COMPANY, INC.
te12=1
:i:*:
60 BROADWAY, BROOKLYN, N.Y.
153
Electron Tube Terminology
AIR
VIBRATOR
POWER
SUPPLIES
ATR VIBRATOR PACKS
For Inverting Low Voltage D.C. to High
Voltage D.C.
REPLACES DYNAMOTORS!!
ATR D.C. -A.C. INVERTERS
For Inverting 6, 12, 32, or 110 Volts D.C.
to 110 Volts, 60 Cycle A.C.
REPLACES
ROTARY CONVERTERS!!
Vibrator Power supplies have a
proven background for performance,
ATR
reliability and high quality.
AMERICAN TELEVISION
&
RADIO CO.
St. Paul, Minnesota
154
(Continued from page 45)
as true that a new name with official
or sponsored backing may make little practical headway. This is just
another way of saying that new
names come into general use in their
own field entirely on the basis of a
need for them, the ease of remembering them, and their general phonetic quality. The word "mutator"
is an example of a good name that
has made little progress even in the
face of international standardization. On the other hand, it is difficult to find many references in
Adoption of These Special Names
which the device we call an "igA survey of the available latest nitron" is given any other name.
One basic difficulty in this whole
editions of general, as well as technical, dictionaries indicates the ex- matter arises from the fact that
tent to which these tube names have electron tubes are used in so many
been adopted. Table 2 summarizes widely different spheres that cornplete adoption of any group of names
this point.
Certain other tube names also ap- is too much to be expected. For inpear in these same dictionaries as stance, mercury -arc, tank rectifiers,
shown in Table 3. The definitions ac- fluorescent lamps, and X-ray tubes
companying these words vary to all employ basic and, in certain resome extent and some even appear to spects, similar electronic phenomena.
However, the engineers involved in
be incorrect.
The classification shown in Table their development, design, and use
are in such widely separated fields
1 is by no means a closed or finished
affair. Whenever some real new that it is very difficult for any single
electron tube incorporating a new standardizing group or organization
combination of these variables or to include these items. However, an
new variables comes into the picture, agency like the American Standards
a new name is in order if it can take Association can standardize on certhe place of a long descriptive phrase tain names when their usage and
and can later be standardized as it meaning indicate that they are defincomes into general use. For instance, ite and are quite universally accepin the June issue of ELECTRONICS, ted. Such standardization by the
a classification of electron tubes is A.S.A. is already an accomplished
shown on page 52. This contains the fact in the case of the word `photo word "permatron," which is a com- tube.'
This body might well consider
bination of a hot -cathode, gas, or
vapor-content diode with magnetic certain other suitable names for
control. If this word is not trade- standardization, such as grid -glow
marked, there is no reason why it tube, ignitron, thyratron, and posshould not be a candidate for stand- sibly others that are definite, cornardization if and when it comes into monly accepted, and regularly used.
common use and takes the place of a
REFERENCES
more cumbersome description.
(1) Millikan, R. A., "The Electron," The
As was indicated in the reception University of Chicago Press, Chicago, Ill.,
1917.
to the use of the early term 'audion,'
(2) Thomson, J. J., "Conduction of ElecThrough Gases," University Press,
there is a considerable weight of tricity
Cambridge. England, 1906.
Fleming.
(3)
J. A., "The Principles of
much
opinion against new names and
Electric Wave Telegraphy and Telephony."
Green & Co., London. England,
is to be said for this viewpoint. Ex- Longmans.
1910.
(4) Langmuir. Dr. Irving, The Pure Elecperience has shown, however, that
tron Discharge, Proc. I. R. E., 3, 261, 1915.
such a name for a new device cannot
(5) Hull, A. W., The Dynatron, a Vacuum
Possessing Negative Resistance, Proc.
be discouraged by official pronounce- I.Tube
R. R.. 11, p. 5, 1935.
(6) Tronton, Prof. F. T., Obituary of Dr.
ments if it fills the need and it is just Stoney,
Nature, July 13. 1911.
because of this very fact that certain
of the vacuum tube names are so well
established.
About six years ago, Westinghouse and General Electric agreed
between themselves to the use of
certain definitions so as to minimize
misunderstandings. This list is reproduced in Table 1 and was published in the February, 1937, issue of
Electrical Engineering (page 284).
This list, of course, includes no
trademarked words.
December 1942
-
ELECTRONICS
Harmonic Wave Analyzer( 0llttimed rront page
used as it gave very nearly a straight
line scale. It was thought that this
system would also require no zero
adjustment. This did not prove true
as a steady current of about 0.05
milliampere had to be bucked out by
feeding a small voltage back from
the power supply. The tap on the
voltage divider is determined by
trial as the current to be bucked out
varies for different tubes.
Since the calibration of the voltmeter was very nearly linear, it was
found convenient to provide three
ranges having full scale distortion
readings of 100 percent, 50 percent
and 10 percent. These scales will
give readily ascertainable readings
of harmonics to a low as 0.2 of 1
percent. The scale change was accomplished by means of a series of
resistors and a three point tap switch
connected as the grid resistor of the
75 triode. With R, and R_ equal, and
R, equal to 8 R the full scale
readings of the meter will be 100,
50, and 10 percent.
Instrument Calibration
Calibration of this instrument is a
rather simple procedure and can be
done in either of two ways. The first
method used was to feed a 2000 cps
signal of adjustable amplitude into
the instrument and to determine the
output meter reading in terms of
the input voltage. This procedure
was then repeated with adjustable
voltages of 4,000 and 6,000 cps. The
harmonic distortion was then calculated and calibration curves were
then plotted showing the percent of
harmonic distortion against the output current. With this method there
will be little error introduced by
aging of the tubes.
The second method of calibration
uses two oscillators, the first of
which must be free of harmonics.
Such a sinusoidal oscillator may be
obtained by inserting a 2000 cps
band -pass filter in the output of the
laboratory oscillator or generator.
The output of the second oscillator
is fed into the instrument in series
with that of the 2000 cps oscillator
as shown in Fig. 4. Meters are
placed across the output of both
oscillators and the harmonic voltage,
which is thus artifically generated,
can be read directly. It is important
that the mixing resistances be linear
ELECTRONICS
-
62)
(i.e., independent of voltage or cur-
rent) to prevent modulation of one
oscillator by the other.
The voltage of the No. 1 or distortionless oscillator is adjusted for
full scale reading of the meter with
the 2000 cps filter connected in the
wave analyzer. The 4000 cps filter
of the analyzer is then cut in. The
voltage of the 4000 cps oscillator is
gradually increased and a curve of
harmonic voltage against output current is plotted for second harmonic
distortion. This procedure is repeated for the third harmonic and
the percentage distortion is determined as in the previous method.
These two methods of calibration
checked with a maximum difference
of 2 percent, which occurred near
full scale readings. Calibration curve
for the second harmonic is shown in
Fig. 5. The third harmonic calibration was practically identical.
By properly apportioning the scale
changing resistances R R, and R
as previously described, a single
calibration curve may be used for
the instrument if all filters have the
same mid -frequency attenuation.
The mid -frequency attenuation of
the filters may be adjusted by connecting an appropriate resistor
across the shunt arm inductance, L2.
In this instrument, it was necessary
to shunt the 4000 cps filter with a
220 ohm resistance to make the attenuation equal to that of the 6000
cps filter.
Operation of this analyzer is relatively simple and rapid. The device
to be measured is supplied with a
2000 cps distortionless or sinusoidal
voltage and the output from the device connected directly to the analyzer. With the 2000 cps filter in
the circuit and the meter switched
to the 100 percent position, the gain
control of the analyzer is adjusted
to give full scale reading of the
meter. The 4000 and 6000 cps filters
are then switched in and the magnitudes of the second and third harmonic voltages are read respectively.
The minimum voltage necessary to
operate this instrument is approximately 4 volts.
This instrument has been found
very useful in measuring the harmonic content of various amplifiers
constructed in the laboratory and in
other experiments.
December 1942
Hello, Honey...I'm on my
way back From New
be in by
York-
7:00!"
*
*
Our entire resources
are at the command of
our National Govern-
ment
... we are
doing
our utmost to fulfill the
demands of our various
military services by supplying precision -built
radio communications
equipment.
*
HARVEY -WELLS
COMMUNICATIONS
Are Helping to Win
the war
*
7
eRVEY-WELLS
eii/rutrúcidiett,( íuc.
HEADQUARTERS
For Specialized Radio Communications Equipment
SOUTHBRIDGL, MASS.
155
www.americanradiohistory.com
Time Control
(Continued from puye 49)
NO PLACE TO MONKEY AROUND
WITH THE LAW
OF
GRAVITY!
...
Man going down
in a burry. The geography of the territory
must be surveyed and the movements of the em
observed ...and
,reported.. on the way down.
-
The law of gravity still holds good ... and the man at parachute's end
most be keen-eyed and quick. minded. However, these important human
qualities won't help him much without proper equipment.
An integral part of
a
teries. Change -over takes place so
quickly that the operation of the
clocks is not affected.
parachutist's paraphernalia is the Phone-Switch
unit made by American Radio Hardware Co. This to the vital connecting link between air and ground communications -and it has
got to work. It does!
Phowt
Technically Simple System
In its technical essentials, the timing system is not complicated. The
output of the tuning fork is amplified by eight 50 -watt amplifiers with
outputs connected in parallel to provide a total power output of 400
watts.
The stand -by power supply is
equally simple. A 60 -cps a -c generator is on a common shaft with a
110-v a -c motor and a 32 -v d -c motor.
Under normal conditions, the generator is driven by the a -c motor
The
I
:lseembly is but one or the massy precision instru..
ments which are ourr motribuiim t ton.ard .inning this war.
when it becämcn a parachutist's job d0 report a picnic railler thin, a
battle the PhoneSwiteb. along olai all others of our products, will be
an important influence in the field of civilian communications, trod
n
Sode,
speed the day.
SUP WAR PONDS AND STAMPS
onPiti,can
Radi,o
476
e161ü(lrr(rie
WAY, NEW YORK, N.
(o. goic.
Y.
W.r. b, Caroled.
MANUFACTURERS OF SNORT WAVE
TELEVISION
.
RADIO
SOUND EQUIPMENT
including
Rear -panel view of precision clock control
equipment, showing tuning -fork units, am-
THE LATEST TYPE OF HIGH FREQUENCY TUBES
plifiers and power supplies. All units are
in duplicate and are interchangeable
such as:
832
A
829
615
COMPLETE LINE
ALL
IMPORTANT
813
1201
1203A
OF TRANSMITTING TUBES IN
SIZES UP TO 200 WATTS
for your ELECTRONIC
SEE
114B
tubes
parts
supplies
YOUR
LOCAL NATIONAL UNION DISTRIBUTOR
department today is working with elecprinciples. NATIONAL UNION DISTRIBUTORS
handle Notional Union Radio tubes and allied products.
They specialize in radio and electronic items and you
will find their socks very complete. Coll or
write your N.U. distributor for his industrial
catalogue. If you do not know
his address send your letter to
us and we will forward it.
EVERY research
tronic
.
NATIONAL UNION RADIO CORP.
57 STATE STREET, NEWARK, NEW JERSEY
which, in turn, is connected to the
city mains. If this source of power
should fail, an automatic switch
causes the d -c motor to assume the
load, operating from storage bat-
teries.
As an additional precaution, the
clocks in all studios are placed on
one circuit, while those in all studio control booths are placed on
Thus, if trouble
should develop in one circuit the
programming staff would have recourse to the clocks on the remaining circuit.
When checking the master clock
with Naval Observatory time signals, the engineer in charge may
another circuit.
December 1942
156
www.americanradiohistory.com
-
ELECTRONICS
The will to produce the rotary electrical units our fighting forces need is a vital factor in the rapid growth of
Eicor. It has led to many important developments by Eicor Engineers.
Today -this will to produce is given new impetus by a further expansion of the means of production. Our larger plant and increased
facilities for precision manufacture provide the opportunity to produce more ... faster -more Dynamotors, D. C. Motors, Converters,
Power Plants and other units for planes, tanks, ships, and field
equipment. It will also enable us to provide better units for your
peacetime needs after the battle is won.
An inter -office distribution panel for the
precision clock control circuits
speed up or retard the entire time
clock system for correction purposes
by bringing into play either one of
two secondary tuning forks. One of
these vibrates at 65 cps ; the other
at 55 cps. The actual correction is
the
automatically,
accomplished
4, ll;Nlea 1501
proper correction frequency being
applied for the required period of
time by an auxiliary clock device..
The new system is now transmitting time signals to the NBC network at 9 AM and at 5 PM, EWT.
Each of the pulses transmitted consists of a 750 cps tone of approximately one -half second duration,
transmitted at a volume somewhat
less than that of programs carried
on the same lines. The reduced
volume minimizes any objections by
listeners if the time signals should
occur during broadcasts.
11
DYNAMOTORS
D. C. MOTORS
W. Congress St., Chicago, U.S.A.
POWER PLANTS
CONVERTERS
U. S. A. Cable:
Auriema, New York
Export: Ad Auriema, 89 Brood St., Nèw York,
Designed for the engineer
who aims for greater production
MArHEMATics
OF MODERN
ENGINEERING
. .
.
MATHEMATICS
OF MODERN
ENGINEERING Volume II Mathematical Engineering
..g
INDUCTION PROBES FOR
MEDICAL USES
By ERNEST
G. KELLER
Published This Year!
Those aspects of mathematics which pertain to engineering are presented
in this top -notch volume, jam -packed with information which bridges the
gap between physics and mathematics by the scientific method. Like the
already famous Volume I, this new volume is a practical, usable book
which will prove invaluable to student, engineer, architect, or anyone else
concerned with structural problems.
The material is the product of the theoretical engineering work of the
General Electric Company, and includes many references and numerous
problems of varying degrees of difficulty.
Eç
Engineering Dynamics and Mechanical Vibrations; Introduction to
Tensor Analysis of Stationary Networks and Rotating Electrical Machinery Non linearity in Engineering.
$4.00
6 x9
Illustrated
309 Pages
Volume III Now in Preparation
THE CONTENTS:
;
Samuel Berman. New York engineer, holds
two of his electromagnetic induction
probes, designed to speed the location of
imbedded metal. The device can be used
directly in an incision and in some in.
stances has cut the probing time from
three hours to ten minutes
ELECTRONICS
-
.
Let Us Send You Your Copy on Approval
0 FOURTH
44 NEW YORK,4N.EYUE
i
JOHN WILEY & SONS, INC.
157
December 1942
www.americanradiohistory.com
Power Amplifier
Performance
(Continued from page 56)
Might effect upon the driving power
or grid dissipation. If, on the other
hand, power output is a primary consideration, we would move A slightly
in the direction (b) until the plate
or grid dissipation would limit operation. The possible positions which
...the
"MEGGER"
is
Tester
ALWAYS READY for use
When the need arises for emergency insulation testing of electrical equipment -it calls for immediate
and
positive action. "Megger" Insulation Testers are always ready
for use, day or night, even in the most remote, isolated,
inaccessible locations. The self- contained hand -cranked generator
is a source of power that is reliable and wholly independent
of any battery or other outside source. The "Megger" Tester
is a complete unit in itself.
For occasional use, for periodic tests and for emergency
tests, your "Megger" Tester is always ready. If you do not have
full information on how to use and operate "Megger" instruments, write immediately for a free copy of the Pocket Manual
of "Megger" Practice, No. 1420 -E.
1211-13
James
ARCH STREET
G.
(&L,qe and A
Biddle Co.
is Ashurnents
PHILADELPHIA, PA.
A may assume on
the
eb
-e,
plate are
restricted by excessive electrode dissipation in the manner indicated
qualitatively on Fig. 5.
The calculating device which has
been described has been used quite
successfully by the students at the
Illinois Institute of Technology. A
zinc plate was made of the drawing
shown in Fig. 6, and the calculators
were printed from it on plastic
sheets. It was found convenient to
include on the sheet the formulae
used in the calculating process, so
that they might be readily available.
The book store at the Illinois Institute of Technology or the Harvard
Cooperative Society, Harvard Square,
Cambridge, Massachusetts, will be
glad to supply the calculators, at
manufacturer's cost, to anyone who
desires them.
REFERENCES
(11 E. L. Chaffee. A Simplified Harmonic
Analysis. Rev. Sei. Instr., 7, 384, 1936.
1_t E. L. Chaffee, The Operating
teristies or forcer Tubes. Jour. ('liaraeApplied
I'L u.cirs. 9. 471. 1938.
NEW NAVAL HOSPITAL
new Naval medical center with the
most modern medical devices was opened
recently. Commander C. F. Behrens is
shown adjusting the Kieffer laminagraph
machine, which is used for x -rays of any
predetermined layer in the body, without
A
showing any other tissues
December 1942
www.americanradiohistory.com
-
ELECTRONICS
11.
11. Avoiding
Patent
Pitfalls
iVe w!
(Continued from page 78)
himself translate his abstract idea
into an embodiment in order to proMFG. CO.,
vide the basis for a patentable HAYDON
invention.
Forestville, Conn.
4-REMAI(
On Sea!
Records
Makers of
On Land!
The necessity of keeping records
of the invention and all work relatIn the Air!
ing thereto is due to the fact that in
this country a patent is granted to
the first inventor. If two or more
inventors apply within certain time
limits for a patent covering the same
invention, the Patent Office assumes
For Fixed or Mobile
that the applicant who filed his application first is also the inventor,
Communications Duty
but gives the later applicant the
Standard designs in Premax Adjustable
the
meeting
opportunity to contest this position
are
Telescoping Antenna
rigid requirements of the fighting
and to prove, if he can, that he is the
forces. Send for Bulletin or let us have
first inventor and entitled to the
your specifications for special designs.
patent although he is the later applicant. The proceedings instituted
did
by the Patent Office to determine the
priority of inventorship is called an
Division Chisholm -Ryder Co., Inc. "interference ". The decision on the
A. Y.
131)2 Highland _1%c.. ,"Niagara Dull
priority of inventorship is made by
the Patent Office on the basis of the
evidence submitted. This evidence
consists of the records kept by the
inventor and his co- workers, if any,
his oral testimony as well as that
of his co- workers and other witnesses. Since oral testimony alone
does not carry too much weight,
written records are of great importance.
The important factors in an interference proceeding are the conception of the invention, the
disclosure thereof to others, continuous diligence in completing and
perfecting the invention, the reducUHF and MICROWAVE
tion to practice thereof, and the
Precision Frequency Meter
filing of a patent application.
RECOMMENDED FOR:
There are two types of reduction
Production testing
practice which constitute a comto
drift
oscillator
Measurements of
transmitters
of
pletion of the invention, actual
Independent alignment
and receivers
reduction to practice by successful
Precise measurements of frequencies
operation of a model or of the
COMPLETELY PORTABLE
OPERATED
ACor
BATTERY
method according to the invention,
ACCURACY 0.1 °o
and constructive reduction to pracModels available from 100 to 4000 megafrequency coverage on
cycles with 2 to
tice by filing a patent application.
each model.
Both types generally bear the same
weight.
The evidence of these acts on the
MICROWAVE EQUIPMENT
part of the inventor must be concluNEW JERSEY
MORGANVILLE
sive as to fact and date.
In order that a later applicant
Haydon Timing Motors
Telescoping Antenna
/3"emax Pro
cls
1
Xctrek Xakpakitia_
Inc.
11 nnoirnces
A New Timing Motor Construc-
tion which allows instant
Automatic Reset of the Motor
Shaft
-
FOR USE IN
-
Automatic Reset Timers, Time
Delay Relays, Vacuum Tubes
Circuit Controls, Etc.
Extensively used in Plate
Circuit Time Dclays for Communications Equipment.
Counterbalanced
Clutch
Releases
Gear Train
Upon Current
Interruption
This is only one of a Complete
Line of Hay(lon. Timing Motors.
Hav(lon Employees are 100%
-10%
in Rear Bond Pur-
chases.
L
ELECTRONICS
--
December 1942
159
For oil- filled capacitor performance and
dependability in compact assemblies,
Aerovox "bathtub" capacitors are the
logical choice. The non -inductive oilimpregnated paper sections are encased
in a one -piece drawn metal case, with
a soldered bottom plate, hermetically
sealing the capacitor. Terminals are of
the "double rubber bakelite" Aerovox
construction, for an absolutely immersion -proof job.
These space-saver oil
capacitors are known for their long and
continuous service.
AEROVOX
"BATHTUBS"
Terminals
normally on
one side
of case, but
can be placed
both sides, on
on
top or on
bottom.
Mounting lug
Or
arranged for
flat
upright mounting.
Oil -filled
oil -impregnated
tions. Single,
secdual and triple
units:
400 to 1000
V.
of capacities
D.C.W.
Coice
and combinations.
These and other heavy -duty capacitors are
listed in our Transmitting Capacitor Catalog.
If you still lack this catalog in your working
library, write on your business stationery for
your copy.
NEW BEDFORD, MASS., U. S. A.
In Canada: AEROVOX CANADA LTD., Hamilton, Ont.
EXPORT: 100 Varick St., N. Y., Cable 'ARLAB'
160
may prevail over an earlier applicant, it is necessary that the later
applicant present a complete history
of his activities, supported by evidence, consisting of a preferably
uninterrupted chain of events in the
sequence: conception of the invention, disclosure to others, diligence
in perfecting and completing the invention and (a) actual reduction to
practice and filing of a patent application or, (b) constructive reduction
to practice by filing a patent application. The earlier applicant may
also present a complete history of
his activities or rely solely on his
constructive reduction to practice as
evidenced by the filing of the application, if he believes the opponent's
case is weak or, if he has insufficient
evidence to support his history.
Due to particular fact situations
in the activities of the contestants
various complications can arise,
which will not be discussed here.
The best proof of conception is a
complete description of the embodiment of the invention shown in the
patent application, preferably illustrated where feasible, written by, or
at least signed by the inventor and
bearing the date of the signature.
Proof of disclosure is established
by having the person to whom the
disclosure is made, sign the description under the words "witnessed and
understood ", together with the date
of the signature. It is essential that
the person to whom the disclosure
is made be sufficiently skilled in the
art to which the invention relates,
to understand the invention, otherwise the disclosure is not considered
valid.
Diligence in perfecting or completing the invention or in preparing a patent application must be
proven in order to show that the invention was not abandoned. Diligence may consist in improving the
embodiment of the invention, in
calculations to determine preferred
dimensions of the elements of the
invention, in work on a theory of
operation, or in work leading to the
construction of a model or to the
operation of the method according
to the invention. Diligence may also
consist in the preparation of a patent application, but it should be
noted that the applicant cannot be
excused for any lack of diligence on
the part of his attorney.
Actual reduction to practice can be
proven by recording the successful
Engineers E Procurement Ofi
cia /s
. write
for this 12 -page
Industrial Catalog now!
GET TO
KNOW
THE GREATER INSULINE
COMPLETELY GEARED
fo the needs of
THE ARMED SERVICES
!
Our greatly enlarged plant and facilities are
completely devoted to manufacturing these
Electronic Products and Parts for the Armed
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Metal Cabinets, Chassis, Panels
Metal Stampings
Name Plates.
Dials
Plugs and Jacks
Completely assembled Screw
Machine Products
Hardware and essentials
Antennas for
"WalkieTalkies", Tanks, etc.
Manufacturers .f Contractors:
specifications far estimates.
Send
INSULINE CORP. OF AMERICA
INSULINE BUILDING
LONG ISLAND CITY, N. Y.
ARGON
NEON
HELIUM
KRYPTON
XENON
MIXTURES
RARE GASES
`.
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AND MIXTURES
Spectroscopically Pure
Easily removed from bulb
without contamination
Scientific uses for Linde rare gases include
1. The study of electrical discharges.
-
2. Work with rectifying and stroboscopic
devices.
3. Metallurgical research.
4. Work with inert atmospheres, where heat
conduction must be increased or decreased.
Many standard mixtures are available.
Special mixtures for experimental purposes
can be supplied upon request.
The word "Linde" is
a
trade -mark of
THE LINDE AIR PRODUCTS COMPANY
Unit of Union Carbide and Carbon Corporation
l
Offices in Principal Cities
In Canada: Dominion Oxygen Company, Ltd., Toronto
.30 E. 42d St., New York l
December 1942
-
ELECTRONICS
operation and preferably demonstration thereof to others. Proof of the
constructive reduction to practice
obviously lies in the patent application.
Records should preferably be kept
in a bound notebook in which daily
entries of the inventor's activities
are made. Notes not relating to the
invention need not be revealed in
the interference proceedings.
It is essential that the disclosure
show all elements of the invention
and their correlation. If the invention relates to a device for use in a
complex system, care should be
taken to show how the new device
fits into the complete system. Conventional elements may be shown by
blocks bearing legends. For inventions relating to electrical circuits it
may suffice to provide the circuit
terminals with the proper legends to
indicate its relationship with associated circuits. For inventions relating to tubes, a characteristic circuit
is preferably shown, or at least the
leads to the various electrodes
marked by the proper legends.
Some inventors are much concerned about establishing the proof
of the dates of their records. If a
witnessed notebook is kept in which
entries are made regularly, no difficulty arises in convincing the Patent
Office of the veracity of these dates.
So much thought is given to the
dates that sometimes the importance
of the subject matter of the records
is overlooked, particularly the completeness of the disclosure. An incomplete disclosure even with a perfectly established and proven date is
worthless.
The records should include notes
relating to the ordering and receipt
of materials and parts needed to a
model of the invention, for the purpose of explaining inactivity over
any appreciable length of time. The
purpose of such notes is to prevent
inactivity during periods of waiting
from being construed as evidence of
an abandonment of the invention,
which can happen if the lack of activity is unexplained or inexcuseable.
Other business is not an acceptable
excuse for inactivity.
If models of mechanical inventions
are made, they should be preserved
in exactly the same condition in
which they were first successfully
operated. If this is not possible,
photographs showing all significant
details should be made, preferably
ELECTRONICS
-
December 1942
MOLDED
THESE widely used Resistors are favored
because of their noiseless operation and
durability and because they retain their
values and characteristics under extremes
of temperature, humidity and climatic
changes.
TYPE 65X
Actual Site
in
Other types available
values
the lower
RESISTOR
STANDARD RANGE
1000 ohms fo 10 megohms.
37
BULLETIN
GIVES FULL
AI
S
of the differIt shows illustrations
Molded
of S. S. White
about
ent types
and gives details
etc.
dimensions,
mailed
construction,
List, will be
Price
copy, with
for it-today.
Write
on request.
Resistors
NOISE TESTED
At slight additional cost, resistors in the
Standard Range are supplied with each resistor noise tested to the following standard:
complete audio frequency
range. resistors shall have less noise
than corresponds to a change of repart in 1,000,000."
sistance of
"For the
1
HIGH VALUES
to 1,000,000
15 megohms
megohms.
s. s. WHITE
The S. S. White Dental Mfg. Co
INDUSTRIAL DIVISION
Department
R, 10
East 48th St., New York, N.
Y.
Vaiétrk,Pteckft
.
.
..
Accuracy and
dependability are
built into every
Bliley Crystal Unit.
Specify BLILEY for
assured performance.
BLILEY ELECTRIC COMPANY
UNION STATION BUILDING
ERIE, PA.
161
Quick Delivery
showing a calendar page with the
date on which the photograph was
taken. A model from which vital
parts have been removed is mostly
useless as evidence of a reduction to
practice.
The importance of all these records might be questioned in view of
the fact that many patents are issued on applications which never
became involved in interferences.
However, it is not possible to foretell
whether another inventor has filed
an application on the same invention, and the probability that this is
the case is relatively high, since the
same problems are being attacked
simultaneously by a number of different inventors. If the invention
is worth the expense of filing a patent application, it is certainly worth
while to keep accurate records,
thereby to safeguard the rights to a
patent as much as possible.
ON CAPACITORS!
Industrial Condenser Corp. through
a new distribution plan enables you
lo secure small lots of condensers
locally. Contact the Industrial Condenser district office nearest you:
TELEPHONE
ADDRESS
Box 1052
Dallas, Texas
117 Water St.
Bolton, Mass.
1406 S. Grand Ave.
Los Angeles. Calif.
Hancock 0200
Richmond 6161
Box 20
Ashev1ille2 . N. C.
27 Park Place
New York, N. Y.
Rm. 220 -Medical
7149 -J
Barclay
Arts Bldg.
34th and Broadway
Kansas City, Mo.
1456 Waterbury Road
Lakewood (Cleveland),
Ohio
22nd St.
24.
Minn.
Minn34 eWapolis,
1135 Lincoln Tower
rt. Wayne, Ind.
2016 Third Ave.
Seattle, Wash.
Lutz (Tampa), Florida
6432 Cass Ave.
Detroit, Mich.
401 N. Broad St.
Philadelphia,
235 9th St.
San Francisco,
Pa.
Calif.
NO.
Logan 6 -1685
7 -4977
Westport 5323
Academy 4932
Kenwood 2833
Anthony 5278
Seneca
1088
99 -144
Madison 6300
Walnut 4163
Market 4166
Condensers immediately available from distributor's
stocks meet Army and Navy requirements
Industrial Condensers are specified where precision is vital
Capacitors to 150,000 volts-WRITE FOR COMENGINEERS ATTENTION!
PLETE NEW CATALOG.
...
...
Information required by the attorney
INDUSTRIAL CONDENSER CORP.
1725 W. North Ave.
Chicago, U. S. A.
Manufacturers of Quality Oil, Wax and Electrolytic Capacitors
J
ACCURATE FORMING WITHOUT DIE5
2000 Delicate Reeds Daily
for 1st
American Made Frequency Meter
"The new model 30 -F Vibrating Reed Frequency Meter manufactured under Triplett patents
pending, incorporates a precisely shaped special spring material metal reed .0045" thick.
This meter of exclusively American manufacture requires 10 accurately shaped vibrating
reeds which are rapidly and economically produced by women operators with DI -ACRO
EQUIPMENT. The reed material is sheared to size on the DI -ACRO Shear by the girl in
the background. The operator in the foreground is forming reed to a 90° angle with a .010"
precisely formed radius at point of angle.
"These
DI -ACRO
Units are used exclusively by women
operators and are
considered particularly suitable for
them. Little maintenance has been re-
quired
months
during
4
of heavy
production."
Very truly yours,
Instruments, Inc.
Roland M. Bixler,
J -B -T
General Manager
Write for Catalog
"Metal Duplicating
Without Dies."
O'NEIL -IRWIN MFG. COMPANY
162
321 8th Ave. S.
MINNEAPOLIS, MINN.
It is necessary that all information concerning the invention be
transmitted to the attorney. It is
his business to convince the Patent
Office that the invention submitted
is new and useful and merits a patent, and for this purpose he requires
all information available to the inventor as to the aims of the invention, the improvement which the
invention represents over known devices, structures and methods, and
wherein it differs therefrom. The
complete disclosure of the invention
together with all records pertaining
to the invention should be shown to
the attorney. He should also be
made familiar with the theory of
operation of the invention and with
the equivalents of the elements of
the embodiment which can be used
successfully, in order to enable him
to choose terms of proper scope in
the claims.
The inventor should familiarize
the attorney with the embodiment
of the invention, as well as its aims,
advantages and novelty. The time
required therefor is well spent and
the inventor should keep in mind
that the attorney is usually not as
familiar as he is with the particular
problems leading to the invention,
and therefore should not place upon
the attorney the burden of reconstructing or and re- inventing the
invention from meager information
supplied.
December 1942
ELECTRONICS
Temperature
Instrumentation
(Continued front page 7#)
THE
fflIHCHILD
PEGASUS
IS A WAR HORSE NOW
This mark represents Fairchild
research, advanced engineering design, and superlative craftsmanship.
Today it is concentrated on essential
materials for war requirements.
Fairchild Precision Sound Equipment
is irreplaceable for commercial purposes for the present.
TAKE GOOD CARE OF YOUR
FAIRCHILD EQUIPMENT
In order to protect and extend its life.
our Service Department will lend
every assistance possible. Please call
upon us.
"...it had
to satisfy Fairchild
first"
rniruii
Sound Equipment Division
AVIATION
86.06 Von Wyck
TECHNIQUE
Government Departments, Universities,
Schools and Thousands of Individuals
Have Bought this Booklet.
WHY?
Because it is the first up -to -date treatise
on the all-important new ultra-high -frequency technique.
In plain, simple, understandable text, the
philosophy of ultra -high frequency technique is given to outline the nature of the
problems at frequencies for which 'line of
sight" transmission is of paramount im-
portance.
graphs, tables, and equations,
the more important quantitative results are
given to familiarize the technician with
the general magnitude of the quantities
involved -to provide a sense of quantitative proportions and the fitness of things.
Finally, since u -h -f technique cannot be
treated thoroughly in a 60 -page booklet a
convenient bibliography is included at the
end of each section.
The cost is 50ee per copy-35e each in lots
By moans of
more-
The supply is limited -order now.
ELECTRONICS EDITORS
330 West 42nd St.
ELECTROi\ICS
New York, N.
-
Temperature. the Variable Factor
Some electrically-trained workers
need re- educating when entering the
field of temperature instrumentation
because "That peculiar thing, temperature," is so unlike any other
measurable magnitude. It is an intensive magnitude, like voltage, but
here the resemblance ends. Voltage
bears an exact relation to other electrical magnitudes and its scale of
values from microvolts to megavolts
is a "regular" scale. Not so with
When you read an indicating ammeter you know that it indicates
L. I.. N. Y.
"fi-(91
of 26 or
:
curacy, (2) precision, (3) scale law,
(4) unit sensitivity, (5) ultimate
sensitivity and dead zone, (6) hysteresis, sticking, etc., (7) readability, (8) lag, (9) damping, (10)
stability (and its opposite, drift) and
(11) error source.
temperature.
CORPORATION
Boulevard. lamaìca.
properties which are (although not
in order of importance)
(1) Ac-
Y.
what the current is -not what the
current was fifteen seconds ago.
When you observe the indicating
element of an industrial temperature- responsive system, however,
you are reading what the temperature was -perhaps only a quarterminute ago, perhaps a quarter-hour
ago. And if the reading is what the
temperature was a quarter- second
ago, the case is neither average nor
typical but exceptional because there
are relatively few low-lag electronic
systems today.
It is in connection with this all important
measuring
property,
known as thermometric lag, that the
readers of ELECTRONICS will be able
to make their greatest contributions
to the advancement of industrial
temperature instrumentation. A
study of Table I will disclose numerous opportunities. Some of these
opportunities have already been discovered. As far back as 1932 -34,
several industrial systems were developed, utilizing low -lag photocells,
phototubes or total- radiation receivers, some with and some without
radiation filters, whose output was
fed to electronic amplifiers and
thence to indicators and recorders
likewise characterized by extremely
December 1942
Photo by U. S. Arran
Signal Corps.
Vital Link in the Victory
Chain-Sensitive,
Rugged Microphones
He seldom gets a hero's mention, but
the "man with a mike" plays a mighty
important part in modern war. Along
with the pilots, bombardiers, gunners,
and men with more spectacular roles, he
is in the thick of every fight. His chief
weapon: a small, compact, supremely devital unit in
pendable microphone
his supply of communication equipment.
Kellogg Microphones meet the high
performance standards required for military use: excellent sensitivity; great resistance to climatic changes, shock and
hard usage; accurate transmission of
voice frequencies; etc.
Kellogg invites prime or sub- contractors of the U. S. Government to consider
this company as a source not only for
microphones, but also for the many other
types of communication equipment for
military use which this 45 year old
firm is equipped to manufacture to speci-
-a
fications.
SWITCHBOARD & SUPPLY CO.
6682 S. Cicero Avenue, Chicago, Illinois
KELLOGG
KELLOGG
WHERE ENGINEERING AND RESEARCH BUILD
14.4.
KL
FOR WAR
AND PEACE
7
163
www.americanradiohistory.com
low lag. Some of these have won ac-
ceptance beyond the special trial installations for which they were
originally made to order; and they
are on the market today in practical
forms. None of them is customarily
referred to as an electronic type.
This is not due to prejudice but to
usages and to nomenclature based on
functional classification. None is
"an electronic instrument" to a
greater extent than it is some other
functional type. Electronic products
minimized the lag but did not contribute to accuracy.
Accuracy, Sensitivity and Sensitiveness
"da
COLLOIDAL GRAPHITE
For Cathode Ray Tubes
A
coating
of
"dag"
colloidal graphite
on the interior walls of cathode ray
tubes as a focusing anode provides
the following advantages:
1.
2.
Being
a conductor,
second anode.
it
acts as
a
Being opaque with a dark mat
surface, it does not reflect light
from the elements.
3. It
resists oxidation and acquires
-getter- properties.
easily applied to all types
glass and metal.
4. It is
of
s. It eliminates the necessity for a
silver coating.
For complete information on the characteristics of "dag" colloidal graphite
and its application to cathode ray tubes
write for Bulletin 191K.
ACHESON
COLLOIDS CORPORATION
POST HURON
MICHIGAN
This brings up the question of accuracy. Here again some electrical
concepts must be erased from one's
mind. The zero point, so easily attainable in electrical phenomena by
simply opening a circuit, is not attainable in thermal phenomena because there is no sure way of removing all heat from a substance.
By international agreement, the ice point and the steam -point (at normal
atmospheric pressure and with other
precautions specified) are assigned
the values "0.000" and "100.000,"
thereby defining the fundamental
interval of the thermodynamic scale.
This scale is only an ideal. The scales
of tangible thermometers and pyrometers follow it more or less closely,
depending upon factors too numerous to discuss. Suffice it to mention
that a thousandth of a degree Centigrade is the limit of accuracy between the ice point and steam point,
a hundredth of a degree between the
steam point and the sulphur point
(44.60 deg. C) a tenth of a degree
thence to the silver point (960.5 deg.
C) and only one degree to the gold
point (1063 deg. C). It is not permissible to assert that a pyrometer
can measure the temperature of steel
with an accuracy of a hundredth of a
degree, not even a tenth of a degree,
because the nearest reference point
on the International Standard is defined as a whole degree. Various temperature effects, however, permit
measuring temperature changes of
a millionth of a degree or better. The
measuring property here involved is
not accuracy but sensitivity-spe cifically the ultimate sensitivity of
the device. Needless to say, a thermometer guaranteed accurate to a
tenth of a degree will probably be
sensitive to a hundredth. If its ultimate sensitivity were only a tenth,
its uncertainty would be two tenths
and its certified accuracy about four
tenths.
In industrial temperature work,
sensitivity is often preferred to absolute accuracy. This is particularly
true in temperature control applications, where speed of response to
temperature changes is often specified as the essential requirement.
Rapid response to temperature
changes usually means sensitiveness** to small temperature changes.
Here, then, is another promising
field for electronic devices, some of
which possess the property of sensitivity to a superlative degree. Several excellent starts have been made,
although none (to the author's
knowledge) has been a purely electronic solution to this particular
problem.
Closely linked with ultimate sensitivity are its enemies, friction and
other effects usually denoted by the
term sticking. This term is usually
applied to a measuring element per
se. In industrial temperature instrumentation, a primary measuring
element often has no other function
than to actuate the relay or pilot of
a servo mechanism which in turn operates a recording device, a rheostat,
a valve, or other power- driven unit.
In such cases the primary element
commands the servo without effort.
The pilot or relay must not impose
any drag on the primary element
because such drag would impair its
sensitivity and accuracy. To this
well -known problem of temperature
instrumentation, the science of electronics has provided four distinct
solutions:
(1) Retain the usual temperature measuring system which ends in a
deflecting pointer or pen -arm. To
this pointer or pen -arm, associate
without contact the pick -up of an
electronic system. This is the solution introduced by a Chicago firm
some ten years ago. Several firms
now offer it.
(2) Substitute an electrical system for the previously-used temperature- measuring system ending in a
pointer. Make the electrical output
of this system the input of an electronic system. This solution, too, is
found in various commercial em-
bodiments.
**Sensitiveness is the term for the property of a controller also known as "dead
zone" and sometimes as "differential setting."
It is always greater in scale value than the
sensitiritt/ of the primary measuring element;
example. a two contact thermostat.
December 1942
164
www.americanradiohistory.com
-
ELECTRONICS
(3) Replace the old temperature measuring system by a strictly electronic device such as a gas or vapor
triode, a crystal oscillator, for example, which is temperature- sensitive. Feed its output either to an
electronic or to an electrical servo
system. The author has heard of
this being done but he had not yet
seen any commercial announcement.
(4) Replace the old primary system and servo by only one strictly
electronic device which is temperature- sensitive and whose output is
sufficiently powerful to operate a recording mechanism, a solenoid valve,
a proportional-action voltage regulator or even a proportional- action
motorized valve. * **
It may not be amiss to conclude
with a quotation from one of the author's writings on automatic-control
technology, and which outlines the
essentials of a satisfactory temperature control system.
T IE L C o N
II
Design, Development and Manufacture
of
SUPERSONIC
INSTRUMENTS
tot all appI cat »ti
Defense, Industry, Science,
Medicine, Short Time Measurements.
The Four Requirements
'
_Onuitias Welcomed
thermometer or pyrometer
merely reports -as would a subordinate sent by a manager to look
over a situation; an automatic controller takes action -as would an
A
* *+ This
paragraph constitutes
disclosure wit hen t surrender of
rights.
in
305 East 63rd Street, New York City
partial
inventor's
a
0144aZ
x AIRCRAFT r
11
SHORTWAVE RADIO
TRANSMITTER
Qßd E5 WITH
'
AMPERITE
BATTERY CURRENT
& VOLTAGE
REGULATORS
-
Features:
1. Amperites cut battery
voltage fluctuation from
approx. 500/e to 2 %.
2.
3.
The new 100 kw transmitter of General
Electric's shortwave station WGEO in
Schenectady, is one of the most powerful
stations in the western hemisphere.
Robert E. Sherwood, director of overseas
branch of Office of War Information,
throws the switch to place the transmitter
in
-
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not affected by altitude,
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or humidity.
Compact, light, and
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in Canada: Atlas Radio Corp., Ltd., 560 King St. W., Toronto
PERITE COMPANY
operation
ELECTRONICS
VOLTAGE OF 24V
& CHARGER
VARIES APPROX.
BATTERY
December 1942
www.americanradiohistory.com
Cable:
Alkem,
New York.
*
alert executive to whom reports are
submitted. All controllers are active, operating, "live" devices, to be
judged by active performance, not
by passive qualities.
11.11IVIANENT
1VIAGNETS
The Arnold Engineering Company produces
all ALNICO types including ALNICO V.
All Magnets are completely manufactured in
our own plant under close metallurgical,
mechanical and magnetic control.
The Arnold Engineering Company
freely
offers engineering assistance in the solution
of your magnetic design problems.
All inquiries will receive prompt attention.
THE ARNOLD ENGINEERING COMPANY
147
INVEST
EAST ONTARIO STREET
CHICAGO, ILLINOIS
loq
IN
CARTER
WAR
BONDS AND
STAMPS
SOLVES
YOVR,,T. PROBLEMS
The proper performance of a controller depends, as does that of a
manager, on the correctness and
timeliness of the information it receives, and on the limits within
which its power may be exercised.
Summarizing, we lay down the basic
requirements for automatic control
of process temperatures in industry:
(1) The temperature to be controlled, or its variation, must be
measurable. No controller can be
better than its primary measuring
element!
(2) The primary element of the
automatic controller must be suitable for the measurement involved
and must be properly installed.
(3) The power device commanded
by the control instrument must adequately control an adequate source
of heat supply.
(4) The measuring means must
command the corrective means effortlessly, i.e., without having its
own measuring properties impaired.
Obvious and simple as are these
four basic requirements, they are
sometimes lost sight of in the maze
of engineering details that have to
be taken into account when working
out elaborate installations.
.e
MOLECULES WRIGGLE
LIKE WORMS
For
For
many years, Carter Dynamotors have been a familiar part of the
of leading Communication Equipment Manufacturers,
Police Departments, Government Agencies, etc. May we suggest you
submit your Dynamotor requirements too, and see for yourself the
reason for this recognized preference.
The latest catalog of Carter Dynamotors, Converters, Permanent Magnet Generators
and Dynamotors, and special rotary equipment will be sent upon request.
1606
Milwaukee Ave.. Carter, a well known name In radio for over twenty years.
Cable: Genemotor
166
Dr. Raymond M. Fuoss, of the
December 1942
www.americanradiohistory.com
General
Electric research laboratory, has found
that some molecules wriggle like worms
when an alternating electric field is applied to them. This phenomenon has been
useful in the development of artificial silk,
rubber, and many plastics used for electrical applications are made from them.
Drs. Raymond M. Fuoss and D. J. Mead
are shown with the apparatus which
makes the molecules wriggle
-
ELECTRONICS
Remote Control
(Continued. from page 60)
Continuously working al capacity, we
are truly
"drawing with all our mightl"
We are proud that Wilbur
B.
Driver Co.
special alloys have so many vital war
applications and of the part they are
playing toward the final complete strangling of the "Unholy Three ".
Perhaps.we can help you make your
product do its part more effectively or
get on the job more quickly. Consult us
for your requirements.
Single Source of Supply
for Everything in
Electronics and Radio
aze
Tubes
Test Equip.
Photo Cells
Transformers
Relays
Condensers
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Rheostats
Switches
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Tools
Coils
Receivers
Generators
Sockets
Wire
Speakers
Batteries
Save time and trouble. Use this
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write
ALLIED RADIO
Dept. 2a -M -2 833 W.Jackson, Chicago
*ALL/FD RADIO*
ELECTRONICS
-
switch to any desired position. Actuation of the release key energizes the
release magnet, through the off -normal contact of the switch, and restores the wiper to normal.
In conventional telephone practice,
it is not ordinarily possible to have
separate operating and release wires
such as those shown in Fig. 4D and,
additionally, it is rarely possible to
handle the power required by the
stepping magnet over the small remote control wires, so the scheme
shown in Fig. 4E is frequently used
to accomplish step -by -step selection.
The operating dial, such as is used in
the usual automatic dial telephone, is
equipped with two contacts in series
with each other. Contact 1 is closed
when the dial is not in use and contact 2 is normally open. The construction of the dial is such that contact 2 is immediately closed the instant the dial is used and stays closed
throughout the entire cycle of operation.
Contact 1 is alternately
opened and closed a certain number
of times by the rotating cam in accordance with the amount of rotation of the dial. Thus, the initiator
circuit is open until the dial is operated and then rapidly opened and
closed until rotation of the dial
ceases.
When studying the circuit of Fig.
4E it is particularly important to remember that relay A is of the fast
operating type and that while relay
B operates quickly it releases slowly.
With this in mind, the effect of initially closing the dial circuit by closing contact 2 is to ground one side of
relay A through contacts 1 and 2,
thereby causing relay A to operate
and transfer a second ground connection from contact 3 to contact 4,
operating relay B. When relay B is
operated in this manner it closes
contact 5, preparing a circuit to
ground for the magnet of the rotary
switch. Thereafter, transmission of
a series of rapid and closely-spaced
impulses from the rotated dial causes
rapid operation of relay A, with relay B remaining energized due to the
fact that its release delay time is
greater than the spacing times between initiator impulses. Thus current flows from the battery attached
to the rotary switch magnet, through
the magnet of the rotary relay,
December 1942
*Precious lives at stake -that was the
predominant thought in the minds of
Clarostat engineers while developing
this split-winding power rheostat now
used for a vital fire -control function in
our fighting planes.
More specifically: 330' total rotation.
Two resistance sections of matched resistance, equally disposed about a center section of virtually zero ohmage.
Smooth transition from one section to
another. Control must operate with
very low torque and yet with positive
contact pressure regardless of extremes
in temperature, vibration, orientation.
This new control was produced
few days. despite a new mold.
rotor and spring, three -winding
Today it is standard equipment.
in a
new
strip.
Typi-
cally a Clarostat assignment -and solution.
* Send your problem to
Clarostat Mfg. Co., Inc.
285 -7 N. 6th St.,
Brooklyn, N.
Y.
cL4Rp5TAT
averlopeOed
167
TIMERS
TIME
DELAY
RELAYS
through closed contact 5 and through
rapidly opened and closed contact 3
to ground, stepping the ganged arms
of rotary switch levels No. 1 and No.
2 around to switch points corresponding to the number of impulses
transmitted by the dial. (Throughout this operation, contact 6 remains
open and rapid action of interrupter spring contact 7, actuated by the
magnet of the rotary switch, is of no
consequence while this condition applies.) When the dialing operation
has been completed, all relay contacts
are restored to the positions shown
in the diagram but the rotary switch
arms are resting upon some particular switch points. It will be seen that
when this is the case the magnet of
the rotary switch is energized as follows current flows from the rotary
switch magnet battery through the
magnet coil, through interrupter
spring contact 7, through one of the
arms on the level No. 2 deck of the
rotary switch, through the bank wiring of this switch deck, through contacts 6 and 3 to ground. This "homing" current flows through the rotary switch magnet long enough to
rotate both switch arms to the next
switch points and then interrupter
spring contact 7 is opened. When
contact 7 opens current flow through
the rotary switch magnet ceases so
contact 7 again closes, rotating the
rotary switch arms to the next switch
points. This process continues, the
switch arms rapidly stepping or
"buzzing" toward the home position,
until the arm of level No. 2 reaches
the home position and opens the circuit. The system is thus entirely deenergized.
A variation of the step -by -step se:
MODEL 21
FOR TRANSMITTERS
TIME CONTROLS
FOR EVERY PURPOSE
Interval Timers
Running Time Meters
Cycle Timers
Repeat Cycle Timers
Time Switches
Signal Control Switches
Multi-Contact Timers
Impulse Timers
Instantaneous Reset Timers
Process Timers
Beacon Flashers
Siren Timers
WRITE FOR SALES CIRCULARS
SANGAMO
ELECTRIC COMPANY
SPRINGFIELD, ILLINOIS
lection scheme may be accomplished
by the use of relays of the non -stepping variety. Fig. 4F shows a circuit commonly known as a "counting chain." Closure of the operate
key energizes relay A. Operation of
relay A prepares an energizing circuit for relay A' through contact 1
and the release key but A' does not
operate at this time since its winding is effectively short -circuited inasmuch as both the operate and release
keys are grounded. As soon as the
operate key is opened, relay A' is energized in series with relay A,
through the previously prepared circuit, and transfers the operating circuit to relay B by opening contact 2
and closing contact 3. Thus, successive closures of the operate key oper-
168
Bringing you
FM
.
.
FUNDAMENTALS
AND PRACTICES
in a well- organized
up - to - date treat-
ment for radio and
communication
engineers
I
Now August Hund, writer
of widely -used radio engineering books, has prepared this thorough, dependable text to aid you
in handling the specialized problems of designing and working with frequency modulation apparatus.
What are the special theoretical aspects of frequency modulation? How are they applied
What
in existing apparatus?
short cuts in calculation may be
safely employed? These and similar
questions are answered in this book,
in a way to give you a working Imowledge of this important branch of radio technique.
`..
JUST OUT!
-
FREQUENCY
MODULATION
By
375
August Hund, Consulting Engineer
pages, 6x9. 113 illustrations, 54.00
Radio
Communication
Here is an engineering
treatment of frequency
modulation, covering both
basic principles and the design of commercial apparatus. The phenomena and
features of frequency and phase modulation are described in a thorough approach
that included comparison with customary
amplitude modulation, following which applications in FM transmitters, receivers,
auxiliary apparatus, and antennas are fully
discussed. The use of tables and curves
to simplify design is emphasized.
Series
THIS NEW BOOK
demonstrates In numerical and gradual steps how
mathematical formulas may be applied readily to engineering solutions by the use of tables or curves.
gives many explanations directly in the illustrations.
so that figures can often be used without consulting
the text.
gives information to help in employing special design
formulas in connection with band width characteristics of networks.
gives methods of testing, useful both in designing and
maintaining FM receivers.
10 DAYS' FREE EXAMINATION
McGraw -Hill Book Co., 330 W. 42nd St., N. Y. C.
Send me Hund's Frequency Modulation for 10 days'
examination on approval. In 10 days I will send you
$4.00 plus few cents postage or return book postpaid. (We
pay postage on cash orders.)
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December .1942
www.americanradiohistory.com
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L
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12-42
ELECTRONICS
ate successive pairs of relays in the
chain while operation of the release
key restores all operated relays. The
chain may be made endless by carrying the locking circuit of any preceding pair of relays through a break
contact on the prime relay of any
succeeding pair and by carrying the
locking circuit for the last pair of
relays through a break contact on
the prime relay of the first pair. If
this is done, only one pair of relays
will remain operated at a time yet
the chain will repeat endlessly.
A time relation selection scheme
commonly used in printing telegraphy consists of two brushes, driven
by local motors so that they traverse identical switch -point paths at
opposite ends of the transmission
line. A circuit of this type is shown
in elemental form in Fig. 4G. As the
sending brush passes a given point
the receiving end brush passes a
corresponding point and, consequently, if power is applied to a
given point at the sending end a relay may be operated from a corresponding point at the receiving end.
Contact 1 merely locks the particular
relay that is energized in the operate
position. Time relation systems of
this type frequently use synchronous electric driving motors operating from the same a -c power source
and inter-connected by means of
three wires. Inasmuch as we are
here concerned primarily with the
utilization of relays in remote control work such motors will not be
discussed in greater detail.
Many of the electrical remote control circuits shown in elemental form
within this paper may be used in
combination. For example: A pair of
relays such as those shown in Fig.
3C could be inserted ahead of the
counting chain shown in Fig. 4F to
provide impulses to the counting
chain at half the speed of impulses
transmitted by the operating key or
initiator. In this case the counter
relay would operate at the beginning
of one impulse and its associated
prime relay would operate at the beginning of the next impulse. With
such an arrangement, ten selections
could be made using five pairs of
counters and two inter -lock relays.
Literally thousands of circuit actions can be obtained by modifying
and combining control circuits. Many
additional refinements may be made
by using such circuits in combination with vacuum tubes.
ELECTRONICS
-
December 1942
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Wire, Tubing and Special Shapes
Every step in the production of Platinum and alloys -from ingot to finished
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169
Experimental
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(Continued front page ;'1)
Actual Sim
Alodel No.400
PILOT LIGHT ASSEMBLIES
Deliveries are not a problem
at GOTHARD. If standard
models do not fit your requirements, send your specifications and proposed delivery
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MFG. COMPANY
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immediately.
ST.
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Or write for new catalog.
CALCULATION
A -C
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by
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greatly reduces the time required
for alternating current engineering calculations-speeds
up the design of apparatus and the progress of engineering students. Two to five times as fast as using a slide
This new Rider Book
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A -C CALCULATION CHARTS are designed for use by
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calculations.
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Pages
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Frequency
Inductance
inches
JUST
OUT-
ORDER TODAY!
JOHN
F.
Caoac, tance
R..a ctancn
conductance
10
cycles to
1000
megacycles
rohenr
0.0001
10
100,000
henrys
cromi o
farad to 1 farad cr
0.0t ohm to 10 meg-
Reactance
0.01 ohm to 10 mes -
Susteptante
to 100
0.01 ohm to 10 mesohm
0.1
ro mho to 100
mhos
Impedance
i
0.3
mhos
RIDER
ro mho
to 100
Admittance
Phase Angie
ms
h
0.tcromh0
hos
,
6
85.5
to
PUBLISHER, Inc.
404 FOURTH AVENUE,
NEW
YORK CITY
Export Division: Roche- International Elec. Corp., 100 Varick St., N. Y. C.
Cable: ARLAB
resonate at the desired frequency
with the tuning capacitor at maximum. Any attempt to trim an inductance much too large will result
in a tank impedance less than that
obtained using a parallel -tuned circuit. As the tuning range obtained
by series -tuning is quite restricted,
it is usually necessary to take into
account the capacity involved in
coupling to the following stage.
The output of the 815 driver amplifier stage is transferred by
link coupling to the input circuit
of the final amplifier, and is largely
dissipated in two resistors of 150
ohms in series across the grid coil
of the final amplifier. The input
impedance of the final amplifier is
thus kept low and good regulation
is obtained, while sufficient energy
remains to drive the final amplifier.
Bias for the final amplifier is provided by combining cathode and battery bias. Adjustment of battery
bias for proper operation of the
final amplifier is critical and must
be made carefully. A resonant line
plate circuit is employed in the final
amplifier. The plate is tuned by adjusting the shorting -bar and /or the
disc -type capacitor across the line.
The power supply for the radio
frequency portion of the transmitter uses two type 83 rectifiers and
supplies 500 v. A similar power supply, using one type 83 rectifier, supplies plate power at 400 IT for the
modulator unit.
The antenna used during pre -war
air tests was a three -quarter wave
folded dipole fed by an open two wire, 440 ohm transmission line. Inductive coupling to the transmitter
provided sufficient loading and was
not critical.
Modulator Unit
The modulator unit consists of a
pre- amplifier employing an 1852 tube
fed directly from the picture tube
through a transmission line, and
two 807 tubes. The pre- amplifier is
capacitively connected to the'modulator stage as shown in Fig. 4.
Originally, the transmitter was
grid -modulated and satisfactory
linearity of modulation necessitated
operating the final amplifier in such
December 1942
www.americanradiohistory.com
-
ELECTRONICS
a manner that the grid would just
begin to draw grid current at the
l'1;1_I;[]
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Where complete dependability
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is
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DYNAMOTORS!
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ELECTRONICS
-
IOWA
December 1942
positive peak of video modulation
(sync-pulses). Despite the use of
battery bias, poor regulation of radio
frequency driving voltage caused
clipping of the sync -pulses. To
avoid this condition a comparatively
high power driver was used and
most of its output was dissipated
in the 300 ohm load already mentioned.
Under these conditions it was
found possible to obtain linear grid
modulation but this was accomplished at the expense of power input and final amplifier efficiency. In
an effort to obtain higher power output and less critical operation the
circuits were revised to permit cathode modulation. The addition of a
d -c restorer tube for automatic
background control was contemplated as a future addition. It was
therefore desirable to maintain the
d -c coupling between the radiofrequency amplifier and the modulator. Such coupling also resulted
when cathode modulation was used.
D -c coupling between modulator and
r -f amplifier has the added advantage
of eliminating the large coupling
capacitance which would otherwise
be necessary to insure satisfactory
square wave response.
The 400 -ohm resistor in the cathode circuit of the modulator was
a compromise between the desire to
obtain from the 807 tubes a gain as
near unity as practicable and yet
not place an excessive impedance in
the cathode circuit of the 829 r-f
amplifier. It was further desired to
retain the low output impedance offered by the 807 when connected in
this fashion. The gain of the modulator stage is about 0.8. The outpnt
impedance of the 807 tubes is approximately 70 ohms.
Since the bias on the grid of the
807 tubes is produced by the combined action of the plate current of
these tubes and the plate current of
the 829, it was necessary to make
provision to adjust this voltage to
the proper value. The voltage between grid and cathode at the 807
tubes was adjusted to 20 by means
of a bucking battery. Before turning on the modulator power supply
it is necessary to reduce the bucking voltage to zero so that the tubes
do not heat up because of high positive grid voltage. The bucking battery switch can later be set to the
0
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proper point, as indicated by plate
current.
The output impedance of the cathode- modulated stage is given by
MEb /I,, where M is the percentage
of modulation desired, E, is the
plate voltage and I,, is the plate current. If a value of 20 percent (0.20)
is assigned to M and the values of
E, and lb are 400 IT and 200 ma. respectively, an impedance of 400
ohms is obtained. It is therefore possible to obtain a reasonable match
between the modulator and r -f ampli-
under discussion and diagrammed in
Fig. 5 was set to operate at a frequency on the high side of the signal carrier frequency by adjusting
co and tuning the circuit to 126.75
Mc. The converter grid has oscillator voltage injected into it through
C7, which is of the postage stamp
variety and has one plate drawn out
to the near -minimum capacity. Oscillator frequency adjustment must
take this capacity into consideration.
Too great an oscillator voltage
should not be injected as erratic opfier impedances.
eration results.
Overall adjustments for proper
band
-pass require that considera1852
Ant.
tion be given to the link coupling
0.002
from converter to the intermediate
To ist
frequency of the first amplifier.
I.F.in
Since a standard television receiver
Rec.
is used, it was found advisable to
use a coupling method which would
3,0010
allow any commercial television re20.000.
ceiver to be easily adapted to the
uii
300
r
114 Mc carrier frequency. Removal
/ L31 'tea
La Zt.,3 -in.dia. No.16 en.
of the commercial receiver's regular
L2 +.,J/s-in.dia.No.!6en.
L3 2t., J-in.dia. No.16 en.
Grid
/ oscillator and its link adjustment to
L4 4V4 +. tapped at 21%,
the first i -f amplifier of the receiver
in.olio. No.l6en.
L5 23 t.
dia. No.36 en.,
was the only alteration found necesclose wound
sary. One turn of wire was used in
ce Carol. ZR25AS
Cr Var.30,u.,uf max.
coupling the auxiliary converter to
(set near min.)
the
i -f amplifier and this was drawn
Ce Var.I2µµf max.
Cio Var. 12,uu.f max.
directly over the grid input coil of
the first i -f stage. The position of
Fig. 5- Circuit of converter permitting
the link over the grid coil apprecireception of 114 Mc video signals when
ably affects the band-pass of the
used in conjunction with a standard
commercial type television receiver.
system. Alignment for proper bandThe converter turns out a 12.75 Mc
pass width 3.5 of Mc necessitated
signal
using a television alignment oscilUnlike audio circuits, video ampli- lator, an absorption -type frequency fiers require connection of proper meter and a cathode -ray oscilloscope.
polarity if the standard negative Adjustment of capacitors C8 and Cto
modulation is to be obtained. It is and the link from L; will give the
interesting to note that cathode full band-pass required.
modulation requires a signal of
BIBLIOGRAPHY AND
polarity opposite to that required
REFERENCES
for grid modulation. Change from
plate output at the modulator to Receiving Systems
(1) Mezger, G. Robert, "Single Unit Video
cathode output, simultaneously with Converter,"
ELECTRONICS, p. 31 -34, 74, Feb.
the change in the type of modula- 1938.
(2) Engstrom, E. W. and Holmes, R. S.,
tion, automatically insures this.
"Television Receivers," ELECTRONICS, p. 28 -31,
I
-
Now, as never before, professional radiomen have a golden opportunity to go after
and get the higher engineering positions and
the increased pay that go with them. The
radio industry needs competent men. By improving your own technical ability, you will
help yourself, and at the same time make
yourself more valuable to your employer and
company.
CREI home -study training in practical
radio engineering is a proven method for
equipping yourself for advancement. For the
past 15 years this Institute, its courses and
outstanding faculty have been known and
respected throughout the industry. Now, with
time so important and the need so urgent,
every ambitious radioman should investigate
the advantages of the CREI planned program
of study for advancement and future security.
Write for free
32 -page
booklet
If you have had professional radio
experience and want to make more
money
us prove to you we have
something you need to qualify for
a better radio job. To help us in-
-let
-
telligently answer your inquiry
please state briefly your background
of experience. education and present position.
CREI
Students, Graduates
-
ATTENTION!
The CREI Placement Bureau is flooded with
requests for radiomen. Employers in all
branches of radio want trained men. Your
Government wants every man to perform his
job, or be placed in a job, that will allow him
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CREI Placement Bureau at once.
CAPITOL R:11iio
ENGINEERING INSTITUTE
Home Study Courses in Practical Radio
Engineering for Professional Self- Improvement
-
Dept. E -12, 3224
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WASHINGTON, D. C.
Contractors to the U.S. Signal Corps -U.S. Coast Guard
Preducers of 1Ve11- trained Technical Radiomen for Industry
44
Yz
63 -66, Apr. 1938.
The Receiver Converter
The design of a converter for receiving 114 Mc video signals presents several problems of interest
since the following points have
to be carefully considered: (1)
oscillator stability, (2) minimum
interaction between oscillator and
converter, (3) temperature and humidity effects and (4) adequate
band -pass.
The oscillator in the converter
172
(3) Engstrom, E. W. and Holmes, R. S.,
"Television I -F Amplifiers," ELECTRONICS,
June 1938.
(4) Engstrom, E. W. and Holmes, R. S.,
"Television Synchronization," ELECTRONICS,
p. 20 -23,
p. 18-21, Nov. 1938.
(5) Engstrom, E. W. and Holmes, R. S.,
"Television Deflection Circuits," ELECTRONICS,
Jan. 1939.
(6) Fink D. G., "A Laboratory Television
Receiver," ELECTRONICS.
Part I-p. 16 -20, July 1938
p. 19 -21, 32,
Part II -p. 26-29. Aug. 1938
Part III-p. 22 -25, Sept. 1938
Part IV -p. 16 -19, Oct. 1938
Part V -p. 26 -29. Nov. 1938
Part VI-p. 16 -19, Dec. 1938
(7) Fink, D. G., "Television Receiver for
the Home,' ELECTRONICS, p. 16 -22, Sept.
1939.
(8) Goldsmith, T. T., "Receivers for
Television Using Electrostatic Deflection,"
ELECTRONICS, p. 16 -19, 89, June 1940.
December 1942
www.americanradiohistory.com
-
ELECTRONICS
System Commit(9) "National TelevisionStandards,"
ELECProposes Television
TRONICS, .p. 16, Feb. 1941.
"A
Andrew.
Tait,
and
(10) vl uniz, Richard
ELECTRONICS,
Simple Television
tee
74144
Pream194er
S
Signal Generators
J. A.,
(11) Wilder, M. P. and Brustman,
ELECTRONICS.
"A Picture Signal Generator,"
1940
Apr.
Part I -p. 25 -29,
Readers of Electronics for your response to our serv-
ice messages which appeared on pages 98 and 39
of the October and November issues respectively.
1940
Part II-p. 26-29, May
1940
Part III -p. 30 -33, June
July 1940
Part IV -p. 28 -31, Aug.
1940
Part V -p. 30 -33,
Video Amplification
22 -25,
(13)
plifier
1937.
and Schantz, J. D..
Freeman,
Amplifier Design," ELECTRONICS, p.
1937.
60, 62, Aug.
Freeman, R. L., "Note on Video AmDesign," ELECTRONICS, P. 52-54, Nov.
Everest, F. A., "Wide Band TeleAmplifiers," ELECTRONICS.
(14)
vision
Laboratory Amplifier," ELECTRONICS,
p. 16 -18 Feb. 1939.
Pre(16) Barco, A. A., "An Iconoscope
amplifier," RCA Review, July 1939.
Mitchell-Rand
Band
- Insulation Headquarters.
Impregnated Varnished Tubing
Extruded Plastic Tubing
Varnished Cambric Cloth and Tape
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Insulating Varnishes of all types
Mica Plate, Tape, Paper, Cloth and
Tubing
-
A request on your business letterhead will
bring you a FREE copy of our Engineering
Wall Chart and Electrical Insulation Guide
Book described in our two previous advertisements.
Scanning and Synchronization
(17) Somers, Frank J., "Scanning in TeleOct.
vision Receivers," ELECTRONICS, P 18 -21,
-
1937.
(18) Duncan, J. R., "Paragraphs on Television Synchronization," ELECTRONICS, p. 51,
Feb. 1938.
Scan(19) Davis,
444, Nov.
ning-A
Cable Filling and Pothead Compounds
We will be glad to tell you how you can
SAVE TIME and SIMPLIFY YOUR BUY ING by ordering all of your electrical insulation materials from one source of supply
1938
Part I -p. 16-19, Jan.
1938
Part II -p. 24 -29, May
(15) Everest, F. A., "A High Gain Wide
Fiberglas Varnished Tope and Cloth
Fiberglas Braided Sleeving
Fiberglas Saturated Sleeving and
Varnished Tubing
Insulating Papers and Twines
Cotton Tapes, Webbings and
Sleevings
Asbestos Sleeving and Tape
We heard from a number of our regular
customers and many additional companies.
While M -R is backed by 53 years of electrical
insulation experience, we find that our products and se:vices are of interest to hundreds
of new manufacturers each year.
R. L.
(12)
"Video
eif,t
A PARTIAL LIST OF
M -R PRODUCTS:
Inquiries and orders on your electrical insulation
requirements will receive our prompt attention.
Survey,," ELECTRONICS, P.
1935.
of
(20) von Ardenne, Manfred, "Distortion p.
Saw -Tooth Wave Forms," ELECTRONICS,
36 -38, 84, Nov. 1937.
Sync Signals,"
(21) "Television without Mar.
1938.
ELECTRONICS, P. 33 -34, 68,
(22) Bedford, A. V., "Precision
Television
ReSynchronizing Signal Generator," RCA.
view, July 1940.
Amplifiers
(23) Jaffee, D. L., "Wide Band
and Frequency Multiplication," ELECTRONICS.
p. 56-62, April 1942.
(24) Prersman, Albert, "Some Unusual
Features of Our Television System." Communications, Jan. 1940.
51
-A MURRAY STREET, NEW YORK, N. Y.
COrtlandf
7 -9264
SALT SPRAY
General
(25) Fink, D. G., "Principles of TeleCo.
vision," McGraw -Hill B.,Book
"A Simple Television
(26) Sherman, J.
Demonstration System," Proc. 7. R. E., Jan.
1942.
Electronic
(27) Sherman, J. B., "A New
System for the AmaTelevision Transmitting
teur," QBT, May 1940.
(28) Waller, L. C., "An Efficient UHF Unit
for the Amateur Television Transmitter."
QST, July 1940.
W. A.,
(29) North, D. O. and Harris,
Tube Amplifiers and
"Fluctuation in Vacuum
1941.
July
Review,
RC.4
Systems,"
Input
(30) Mountjoy, Garrard, "Television Signal
Frequency Circuit Considerations," RCA Re-
Corrosion Test Equipment
testing -Electroplated or coated metals
at 95 deg. Fah. in accordance with Army,
Navy and Aeronautical specifications, as
outlined in Bulletin AN- QQ- S -91 -5 dated
Dec. 1938. Also for controlled temperaFor
tures from 65° to 130° Fah. Testing Cabinets lined throughout with
rubber. Made in 4 sizes.
'It' ritr for NEW Literature
and particulars."
view, Oct. 1939.
INDUSTRIAL FILTER
& PUMP MFG. CO.
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Radio transmitter tubes are operated at
General Electric radio factories before
they are tested and shipped to the armed
forces. E. M. Scheiber, assistant general
foreman of G -E radio tube factory, is shown
before one of the aging racks
ELECTRONICS
-
December 1942
STEEL
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&
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(Continued from page 67)
SOLOMONS
This is a war of electrical control -and we'd
like to tell you about the scores of ways in
which Automatic Electric Relays are helping
the armed forces
tanks, aircraft, ships and
guns. But the telling might give aid to the
enemy, so this interesting story will have to
wait.
-in
biased negative at the start of the
load capacitor CL charge and moved
in a positive direction as the voltage
across CL increases. At a voltage
determined by the setting of P_ the
grid of tube 12 becomes positive and
this tube conducts to energize the relay CR_. The contacts of this relay
are in the welder control circuit and
prevent welding unless CR, is energized. Once P_ has been properly
set, changing the setting of P, to
change the output voltage automatically adjusts the undervoltage indicating circuit for the changed conditions.
Meanwhile, if you are designing or building
war products that use electrical control, you
can save time and effort by calling in the
Automatic Electric field engineer nearest you.
He will be glad to work with you in selecting
the apparatus best suited to your needs.
Ask him also for our 80 -page catalog describing the complete line of Automatic ElecDischarge Circuits
tric Relays, Switches and other control apparatus. No other book treats the subject so
To discharge a capacitor bank into
completely. Or write to us direct; and we'll
a welding transformer primary and
forward a copy promptly.
AMERICAN AUTOMATIC ELECTRIC SALES COMPANY
1033 West Van Buren St., Chicago,
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RELAYS
AND OTHER CONTROL DEVICES BY
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Professional Services
frmation
you need fo solve your
problems from
prevent reversal of capacitor voltage
should the R, L, and C combination
be less than critically damped, the
circuit shown in Fig. 9 is used. The
discharge circuit consists of the ignitron tube 13 and tiie thyratron
tube 14. Tube 14 is normallq biased
sufficiently negative to prevent conduction. As the discharge indication
is given by the welding machine sequence, a small capacitor is discharged into the primary of transformer T11. This discharge produces
an impulse in the secondary of T1,
sufficient to momentarily drive the
grid of tube 14 positive. Tube 14
conducts to the ignitor of tube 13,
which then conducts the discharge
WEATHER SPOTTERS ON
WHEELS
particular
STANLEY D. EILENBERGER
Consulting Engineer
Complete
NEW 302 -PAGE 1942 CATALOGUE
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State
FI,
12 -42
63
Consultant
Electronics and Communications
Wall Street
New York City
Army
and Navy personnel obtaining
weather data in a mobile weather station.
making use of the most modern meteoro.
logical equipment.
Left to right. Cadet
Otey adjusting the receiving equipment
and Cadet Knudson finding the surface
pressure with microbarograph
December 1942
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ELECTRONICS
`î
of the capacitor CL into the primary
of the welding transformer.
Should the combination of R, L,
and C in the discharge circuit be
such that the circuit is oscillatory,
the voltage across the primary of
the welding transformer will tend to
reverse as the discharge proceeds.
re.Trel
T
0
FP
TERMIeNTAFn1l
\
.
BALL BEARINGS
OTO METAL
iM1 T
PAP'ER
EY
NATVY,S'GNS
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silLN.r.
Cic.ASO.diaas.CS
FLOORING MATERIAL
UI,mLDIINá,.ei éi.n
ANTCI-S cAT15
rN
CONTANFRS
LIOOr.IeieNi
AMOUFLAGE CLOTH
Instantly, when this occurs, the
anodes of the thyratron tube 16 and
the ignitron tube 15 becomes positive. When the reverse voltage
:S
LUMINOUS PAINT
AG
LOADe UR^
\
e,::uF°;N¿
áN,. ieaéEiRa^L
Oru+rrpe
NST
A.-P!
rests
FLEXIBLE
INSULATIONS
COVFRIJ
AIRPLANEYTAS TA
11LIGHtTS\
N
ARMY CAMPS
reaches a sufficient value (100 to 150
volts) tube 16 conducts sufficient
current to the ignitor of tube 15 to
ionize this tube. This operation effectively limits the inverse voltage
applied to the capacitors to a low
AT.itNo
\
TA[PES
C
tor
AIRILDANF PAINTS'
\\
TEST
AIRPLTANEA PLASTICS
PAPER
SANDe BAGS
IL
oO
DIVE.'BOMBER REIA:
TRANSFORMER
'mow
BIAC aOU.T;AMPS
GLASS
5
CORRE
E.T. L. TESTS
value.
of
War P-oducts
Other Considerations
In addition to the electronic cir-
cuits described complete control for
electrostatic energy storage welding
includes sequencing controls and protective equipment for overload, over voltage and faulty operation. In addition, reversing contactors are provided to reverse the connections of
the welding transformer on alternate
welds to prevent accumulative effects
of discharge and possible saturation
of the transformer.
To illustrate some effects of changing constants in the discharge circuit, Fig. 10 has been included. It
will be seen from this that a very
wide control of discharge waveforms
may be obtained to meet the char acteristic i of the metal being
PAMPHLET
A
TESTS PROCEDURES AS
YOUR
LI APPLY U TO
MAYA
PRODUCTION
YOUR COPY
ADDRESS:
Fighting words -these
FOR
ALL requisitioned
The important consideration in
each in LEE own way be
articles for this conflict is that
Effiesent.
Saur(armry, Convenient, Durable.
at E.T.L. are used
Testing and Research Services
of FACTS
presentation
by suppliers to government for
as reassurances to
as assurance to the authorities,
themselves.
STAFF: Moro than ISO, ecporeonìed
In rosr procedures
M
EOUIIPMEENT:
.
than
,
on rnrontpn
talus
throe
Just ask for
"Pamphlet
T
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79th Street at
East End Ave.
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welded.
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ELECTRONICS
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directed exclusively toward serving our armed
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NEW BOOKS
IF YOUR
PIVOT POINTS
IT'S TIME
Principles of Radio
BY KEITH HENNEY. John Wiley and
Sons, New York, N. Y. Fourth Edition. 549 pages. Price, $3.50.
DO
THIS
TO
SPECIFY
IN
THIRTEEN YEARS, "Principles of
Radio" has gone through four editions.
Originally intended to provide a foundation of practical radio knowledge for
the student who had little background
upon which to build and yet who
wanted to know the basis upon which
radio communication existed, the author has constantly kept in mind the
needs of those who must learn without
benefit of an instructor.
This book has been used in trade
schools, for which it was intended, and
in colleges, for which it was not
aimed, according to the preface. During the past year the volume has been
extensively used in radio instruction on
an elementary level and was recommended by the National Association of
Broadcasters as a suitable text for
courses of instruction given under
their sponsorship. The fourth edition
contains nineteen chapters, the first of
which deals with general electrical
fundamentals based on the circuit elements of L, R, and C, and Ohm's and
Kirchoff's laws. The next three chapters deal with alternating currents,
resonance phenomena, and properties
of coils and condensers. Chapters IX
to XIII inclusive deal with the design
of audio and radio frequency amplifiers, while Chapter XIV treats detection. Receiving Systems are treated in
Chapter XV, Rectifiers and Power
Supplies in Chapter XVI, and Oscillators, Transmitters, etc., in Chapter
XVII. The last two chapters deal
with Antennas, Transmission, and
Facsimile and Television Transmission,
respectively. There is a thirteen page
chapter and useful tables on the inside
covers.
Throughout, the aim has been to
provide practical information. Problems are provided in each chapter for
the student to obtain a sense of values
of electrical quantities involved in
radio communication.-B.D.
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TEN YEARS AGO, 1932, Mr. Dunlap published "The Outlook for Television," a
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only looks into the future, but gives
N. Y.
December 1942
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ELECTRONICS
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RHEOSTATS
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WRITE FOR CATALOGUE
showing a complete line of
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\
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are necessary due to
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\
are
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UNIVERSITY LABORATORIES
N. Y. C.
225 Varick Street.
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SIGNAL INDICATOR Corp
140
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FINE RIBBONS
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FLUORESCENT WISE MAKING EQUIPMENT
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ELECTRONIC EQUIPMENT,
Wr:T GLASS slicing and cutting machines for laboratory use
burners
GENERAL GLASS working machines and
COLLEGE GLASS world to units for students and laboratory
EISLER ENGINEERING CO.
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751 So. 13th St. (near Avon Av .)
of Tungsten and Molybdenum
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can frequently help speed up
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FREQUENCY
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bility of Hipower Precision Crystal
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When essential demand begins to return
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ELECTRONICS
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December 1942
ELECTRON
of every
TUBE
type,- stall dmrl.
The socket is
the thing that
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difference
MACHINERY
nd
rw ei -iI d, stun
KAHLE ENGINEERING t'O)II'AN%'
Specialists in Equipment for the manufacture of
Radio Tubes, Cathode stay 'Pubes, Fluorescent
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Cells, X -ray Tubes and other glass or electronic
products, on production or laboratory basi,
1307 -1309 Seventh St., North Bergen, N. J.
A molded bakelite
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Manufacturers of
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0600 Unit
Transmitters
ELECTRONIC
APPARATUS
447 Concord Ave.
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barrier
and two 6-32 terminal screws with
cup washers.
RADIO LAB'S, Inc.
HARVEY
New York
CRYSTALS by
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Of Electronics, published monthly at Albany, N. Y.,
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State of New York J ss.
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Before me, a Notary Public in and for the State and
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178
New Orleans, La.
llol IIlmnnnunnnnuiunnnunuun,mu,
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tise
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ELECTRONICS
enough of the background and the present status so that it stands on its own
feet as a brief summary of the science
of seeing by radio.
The author asks the pertinent questions that have bothered everyone who
has considered television at all seriously, aside from its purely technical
aspects. What is to become of sound
broadcasting? Who is to pay for television? Does television threaten the
theatre? How much will the public pay
to see as well as hear by their radio
sets? This book does not attempt to
answer finally all or even many of
these questions; it lays the facts before
the reader as though to apprise him of
the difficulties and problems the better
to equip him to answer the questions
in his own way. But if the reader
thinks he will find a neat solution to
the broader aspects of television's future in this book, he is due to be disillusioned. Mr. Dunlap is not naive
enough to "stick his neck out" sufficiently in this direction to have his
head cut off.
This book is for non -technical people; but the technicians will find it
very useful as a survey of the non engineering problems.-K.H.
tary". Accordingly, it is written on
a level such that those with high
school physics and mathematics should
be able to obtain an introduction to
radio theory and practice, although
probably not without some assistance
from an instructor. Five of the authors
are associated with colleges teaching
electrical engineering and this assures
a sound pedagogical point of view.
In wisely devoting the first chapter
to the Mathematics of Radio the authors aim to overcome a weakness
which radio instructors find in their
students, namely a lack of facility in
manipulating algebraic and trigonometric expressions even among those who
have been exposed to those topics only
recently. The following two chapters
are devoted to principles of direct and
alternating currents. There are chapters on electronics, power supplies,
sound, amplifiers, vacuum tube instruments, reception, transmission, wave
propagation, antennas and modulation
methods. Each of the sixteen chapters
contains numerous problems, with the
answers to each at the end of the chapter. Occasionally the student's attention is specifically drawn to important
principles or applications in the ultrahigh frequency field, but so much space
is necessarily devoted to basic fundamentals that this cannot be regarded
as a volume of u -h -f methods. There
Fundamentals of Radio
are several folded pages inserted beBY E. C. JORDAN, P. H. NELSON, W. C. tween appropriate pages, showing complete circuit diagrams of radio equipOSTERBROCK, F. H. HUMPHREY, L. C.
SMEBY, and W. L. EvER[TT, editor. ment.
The book is designed for men seekPrentice-Hall, Inc. 400 pages. Price,
ing induction into military services, for
$5.00.
radio operators, and men in the comACCORDING TO THE PREFACE, "the pur- munication
industry. The material
pose of this volume 4 to present the covers fundamentals of radio as outbasic material of radio required for all lined by the National Association of
types of radio work, both civil and mili- Broadcasters. -B.D.
WOMEN IN THE NAVY
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Naval Station. The Women's Royal Australian Naval Service is portraying a
large part in the vital job of defending the seas. Out -door exercise and games
keep them fit for their work which demands a great deal of concentration
ELECTRONICS
-
December 1942
179
lowing. It is being said that political
and geographical history has to be
4000 Years of Television
A line
as
black
as
night !
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Opaque lines! Lines firm and solid,
lines as black as a black feline.
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Jersey City, N. J.
CONTROL
Without Pressure
By RICHARD HUBBELL, Published by G.
P. Putnam's Sons, New York, N. Y.
1942. Price $2.25.
THE STORY OF SEEING at a distance has
been published at a propitious time,
because it initiates the reader into
America's next great industry, an industry that is to play a revolutionary
role when once again a brighter horizon
is to dawn. It should prove an interesting story to all who anticipate a tomorrow and are willing to prepare for
that tomorrow.
The author has treated the subject
with seriousness and with grace like
an important romance culled from history. He commences with the principles
upon which television is based, speaks
of the rock crystal lens discovered in
2000 B.C. in Assyria, and of Thales
the founder of Greek geometry who
made practical use of amber. It dwells
on the lodestone found in Magnesia, of
which our present magnets are the
modern counterpart, and acquaints the
reader with William Gilbert and the
various "stones" he called "electrics ".
From 1891 A.D. after the smallest natural unit of electricity had been named
"electron" the story gains in leaps and
bounds on astounding information, embracing with due reverence the important role of the science of "electronics ".
It tells of the performances at Alexandra Palace, popularly called the "Palace
of Magic" (where this reviewer witnessed intriguing performances), the
fateful day of September 1, 1939 which
closed high- definition television at London's Olympia, and of the vistas that
will open in a televisionized America
after the war.
"4000 Years of Television" is an excellently written book and worthy the
attention of the engineer. To the layman its reading should be regarded as
a fascinating experience because it
brings in nontechnical, yet precise
terms the history and the development
of one of the most miraculous sciences.
Mr. Hubbell comes well prepared for
his task; for many years he has devoted his time and ambition to television. At present he is in charge of
CBS' Television News Dept. and is a
commentator with an appreciable fol-
written again and again, but television's history shall remain the result
of several important sciences combined
into one, and it has found a capable
interpreter in Mr. Hubbell -B.D.
Short Course in Tensor
Analysis for Electrical Men
A
Consulting
neer, General Electric Company,
nectady. John Wiley & Sons,
York. 250 pages. 146 figures.
BY GABRIEL KRON,
EngiScheNew
Price
$4.50.
THE MATERIAL IN THIS VOLUME is essen-
tially that contained in a series of lectures delivered to students in the advanced course in engineering of the
General Electric Company, and already
recorded in considerable detail in a
series of articles in the General Electric Review during the past seven or
eight years. The primary purpose of
the volume is to establish an organized
system for solving the equations of
performance of engineering problems.
Specifically the volume is concerned
with problems encountered in the field
of electric power generation and distribution, but the electrical applications are only used to illustrate the
basic concepts which are of considerably wider application.
The book is divided into two parts:
In the first part of the volume which
contains 112 pages divided into fourteen chapters, the fundamentals of
matrix algebra are established after
which they are applied to unbalanced
multi -winding transformers, symmetrical components, phase shift transformers, and the field equations of
Maxwell, and the mercury arc rectifier.
Part II of the volume is devoted to
rotating machinery and contains eighteen chapters. In this section the principles of tensor analysis are applied to
various systems employing rotating
electrical machinery.
In general the volume is one which
will make its appeal to the mathematically inclined investigator or research engineer who is concerned with
generalizing the methods available to
him through the usual three- dimensional vector analysis. -B.D.
Electronic Switches
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Operation 110 Volts AC.
Write for bulletin D
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NORRISTOWN, PA.
Pacific
Cent Headquarters: 544 S. Sae Pedro St., Las Angela, Cal.
Manufacturers of Electronic Controls
December 1942
180
www.americanradiohistory.com
-
ELECTRONICS
Index to
electronics
Volume XV
January to December issues, inclusive, 1942
McGraw -Hill Publishing Company
330 West 42nd St., New York
Mar.
fier
Audio frequency compensating cirSept.
cuits. Stanley Cutter
Circuit elements in electrical remote
Dec.
control. Dorr & Galton
Circuit for cathode ray photography.
Sept.
H. C. Roberts
S.
Controlled transitron oscillator
July
R. Jordan
Delayed single sweep circuit to be
used in conjunction with cathode
ray oscilloscope. W. E. Gilson Mar.
Electronic counter for rapid impulses.
Wellman & Roeder
Oct.
Accoustics:
Atmospheric propagation of sound...
Dec. 102
Aeronautics:
Aircraft antenna charts. P. J. Holmes
Dec. 46
Commercial aircraft aids
Dec. 86
Amplifiers:
Amplitude characteristic of an amplifier
Mar. 80
Controlled transitron oscillator. S. R.
Jordan
July 42
Flexible equalizing amplifier. E. G.
Cook
July 36
Graphical determination of power amplifier performance.
R. I. Sarbacher
Dec. 52
Hearing aid design. Ira Kamen July 32
Improved amplifier for frequency
modulation transmitters
Nov. 106
Relaxation amplifier
June 145
Telephone amplifier for power company circuits. W. H. Blankmeyer..
Apr. 78
Wide band amplifiers and frequency
multiplication. D. L. Jaffe.... Apr. 56
Broadcast Engineering Conference of 1942:
Program
Feb. 84; Apr. '30
wood
Cameras:
Camera, electroplane
pt. I
Mar.
44
Aug.
-
24
Oct.
Circuits:
Amateur television station. Maunter
& Somers
Dec.
Amplitude characteristic of an ampli-
ELECTRONICS
34
63
60
82 Contacts:
Rhodium contacts
Jan.
39
36 Electron Tubes:
77
Amplification factor with square mesh
Cathode Rays:
Applications of cathode ray tubes.
Beverly Dudley
Oct.
Circuit for cathode ray photography.
H. C. Roberts
Sept.
Delayed single sweep circuit to be
used in conjunction with cathode
ray oscilloscope. W. E. Gilson Mar.
Graphical analysis of saw tooth
waves. U. R. Furst
July
High speed oscillography
July
Time bases
July
Wave form circuits for cathode ray
tubes H. M. Lewis, pt. 1, July 44;
59
65
'49
74
70
68
57
'59
'42
'65
'74
88
grids
Dec. 106
Classification of electron tubes (table)
June 52
Controlled transitron oscillator. S. R.
Jordan
July 42
Electron tube terminology.
W. C.
White
Dec. 42
Gaseous tubes-and how to treat
them. Watrous & Marshall
Jan. 422
Industrial tubo characteristics June '52
List of tubes barred from manufacture for civilian use
May 93
Non -metal shields. B. H. Porter....
Apr. 33
Radiation instruments using Geiger
Muller tubes. Paul Weisz
Oct. 44
Rheotron a new electronic tool Feb. 22
Rheotron or induction accelerator July 76
Tubes and their functions
June 61
Vacuum type trigger tube using secondary emission
Oct. 100
49
48
'80
'63
Electronic differentiation
June 143
Electronic phase-angle meter. E. L.
May 60
Ginzten
Electronic phase bridge for measureNov. 96
ments
Evaluating the transmission characteristics of four -terminal networks. E. S. Purington, pt. 1 Nov. 54
F.
Harmonic wave analyzer.
R
Dec. 61
Thomson
Impedance determinations of eccentric lines. G. H. Brown (Ref. Sheet)
Feb. 49
Impedance magnitude and phase shift
curves. V. L. Edutis (Ref. Sheet)..
Nov. .76
L -type impedance transforming circuits. P. H. Smith
Mar. *48
Low- frequency timing circuits. C. E.
Berry
Oct. 84
Propagation constant and characteristic impedance of high loss lines.
Karl Spangenberg (Ref. Sheet) .Aug. '57
Reactance tubes in frequency modulation applications. August Hund..
Oct. '68
Simplified inductance chart. E. S.
Purington (Ref. Sheet)
Sept. 61
Solenoid inductance calculations. T.
C. Blow (Ref. Sheet)
May '63
Some graphic solutions of parallel
circuits. R. C. Paine
Dec. 90
"T" to "Pi" transformations simplifled. H. Stockman
Oct. '72
10- megacycle oscilloscope
Feb. 72
Unsymmetrical attenuators. P M.
Honnell
Aug. '41
Wave form circuits for cathode ray
tubes. H. M. Lewis, pt. 1, July 44;
pt. 2
Aug. '48
Wide band amplifiers and frequency
multiplication. D. L. Jaffe
Apr. 66
Antennas:
Aircraft antenna charts. P. J. Holmes
Dec. 46
Radiating systems and wave propagation. A. G. Kandolan
Apr. 39
Broadcasting:
Acoustics at the new NBC studios....
Mar.
Audio frequency compensating circuits. Stanley Cutler
Sept.
Automatic air raid monitor
July
Broadcasting under war conditions.
Epperson & Dudley
Aug.
Conserving station equipment. A. H.
Smith
Nov.
Electronic device to relieve broadcast
station operators of monitoring another station. Frank Marx.
Mar.
Flexible equalizing amplifier. E. G.
Cook
July
Reducing fader leakage. J. H. Green-
City
Electron Tubes -Applications:
Analyzing high -speed action
Jan. 80
Anti -electrolysis relay. Davis & Wainwright
Mar. 72
Automatic blood pressure recorder.
W. E.
Gilson
May '54
December 1942
Automatic control for grinding ma- 82
Nov.
chine feed motors
Ballast tubes as automatic voltage
Jan. 26
regulators. S. G. Taylor
Feb. 38
Burglar -alarm systems
Carbon arc control unit. Wilbur Fla- '65
Mar.
herty
Checking auto breaker -points by elecApr. 34
tronics. G. V. Eltgroth
Dec. '82
Control for one way tunnel
CalElectrical remote control. Dorr & Dec.
57
ton, pt. 1, Nov. 60; pt. 2
Dec. 86
Electrolytic tin plating
Electronic counter for rapid impulses. 74
Oct.
Wellman & Roeder
June 143
Electronic differentiation
Electronic robot measures creep of '86
Nov.
metals
Electronic welding control. H. L.
Palmer, pt. 1, Aug. 36; pt. 2, M.
E. Bivens, Sept. 55; pt. 3, M. E.
Bivens, Oct. 62; pt. 4, S. A. Clark,
Dec. 63
Nov. 65; pt. 5, G. L. Rogers
Electronics at the Chemical ExposiJan. 56
tion
Electronics serves transportation inSept. 63
dustry
Mar. 44
Electroplane camera
Feedback for stabilizing light- valves.
May 84
May 88
50 -kv voltage stabilizer
F.
R
Harmonic wave analyzer.
Dec. 61
Thomson
Heating by high- frequency induction.
June 142
High speed relay and switch tester..
Sept. 70
Industrial temperature control by
Dec. 72
electronics. M. F. Behar
Mar. 73
Intrusion detection system
Jan. 72
Nail detector
An oscillator for remote frequency
Sept. 42
control. H. C. Lawrence
Photoelectric controlled coal larry..
Dec. 84
Photoelectric densitometer. C. C.
Dec. 80
Smith
Mar. 70
Photoelectric scanner
Photoflash synchronizer tester. P. A.
Jan. 34
Mareal
Phototubes in multicolor printing...
Feb. 72
Radio frequency heating speeds plywood bonding
Nov. 79
Reactance tubes in frequency modulation applications. August Hund..
Oct. 68
Recording low intensity flashes Oct. '108
Revolving door controlled by photo tube
Mar. 72
Thorium detector
Dec. 82
Tubes and their functions
June 61
Tubes at work
June 70
Universal electronic relay. L. F Boss
May 68
Wired radio controls street light circuits
Feb. 80
.
Engineering:
Electronics and communication courses
in American colleges
Sept.
Engineering, Science, and Management
Defense Training. Beverly Dudley.
84
Mar. '36
Filters:
Notes on band pass and band rejection filters. H. Holubow
Aug.
Frequency Modulation:
Frequency -modulated
reproduction
control for sound films
Mar.
Frequency modulation carrier current
telephony. Braulio Dueno
May
Inductively coupled frequency modulator
Jan.
Modern 10 -kw frequency- modulation
transmitter. Winlund & Perry.Mar.
Modulation relations. August Hund..
054
88
57
80
40
Sept. 48
181
www.americanradiohistory.com
Principles of frequency -modulation applied to carrier- current telegraph..
Apr. *106
Reactance tubes in frequency modulation applications. August Hund...
Oct.
Harmonics:
Harmonic analysis schedules.
G. Denman
68
R. P.
Sept. *44
Hearing Aids:
Hearing aid design. Ira Kamen..July
Telephone set for hard of hearing...
*32
Dec. *106
High Frequency:
Electrical concepts at extremely high
frequencies. Simon Ramo.... Sept. *34
Generators for ultrahigh frequency.
Mouromtseff, Retherford & Findley.
Apr. *45
Measurements in the ultrahigh frequency spectrum. R. F. Lewis..Apr. *63
Pennsylvania Turnpike ultrahigh frequency traffic control system.May *34 -51
Radiating systems and wave propagation. A. G. Kandoian
Apr. *39
Skin effect formulas. J. R. Whinnery
Feb. 44
Ultrahigh frequency reception and receivers. Beverly Dudley
Apr. *51
Wide band amplifiers and frequency
multiplication. D. L. Jaffe
Apr. *56
Wide -band high- frequency sweep generator. Bussard & Michel
May *58
Inductance Chart:
Inductance chart.
(Ref. Sheet)
E.
S.
Purington
Sept.
61
Institute of Radio Engineers:
Cleveland convention
Aug. 62
Feb. '31
Convention in New York City
Program for convention
Jan. 76
Iron cores, Powdered, used by radio..Feb. *35
Laboratory Practice:
Photographic short cut in making
laboratory records. S. G. Taylor...
Feb.
RCA dedicates new electronics laboraNov.
tories
Manufacturers, directory of
*64
*52
June D -1
Measurements:
Cathode -ray oscillograph tor freApr. '94
quency comparisons
Cathode -ray oscilloscope impedance
comparator.
Vincent Salmon Feb. 54
Checking auto breaker -points by elecApr. *34
tronics. G. V. Eltgroth
Circuit for cathode ray photography.
Sept. *59
H. C. Roberts
Aeronautics
Administration's
Civil
part in instrumentation
Jan. 89
Continuance balance potentiometer
pyrometer. Towne & Considine....
Aug. 92
Direct- reading
aircraft
insulation
tester. W. N. Lambert
Apr. 84
Direct reading densitometer
July *68
Direct- reading impedance comparator
Nov. *88
Electric tool -pressure gage
Feb. *78
Electro- kymograph. Moore & Bloomer
July *51
Electronic phase -angle meter. E. L.
Ginzton
May *60
Electronic phase bridge for measurements
Nov. *96
Electronic profilometer
Aug. *94
Electronic watt -hour meter tester..
Apr. *82
Electronics in the measurement of
dielectric constants
Oct. 116
Extending range of meters
Dec. 114
Feedback voltmeter
July 54
Field intensity recorder. H. W. Kline
Jan. *50
The Fluxgraph. P. G. Weiller May *52
Harmonic wave analyzer.
R
F.
Thomson
Dec. 61
High frequency field strength measurements
Nov. *96
High speed oscillography
July *74
Hydrogen moisture check by direct
electronic method
Aug. *100
Instrument for measuring surface
roughness. C. K. Gravley
Nov. 70
Liquid column varies quartz plate resonance frequency
Apr. 100
Low- frequency timing circuits. C. E.
Berry
Oct. *84
Mass spectrometer
Dec. 102
Measurements of very short wavelengths
Dec. 108
Moisture determination in non -polar
compounds. H. Loughnane
Aug. '9S
Phase meter calibrator.
Dawkins
Espy
Oct. *80
Photoelectric densitometer.
C.
C.
Smith
Dee. *80
Photoelectric width gage. E. H Alexander
Jan. *66
Phototube control dynamometer load
Oct. 110
Precision frequency comparisons.Apr. *92
Rectilinear rectification applied to
voltage integration. S. S. Stevens
Jan. *40
Sensitive feedback voltmeter with
rugged milliameter indicator. Lawrence Fleming
Apr. 88
Surface analyzer
July 54
Temperature measurement and control by electronics. Craig Walsh..
Oct. 56
10- megacycle oscilloscope
Feb. 72
36 and 72 ordinate schedules for general harmonic analysis. R. P. G.
Denman
Sept. *44
Transient peak voltmeter
Oct. 104
Transmitter production test
Aug. '94
Two aids for transient study
May *76
Wave analysis by cathode -ray oscilloscope
Jan. 84
Wide -band high- frequency sweep generator. Bussard & Michel
May 58
Microphones:
Super -cardioid directional microphone.
B. B. Bauer
Jan.
Correction
Mar.
*31
94
Radio Components:
Metal -coated mica condensers ...July
July
Solder fluxes
82
82
Receivers:
30 -40 nie receiver for the U. S.
Forest Service. Lawson & BelleJan. 22
ville
Production of broadcast receivers for
Jan. 100
nine months of 1941
Radio receiver production Oct., Nov.
Mar. 104
1940 and 1941
Superheterodyne tracking simplified.
Nov. *74
P. C. Gardiner
Superheterodyne tracking solution.
Feb. 4'39
Rinaldo De Cola
Transmitter -controlled receiving sysJan. *86
tem
Ultrahigh frequency reception and reApr. '11
ceivers. Beverly Dudley
Mobile
Recording:
Feb. *24
Automatic record changers
Embossed groove recording. Lincoln
Mar. '30
Thompson
Machinery noise characteristics reNov. *46
corded. H. D. Brailsford
response scanning slit Optimum
June 140
image. George Logan
Photographic short cut in making
laboratory records. S. G. Taylor..
Feb. *64
Preamplifier -filter for crystal pickup.
Apr. *78
Charles Affelder
Networks:
Design chart for phase shifting and
amplitude control networks. W. S.
Duttera
Oct. 53 Rectifiers:
Evaluating the transmission characDec. 100
ignitron rectifier in industry
teristics of four -terminal networks.
Kinescope power supply. Esten Moen
E. S. Purington, pt. 1
Nov. *54
May *68
Impedance magnitude and phase shift
Rectilinear rectification applied to
curves. V. L. Edutis (Ref. Sheets)
voltage integration. S. S. Stevens..
Nov. *76
Jan. '40
Impedance of some simple electrical
Voltage surges in rectifier circuits...
circuits.
Beverly Dudley (Ref.
Oct. 114
Sheet)
Dec. 79
L -type impedance transforming circuits. P. H. Smith
Mar. 48
"T" to "Pi" transformations simpliReference Sheets:
fied.
H. Stockman
Oct. 72
Graphical analysis of saw tooth waves.
Unsymmetrical attenuators. P M.
July 549
U. R. Furst
Honnell
Aug. '41
Graphs for transmission lines. BerJan. *47
nard Salzberg
Graph of impedance of eccentric conductor cable. Barclay & SpangenOscillators:
Feb. *50
berg
Generators for ultrahigh frequency.
Impedance determinations of eccentric
Mouromtseff, Retherford & Findley
Feb. *49
lines. G. H. Brown
Apr. 45
Impedance magnitude and phase shift
Nov. 76
curves. V. L. Edutis
Impedance of some simple electrical
Dec. 79
circuits. Beverly Dudley
Patents:
Propagation constant and characterArnold's aim
to correct abuses
istic impedance of high loss lines.
Ncv. *4 2
Aug. *57
of patent system
Karl Spangenberg
Feb. 7 6
Patent law handbook
Simplified copper wire calculations.
Patent pitfalls. Rodolph Wild Dec. 7 8
Leonard Tulauskas
Oct. 75
Rebuttal to Arnold
change in
Simplified Inductance chart.
E. S.
patent system not advisable
Nov. 44
Sept. 61
Purington
Solenoid inductance calculations. T. C.
.
May
Blow
Photoflash:
Photoflash synchronizer tester. P. A.
Marsal
Jan.
*34
Plastics:
Plastics in the electronics field. John
July 26
Sasso
Radio:
Nazi aircraft radio. J. H. Jupe..Nov.
1941 radio audience statistics.... Mar.
Public utility emergency radio system.
May
W. H. Blankmeyer
Dec.
Radio in U. S. Army
Jan.
Ship to shore radio unit
Standby filament saver for police
transmitters. J. E. Wa.genseller..
May
Feb.
Uses of powdered iron cores
58
*84
*65
*50
Relays:
Circuit elements in electrical remote
Dec. 57
control. Dorr & Galton
Nov. '102
Sensitive tube relay
Sound Pictures:
Frequency - modulated
reproduction
Mar. 88
control for sound films
Standards:
New radio standards
Oct. 110
36 Television:
*65
35
Amateur television station. \taunter
Dec.
& Somers
an agency for preTelevision
paredness. N. E. Kersta
'llar.
Television in national defense. .. July
Three -dimension color television May
.
Radio Communications:
July *54
Airport control console
Bibliography of submarine communication
Oct. 116
Carrier -current telegraph system....
Apr. *106
Carrier current telephony. Braulio
Dueno
May *57
Commercial aircraft aids
Dec. *86
Corrosion of communication systems
Feb. 82
Electronic switching simplifies power line communications. J. D. Booth.
Aug. *44
OCD carrier current tests for air
raids
Aug. 59
Pennsylvania 'turnpike ultrahigh frequency traffic control system
May *34 -51
Ship to shore radio unit
Jan. *36
Uni -directional carrier -current communicator. J. L. Smith
Feb. *54
U. S. Forest Service communication
facilities
.Jan. 80
Therapeutics:
Automatic blood
W.
E.
Gilson
www.americanradiohistory.com
68
*26
SO
*76
pressure recorder.
May *54
Timers:
Welding control timers.
pt. 4
S. A.
Clark,
Nov. *65
Transmission Lines:
Concentric transmission line as harMay 63
monic filter. R. E. Snoddy
Graphs for transmission lines. Bernard Salzberg tRef. Sheets) ...Jan. '47
Graph of impedance of eccentric conductor cable. Barclay & Spangenberg (Ref. Sheets)
Feb. 50
December 1942
182
63
-
ELECTRONICS
Impedance determinations of eccenBrown (Ref.
tric lines.
G. H.
Feb.
Sheets)
Measurements in the utrahigh frequency spectrum. R. F. Lewis.Apr.
Propagation constant and characteristic impedance of high loss lines.
Karl Spangenberg (Ref. Sheets)..
*49
*63
Aug. *57
Voltage Regulators:
Ballast tubes as automatic voltage
Jan. 26
regulators. S. G. Taylor
Welding:
Electronic welding control. H. L.
Palmer, pt. 1, Aug. 36; pt. 2, M. E.
Bivens, Sept. *55; pt. 3, M. E.
Bivens, Oct. 62; pt. 4, S. A. Clark,
Nov. *65; pt.
5, G.
L.
Rogers....Dec.
Wire Calculations:
Wire calculations, copper.
Tulauskas (Ref. Sheets)
Leonard
Oct.
-l- -rays:
63
AUTHORS' INDEX
Preamplifier Apr. 78
filter for crystal pickup
Photoelectric width
Alexander, E. H.
Jan. 66
gage
AFFELDER, CHARLES.
BARCLAY, WILLIAM J. & KARL
SPANGENBERG. Graph of impedance of eccentric conductor
Feb.
cable
Bauer, B. B. Super- cardioid directional
microphone, Jan. 31; correction
Mar.
Behar, M. F. Opportunities for electronics
in industrial temperature conDec.
trol
Belleville, L. M. & H. K. Lawson. Mobile
30 -40 me receiver for the U. S.
Jan.
Forest Service
Berry, Clifford E. Low- frequency timing
Oct.
circuits
Bivens, M. E. Seam and pulsation welding controls, pt. 2, Sept. 55; pt.
3
Oct.
Blankmeyer, W. H. Public utility emergency radio system
May
Telephone amplifier for power comApr.
pany circuits
Bloomer, Harlan & Charles Moore. Versatile electro- kymograph
July
Blow, Thomas C. Solenoid inductance
calculations
May
Booth, J. D. Electronic switching simplifies power -line communications
Aug.
Boss, Lester F. Universal electronic relay
May
Brailsford, H. D. Recording machinery
noise characteristics
Nov.
Brown, George H. Impedance determinations of eccentric lines
Feb.
Bussard, E. J. H. & T. J. Michel. Wide band high -frequency sweep generator
May
CLARK,
50
94
72
22
84
-
45
34
C. Some graphic soluDec. 90
tions of parallel circuits
Palmer, H. L. Electronic welding control,
Aug, *36
pt. 1
10Perry, C. S. & E. S. Winlund. Modern
kw frequency- modulation transMar. *40
mitter
Porter, Bernard H. Non -metal shields..
Apr. 33
Purington, E. S. Simplified inductance
Sept. 61
chart
Symmetrical electrical systems, pt. 1
PAINE, ROBERT
FINDLEY, J. H., I. E. MOUROMTSEFF
Gen& R. C. RETHERFORD.
erators for ultrahigh frequency..
Apr.
Flaherty, Wilbur. Electronic control for
Mar.
carbon arcs
Fleming, Lawrence. Sensitive feedback
voltmeter with rugged milliameter
Apr.
indicator
Furst, Ulrich R. Graphical analysis of
July
saw tooth waves
45
65
88
49
GALTON, L. N. & C. J. DORR. Circuit
elements in electrical remote conDec.
trol, pt. 2
Electrical remote control, pt. I Nov.
Gardiner, P. C. Superheterodyne trackNov.
ing simplified
Gilson, W. E. Automatic blood pressure
May
recorder
Cathode ray oscilloscope delayed single sweep circuit
Mar.
Ginzton, Edward L. Electronic phase angle meter
May
Gravley, Charles K. Instrument for measNov.
uring surface roughness
Greenwood, James H. Reducing fader
leakage
Oct.
57
60
74
54
65
60
70
77
HOLMES, PAUL J. Aircraft antenna
charts
Dec.
Holubow, H. Notes on band pass and
Aug.
band rejection filters
Honnell, P. M. Unsymmetrical attenuators
Aug.
Hund, August. Modulation relations Sept.
Reactance tubes in frequency modulation applications
Oct.
46
54
41
48
68
D. L. Wide band amplifiers and
65 ¡AFFE,frequency
..Apr. '56
multiplication
Stanley R. Controlled transi 78 Jordan, tron
July 42
oscillator
51 Jupe, John
63
44
'68
*46
49
H.
Nazi aircraft radio Nov. *58
KAMEN, IRA. Hearing aid design.July '32
Kandoian, A. G. Radiating systems and
Apr. 39
wave propagation
an
Kersta, Noran E. Television
Mar. 26
agency for preparedness
Kline, H. W. New field intensity recorder
58
Jan.
*50
LAMBERT, W. N. Direct -reading airApr. 84
craft insulation tester
Lawrence, Howard C. An oscillator for
Sept. 42
remote frequency control
Lawson, H. K. & L. M. Belleville. Mobile
30 -40 me receiver for the U. S.
Forest Service
Jan. 22
Lewis, H. M. Wave form circuits for
cathode ray tubes, pt. 1, July
Aug. 48
44; pt. 2
Lewis, R. F. Measurements in the ultraApr. 63
high frequency spectrum
Logan, George. Optimum response scanning slit -image
June 140
Loughnane, H. Moisture determination
in non -polar compounds
Aug. 98
34
.
ELECTRONICS
51
Oct. *80
C. R. & R. M. WAINWRIGHT.
Anti -electrolysis relay
Mar. '72
tracking solution
Feb. *29
Denman, R. P. G. 36 and 72 ordinate
schedules for general harmonic
analysis
Sept. *44
Dorr, C. J. & L. N. Galton. Circuit elements in electrical remote conMARSAL, P. A. Photoflash synchrotrol, pt. 2
Dec. 57
nizer
Jan.
Electrical remote control, pt. 1 Nov. 60 Marshall, D. E.tester
& W. W. Watrous. GaseDudley, Beverly. Applications of cathode
ous tubes -and how to treat them
ray tubes
Oct. *49
Jan.
Engineers train for victory
Mar. 36 Marx, Frank. Automatic monitoring cirImpedance of some simple electrical
'liar.
cuit
circuits
Dec. 79 Maunter, Robert & F. J. Somers. An amaUltrahigh frequency reception and reteur television station
Dec.
ceivers
Apr. *51 McGraw, James H. Jr.
"Ten silver
Dudley, Beverly & J. B. Epperson. Broadmonths"
Mar.
casting under war conditions.Aug. 34
What can I do'
Jan.
Dueno, Braulio. Frequency modulation
Michel, T. J. & E. J. H. Bussard. Wide carrier current telephony
May *57
band high- frequency sweep genDuttera, W. S. Phase shifting and amerator
May
plitude control networks
Oct. 53 Moen, Esten. Kinescope power supply..
De Cola, Rina. Ido. 'Superheterodyne
*34
*62
S. A.
Timers for welding control, pt. 4
Nov. 65
Considine, D. M. & R. D. Towne. Continuous balance potentiometer pyrometer
Aug. *92
Cook, E. G. Flexible equalizing amplifier
July *36
Cutler, Stanley. Audio frequency compensating circuits
Sept. 63
DAVIS
*76
Nov.
54
75
Nov. 104
Grid controlled x -ray tube
Versa& Harlan Bloomer.
July
tile electro- kymograph
&
Retherford
R.
C.
Mnuromtseff, T. E..
Generators for
J. H. Findley.
Apr.
frequency
ultrahigh
Moore, ('harles
ImpeLEOPOLD.
dance magnitude and phase shift
Nov.
curves
Eltgroth, G. V. Checking auto breaker Apr.
points by electronics
Epperson, J. B. & Beverly Dudley. Broadcasting under war conditions.Aug.
Espy, Dawkins. Phase meter calibrator..
EDUTIS. VITOLD
42
*39
68
25a
21a
58
Slay *t;8
December 1942
at
RAMO, SIMON. Electrical conceptsSept.
*34
extremely high frequencies..
&
Retherford, R. C., T. E. Mouromtseff for
Generators
J. H. Findley.
Apr. 45
ultrahigh frequency
Roberts, Howard C. Circuit for cathode
Sept. *59
ray photography
Roeder, Kenneth & Bertram Wellman.
Electronic counter for rapid imOct. '74
pulses
SALMON, VINCENT. Cathode -ray oscilloscope impedance comparator...
Feb.
Salzberg. Bernard. Graphs for transmisJan.
sion lines
Sarbacher, R. I. Graphical determination
of power amplifier performance..
Dec.
Sasso, John. Plastics in the electronics
July
field
Smith, Alvin H. Conserving station equipNov.
ment
Smith, Carl C. Photoelectric densitomDec.
eter
Smith, James L. Simple uni- directional
carrier- current communicator....
Feb.
L-type impedance
Smith, Phillip H.
Mar.
transforming circuits
Snoddy, Raymond E. Concentric transmission line as harmonic filter...
May
Somers, F. J. & Robert Maunter. An
Dec.
amteur television station
Spangenberg, Karl. Propagation constant
and characteristic impedance of
Aug.
high loss lines
Spangenberg, Karl & W. J. Barclay. Graph
of impedance of eccentric conducFeb.
tor cable
Stevens, S. S. Rectilinear rectification
applied to voltage integration...
Jan.
Stockman, H. "T" to "Pi" transformaOct.
tions simplified
TAYLOR, S. GORDON. Ballast tubes
as automatic voltage regulators..
Jan.
Photographic short cut in making labFeb.
oratory records
*54
*47
52
26
82
80
*54
48
68
68
57
50
40
72
226
*64
Thompson, Lincoln. Embossed groove recording
Mar. 30
Thomson, R. F. Simple harmonic wave
Dec. 61
analyzer
Towne, Robert D. & D. M. Considine.
Continuous balance potentiometer
Aug. *92
pyrometer
Tulauskas, Leonard. Simplified copper
Oct. *75
wire calculations
Standby
JOHN E.
WAGENSELLER,
filament saver for police transMay
mitters
Wainwright, R. M. & C. R. Davis. Anti Mar.
electrolysis relay
Walsh, Craig. Temperature measurement
and control by electronics
Oct.
Watrous, W. W. & D. E. Marshall. Gaseous tubes -and how to treat them
.ran.
Werner, P. G. The Fluxgraph
May
Weisz, Paul. Radiation instruments using
geiger mutter tubes
Oct.
Wellman, Bertram & Kenneth Roeder.
Electronic counter for rapid imOct.
pulses
Whinnery, J. R. Skin effect formulas...
Feb.
White, W. C. Electron tube terminology
Dec.
Wild, Rodoti h. Patent pitfall,:
Dec.
\\-inlund. E. S. & C. S. Perry. Modern 10kw frequency- modutaI ion trans mitter
Mar.
*05
72
*56
42
52
*44
*74
44
42
70
*40
183
www.americanradiohistory.com
INDEX TO ADVERTISERS
EAR TEST
Acheson Colloids Corp
.\erovox Corp.
Allied Control Co
Allied Radio Corp
. \merican
Lava Corp
American Radio Hardware Co., Inc
American Screw Co.
American Television & Radio Co
American Transformer Co.
164
160
136
167
16
156
24
154
127
\mperex Electronic Products
Inside Front Cover
Amperite Co.
165
Arnold Engineering Co
166
.
AUDAX has mastered wide -range so
thoroughly that, today, even the
lowest priced MICRODYNE has a range
(other models over
to 7,000 cycles
10,000 cycles) .
True, wide -range
-
--it
makes for naturalness but,
is highly
objectionable if without quality.
For example, of two full -range pianos,
of different make, one may have pleasing quality,-while the other not at all.
Likewise,-full range in a pickup does
not mean quality. To achieve EAR ACCEPTABILITY, all other factors
must be satisfied. Of these "VIBRATORY-MOMENTUM" is most important. (Needle pressure, point impedance, etc., are comparatively secondary).
Science knows of no way to determine
the EAR -ACCEPTABILITY of a pickup.
As with all musical instruments, to decide that, it must be put to the only
test that really counts . . . the EAR TEST.-The sharp, clean -cut facsimile
performance of MICRODYNE (inductive),- regardless of climatic conditions,-is a marvel to all who know that
EAR -ACCEPTABILITY is the final
criterion.
WITH OUR COMPLIMENTS
"PICKUP FACTS" is yours
for the asking. It answers many questions concerning record reproduction.
A copy of
HIGH
FIDELITY CUTTERS
If there is any information
you wish, do not hesitate to
write us.
AL"I)AH COMPANY
500 Fifth Ave.
[
New York City
In Chicago. 'phone: Webster 48401
"Creators of High Grade Electrical
and Acoustical Apparatus since 1915."
Audak Co.
184
Automatic Electric Co.
174
Avery Adhesives
134
Barker and Williamson
96
Bendix Aviation Corp
25
Biddle Co., James G
158
Blaw -Knox Co.
118
Bliley Electric Co
161
Brach Mfg. Corp., L. S
175
Bradley Laboratories, Inc.
148
Brand & Co., William
11
Bristol Co.
24
Bud Radio, Inc
150
('allite Tungsten Corp
84
Cannon Electric Development Co
92
Capitol Radio Engineering Institute
172
Carborundum Co.
20
Cardwell Mfg. Corp., Allen D
94
Carter Motor Co
166
Celanese Celluloid Corp
29
Centralab Div., Globe Union, Inc
4
Central Screw Co
24
Chandler Products Corp
24
Chicago Telephone & Supply Co
111
Chicago Transformer Corp
149
Cinaudagraph Speakers, Inc
98
Cinch Manufacturing Corp
83
Clare & Co., C. P
121
Clarostat Mfg. Co., Inc
167
Cohn, Sigmund
169
Connecticut Telephone & Electric Corp
32
Continental -Diamond Fibre Co., Inc
145
Continental Screw Co
24
Corbin Screw Co
24
Cornell- Dubilier Electric Corp
13
Cross, H.
177
Haven Co.
Inside Back Cover
De Jur -Amsco Corp.
37
Dinion Coil Co
146
Dixon's Typhonite ELDORADO Pencils
180
Driver Co., Wilbur B
167
DuMont Labs., Allen B
113
Eicor, Inc.
157
Eisler Engineering Co
177
Eitel- McCullough, Inc.
103
Electrical Testing Laboratories, Inc
175
Electro -Voice Mfg. Co., Inc
122
Emby Products Co
132
Erie Resistor Corp
8
Espey Mfg. Co., Inc
128
Fairchild Aviation Corporation
163
Federal Telephone & Radio Corp
26, 131
Felker Mfg. Co
36
Ferranti Electric, Inc
103
Formica Insulation Co
19
General Ceramics & Steatite Corp
27, 85
General Electric Co
80. 81, 123
General Radio Co.
125
G -M Laboratories, Inc
122
Goat Metal Stamping, Inc
148
Gothard Mfg. Co
170
Gould -Moody Co.
144
87
12
Guardian Electric Mfg. Co
Hallicrafters Co.
Hammarluncl Mfg. Co., Inc
Hardwick- Hindle. Inc.
Harrison Radio Corp.
Harvey Radio Co
Harvey Radio Lab's., Inc
Harvey-Wells Communications. Inc
Haydon Mfg. Co., Inc
Heintz & Kaufman, Ltd
Hewlett- Packard Co.
Hipower Crystal Co
Hudson Wire Co
Hunter Pressed Steel Co
IIytron
10
18
177
177
177
155
159
30
108
177
124
33
Corp.
Industrial Condenser Corp
Industrial Filter & Pump Mfg. Co.
Industrial Timer Corporation
Instrument Resistors Co
insuline Corp. of America
International Tel. & Tel. Corp
International Resistance Co
International Screw Co
Irvington Varnish & Insulator Co
Isolantite, Inc.
28
162
173
140
138
IOU
26,
Jefferson Electric Co
Jefferson- Travis Radio Mfg. Co
Jensen Radio Mfg. Co
Tones. Howard
13
Kahle Engineering Co
Kellogg Switchboard & Supply Co
Kenyon Transformer Corp
Kester Solder Co
Keuffel & Esser Co
Kirkland Co., H. R
bold -Hold Mfg. Co
Lafayette Radio Corp
I.ampkin Laboratories
Lamson & Sessions Co
www.americanradiohistory.com
3
177
146
Lapp Insulator Co
Lavoie Laboratories
Lepel High Frequency Lab's., Inc
Lewyt Metal Products Co
Linde Air Products Co
Lingo & Son, Inc., John E
Lord Manufacturing Co
L -R Manufacturing Co
Mallory & Co., Inc., P. R
McGraw -Hill Book Co., Inc
Meissner Mfg. Co
Millen Mfg. Co., Inc., James
University Laboratories
Utah Radio Products Company
Walker Turner Co., Inc
Ward Products Corp
Western Electric Co
Weston Electrical Instrument Corp
White Dental Mfg. Co., S. S
Whitney Screw Corp
Wiley & Sons, Inc., John
Wilson Co., H. A
Wincharger Corp.
Zophar Mills, Inc
PROFESSIONAL SERVICES
31
89
24
100
97
86
17
107
146
177
163
128
151
177
24
35
159
176
153
160
152
129
179
40
120, 168
179
101
Minneapolis -Honeywell Regulator Co
152
Mitchell -Rand Insulation Co., Inc
173
Mycalex Corporation of America
15
National Company, Inc
119
National Screw & Mfg. Co
24
National Union Radio Corporation
156
New England Screw Co
24
Ohmite Mfg. Co
99
O'Neil -Irwin Mfg. Co
162
Parker Co., Charles
24
Parker -Kalon Corp.
24, 115
Par -Metal Products Corp
158
Pawtucket Screw Co
24
Perkin -Elmer Corporation, The
88
Permo Products, Inc.
176
Pheoll Mfg. Co
24
Phillips Screw Manufacturers
24
Pioneer Gen -E -Motor Corp
151
Polymet Condenser Co
148
Potter & Brumfield
134
Premax Products
159
Radio City Products Co
38
Rauland Corp., The
39
Raytheon Mfg. Co
21, 126
RCA Mfg. Co., Inc
6 7, Back Cover
Remler Co., Ltd
106
Rex Rheostat Co
177
Rider Publishers, Inc., John F
170
Rogan Brothers
126
Russell, Burdsall & Ward Bolt & Nut Co
24
168
Sangamo Electric Co
24
Scovill Mfg. Co
Shakeproof Lock Washer Co
24
114
Shallcross Mfg. Co
Shure Brothers
95
130
Sigma Instruments, Inc
177
Signal Indicator Corp
133
Simpson Electric Co
109
Sola Electric Co
24
Southington Hardware Mfg. Co
105
Sprague Specialties Co
14
Stackpole Carbon Co
152
Standard Pressed Steel Co
91
Standard Transformer Corp
32
Sylvania Electric Products, Inc
93
Synthane Corp.
180
Taylor Fibre Co
165
Telicon Corporation
135
Tenney Engineering, Inc
23
Thermador Electrical Mfg. Co.
173
Thomas & Skinner Steel Products Co.
112
Thordarson Electric Mfg. Co
5
Triplett Electrical Instrument Co.
Turner Co., The
147
31
United Carr Fastener Corp
180
United Cinephone Corporation
9
United Electronics Co
2
United Transformer Co
160
Union Carbide & Carbon Corp
177
102
117
110
141
22
161
24
104, 157
124
171
176
174
I
SEARCHLIGHT SECTION
(Classified Advertising)
BUSINESS OPPORTUNITY
EMPLOYMENT
USED EQUIPMENT FOR SALE
American Electric Sales Co., Inc
Freeland & Olschner, Inc
December 1942
184
150
-
178
178
178
178
ELECTRONICS
Photo G'oto7r.vu Purr :Urrrrienrr diruau.v
Vital Battlefront
Modern battlefronts are not limited to theaters of war since successful production lies behind military victories. Not only tanks, planes and guns are needed,
but machines to make ever-increasing amounts of fighting equipment.
DAVEN builds component parts for many of these machines ... parts for electronic devices which increase efficiency and speed production.
AttenMore than 80 models of Output Power Meters, Transmission Measuring Sets, Decade Resistance Boxes,
are
Equipment
Test
uation Networks, Volume Level Indicators and many other types of DAVEN Laboratory
most
lists
the
used extensively in electrical, broadcast, sound picture and television fields. The DAVEN catalog
netcomplete line of precision attenuators in the world; "Ladder ", "T" type, "Balanced H" and potentiometer
accurawith
well as Super DAVOHM precision type wire -wound resistors,
works -both variable and fixed
should be in your reference files.
A
copy
cies from -±I% to -±0.1%.
-as
THE RAVEN COMPANY
NEWARK, NEW JERSEY
158 SUMMIT STREET
www.americanradiohistory.com
TRANSMITTING TUBES
aad
%are titac4 ZlZ COJft/114K
Good tires are able to carry the terrific strain of operating at 100 miles per hour -but they last much longer
when they're operated at 40.
RCA Transmitting Tubes have frequently been
cited for outstanding performance under severe overload conditions -but that isn't what counts now.
Service -as many hours of it as you can possibly get
is the all- important thing.
Actually, almost all of the important rules for tire
conservation find a close parallel in the job of making
Transmitting Tubes last longer.
Just as tires should be rotated from wheel to wheel,
from spare to active, so should tubes be interchanged.
Tube spares should be used from time to time in order
to guard against deterioration.
Just as proper, specified air pressure will add much
to tire life, so does operating tubes in strict accordance
with specified conditions and conservative ratings provide the best assurance against premature failure.
Just as slower driving and careful handling
are important tire conservation measures, so
-
is it important to avoid unnecessary strains on tubes.
As pointed out previously, as little as 5% reduction in
filament voltage of pure- tungsten - filament types increases life 100 %!
Another way of making an easier schedule for your
tubes is to keep them cooler -by reducing plate voltage
and dissipation, and by additional air cooling even
beyond what may be specified. Still another way is by
reducing filament voltage to 80 %, whenever feasible,
during standby periods.
Just as wheel alignment has an important bearing on
tire life, so does the performance of related parts have
much to do with tube life. For instance, properly designed smoothing filters are essential to obtaining
optimum life from mercury-vapor rectifier tubes.
In short, these are the days when tube handling and
operation are dictated by the necessity of obtaining
every possible hour of tube life -just as is true of tires.
Care in this direction -far above what you might consider giving in ordinary times -will pay
worthwhile dividends.
116,
TRANSMITTING TUBES
RCA
/
TIRES
Manufacturing Company, Inc., Camden,
www.americanradiohistory.com
N. J.
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