r - American Radio History
Electronics World
i
1963
50 CENTS
DECEMBER,
SCA BACKGROUND -MUSIC MULTIPLEXER
SIMPLE TESTS FOR SEMICONDUCTORS
THE LOUDNESS CONTROL
CB RADIO-WAVE PROPAGATION
CAPACITOR FORMER FOR ELECTRONIC FLASH UNIT
ELECTRONIC INSTRUMENTßTION for OIL EXPLORATION
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NRI
Choose From NRI'S
not satisfied, or if
.ions arise, he may
ging at any time
to pay for further
GIs
or privileges"
NRI policies like this -plus the performance of tens of
have earned
thousands of men NRI has trained
-that
the confidence and respect of leaders in all
for
branches of the Electronics industry. We invite you to
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Washington 16, D.C.
Specialized Instruction Plans
TELEVISION -RADIO SERVICING
Learn to service AM -FM Radios, black and whi'ae and color TV sets,
1
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part -time or full -time business of your own.
INDUSTRIAL- MILITARY ELECTRONICS
2
Learn Principles, Practices, Maintenance of Electronic equipment
used today in business, industry, defense. Covers Electronic controls
and measurement, computers, servos, telemetry, multiplexing, many
other subjects.
COMPLETE COMMUNICATIONS
3
A comprehensive training program for men seeking careers operating and maintaining transmitting equipment in Radio -TV Broadcastirg
or mobile, marine, aviation communications. Prepares you for your
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FCC LICENSE
4
Prepares you quickly for First Class License exams. Every communications station must have one or more FCC -licensed operators.
Also valuable for Service Technicians.
BASIC ELECTRONICS
5
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An abbreviated, 26- lesson course covering Automation- Electronics,
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with the fundamentals of this fast -growing industry.
MATH FOR ELECTRONICS
6
A short course package of carefully prepared texts that take you
from basic arithmetic review through graphs and Electronic formulas.
Quick, complete and low in cost.
AVIATION COMMUNICATIONS
1
For men who want careers working with and around planes. Covers
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systems, transmitters. Prepares you for FCC License.
MARINE COMMUNICATIONS
8
Shipboard transmitting equipment, direction finders, depth indicators,
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MOBILE COMMUNICATIONS
9
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BELDFOIL
BREAKS THE NOISE BARRIER!
APPLICATIONS: Beldfoil is effective over the entire audio frequency
range. Typical applications include instrumentation, data processing, and
telemetering equipment, and any information and measurement circuits.
QUIET PERFORMANCE!
Yes, Beldfoil* shielding definitely breaks the noise barrier. It breaks the noise
barrier by being a noise barrier. Beldfoil gives total shielding ..100% isolation
between adjacent pairs. For audio and radio frequency, it completely eliminates cross talk, spurious signal impulses . . and it's ideal for stationary or
limited flexing. Beldfoil is lighter in weight, requires less space, and is usually
lower in cost.
MINIATURIZES!
WHAT IS BELDFOIL? It's a lamination
of aluminum foil with Mylar** that provides a high dielectric insulation. A patented Belden method of folding * **
gives definite benefits. An inner fold
creates a continuous metallic path
around the surface of the cable.This
eliminates any possible inductive effects. An outer fold tucks the cut edge
of the aluminum under the Mylar. This
gives complete isolation from other
adjacent shielded cables.
Beldfoil shielding reduces the diameter of multi- conductor cables . . by as
much as 662/3 %. It gives design engineers extra space .. extra conduit space,
extra raceway space, extra console and rack space. Beldfoil shielding means
that you can "think small."
Typical cross section looks like this.
ASK FOR DATA SHEET.
*'du Pont
Get your copy of newly published bulletin
8 -63 -A and technical data sheet. They give complete information on Beldfoil
shielding. Write Belden Manufacturing Company, 415 South Kilpatrick Avenue,
Chicago, Illinois 60644.
8 -1 -3
December, 1963
CIRCLE NO. 106 ON READER SERVICE PAGE
'Belden Trademark Reg: U.S. Patent Office
""*U.S. Patent 3,032,604
Trademark
Beiden
WIRCMMER
FOR INDUSTRY
SINCE 1003
- CHICAGO
Wwith makeshift
twist -prong capacitor replacements ?
When you substitute capacitor sizes and ratings, you leave
yourself wide open for criticism of your work ... you risk
your reputation ... you stand to lose customers. It just
doesn't pay to use makeshifts when it's so easy to get the
exact replacement from your Sprague distributor!
Get the right SIZE,
right RATING every time
with improved
SPRAGUE
TWIST-LOK'
CAPACITORS!
Over 1,690 different capacitors to choose from!
The industry's most complete selection of twist -prong capacitors, bar
none. Greater reliability, too. Exclusive Sprague cover design provides
a leak-proof seal which permits capacitors to withstand higher
ripple currents.
GET YOUR COPY of Sprague's comprehensive Electrolytic
Capacitor Replacement Manual K -106 from your Sprague
Distributor, or write Sprague Products Co., 51 Marshall St.,
North Adams, Massachusetts.
SPRAGUE®
THE
E5131.63
2
MARK OF RELIABILITY
WORLD'S LARGEST MANUFACTURER OF CAPACITORS
CIRCLE NO. 139 ON READER SERVICE PAGE
ELECTRONICS WORLD
DECEMBER 1963
VOL. 70 NO. 6
II(C1 rmies 11or1d
27
Electronic Instrumentation for Oil Exploration
31
Negative- Feedback Nomogram
32
Recent Developments in Electronics
34
The Loudness Control
A.
L.
Frenzel, Jr.
E.
Llt,elironic,s 1tiu0t.l
Teubner
L.
ELECTRONI) INSTRUMENTATION loi OIL EXPLDRATIDN
Rudolph A. Jacobs, Jr.
tiI/tn.,,nrrn in hi -fi rtntplifìers.
lírrr..r,rr.. Ins, /its, t.c oÍ lnurinr...
the amount of (ssrrPrtion l'P(l!(il'PCI, alld a desrriptintì Uf it 5i;11ple
londness-rorttrol rirruit that can be added to any prewttpit(s r.
s
36
39
42
Simple Tests for Semiconductors
Carl David Todd
Quantum Devices: How They Work
SCA
John
Background-Music Multiplexer
tuner 155 fur ir (r Plc
unin(rnnptr./, ,f,\ t()-
46
49
CB
Color -TV in Kit Form
98
An Indoor Horn
I
for
illustrates the
subsurface layers in a cross section of earth that is typical of the structure found
with an oil deposit. Note
how the oil is trapped in
OUR COVER
used rritlt an F11
(rnnsrtti.asiun., lu-aridin
to music (ur the lu,nte listent-r.
>lrrrrn,-
Radio -Wave Propagation
that its new rolar -1
50
52
54
57
64
75
80
85
-{.r.
Collins
Robert W. Winfree
n Ge
r,
R.
R.
L.
Conhaim, 19W7577
which is an upfold, bend or
arch in the rock strata.
Acoustic shock waves are
reflected from the various
subsurfaces, are picked up
by a number of microphone -
coil and built -in dot ;venerator. /bath feels
hit can be built by any experienced hit Guilder.
TV -FM Reception
B.
V. K. French
like transducers (geo-
Choosing a Two -Way Radio System (Part 2)
Capacitor Former for Electronic Flash Units
phones), and their signals
Howard H. Rice
Melvin
S.
are passed through electronic circuits to a recording oscillograph or special
tape recorder. For details on
this important technique for
finding oil, see our lead
story (p. 27)
(Illustration by Otto E. Markevics.)
Lieberman
Output- Transformer Chart
Audio Trends in Britain
anticline structure,
the
Patrick Halliday
Technical Personnel Shortage
Hum Interference in Car Radios
Transistors vs Tubes for Hi -Fi
David
Richard
S.
T.
Geiser
Burwen
Electronics World 1963 Index (Vols. 69 -70)
For the Record (Editorial)
W. A. Stocklin
Publisher
PHILLIP
T.
HEFFERNAN
Editor
WM. A. STOCKLIN
EW Lab Tested
1
Ilrrrllt
-I
1
-_'1
Hidv rtr
Ill" llicrophone
Technical Editor
MILTON
l'rrnt.sistnri :ed Stereo .Intplifìer
S.
SNITZER
Associate Editor
Case of the Bad Bypass
LESLIE
John Frye
SOLOMON
Associate Editor
'çs
P.
Test Equipment Product Report
M. I III - -r,.I .1.(.. .1 .1 .1 /.
Simpson 1/udel 261
I'.Iter llotlr.l hull Frequenr-1 tit,nuhrrrl
.
B.
HOEFER
Editorial Consultant
I
OLIVER READ
Industrial Consultant
WALTER H. BUCHSBAUM
Art Editor
MONTHLY FEATURES
Coming Next Month
Letters from Our Readers...
Reader Service Page
4
8
15
Book Reviews
Radio & TV News
New Products & Literature..
Copyright ', 1963 ity Zitto,svis Publishing Company. All rights reserved.
December, 1963
MILTON BERWIN
73
86
90
.4rt and Drafting Dept.
J. A. GOLANEK
Advertising Sales Afanager
LAWRENCE SPORN
Advertising Service Manager
ARDYS C. MORAN
3
NEW!
ENGINEERING BREAKTHROUG
Ì
CObtInC.
NETT
i
Fl('('lIY)Il!(
11())'lii
UNIQUE DISPLAY TUBES
tar COLOR
TV
MONTH
15
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stereo albums
for the price
of one!
Now, 8 hours of full- range, true, high fidelity
stereophonic music, or 16 monaural hours, can be
yours on one 7" reel, with the revolutionary new
Roberts Cross Field "770" Tape Recorder. The average tape cost per album: only 33¢. The "770"
has an exclusive patented third head, the Cross
Field Head, which separates recording and biasing
functions. The result: the "770" records 40 to
22,000 cps, producing true fidelity at 1r/B ips and
preserving the high frequency harmonics that
breathe life into music playback. The Cross Field
playback head has a gap width of only 40 micro
inches, the smallest, most responsive head ever
engineered. For this head, Roberts employs
NC -88, a new alloy, that is practically wear -proof.
Other features: 2- speed, electrically- switched,
heavy -duty hysteresis synchronous motor, miniscule wow and flutter at slow speeds; special ventilation system keeps the "770" cool even after
8 hours; two 5" x 7" self- contained elliptical,
extended -range, heavy -duty Alnico
V-
magnet
speakers; new automatic total shut -off. $499.95.
SEE ROBERTS TAPE RECORDERS AT BETTER
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AUTOMATIC ELECTRONIC TESTING
Current giant electronic installations are
simply too sophisticated for human
checking and troubleshooting. For this
reason, other electronic systems are being used to locate troubles even before
they occur. Ken Gilmore describes the
various systems and equipment being
used for this purpose.
UNIQUE DISPLAY TUBES
FOR COLOR -TV
While most present -day color -TV sets
use a variation of the three -gun, shadow mask CRT, there are many other approaches to color display tubes. This
article surveys 11 of the new designs,
ranging from a completely new optical
projection device to a thin picture tube.
SOLID -STATE COLOR ORGAN
New methods of firing controlled rectifiers, recently available parts, and simplified filter circuits make possible this
economical unit for both commercial and
home use.
IN
IN
synchronous instantaneous electrically controlled
2 speed motor
Automatic total shutoff
Operates Horizontally or Vertically.
proper impedance matching? What
about motional feedback and integrated
amplifier- speaker systems? Victor Brociner of H. H. Scott, Inc. answers these
and other important questions for the
prospective buyer of transistor hi -fi.
THE UNIJUNCTION TRANSISTOR
The operation and applications of a special type of semiconductor device employing a single p -n junction are covered
by David L. Pippen of the White Sands
Missile Range. Its use in timing and
delay circuits, multivibrators, sawtooth
and pulse generators, SCR firing circuits,
and counters is discussed.
CB RANGE -FINDER NOMOGRAM
Gene Karlin of Hammarlund has devised
a handy nomogram for determining the
approximate useful range for various
output powers and antenna heights in
a Citizens Band installation.
NEW FACILITIES FOR WWVB & WWVL
The National Bureau of Standards has
recently put into operation new faciliSPEAKERS FOR
TRANSISTOR AMPLIFIERS
ties at its precision -frequency standard
What characteristics are important in broadcast stations, WWVB and WWI /L.
selecting a speaker system for use with Here are the frequencies and services
a transistor hi -fi amplifier? What are the being provided by these transmitters.
All these and many more interesting and informative articles will be yours
in the JANUARY issue of ELECTRONICS WORLD ... on sale Dec. 19th.
Specifications: 71/2, 33/4, 1N ips. Power Amplifier
Output: 12 watts
Frequency response: at 71/2
ips, 40 to 22,000 cps 72 db; at 33/4 ips, 40 to
18,000 cps -±2 db; at
ips, 40 to 13,000 cps
3 db
Signal to noise ratio: -55 below 0
recorded level Wow and flutter: at 71/2 ips, less
than 0.12% rms; at 33/4 ips, less than 0.20 %; at
ips, less than 0.30%
Blower vent system
2 large stereo 5" x 7" elliptical, extended range,
heavy duty Alnico V magnet speakers Hysteresis
effects of changing impedance and im-
ZIFF -DAVIS PUBLISHING COMPANY
Ziff
Chairman of the Board (1946-1953)
William Ziff
William
B.
President
W. Bradford Briggs
Executive Vice President
Hershel B. Sarbin
Vice President and General Manager
T. Birmingham, Jr.
Vice President and Treasurer
M.
Robert
P.
Breeding
Circulation Director
ZIFF -DAVIS PUBLISHING COMPANY
Editorial and Executive Offices
One Park Avenue, New York, N.Y. 10016
212 ORegon 9 -7200
MIDWESTERN and CIRCULATION OFFICE
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312 WAbash 2 -4911
Midwestern Advertising Manager, Gilbert J. Jorgenson
WESTERN OFFICE
9025 Wilshire Boulevard, Beverly Hills, Cal. 90211
213 CRestview 4 -0265
Western Advertising Managet, Bud Dean
FOREIGN ADVERTISING REPRESENTATIVE
D. A. Goodall Ltd., London, England
R. Greenfield
Vice President
Phillip T. Heffernan
Vice President
Stanley
A
"40
AND
ROBERTS TAPE
FREE BOOKLET!
MORE WAYS TO USE
REORDER"
Roberts Electronics. Inc.
5978 Bowcrcft. Dept. EW -12
Los Angeles 16. Calif.
Please send free booklet
Please send me complete information
about Roberts Tape Recorders [No
Address
City
State
....is =we, teeevieeete ==== .111111111411111111101111111MIIIIIIItgal
IN CANADA: J. N. Nelson Electrorics Ltd., 7725 Adera St.,
Vancouver 14, B. C. (Prices slightly higher in Canada)
CIRCLE NO. 134 ON READER SERVICE PAGE
4
et.
ABC
Member
Audit Bureau of
Circulations
Radio -Electronic Engineering Trademarks Reg. U.S. Pat. Oft.
Radio News
Radio & TV News
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manuscripts.
ELECTRONICS WORLD is published monthly by Ziff -Davis Publishing Company at 434 South Wabash
-Davis
also
publishes Popular Photography, Popular Electronics, HiFi/
(Ziff
Ill.
60605.
Avenue, Chicago.
Stereo Review, Popular Boating. Car and Driver, Flying. Modern Bride, Amazing, and Fantastic.) Subscription rates: one year United States and possessions $5.00: Canada and Pan American Union countries
$5.50; all other foreign countries $6.00. Second class postage paid at Chicago, Illinois and at additional
mailing offices. Authorized as second class mail by the Post Office Department, Ottawa, Canada and for
payment of postage in cash. December 1963, Vol. 70, No. 6.
PAYMENT MAY ALSO BE REMITTED in the following foreign currencies for a one year subscription
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ELECTRONICS WORLD
Want a magic formula for success in electronics?
You won't find it here!
If you work in electronics, you know why we can't offer
you an easy way to success. There isn't any. Electronics is a demanding field. To earn more money,
you need more technical education- especially in the
areas of electronics that have changed so much in
the last few years. Getting more education isn't easy,
especially if you hold down a full -time job and have
family obligations.
CREI Home Study Programs offer you a practical way
to get more education -and the right kind of education
-without going back to school. You benefit almost
immediately because you study the material technical
organizations want their employees to know. You
choose the specialty that matches your interests and
emp,oyment objectives. CREI Programs cover every
major area of electronics from communications to
servomechanisms and computers, even the new field
of space electronics. And you study at home, set
your own pace, apply your knowledge daily on the job.
You're eligible if you work in electronics and have a
high school education. Our FREE book gives all the
details. For your copy, mail coupon today or write:
CREI, Dept. 1112 -A, 3224 Sixteenth St., N. W., Washington 10, D. C.
SEND FOR FREE BOOK
r
Accredited Member of the National Home Study Counc
ELÉCTRONICS''
The Capitol Radio Engineering Institute.
Dept. 1112 -A 3224 Sixteenth St., N. W.
CREI
Washington 10, D.
C.
Please send me FREE book describing CREI Programs in Electronics and Nuclear Engineering
Technology.
am employed in electronics and
have a high school education.
Founded 1927
I
Name
Age
Address
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Zone
State
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Type of Present Work
Che k:
Le
Home Study
Residence School
G. I.
Bill
E.4
Of the
-offirstthosechoice
who
WM. A. STOCKLIN, EDITOR
demand the best!
TIME FOR REAPPRAISALS
NEW
FOR years now, in fact ever since the
advent of TV, the service industry
has had many complaints. Probably we
have been equally guilty in publicizing
the various industry problems as they
appeared: cut -rate TV -set sales, drugstore tube testers, parts dealers selling
direct to consumers, poor set designs,
captive service, etc. We could go on
and on, but all of you know by now that
conditions will not change materially
and these problems will be with us for-
Solid
State
ever.
CONTROL CENTER
800, 1000
AND 1400 MODELS
FOR SERIES
DOUBLES
former performance
Quarter -Track Record /Play Data
ips
db
7 -1/2
±2
3 -3/4
±2
±3
±3
1-7/8
15/16
s/n
cps
50-30,000
30-20,000
30-16,000
30-10,000
56db
52db
50db
48db
The most complete recording instruments ever designed for stereo use.
Audio circuity, ± 1/4 db from
10- 100,000 cps; extended range,
5- 500,000 cps. Plug -in circuit modules
are printed on epoxy and gold plated.
Engineered to space craft reliability.
-
SUPERLATIVE
CRAFTSMANSHIP
THROUGHOUT!
INDIVIDUAL PERFORMANCE
RECORD SUPPLIED
WITH EACH CROWN
WRITE DEPT. EW -12
I
1718
N
T
E
R
N A
Mishawaka Rd.
T I
O N A
L
Elkhart, Ind.
CIRCLE NO. 111 ON READER SERVICE PAGE
6
Frank J. Moch, Executive Director,
NATESA (National Alliance of TV and
Electronic Service Associations), at a
recent Inaugural Dinner, did more than
just rehash all of the problems that
plague our industry. We feel that his
over -all analysis, his direct approach,
and suggested solution are of such importance to the service industry that we
would like to take this opportunity of
quoting, in part, what he had to say.
"Ours is an industry of paradoxes. We
cry among the midst of plenty and we
seek help but refuse to avail ourselves
of that given. We call ourselves little
businessmen, yet we are part of a business that in the last year shared an almost 4- billion dollar parts and service
fee market. Each year this grows and
grows. At the same time the number of
professional practitioners dwindles while
the total number, including dabblers
who operate without restraints, increases.
"We have been accused of business
stupidity and, noting the lack of Cadillac's at association meetings, I must admit we aren't smart. .. .
"One thing sure, the service of home
electronics is a massive and lucrative
business. but only for progressive, intelligent businessmen. This year's figures
reveal SIr. & Mrs. American . will
spend almost 4-billion dollars to maintain millions of devices. Government
figures show that a total of 120,000
cervicers in all categories, including part timers, will share in this business. The
average take then is $33,000 plus per
average man. Note I said average. I'm
sure NATESA'ns are not average and
that each should account for far more
than $33.000. Did you get your $33,000
per man? Probably not -and the reason
is that most of its are trying hard to
lower ourselves to the status of an average man instead of shooting for the
skies.
It is time for us to junk our old
ideas about business. The days of piddling jack -of- all -trades little operators
are over. The day of bigness is here. Only
.
THE HALLMARK
OF CROWN
FCC OF(
.
specialization can make of us little guys
`big.' The time is now for each of us to
realize that none of us is a jack-of -alltrades and yet each of us is a master of
some phase. Each of us performs functions we are unqualified to do and we
hate every minute of it and pay dearly
for it. What is the solution? It's really
simple. Why can't members of this fine
association appraise the abilities and talents of each member and then channel
the various activities necessary to the
conduct of a solid, growing, and prosperous service business to those most
capable to do them? The total volume
of business waiting to be done in your
area is so great that each expert in a
phase or two could be occupied full
time doing what he can best and most
happily do. Every member then could
offer truly expert services on a wide
range of equipments at truly competitive prices and of such quality that no
one, not the factory and surely not the
catch -as- catch -can `some timer' could
possibly compete.
"This is the way to stabilize this business. This is the way to compete with
bigness. This is the way to make a business out of a rat race. .
"As with any plan, this calls for intelligent leadership, trust, and fair play.
In the past service people have too often
abused leadership and accused it of ulterior motives. This is a luxury we can't
afford. As for trust, by now every member of any worthwhile association knows
that the fellow servicer down the street
really did have a father and he is in
the saine mess we all are in, so trust
should be an accepted fact. Fair play
is an ingredient of any truly successful
operation.
"Thus on the plus side we have fantastically good business prospects growing each year, and . . we have the
cumulative talents ... to fulfill the needs
of the business. On the negative side we
have inertia, generally and conveniently
labeled independence. The path we follow is yet for us to choose. Will you
become big and enjoy all the benefits it
brings by helping your fellow member,
or will you sit under your spreading
chestnut tree and die watching progress rush by ?"
His comments and suggested solution
are extremely realistic. We have seen it
work in certain areas where service
shops divide their business into three
main areas: automobile sets, radio and
TV, and antenna installations. We see
no reason why this could not be broken
down ever further. It should be worth
trying.
.
ELECTRONICS WORLD
SIT RIGHT DOWN AND
EARN $600 A MONTH
...after
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...
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tronics skill and knowledge ... a Commercial FCC License. never be a better time to start towards a high -paying,
And the quickest, easiest, most economical way to get interesting job in electronics.
your license is Cleveland Institute of Electronics Home
Study. Will it work for you? Cleveland Institute is so
Mail Coupon TODAY For FREE Catalog
sure of it they make this exclusive promise: "Should
you fail to pass your Commercial FCC License examination
Cleveland Institute of Electronics
after completing one of our licensing programs, we will
1776 E. 17th St., Dept. EW-84
refund all your tuition payments." The offer is as straightCleveland 14, Ohio
How to Succeed
forward as it sounds ... you get your FCC license or your
Please send FREE Career Informamoney back
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mark your choice on the coupon, and mail it today. We'll
That's right
!
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Name
Cleveland Institute
of Electronics
1776
E.
17th Street, Dept. EW-84 Cleveland 14, Ohio
December, 1963
Age
(please print)
Address
City
yrc
Accredited Member
I
Zone
Stat.e
Approved for Veteran's Training under Korean GI Bill.
E W-84
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CIRCLE NO. 115 ON READER SERVICE PAGE
8
To the Editors:
I concur thoroughly with your July
editorial on the desirability of and the
opportunities for the woman engineer.
We ordinarily graduate one or two each
year, all of whom are quite outstanding
in ability.
I would like to bring you tip to elate
on the going rate for B.S. graduates
from Colleges of Engineering. You state
that this is $5200 for electronic engineering graduates, whereas our current
figures for the class of the past year approximate $7400. Master's degrees command approximately $9000 and doctorates whatever the man is able to sell
himself for, but usually in excess of
$12,000 per year.
J. D. RYDER, Dean
Michigan State University
East Lansing, Michigan
To the Editors:
Your editorial on women in engineering was a welcome part of the Jul- issue
of ELECTRONICS WORLD. There are three
points I should like to have emphasized
in any future articles- concerning .salary,
opportunity, and motivation.
First, the average salary offered to
me and my classmates in January 1963,
was well over $600 /month or S7200/year. My offers ran from $570 to $650,
with only two offers below $600. The
average electrical engineer makes over
$10,000/year. These figures can be
verified at any college placement office.
Opportunity is less for women initially. Half of the companies who interviewed at my college refused to even
interview a woman, no matter how good
or bad she might he. Your "too -eager
companies" are highly unusual.
As for motivation, too much has been
said about challenge. The person who
wants to be challenged doesn't have
to be talked into engineering as a career.
He or she is already there, for engineering today is the most challenging of
professions. What other professional
person loses 507 of his value in 10 years'
time unless he keeps at top pitch?
Rather, let's emphasize the actual
glamour of the job in engineering; the
overwhelming majority of interesting
men in college classes; the delightful
thrills of being flown by jet all over the
United States for interviews; the publicity attendant upon graduation; the
clown -right fun and stimulation of conferences and meetings in plant and at
conventions all over the world. There
is no job I know of as glamorous and
exciting as that of a woman engineer.
(MISS) FAITH LEE
Project Engineer
Motorola Inc.
Phoenix, Arizona
TEST -EQUIPMENT ISSUE
To the Editors:
The test -equipment technicians here
at the Grand Forks ( North Dakota) Air
Force Base were extremely interested in
your August issue of ELECTRONICS
WORLD devoted to test equipment. The
article written by C. Gedney and F.
Winterburg ( "The Instrument Calibration and Repair Technician ") as well as
the feature articles throughout the issue
were of extreme interest to us.
Some of your readers might be interested to know that the U.S. Air Force
has a very fine program of calibration
and repair of their vast inventory of
precision test equipment. In today's age
of supersonic aircraft, guided missiles,
and extremely accurate radar and communications and control systems, a need
exists for a program of this type. Such
a program will play an even more important role in the future as our military
equipment becomes more advanced.
Because of the nature of this work,
the U.S. Air Force allows only the wellqualified electronics technician to enter
the program. A very tough pre -entrance
exam must be passed before a technician is eligible to enter the Precision
measurement Equipment School at
Lowry Air Force Base at Denver, Colorado. An additional requirement exists
allowing only airmen with four years'
electronics experience in a related career
field to be selected. This allows the
"cream -of- the -crop" to enter the calibration program enabling the precision
measurement equipment to be handled
by some of the best technicians the Air
Force has.
Being a member of one of the 149
Laboratories mentioned in your article
and a career airman, much of the test
ELECTRONICS WORLD
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Model 700
DYNA-QU
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See your B &K Distributor
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All over the nation, thousands of professional servicemen rely on the
"700 ". Once you use it, you'll be as enthusiastic as they are. Everyday
its efficiency. This up -to -date,
its accuracy
use has proved its speed
obsolescence-proof tube tester is designed for maximum use today and
tomorrow. Provides multiple- socket section to quick -check most of the
TV and radio tube types the true dynamic mutual conductance way
...
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plus simplified switch section to check new tube types in Dyna -Quik
emission circuit. Also includes provision for future new sockets.
Makes test under set -operating conditions. Checks each section of
multi- section tubes separately. Checks for all shorts, grid emission,
leakage and gas. Makes quick "life" test. Exclusive adjustable grid
emission test provides sensitivity to over .100 megohms.
Makes complete tube test in seconds. Checks average set in a few
minutes. Discovers weak tubes that need replacement. Satisfies more
customers. Sells more tubes. Saves call- backs. Insures your reputation.
Net, $16995
Pays for itself over and over again.
Time -Saving, Money -Making Instruments Used by Professional Servicemen Everywhere
__
Model 960 Transistor
Radio Analyst
Model 360
V O
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Automatic VOM
B
NEW TUBE INFORMATION SERVICE
Available every 3 months, on subscription,
for all B &K Dyna -Quik Tube Testers
December, 1963
Model 1076
Television Analyst
Model 375 Dynamatic
Automatic VTVM
&
Model 445 CRT
Rejuvenator Tester
MANUFACTURING CO.
K
Division of DYNASCAN CORPORATION
CHICAGO 13, ILL.
1801 W. BELLE PLAINE AVE.
Canada: Atlas Radio Corp., 50 Wingold, Toronto 19, Ont.
Export: Empire Exporters, 277 Broadway, New York 7, U.S.A.
CIRCLE NO. 105 ON READER SERVICE PAGE
9
new
FROM
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FLYBACK TRANSFORMERS
#
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Part
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Setchell Carlson
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VERTICAL OUTPUTS
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equipment described in your issue has become familiar to
me, and to the other Precision Measurement Technicians
throughout the USAF Calibration and Repair Program.
Thanks for a fine magazine.
S
/SGT. ALFRED A. ST. ARNOLD, USAF
Precision Measurement Lab.
Grand Forks Air Force Base
North Dakota
TV INTERFERENCE
To the Editors:
My neighbor told me that he had called a TV service shop
to find ont what could be done about TVI on channel 2. The
serviceman told him that it could not be fixed and that he
would have to get the amateur off the air. I showed my
neighbor how to install a high -pass filter on his set which
completely cleared up the problem. Then I made a phone
survey of ten local TV service shops. I told them that I was
having interference on channel 2 from a nearby amateur who
was transmitting on six meters. I was amazed at he answers
that I got. They ranged from "call the FCC," "it can't be
fixed," "I'll have to take the set to the shop and try different
filters," to "see the amateur and have him transmit on another
frequency." One serviceman told me to write to the FCC and
they would give me a free filter.
Not one of the servicemen that I called had any idea of
what to do. And I suspect they had never heard of a simple
high -pass filter.
\V. P. PENCE, WA6JEU
Santa Monica, Calif.
There are quite a few TV technicians who are hams and
these men are very well acquainted with TVI, its causes and
cures. On the other hand, some TV technicians may not have
had too much experience with the problem and how to eliminate it. There have been many good articles published on
this subject, and complete chapters in the radio amateur
handbooks are devoted to the subject. In addition, we have
run several stories on TVI in past issues. -Editors.
a
Philco
i
Merit
Manufacturer
C -4115
Wells Gardner
#
52X95-2/ -3/ -4
C -4133
RCA
105195
10
CIRCLE
NO. 129
ON
CARL FAZIO..
Part
-
n
To the Editors:
One of your laboratory reports on a stereo cartridge and
tonearm indicates various measurements of tracking error at
different points on a record. Just how is this tracking error
measured with any amount of accuracy? I am especially interested in this since some of the figures given are on the
order of one or two degrees.
FILTER CHOKES
PLAZA
a
TRACKING ERROR
Milano, Italy
etc.
HOLLYWOOD, FLORIDA
READER SERVICE PAGE
The method used by Hirsch -Houck Laboratories for measuring tracking error requires the use of a special protractor like device that was imported from England and distributed
in this country a few years ago. The device actually consists
of wo long, movable arms, a protractor scale that reads the
angle between these two arms, and a fixed arm that fits over
the turntable spindle. To use the device, the two movable
arms are first placed at the point on the record at which the
tracking error is to be measured. The stylus of the pickup is
then put down in a small hole which is at the apex of the two
movable arms. One of these arms is exactly at right angles
to the radius of the record. The second arm is aligned optically so that it is parallel to the pickup and stylus. Then the
angle between the two arms is read on the protractor. This
represents the tracking error. The device used is accurate
enough so that one can read tracking errors to a fraction of
a degree. It is Hirsch -Houck Laboratory's practice to measure tracking error at several points along a record. Incidentally, the device described is no longer available in this
country.- Editors.
ELECTRONICS WORLD
PORTRAIT OF AN EARLY AMERICAN
ELECTRONICS STUDENT
The illustrious gentleman pictured above is, of course, Benjamin Franklin, who took time out one day from his fu -time
career as a diplomat to discover electricity! Now, the Electronic Technology Series offered by Grantham School of Electronics does not go quite back to Mr. Franklin's kite and key experiment, but it does start right at the beginning of the modern
subject of electronics. And, it builds from this basic beginning, in a logical step -by -step manner up through the complex
theory of the missile age.
I
The following is
a
brief description of Grantham's
3 -step
program for electronics advancement:
FCC LICENSE TRAINING
the first class FCC license is a
LABORATORY TRAINING
ADVANCED TRAINING
Men who add equipment experience to
To continue to grow and advance as
"diploma" in electronics issued by the
U.S. Government. To obtain this
their knowledge of electronics theory
an electronics man, you will more than
likely need further training. Grantham
license, you must pass a comprehensive electronics examination. Section
IA of
the Grantham Series qualifies
you thoroughly and quickly to obtain
this license, which is a "door- opener"
to industrial electronics employment
and a necessity in many phases of
communications electronics.
have an added employment advantage
in that they require little or no on -thejob training. Section IB of the Grantham Series gives you this experience
in four weeks (160 hours) of intensive,
supervised laboratory training. Gran-
tham offers free placement assistance
to students when they complete Section IB of the Series.
supplies this advanced electronics
training in Section II of the Series.
Section II is designed to be taken after
you are employed in electronics, and
provides thorough training in such
subjects as Microwave, Radar, Corn puter Theory, Mathematical Analysis,
Pulse Circuitry, etc.
-Mail in envelope or poste on postal cord
Grantham training is available in the classroom, in the laboratory, or by
home study. For full details on this proven electronics program, complete and send us the coupon on the right. We will be glad to send you
(without charge or obligation) our free 44 -page booklet, "CAREERS IN
To: GRANTHAM SCHOOL OF ELECTRONICS
'NATIONAL HEADQUARTERS
Name
December, 1963
3123 Gillham Road
Kansas City 9, Mo.
JE 1 -6320
PRINT)
Address
City
FOUR CONVENIENT LOCATIONS:
408 Marion Street
Seattle 4, Wash.
MA 2 -7221
Age
-
(PLEASE
SCHOOL OF ELECTRONICS
1505 N. Western Ave.
Hollywood 27, Calif.
HO 7 -7727
ICE
Please send me your FREE 44 -page booklet,
"CAREERS IN ELECTRONICS."
ELECTRONICS."
GRANTHAM
Oil
1505 N. WESTERN AVE., HOLLYWOOD, CALIF. 90027
821-19th Street, NW
Washington 6, D. C.
ST 3 -3614
State
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SYSTEMS
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CIRCLE NO. 122 ON READER SERVICE PAGE
OKLAHOMA CITY, OKLAHOMA
ELECTRONICS WORLD
READER SERVICE PAGE
Please use the coupon at the bottom of this page to obtain more information about products advertised in this issue.
Simply circle the number on the coupon that corresponds to the
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Additional information on items mentioned in "New Products & Literature" can also be obtained by foil owing this same procedure.
PRINT your name and address on the coupon and mail it to:
ELECTRONICS WORLD
P.O. BOX 7842
PHILADELPHIA
1,
PA.
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ELECTRONICS WORLD
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NEW PRODUCTS &
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(Key numbers for advertised products also appear in Advertisers Index)
NAME
(PRINT CLEARLY)
ADDRESS
CITY
ZONE
STATE
VOID AFTER DECEMBER 31, 1963
December, 1963
12
15
Exclusive with
RCA ...
the faster,
easier way
toward a career
in electronics
Amazing home training method makes learning almost automatic
Exclusive with RCA. " AUTOTEXT" the revolutionary home
training method introduced by RCA Institutes, Inc., is stirring the interest of thousands. Every day, " AUTOTEXT" is
helping people like yourself join the thousands of other successful electronic students who are working toward profitable careers right now! This faster, easier way to learn electronics uses the latest scientific development ,n the field of
home training -and " AUTOTEXT" is exclusive with RCA.
New trend in education. This exciting new trend in
education represents a significant advance in teaching
electronics. People who have been interested in careers in
electronics in the past, but have had difficulty with conventional home training methods, can now begin to master the
fundamental principles of electronics almost automatically.
Tested in schools throughout the country, checked out and
proved with thousands of students, programmed instruction
is helping people learn more quickly and with less effort.
And the future is unlimited. Jobs are available for qualified
technicians in Space Electronics, Communications, TV,
Computer Programming, Automation, and many other electronic fields. The important thing is to get started now!
Complete course available. Right now, RCA Institutes offers
you a complete Home Training Course ( "Introduction to
Electronics ") using the " AUTOTEXT" method. You get a
complete set of theory lessons, service practce lessons,
experiment lessons, and all the kits you need. And most important, " AUTOTEXT" takes most of the effort out of learning the all- important groundwork of the electronics field.
FREE OFFER!
Well send you complete information on amazing new RCA " Autotext" along
with
Prove it to yourself now! If you have a natural inclination
or interest in the exciting field of electronics, that's all
you need. RCA " AUTOTEXT" will help you do the rest.
16
a FREE SAMPLE of a lesson to prove to you how
easy it is to learn this new way. Send the attached
postage -paid card and check "Autotext ".
ELECTRONICS WORLD
Wide choice of Home Training
courses in Electronics:
Autotext
Introduction to Electronics
Introduction to Semiconductors
TV Servicing
Color TV
Communications Electronics
FCC License Preparation
Mobile Communications
Automation Electronics
Electronic Fundamentals
(also available in Spanish)
Computer Programming
Transistors
Electronic Drafting
Industrial Electronics
Automatic Controls
Industrial Applications
Nuclear Instrumentation
Digital Techniques
RCA Institutes Home Training Courses are complete step by step easy-tounderstand units. You get prime quality equipment in the kits furnished to
you, and all of it is top grade. It's yours to keep and use on the job.
Liberal Tuition Plan. RCA Institutes Home Training Courses are available
under a liberal tuition plan that affords you the most economical possible
method of home training. You pay for lessons only as you order them. If, for
any reason, you should wish to interrupt your training, you can do so and you
will not owe a cent until you resume the course. No long -term obligations!
Set Your Own Pace. RCA Institutes Home Training takes into consideration
your own ability, finances and time. You learn at your own speed, in the most
effective manner, with personalized instruction every step of the way. You get
theory, experiment, and service practice beginning with the very first lesson.
All lessons are profusely illustrated -a complete training package in every way.
CLASSROOM TRAINING
RCA Institutes Resident Schools in New York City, Los Angeles and RCA
Technical Institute in Cherry Hill near Camden, N. J., offer classroom training
that will prepare you to work in rewarding research and production positions
in many fields of electronics. No previous technical training required for
admission. You are eligible even if you haven't completed high school.
Free Placement Service. RCA Institutes Resident School graduates are now
employed in important jobs at military installations, with important companies
such as IBM, Bell Telephone Labs, General Electric, RCA, in radio and TV_
stations and in communications systems all over the country. Many other
graduates have opened their own businesses. A recent New York Resident
School class had 92% of the graduates who used the FREE Placement Service
accepted by leading electronics companies, and had their jobs waiting for
them on the day they graduated!
Coeducational Day and Evening Courses are available at Resident Schools.
You can prepare for a career in electronics while continuing your normal, full time or part -time employment. Regular classes start four times a year.
SEND POSTCARD FOR FREE ILLUSTRATED BOOK TODAY! SPECIFY "AUTOTEXT ", HOME STUDY OR CLASSROOM TRAINING.
RCA INSTITUTES,
INC.
Dept.EW -D3
A Service of Radio Corporation of America,
350 West 4th St., New York 14, N. Y.
Pacific Electric Bldg., 610 S. Main St., Los Angeles 14, Calif.
The Most Trusted Name in Electronics
December, 1963
19
HI -Fl PRODUCT
REPORT
TESTED BY HIRSCHHOUCK LABS
Shure 545S "Unidyne Ill" Microphone
Heath AA -21 Transistorized Stereo Amplifier
Shure 545S "Unidyne III" Microphone
For copy of manufacturer's brochure, circle No. 56 on coupon (page 15).
of the microphone at a distance of 12
inches from a loudspeaker, comparing
its output with that of a calibrated standard microphone in the same location.
The difference between the two, corrected or the response of the standard
THE Shure 545S "Unidyne III" is microphone, is plotted on the accoma moving -coil microphone with a
panying graph.
cardioid directional response. It is conThe measured response is generally
structed in a slim, cylindrical shape, similar to the curve supplied by the
ruggedly built, and attractively styled.
manufacturer in the instruction booklet
Most directional microphones are for the microphone. Our measurement
quite bulky and have different polar shows a small dip at 4500 cps which
patterns in the horizontal and vertical does not appear on the manufacturer's
planes. This microphone, which physi- curve, as well as much stronger bass recally resembles the usual non -directional sponse below 100 cps. The over-all remicrophone, is constructed symmetri- sponse is ±5 db from below 30 cps to
cally and has the same polar response in 13,000 cps. This is unusually wide for a
all planes. The polar pattern is wide, public -address microphone and makes
being down only 6 db at the sides, yet this one quite suitable for music as well
the unit has a rejection of 15 to 20 db as vocal amplification. Listening to refor signals arriving from the rear. This cordings made on a high- quality tape
enables it to be oriented to reduce pick- recorder with this microphone revealed
up from the audience or from the speak- a crisp, clean sound, with noticeable
ers in a public- address installation. In sibilants on close talking. The bass did
this way, higher amplifier gain can be not sound as heavy as the curves would
used without acoustic feedback.
suggest, but this is probably a function
The unit is equipped with a swivel - of the distance between the microphone
mount and an "on -off" switch. It has two and sound source.
output impedance connections, for driv(Editor's Note: The dip at 4500 cps
ing loads of 50 to 250 ohms or a 100,- has also been observed with other micro000 -ohm high- impedance load. The de- phones; it is probably the result of the
sired impedance may be selected by peculiar sound field radiated by the two making connections to the appropriate
way speaker system used to test the
two wires of its three -wire output cable.
mike. Also, the manufacturer's curve was
This shielded cable, supplied with the taken at a distance of 24 inches from the
microphone, is 18 feet long and is fitted sound source rather than 12 inches used
with a connector mating with the con- by our laboratory. As a result, the bass
nector on the microphone mount.
response shown in our curve is higher
We measured the frequency response than that shown by the manufacturer.)
20
20
200
500
IKC.
FREQUENCY -CPS
The Shure 545S microphone sells for
$54.00. It is also available without the
"on -off" switch, as the Model 545, for
$50.00.
Heath AA -21 Transistorized
Stereo Amplifier
For copy of manufacturer's brochure,
circle No. 57 on coupon (page 15).
THE Heath AA -21 is one of the first
all- transistor integrated stereo amplifiers to overcome the power, bandwidth,
and stability limitations of many such
units. Early efforts at transistorizing
high -fidelity amplifiers were plagued by
the fact that the moderate-priced power
transistors of that period would not function above a few kilocycles. Improperly
stabilized circuits were prone to run
away at elevated temperatures or when
driven hard. With inadequate overload
protection, the output transistors would
frequently be destroyed in a fraction of
a second.
Heath engineers set out to eliminate
these weaknesses when they developed
the AA -21, and they have succeeded admirably. The AA -21 is rated at 35 watts
per channel (continuous) with both
channels operating into 8-ohm loads.
Better than 27 watts (at I% THD) can
be obtained at both upper and lower
limits of the audible spectrum. The special power transistors, four of which are
used in each output stage, are mounted
on large finned radiators, or heat sinks,
which allow them to run cool in normal
service and at safe temperatures even
when delivering large continuous power
outputs. The problem of transistor damage by overdriving or by speaker short
circuits has been neatly solved by using
ELECTRONICS WORLD
No manufacturer can make
a
top-quality 50 -watt stereo control -amplifier
for less than $130.
But you can.
(With the Fisher KX -100 StrataKit, for only $129.50.)
fier. The exclusive Fisher DIRECT-TAPEMONITOR* permits the use of all controls
If you want a no-compromise amplifier
at a compromise price, you can't buy ityou have to build it yourself. And no one
can build a better 50-watt single -chassis
stereo control -amplifier than the Fisher
KX-100, at any price!
Here is today's most spectacular value
in amplifier kits. The 50 -watt music
power output (IHFM Standard, both
and switches during tape monitoring
without any change in cable connections.
The convenient front -panel headphone
jack is equipped with a switch for silencing the main loudspeakers, if desired. All
other control and switching facilities are
equally professional in their flexibility.
And who can build the KX-100? Anychannels) assures superior dynamic
range regardless of speaker efficiency. one. Previous experience is immaterial.
Harmonic distortion at rated output is The exclusive Fisher StrataKit method
only 0.5 %. A special power output is makes kit construction so easy and error provided for driving a third speaker proof that there is no longer a difference
(center channel or mono extension) between the work of a skilled technician
without the use of an additional ampli- and that of a total novice. You can't help
ending up with a faultless Fisher amplifier. All you need is the desire, a few
'
evenings of free time and $129.50.;T
FREE! $1.00 VALUE! The
Kit Builder's Manual: a new,
illustrated guide to high -
fidelity kit construction.
10
Fisher Radio Corporation
21 -38 44th Drive
Long Island City 1, N. Y.
Please send me without
charge The Kit Builder's Manual, complete
with detailed information on all Fisher
StrataKits.
Name
Address
Zone_ State
City
071211
The Fisher
WMLNOT
OP MAHOGANY CABINET.
December, 1963
'IM
SS. METAL CABINET.
Uí95.
MAKES SLIONTLT HIOHENIN THE FAR WEST. EXPORT
1.
FISHER
FAO.
In TERIIET.NML. INC.. LONG ISLAND
CIRCLE NO. 118 ON READER SERVICE PAGE
The
Kit Builder's
Manual
CITY S,
N. T. CANMOM.
iMI
TEL ASSOCIATES.
LTD., WILLOWOALE. ONT.
21
5.00
2.75
2.50
225
'
INTERMODULATION DISTORTION
60/60000 CPS
2.00
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50
POWER OUTPUT -WATTS (ECUIV. SINE WAVE)
-
70
IDO
five tiny, quick -acting thermal circuit
breakers. One is in each power supply
line ( + 35 volts,
35 volts) one in
each speaker line, and One in the a.c.
power line. Momentary overloads trip
one or more of these breakers, which reset automatically in a few seconds. They
are more convenient than fuses and act
quickly enough to afford real protection
to the transistors.
The amplifier uses a total of 28 transistors and 10 diodes. The output transistors are driven through transformers,
but are direct -coupled to the speakers.
Combined current and voltage feedback
is used to obtain unity damping factor.
Normally, the unit is meant to drive 8or 16 -ohm speakers, with power reduction of about 30% into a 16 -ohm load.
Four -ohm speakers are driven through
-
5
co 3
I-
2
31
CONTINUOUS
nM!-Ñ
Mnm
_
The volume and tone controls are concentric types with slip clutches to allow
independent adjustment of the two
channels. Channel balancing is done
with the two volume controls.
The measured frequency response of
the unit was ± 1 db from 20 to 16,000
cps with the tone controls mechanically
centered. The tone -control ranges were
+ 18.5 to -17.7 db at 50 cps and + 13.5
to -17 db at 10,000 cps, with negligible
effect on the 1000-cps level. The volume- control tracking was good when
both channels were set to the same gain,
but if they were offset by only a few db
the tracking error became excessive. If
this amplifier is used with speakers of
different efficiencies, we recommend balancing levels with the input level adjustments rather than with the main volume controls.
The hum and noise were 57 db on
phono and tape head inputs, and -64 db
on the "Aux." input, referred to 10 watts
output. The gain was very high, with
only 0.75 mv. needed at the tape head
input to produce 10 watts output. The
phono sensitivity was 1.2 mv. Stereo
crosstalk was -. 44 db to
56 db and
there was no crosstalk from unused inputs.
The power output at 1% harmonic distortion, with both channels driven and
with 8 -ohm loads, was 41 watts between
100 and 7000 cps, falling off. to 27 watts
at 20 cps and 29 watts at 20,000 cps.
Hence the amplifier could have been
rated at + 0, -2 db of 41 watts from 20
to 20,000 cps. Intermodulation distor-
-
-
SINE -WAVE POWER PER
_.._..____ _.... _..
.
1
RIGHT CHANNEL 11°/. THD)
I
en
i
I
IKC.
FREQUENCY-CPS
1. More "look- alike" exact replacement models than any other brand.
Over 350 needles, 225 cartridges.
2.
Easy -to -use reference material.
computer- printed catalogs make
proper needle/cartridge selection easy,
fast and accurate.
E -V
3.
Highest standards. Rigid quality
control and inspection cuts call- backs,
gives full value to every customer.
Stock and sell E-V needles and
cartridges for more profits, today!
Write for FREE replacement guides!
ELECTRO- VOICE. INC.
Buchanan, Michigan, Dept. 1237N
gke,r0-
OICZ
SETTING NEW STANDARDS IN SOUND
CIRCLE NO. 114 ON READER SERVICE PAGE
22
an internal 4 -ohm series resistor, which
reduces the available power by 50 %.
The amplifier is styled like the company's other audio components, with an
attractive tan vinyl- covered steel case
and a panel featuring contrasting portions of chrome, clear and black plastic,
and tan surfaces. Many infrequently
used controls are located in front, behind
a hinged panel which swings down for
access. These include switches for tape
monitoring, loudness compensation, and
speaker phasing plus a complete set of
individual level-setting controls.
The exposed controls include source
and mode selectors, volume, bass, and
treble tone controls. The AA-21 source
selectors are independent for the two
channels, mounted concentrically. This
allows the amplifier to be used as two
separate mono amplifiers, or for mixing
two input channels. The mode switch
has positions for mixing both channels,
connecting either channel to both speakers, and for normal and reversed- channel
stereo operation.
1
LOADS-117 V.A.C. LINE
T
2KC.
3KC.
IM
..M..
5KC.
7KC.
IOKC.
20KC.
tion was between 0.83% and 1.35% for
all power outputs up to about 10 watts,
falling to 0.72% at 35 watts, and rising
again to 3% at 41 watts. These figures
are within the manufacturer's rating of
1% IM at 35 watts.
In listening tests, the Heath AA -21
had all of the attributes of a good, highpowered amplifier. It was very clean,
solid, and effortless in its sound. Like a
few other high -quality transistor amplifiers we have heard, it gives the impression of limitless power reserves. There
is no sign of break-up or other unpleasantness at extremely high listening levels, possibly due to superior overload recovery characteristics.
Although many of the circuits are in
the form of encapsulated modules, which
mount on the printed circuit boards, the
assembly procedure is lengthy and this
does not appear to be a project for the
novice kit -builder. The unit we tested
took an experienced kit -builder about 24
hours to complete. The unit sells for
$139.95 in kit form.
ELECTRONICS
WORLD
A
gift
any man
want and use,
Especially you
will
Dual Heat Soldering Gun Kit
Everything that's needed for quick, easy
soldering and scores of household repairs.
Features the same Weller "Expert" Dual Heat
Gun that's used by p- ofessional servicemen
and homecrafters the world over. Pull the
trigger -tip heats instantly and spotlight illuminates work. Two trigger positions give a
choice of two soldering temperatures. You
can switch instantly to high 140 -watt or low
For hi -fi
kit building
December, 1963
For electrical repairs
100 -watt heat to suit the job. By using high
heat only when necessary you prolong tip life.
Tip is made of copper for superior heat transfer and premium plated for rigidity and long
life. Included: 3 soldering tips, tip- changing
wrench, flux brush, soldering aid, solder. And
everything is in a colorful, break -proof plastic
95
carrying case. Model 8200PK.
$
S list
Weller Electric Corp., Easton, Pa.
For mending metal
CIRCLE NO. 142 ON READER SERVICE PAGE
For many other jobs
23
PICK YOUR M ARK TI Mail
it down
"CROSSFIRE"-MOST POWERFUL TV ANTENNA DESIGN IN THE FIELD!
1. GOLDEN CROSSFIRE
3600 Series
U.S. PAT. NO. 3,086,206 CONFIRMS AND PROTECTS EXCLUSIVE
DUALDIPOLE SYSTEM-THE SYSTEM THAT STILL GIVES HIGHER,
CLEANER GAIN
(WITH LEAST BULK) THAN ANY COMPETITIVE ANTENNA! DOES IT
AT LOWEST
COST. EVEN INCLUDES FM! COMPETITIVE FRINGE ANTENNAS DON'T.
High -performance balance can be obtained only by using the
right combination of both driven and parasitic elements. Only the Crossfire -with
its unique dual dipole system-has this power combination. The Crossfire
patent protects this system -and no other antenna, old or new, can use it.
2. GOLDEN SUPER -CROSSFIRE Model 3607
The World's Most Powerful Antenna
1. Up to 48% rrore TV gain than 28- element Crossfire.
2. On FM Stereo
... gives
more gain than a 5- element yagi.
EXTRA -POWERFUL BOOSTERS THAT MEET EVERY NEED!
3. BRAND-NEW Nuvistorized "TV ONLY" TELE-VISTA Model 0026
YOUR MARKET: TELEVIEWERS IN AREAS WHERE BOTH TV AND FM
STRONG
SIGNAL OVERLOADING FROM NEARBY STATIONS IS A PROBLEM. The only
"TV /only" Amplifier with the long-life "Duo Nuvistor" circuit ... and a
built -in coupler! Strong local TV and FM signals won't overload it.
4. BRAND -NEW Transistorized "TV ONLY" TELSTAR Model 0027
with Built -In FM Trap
plus 4-set coupler.
...
Gain and Low Noise figure
outstanding features.
6. TELSTAR FMX
...plus built-in Lightning Resistance
and other
(for FM exclusively) WITH 2 -SET COUPLER
Model 0025
YOUR MARKET: THE EXFAND NG NUMBER OF MONAURAL AND
STEREO FM
LISTENERS! Most powerfully stepped -up FM performance of
7.
Improved! Higher
Gain, VUTRON II
all!
FOR TV /FM Model 0024
YOUR MARKET: TELEVIEWERS IN AREAS WHERE FM STRONG
-SIGNAL OVERLOADING FROM NEARBY STATIONS IS A PROBLEM. Twice the TV
overload
protection of any other transistorized booster...thanks to Texas Instruments' brand -new EPITAXIAL MESA TRANSISTOR. Virtually eliminates pos-
YOUR MARKET: THOSE WHO WANT THE BEST IN AN IN- THE
-HOME SIGNAL
AMPLIFIER AND COUPLER.
5. TV /FM TELSTAR WITH 4 -SET COUPLER Model 0023A
8. GEMINI Model 9527
sibility of local FM interference.
America's most outstanding, best -selling booster
YOUR MARKET: VIEWERS AND LISTENERS WHO WANT THE WORLD'S MOST
POWERFUL BROAD -BAND AMPLIFICATION! Unbeatable Combination
of High
...
NOW FOR THE FIRST TIME
OUTSTANDING
ALL-IN -1 ROTATOR AND TV AMPLIFIER!
YOUR MARKET: THOSE WHO NEED AND WANT EXTRA
POWER...PLUS DIRECTIVITY. Fast, neat installation saves money 4 ways! World's
Finest Automatic Rotator (Tenn- a- Iiier)....plus Telstar TV booster. Built-in
FM TRAP.
Simple to Service. 2-set coupler.
10
WÌih
CHANNEL MASTER
WORLD'S MOST POWERFUL NEW INDOOR ANTENNAS
These beautifully- designed antennas open a whole new market
...because they work where only outdoor antennas could work
before!
Transistorized APOLLO Model 3721
(with Built -in Amplifier)
9. NEW! Revolutionary,
GETS CLEAR, GHOST-FREE, TV RECEPTION 15 TO 45 MILES OUT.
YOUR MARKET: SUBURBAN VIEWERS WHO WANT OUTDOOR ANTENNA
POWER FROM AN INDOOR ANTENNA. Exclusive "Miraclick " Switch elec-
tronically adjusts to different signal strengths. Super-effective hidden
amplifier gives extra pull -in power where needed.
10. NEW!
World's First Transistorized FM /STEREO
with Built -in Amplifier. Model 3731
INDOOR ANTENNA
GETS POWERFUL FM RECEPTION 15 TO 60 MILES OUT!
YOUR MARKET: SUBURBAN LISTENERS WHO WANT TOP FM PERFORMANCE
WITH EASY ANTENNA ADJUSTABILITY AND ROTATOR -TYPE DIRECTIVITY.
Booster is peaked-dipoles tuned
-for
FM
exclusively! Fidelity Switch.
11. Golden CANAVERAL Model 3720 (Non-Amplified)
YOUR MARKET: METROPOLITAN AREA VIEWERS WHO WANT TOP TV /FM
RECEPTION UP TO 15 MILES FROM STATION. Same features as Apollo.
12. NEW! FM /STEREO INDOOR ANTENNA Model 3730
(Non -Amplified)
YOUR MARKET: METROPOLITAN AREA LISTENERS... WHO SEEK FM PERFORMANCE WITHOUT COMPROMISE! Same advance features as 3731.
13. Improved ! SHOWMAN Model 3900 (Mahogany and Gold)
Model 3901 (Blond and Gold)
Beautiful
to move! "Metro- Dyne" Variable Inductance Electronic Tuning. Like no other antenna.
YOUR MARKET: CUSTOMERS WHO WANT SOMETHING DIFFERENT!
... improved ... priced
14. NEW! AURORA Model 3718
YOUR MARKET: THOSE WHO WANT A LOW- PRICED LUXURY ANTENNA! Tops
for the money! Magnificently styled. "Automagic" Clarifier Switch.
DEAL.
FREE GIFTS! SEE YOUR CHANNEL MASTER DISTRIBUTOR FOR FULL DETAILS ON INDOOR ANTENNA PREMIUM
NEW! BEAUTIFUL, POWERFUL "VU -CON" UHF CONVERTERS
GIVE YOU THE EDGE IN EVERY RECEPTION AREA
NOW AND IN THE FUTURE!
...
15. Model 6700. YOUR MARKET: FRINGE-AREA LISTENERS WHO WANT THE
ULTIMATE IN RECEPTION. Capacitive tuning (no sliding contacts),
1 long -life Nuvistor, 1 oscillator tube. Prevents strong -signal over-
loading.
16. Model 6701. YOUR MARKET: FRINGE -AREA LISTENERS WHC WANT
Inductive Tuning, 2 long -life
Nuvistors.
17. Translator Model 6703. Same as above but covers only channels 70 -83.
18, Model 6702. YOUR MARKET: METROPOLITAN AND SUBURBAN AREA
LISTENERS WHO WANT TOP QUALITY AT A MODEST PRICE! Your most
profitable UHF conversion market. Inductive Tuning, 1 long -life
TOP QUALITY AT A MODERATE PRICE!
Nuviszor.
19. Translator Model 6704. Same as above but covers only channels 70 -83.
CHANNEL MASTER CORP., ELLENVILLE,
NEW
YORK
TUNER SECTION: In the kit, the two most critical sec :ions
end and the IF strip -are supplied prewired and
pre -aligned and a high quality circuit board and pre -al 3ned
coils are provided for the stereo demodulator circuit The
IF strip has 4 amplifier- limiter stages and a wideband ratio
detector fcr perfect limiting and flat frequency response.
Sensitive bar -type electron -ray tuning indicator pinpoints
the center of each b-oadcast channel for lowest distortion,
and also serves as the stereo program indicator.
-the front
Antenna input: 300 ohms balanced
IHFM usable sens -iv ty:
3 !iv (30 db quieting), 1.5 pm for 20 db quieting
Sens tivi -y
for phase lock ng (synchronization) in stereo: 3 µv E FLIT
limiting sensitivity: 10 µv
IF bandwidth: 280 kc at 6 cb
points
Ratio detector bandwidth: me peak -to -pea. separation
Audio bandwidth at FM detector: flat to 53 kc
IHFM signal -to -noise ratio: 55 db
IHFM harmonic :istcrlion: 0.6 °/o
Stereo harmonic distortion: less than L5 °/c
IHFM captare ratio: 3 db
Channel separation: 30 ci.
1
AMPLIFIER SECTION: High quali :y Baxandall bass and
treble controls do rot interact or affect loucness, permit
booèt or cut at extremes of range without affect ng mid range. Balance control is infinitely variable, permitting complete fade o' either channel. Blend control is va-iakle from
switch -out, for max mum seoaraticn, to f ..II blend. Tape
Monitor switch permits off- the -tape monitor ng .vith the
Eic RP100 Stereo Tape Recorder.
Po er: 36 watts IHFRVI music 28 watts continuous ;-o-al)
IM istortion (each channel): 2% at 14 watts, 0.7 % at 5 watts,
0.20b
1
watt
Harmonic distortion (each chan -el): 0.6 °/o
at 10 watts, 40 cps to 10 kc; 0 23/4 a: 1 watt, SO cps to 20 kc
IHF power bandwidtlh at rated continuous power, 1°10 harmo is distc-tion: 30 cps to 20 kc E Frequency response ±1
db, 15 cps :o 40 kc
peaker output: 8, 16 ohms
Inputs:
Ma netic phono or dapted ceramic phono, tuner, tape
auxiliary
Sensitivi:y: 2.3 mv phono, 250 mv others
Noise:
-65 db at 10 mv, mag phono;-80 db others.
New Eico Classic 2536 Stereo FM Receiver
Now...
every other stereo receiver seems overpriced
Take a superb stereo tuner, guaranteed stable under all conditions, and sensitive enough to give full stereo separation even
on weak, fringe -area signals ...
Add a virtually distortion -free 36 -watt stereo amplifier with remarkable overload and transient characteristics ...
Mount them on one chassis- effectively separated for the performance benefits of components plus the convenience of a
single compact unit.... Price this combination at $209.95 factorywired, and at $154.95 in a new kit pack that makes building a
delightful experience -and what do you have? The Classic x2536
Stereo Receiver, star of the new Eico Classic Series, and a component that matches or surpasses the performance of components selling at substantially higher prices. How? Simple. it's pure
performance. Stripped of everything but the finest basic circuitry.
Examine the specifications yourself. Compare them with those of
more expensive units. Listen to the 2536 -then to higher prized
units. Can you see or hear a difference worth paying for?
If you're interested ,n building a fine stereo receiver, take a long
look at our new kit pack, too. Note the logical, orderly arrangement of parts. How easily it sets up for work. How easily it closes
down between work sessions-with no loose parts to go astray.
Thumb through the 2 -color Construction Manual. Ever see such
graphic diagrams? Every step is clear and unmistakable -and no
diagram shows more than 20 steps. Another thing the diagrams
show you: how simple the wiring is. No tricky frills; no clutter;
no confusion, even around switches and controls. Plenty of space
to work in. And Eico has eliminated the most tedious part by pre mounting jacks, sockets, terminal boards, and transformers.
Does any other kit give you more building ease, or assurance of
success than the Eico Classic? See it at your hi -fi dealer.Optional
Walnut Cabinet WE -73, $19.95, Metal Cover E -12, $7.50. Write for
catalog. Eico Electronic Instrument Co., Inc., 131-01 39th Avenue,
Flushing, N. Y. 11352. Export: Roburn Agencies Inc.,
Greenwich Street, New York 13, New York.
CIRCLE NO. 113 ON READER SERVICE PAGE
431
E/CO
F°° °%,n
E5
i
ELECTRONIC INSTRUMENTATION
FOR OIL EXPLORATION
Geophysical prospecting using electronics has led to
many oil discoveries. Acoustic sounding is now done with
transistorized equipment, oscil:°graphs, and computers.
By LOUIS E. FRENZEL, Jr.
/
McCollum Laboratories, Inc.
LL of the major fields of science and technology have
profited greatly by the use of electronic techniques
over the past years. Persons in the fields of chemistry,
physics, biology, medicine, and engineering are beginning
to realize the great potentials that electronic techniques
offer. Electronic instrumentation, when used, improves existing conditions in addition to offering new avenues of approach unheard of before the use of electronics.
One field that has "discovered" electronics is geophysics.
Geophysics is the science and study of the earth and its various phenomena. Years ago, this was the only definition of
geophysics, but today, because of advances in sciences like
electronics, geophysics is now the study of our solar system
and space as well as the earth. Geophysics includes the fields
of geology, geodesy, seismology,, technophysics, volcanology,
oceanography, petrology, geochemistry, geochronology, me-
A
teorology, hydrology, aeronomy, geomagnetism, solar physics, and others. These are called the geosciences.
One of the most interesting fields is seismology, particularly the seismic oil exploration branch of this field. Oil is
one of our most important natural resources and the need
for large quantities of oil continues to exist. Oil and its byproducts have manyczimportant uses in our world today, and
new uses are continually being found. For these reasons it
is important that we be on the lookout for new sources of
this valuable product. The major oil companies of this country conduct a constant search for new petroleum deposits in
the earth. Geophysical prospecting techniques using electronics developed by these and other companies have led to
many successful discoveries of oil deposits.
Reflection Seismology
Geophysical or seismic prospecting is the science of searching for petroleum, gas, or mineral deposits by making physical measurements on the earth. While many different techniques have been devised for making these measurements,
one of the most effective and widely used in oil exploration is
reflection seismology. In this technique, sound waves are generated in the earth. These waves travel through the earth and
are reflected back to the surface from the various subsurface
layers. These reflections are recorded, and the depth of the
layers are computed by knowing the reflection times and the
velocity of propagation. From this data, special maps of the
subsurface are plotted. These maps are then interpreted by
geophysicists who are able to determine if the subsurface
structures are those which are usually oil bearing in nature.
If results of these measurements show conditions favorable
Fig. 1. A gas -explosion chamber built into
is used to produce an acoustic shock wave
this 18 -ton vehicle
for oil exploration.
earth in a sinusoidal manner have also been used as seismic
signal sources, but many of these are still largely experimental. The "Vibroseis ", a vibratory exploration technique developed by the Continental Oil Company, is already being
used commercially.
(Editor's Note: Still another method of producing the
shock wave was announced recently by Sinclair Oil Corp. A
gas explosion chamber is mounted in the center of an 18 -ton
large- wheeled diesel -driven vehicle, called "Dinoseis." The
chamber is held against the ground surface by part of the
weight of the truck. When the gas mixture is exploded, a
100,000 foot -pound seismic impulse is produced (Fig. 1).)
After the acoustic energy is radiated, it will travel through
the earth with a velocity which is dependent upon the media
through which it passes. Basic physics says that the velocity
of propagation of acoustic energy is dependent upon the
type of material through which the energy passes and other
factors. For example, the velocity of sound waves is higher
in rock than it is in clay soil. The earth's subsurface is made
up of many different types of layers of rocks, soil, sand, and
other substances. The velocity of propagation will change
abruptly as the acoustic wave passes from one layer to another. Because of this velocity change, a reflection is produced. The exact nature of the reflection will depend whether
the signal goes from a high -velocity zone to a low -velocity
zone or vice versa. This reflection takes the form of a very
small vibration of the earth which travels upward vertically
toward the surface. This reflection is actually a low-frequency
(10 to 300 cps ) sound wave.
Detection and Recording
Fig. 2.
Typical geophones employed to pick up sound
reflections.
to oil accumulation, further tests will be made and a pilot
well may be drilled.
Reflection seismology is an acoustic-sounding technique.
In this technique, a generator source is used to produce a
sound or shock wave that will penetrate the earth and be reflected back to the surface. The most widely used method of
generating seismic waves is by detonating a charge of dynamite or other explosive. A hole, called a shot hole, is bored
into the earth and the explosive is placed in it. The explosive
is then detonated and a large impulse shock wave is produced. The wave travels through the earth in all directions
and is reflected from the various subsurface layers. Reflections as deep as 20,000 feet have been recorded.
A newer method, developed by Burton McCollum, involves the dropping of a weight. A three -ton metal weight
mounted on a large truck is dropped from a height of approximately nine feet. This creates a tremendous shock wave in
the ground. This technique produces reflections which are
just as useful as those produced by a dynamite blast.
Electric and hydraulic vibratory sources which vibrate the
The next step in this oil exploration technique is the detecting and recording of the vertical reflections. Here is
where electronics plays a major role. Fig. 4 shows a cross section of the earth and a block diagram of the equipment
used in the reflection method.
The reflections are picked up by a microphone -like transducer called a geophone. Fig. 2 shows two typical geophones.
The geophone, also called a seismometer or detector, is usually buried several inches in the earth. Care is taken to see
that the geophone makes good contact with the earth so that
it moves when the earth moves during a reflection.
A typical geophone consists of a coil of wire which is
suspended by a spring and which moves in the field of a
permanent magnet. When a reflection appears, a small vibration in the earth will be transmitted to the geophone and
will cause motion between the coil and the permanent magnet. This causes a voltage to be induced into the coil which
is a function of the nature of the vibration. The geophone is
made so that it will respond best to vertical movement. A
cable attached to the geophone carries the voltage to other
equipment.
A single geophone is never used in practical work. A large
number of geophones are arranged in various patterns over
a large area to obtain diversity. Diversity improves signal -to-
Fig. 3. Typical low- noise, high -gain, multi- channel transistorized geophysical amplifiers and
28
filter units.
ELECTRONICS WORLD
tion signals will be easier to detect. This record is made by
applying the seismic signal to a light galvanometer. The light
is flashed onto light-sensitive paper which is moved past the
galvanometer. This paper is processed and a record is produced. Timing lines are also put onto the record so that the
geophysicists may know how long it takes the radiated signal
to travel into the ground and to be reflected back to the
surface. These timing lines are usually graduated in steps of
10 milliseconds, and the entire record can be anywhere from
four to six seconds long. A device for producing such a record
is called a recording oscillograph, and a typical unit is shown
in Fig. 5. Fig. 5 also shows a seismic reflection record made
on a similar recording oscillograph.
Magnetic tape recording systems are also used, particularly
in poor _record country where additional filtering and other
processing must be done to obtain usable reflection data.
The magnetic tape record can be sent to a central laboratory
for processing. A record is made by placing a magnetic tape
noise ratio. The geophones are wired together in various
series -parallel combinations in order to obtain a satisfactory
impedance match to other equipment.
The reflection signals from the earth are extremely weak.
Even though a large amount of energy is radiated by, say, a
charge of dynamite, the voltage produced by a group of geophones is still too small to record directly. Noise in various
forms also complicates natters. Just as in communications
and radar systems, the signal -to-noise ratio is important and
steps must be taken to improve it; otherwise, good naps of
the subsurface will not be obtained.
The output voltage from the geophones is fed to a low noise, high -gain amplifier. This low- frequency amplifier provides extremely high gains in the 10- to 300 -cps range. Care
is taken in the design of these amplifiers to ensure a low noise
figure. Fig. 3 shows two such geophysical amplifiers.
These amplifiers contain built -in low- and high -pass filters
which help to improve signal -to-noise ratio by eliminating
RECORDING
SEISMIC SIGNAL SOURCE
(DYNAMITE, WEIGHT DROPPING)
OSCILLOGRAPH
G
ED PH ONES
RECORDS
FRED.
MOD.
GEO.
AMP.
WEATHERED LAYER
i i////
RECORD HEAD
/,SANDSTONE
S
PLAYBACK
HEAD
f3
S
U
R
F
A
C
E
S
iM£S
tONe
ONf
Fig. 4. Cross section of earth showing
the subsurface layers and
unwanted frequencies above and below the reflection signal
frequency. These filters are normally of the constant -K LC
type and are made variable to provide the desired filtering.
Some amplifiers also contain a 60-cps notch filter to eliminate power -line interference which tends to be a problem in
many areas.
All good geophysical amplifiers contain a.g.c. circuits. In
many cases even a form of delayed-a.g.c. is used. This a.g.c.
system improves performance by allowing the amplifier to
operate over a wide range of input signal amplitudes without distortion. Another feature of some geophysical amplifiers is programmed gain. Programmed -gain circuits allow the
gain of the .amplifier to change with time. Since it takes a
longer time for deep reflections to return to the surface
than it does shallow reflections, naturally the deeper reflections will show up much smaller in amplitude on the record.
In some cases it may take five or six seconds from the time the
seismic signal was radiated for the most greatly attenuated,
deeper reflections to return to the surface. The amplifier with
programmed gain changes its gain with time and thereby
brings all the reflection signals to approximately the same
amplitude level.
After considerable amplification and some filtering, the
signals are ready to be recorded. In order for the geologist
or geophysicist to analyze the reflection information, it must
be recorded and put into a suitable form. The most common form is a photographic record showing a number of reflection recordings. These are normally arranged so that the
reflection signals from each dynamite blast or weight drop
appear one beneath the other. In this way, line -ups of reflecDecember, 1963
a
block diagram of associated electronic instrumentation.
about four inches wide and three feet long on a large rotating
chum. The magnetic record and playback heads are placed
adjacent to this drum. The drum revolves as dynamite shots
or weight drops are produced and the resulting reflection
signals are recorded on the tape.
The recording technique actually involves frequency modulation. The amplified reflection signals frequency -modulate
a high audio- frequency carrier (2 -5 kc.) It is this modulated
carrier that is recorded on the tape. This FM technique results in a better recording than would be obtained if no mod ulating system were used. It also eliminates the need for a
bias signal which is usually required in magnetic tape recording systems to reduce distortion inherent in magnetic
recording. Although FM is generally favored, standard magnetic tape biasing techniques are also used successfully in
recording systems of this type.
A typical FM modulator consists of a free- running multivibrator which oscillates at a frequency of 4 kc. The frequency of this oscillator is dependent upon the RC time
constant used in the grid circuits. This oscillator is frequency modulated by the reflection signals. A tube acting as a variable resistance is connected in the grid circuit. As the
incoming reflection signals are applied to this tube, its resistance changes, thus changing the circuit time constant
and the frequency of the oscillator.
The FM signal from the playback head is amplified and
clipped and made into a varying -frequency rectangular wave.
It is then differentiated and the resulting spikes trigger a
monostable multivibrator. One fixed -amplitude, constant duration pulse is produced by the monostable circuit for each
.
29
RE
CTEO ENERGY
I
N NbotI
Nb
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óu
nn
11o
I
REFLECTIONS
,\
hP r h
q
1
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l
000
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1
10
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01
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01
hh
4446
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411
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REFLECTIONS
TIME ZERG
'''.I..
Fig. 5. (Left) A recording oscillograph of the type that is employed to produce seismic records for use in oil exploration. (Right) Typical seismic reflection record. Artificially induced shot break indicates when seismic energy was first
radiated. Refracted energy is the first arrival of seismic signal at the geophones. This is energy refracted from the
first high-velocity zone below the surface. The reflections indicate a change in velocity or the boundaries of reflecting
layers. Reflections are picked by noting where the signals of each trace line up or where the peaks and troughs appear to
fit into one another. Other reflections besides the ones that are obvious in this figure can be picked by close observation.
trigger spike. The pulses are then integrated or averaged in
a suitable low -pass filter. The output is the original geophysical signal.
After the reflection signals have been recorded, they can
be processed in various ways. Mixing (compositing) and
filtering are the most commonly used processes, and both
methods improve the signal -to -noise ratio.
After a number of shots have been recorded, the resulting
reflection signals can be mixed together. The reflection signals may be obscured by noise in all of the recordings, but
because' the noise tends to be random it will cancel to some
extent. The reflection signals, however, being the same on
each record, will add. Practice has shown that the signal -tonoise ratio improves approximately as the square root of the
number of records composited. Each trace in Fig. 5, for example, is actually a composite of 320 individual records.
In addition to the filtering in the geophysical amplifiers,
special filters are used in cases where the signal -to -noise ratio
is low. These filters have many configurations and are largely
of the analog type. Digital -filtering techniques have also been
developed. Because of the transient nature of seismic signals,
filter requirements are rigid and care must be taken to see
that the filter does not distort the signals and give false results.
In addition to filtering and mixing, processing also includes
corrections. In order for the geophysicist to obtain a true picture of the various subsurface layers, there are certain characteristics of the earth that must be taken into consideration.
c
ac
oo,0
ecnee.e.-
Obtaining the Information
To obtain information about the oil -bearing properties of
a particular part of the earth, a crew of men is sent into the
field along with the equipment just described. Since all of
the work is done in the field, the equipment must be portable.
It is made so by mounting it in trucks. For dynamite operations, shot -hole drilling apparatus must be taken, and with
the weight -drop technique, a large truck must be provided
to carry the weight and its associated equipment.
An instrument or recording truck carries most of the electronics. The recording equipment and amplifiers are mounted
in this truck. Because of the complexity of this truck, a skilled
electronics field technician must be present to set up, operate,
and maintain this unit in the field.
The equipment used in oil exploration is sometimes
mounted in boats so that water areas may be worked. Many
oil discoveries have been made beneath large bodies of water
-such as the Gulf of Mexico.
(Continued on page 88)
Fig. 7. One of our nuclear explosion detection stations.
Fig. 6. A central processing system used for geophysical data.
30
The uppermost layer of the earth, the weathered layer,
will give false reflection data if it is not corrected. Since it
varies in thickness with location, information regarding this
weathered layer must be obtained before suitable reflection
data can be obtained.
Ground elevation and geophone placement must also be
considered. Since -thé geophones are spread over a'llrgeasea,
the elevation may be different for some geophones than for
others. Also the distance between the signal radiator and the
geophones may be changed during the shooting. Con-ections
must be made. Other corrections of various kinds must also
be made depending on the equipment and methods used.
NEGATIVE -FEEDBACK NOMOGRAM
By A. L. TEUBNER
Chart employed to determine reduction in stage gain
when given percent of negative feedback is applied.
THIS nomogram can be used to determine the reduction
in stage gain when negative voltage feedback is ap-
plied.
If the gain of the stage without feedback and the percent
of the output voltage fed back to the input are known, the
over -all gain can be found simply by laying a straightedge on
the chart.
For the example already drawn on the nomograms, the stage
- 0.9
100
90-
gain without feedback, G, is 20 and the feedback percentage,
H, is 15%. If 20 on the "G" scale and 15 on the "H" scale are
connected by a straight line, the line will cross the "A" scale
at 5, the gain with feedback applied.
This chart provides an accurate result for a purely resistive feedback network. If the network contains reactances
which produce an appreciable amount of phase shift, the
over -all gain cannot be found by such a simple formula.
-10
-LO
A
G
11-1-GH
BO-
70
-
o
=J
w
d
Y
0
Q
Q
60-
o
co
Q
_
0
w
w
L_
CO
50-
_
o
W
_
w
U_
F-
_
Z
w
-2.0E-
U
w
0
-15
5
_
3
_
á
40-
-
I
I
-
_
1
Q
_
30-
-25
- 3.0
30
20 --
- 4.0
5.0
10
-
5
-
December, 1963
- 40
50
-10
-60
-15
- 20
= 50
-100
- 70
- 80
31
RECENT
DEVELOPMENTS
in ELECTRONICS
Microminiature I.F. Amplifier. (Above) The tiny
i.f. amplifier shown magnified in the foreground
was developed by ITT to replace a comparable
electron -tube unit being held at the left. The miniature transistorized device is 100 times smaller
than the predecessor unit and was made by depositing thin films of conducting, insulating, and
semiconcucting material on top of each other. For
use at intermediate frequencies employed in beyond- the-horizon and satellite communications
equipment, the new amplifier weighs but a quarter
ounce. It consists of four transistors, a dozen capacitors, sixteen resistors, and associated wiring.
Space Flight Via Computer. (Left) Two research
engineers watch a rendezvous and docking maneuver in a simulated space flight at General Dynamics laboratory. The television monitor at the far
left is similar to one in the company's manned
spacecraft simulator, located in another building. The tiny model in front of the screen is pictured by a "zoom" lens running on tracks between
the two engineers. The lens is moved back and
forth to decrease or increase the size of the
image. A computer is employed to "instruct" the
lens- driving system. The view that the spacecraft
pilot sees in his simulator's TV monitor is shown
below. This equipment is being used in a training program to help establish procedures by
which astronauts or trainees can: (1) be screened
for flight ability under conditions resembling an
actual space mission; (2) practice manipulation
of controls such as would be required in actual
flight; and (3) possibly discover before a flight
whether a proposed mission is feasible or not.
32
ELECTRONICS WORLD
Portable Broadcast TV Tape Recorder. (Below)
A new portable broadcast television tape recorder, said to be priced well below other such
recorders of broadcast quality, has been introduced by Ampex. The unit weighs under 100
lbs. and is designed for mobile and studio use.
Its price is $14,500 and it is completely tran-
sistorized. The unit operates at 3.75 ips and
can record up to five hours of continuous program material on a single 121/2 -inch reel of
standard 2 -inch wide broadcasting video tape.
Booster for Lasers. (Above) The small white dot
framed in the lens in a combination photo detector- parametric amplifier which Sperry Rand
claims will boost by 100 times the receiver sensitivity of laser communication and radar systems.
First tests of the new photo- parametric diode
demonstrated detection and amplification of
less than one -billionth of a watt of light and a
modulation frequency response from d.c. to 2000
mc. In the photo above, a technician is aligning the diode for a test in which a laser fires
a beam from the position of your eye into the
tiny aperture of the silicon semiconductor device. Coupled with other all- integrated, solid state devices in a functional block, the photo parametric diode could make up a complete
optical receiver that is no bigger than a matchbox.
. xtl-01.El..
Sta
999900
òññ0ññr)
,.
Automatic Transmitter Locator. (Above) Shown here is the front
panel of the readout unit in a locator- computer system that automatically locates, tracks, and monitors distant transmitters with
unprecedented accuracies. Developed by Weston, the equipment is
able to pinpoint the location of a transmitter within 20 yards
at a distance of 50 miles. At a similar distance, previous tactical
methods would at best be expected to come within one mile.
The answer to the tactical problem is solved by the computer and
read out digitally on the panel.... Radar -Display Consoles. (Left)
The radar detector -tracker display consoles seen through the
transparent plotting board have been installed on the nuclearpowered aircraft carrier U.S.S. Enterprise. Part of the Naval
Tactical Data System, these consoles display radar information
which the operators enter into the computer system. The U.S.S.
Enterprise is one of more than twenty Navy ships which will ultimately be equipped with the consoles designed by Hughes Aircraft.
33
THE
LOU D NESS
CONTROL
By RUDOLPH A. JACOBS, Jr.
review of an important concept and a description
of a simple circuit used for loudness compensation.
A
BACK in the early thirties, when the electronic reproduction of sound was in its infancy, the response characteristic of the human ear became an active subject
of investigation. In 1933, the "Journal of the American
Acoustical Society" published a lengthy and exhaustive paper
by Fletcher and Munson containing the results of a study
made in this area. Along with a great deal of other information, the paper contained a family of curves describing average human ear response versus frequency at different sound
pressure levels. This set of curves is familiar to us as the
"Fletcher- Munson Curves." ( See Fig. 1.) They have been
published and re- published over the years and used ( sometimes misused ) innumerable times. Since the correct application of the data represented by these curves is necessary
in order to obtain proper tonal balance in our sound systems,
let us investigate them in some detail.
The curves were obtained in the following manner: The
researchers produced a tone of 1000 cps (used as their reference frequency) at a specific sound pressure level, and had
a subject listen to it. They then produced a tone at another
frequency and adjusted its pressure level until the subject
said it sounded just as loud as the 1000 -cps reference tone.
The researchers recorded the sound pressure level of the new
tone and then shifted to another frequency, always having
the subject compare its loudness to the loudness of the 1000 cps tone. By shifting the frequency of the second tone up
and down the audio range, they obtained one equal loudness
contour. By repeating the test with a number of subjects they
were able to approximate the response contour of the "average human ear." By shifting the sound pressure of the
1000 -cps tone in ten decibel steps and repeating the whole
process, they obtained equal loudness contours all the way
from the threshold of audibility to the -threshold of pain.
The data they obtained is far from ideal. They investigated
only the region between 62 and 16,000 cps, assuming, per34
haps rashly, that the response trend would continue smoothly
from these frequencies to the limits of audibility. Also, they
used close -fitting headsets for taking their direct data, and
then attempted indirectly to convert the results to what would
have been obtained by projecting the sound via a loudspeaker.
In this rather dubious process they picked up the peculiar
wiggle that appears in the mid-highs, leaving its validity
subject to question. This is especially true when considering
distributed or stereo -type sounds, since Fletcher and Munson
themselves attributed the wiggle to diffraction patterns occurring about the head and ears of a listener facing a point source sound reproducer.
Although the curves do have these flaws, which we should
keep in mind, they still represent the best data available.
Besides when we make our corrections according to their
dictates, the result sounds "right" to the ear and the proof of
the pudding is in the eating-so let's proceed.
Significance of Curves
Now that we have the curves, what is their significance?
It is at this point that most of the misunderstandings occur.
Before attempting to answer the question, let's try to pin
down two elusive adjectives: "loud" and "soft." What is the
power level of a "loud" musical passage? There may be momentary rests when it will drop to near zero, then leap up
with an ear- splitting crash! Let us arbitrarily say that when
a sustained 1000 -cps tone is produced at our ear at 80 db
above reference (reference level is 10-16 watts per square
centimeter) , it sounds as loud as a loud orchestral passage
when we are sitting in one of the first rows of the concert
hall. At the other extreme, when we are spending a quiet
evening at home reading, with the baby asleep in the next
room, and with our sound system adjusted for very low level
background music, that same passage will sound as loud as
our 1000-cps tone at 40 db above reference. These are, of
ELECTRONICS WORLD
course, subjective factors and individuals will vary 10 db or
so in their choice of figures for "loud" and "soft," but the
ones selected by the author are close enough to avoid serious
objections by most people, so they will be used here.
Now that we have established the range in which we are
interested, let us continue by considering a hypothetical example: The Philharmonic is performing a recently discovered work that we will entitle "Loud and Equal," in which
the melody consists of a succession of tones, all sounding
equally loud, running up and down the audio spectrum, with
the 1000 -cps tone at the 80 -db level. In other words, they
are creating sound pressures that exactly follow the 80 -db
loudness contour of Fig. 1. We are listening to the broadcast
on FM at the 80 -db level -just as loud as the original sound.
Since the transmitting equipment, pre -emphasis network, receiving equipment, de- emphasis network, and home audio
system are all naturally perfect, with tone controls flat, it
sounds just like Philharmonic Hall in the parlor! We like
what we hear, so we run right out and buy the record. However, night falls and out of consideration for the neighbors,
we turn down the volume to the 40 -db level and sit back, expecting to hear that "Equal" piece just as before, but at a
nice quiet listening level.
What we have really done is taken sound pressures along
the 80 -db loudness contour and moved them down to the
40 -db level. How does it sound? Terrible! The highs sound
fine but over-all it's thin and weak -no bass. By going to Fig. 1
and superimposing the 80 -db contour on the 40 -db contour
we can quickly see why. From 700 cps on up, the curves
duplicate each other within a decibel or two, so these tones
still sound about equally loud as we go from one to the other.
Below 700 cps, however, a pronounced divergence begins to
appear. It is apparent that, to the human ear, the loudness
of bass sounds decreases faster than the loudness of treble
sounds as the actual sound -pressure level is uniformly decreased. At 200 cps, we should have decreased the sound
pressure 12 db less than we reduced the 1000 -cps tone in
order for them still to sound equally loud. At 100 cps the
difference is 20 db. At 30 cps it's 30 db -a power difference
of one -thousand times!
So our piece "Loud and Equal" does not sound equally
loud at this lower level. In order for it to do so, we should
have attentuated only those tones above 700 cps by 40 db,
attenuating those below this frequency by reduced amounts:
20 db at 100 cps and only 10 db at 30 cps. What we need
then is a control that will discriminate against the higher
frequencies, attenuating them progressively more and more
relative to the bass as we reduce the level, in other words, a
uniform loudness control.
Now let's go a step further. We know that when we reproduce an 80 -db program at an 80 -db level, the sound system must be flat in order for the program to sound like the
original. We have discovered that when we reproduce an
80 -db program at a 40 -db level, we must reduce the level
of the various frequencies by the difference between their
position on the 80 -db contour and their position on the 40 -db
contour. Therefore, assuming that an 80 -db program is the
loudest material we will wish to reproduce without attenuation, and also assuming that 40 db is the maximum attenuation we will normally desire for any program, we are ready
to define the characteristics of our loudness control.
Loudness- Control Characteristics
Simply enough, it will be flat when set at maximum loudness; then follow the difference between the 80 -db contour
and each lower contour as the level is reduced; finally reaching the difference between the 80 -db and the 40 -db contours
at the minimum output setting. These characteristics are
plotted in Fig. 2. (Note that it is the change in the contours
of Fig. 1 that gives us Fig. 2. Do not be fooled by the uniform across- the -board treble
(Continued on page 82)
December, 1963
120{
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100
90
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1
60
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20
10
50
20
100
200
500
IKC.
FREQUENCY-CPS
5KC.
2KC.
10KC.
20KC.
Fig. 1. The Fletcher- Munson curves of equal loudness level.
rT,
1
6-
7C
m
W
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F50
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40
50
20
100
200
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2KC.
OKC. 20KC.
Fig. 2. Characteristic curves for loudness correction attenuator.
OUTPUT
IK
100
INPUT
5 °/o
K
AUDIO
TAPER
Fig. 3. Circuit diagram
of the loudness control used by author.
J1
F.
Fig. 4. Measured frequency response of the Fig. 3 circuit.
.
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35
SIMPLE TESTS for SEMICONDUCTORS
By CARL DAVID
TODD/
Head of Engineering, Modular Circuits, Hughes Aircraft Co.
Here are several ways to check leakage, gain,
saturation, and breakdown voltages with equipment
normally at hand in the average laboratory.
OW many times have you wished you could perform
a few basic tests on a transistor or diode? Perhaps
you wanted to make sure that it was still good after
that test, or maybe you wanted to know the value of some
critical parameter. While there are several different types of
simple testers on the market, it may be that the amount of
testing that you do does not justify their purchase. This is
particularly true where measurement of the relatively low leakage currents of silicon transistors and diodes is concerned.
In some cases, it is desirable to perform a few basic tests
on all transistors and diodes to be installed in a piece of
equipment. There may be quite a few units that you would
like to test in a minimum amount of time, but you cannot
purchase an automatic test set to satisfy your temporary
requirement.
This article discusses several ways in which parameters
such as leakage currents. d.c. current gain, saturation voltage,
and breakdown voltages may be measured with equipment
normally on hand in the average electronics laboratory. bu
spite of the basic simplicity of the tests, the accuracies obtained are usually more than adequate. Some of the tests
will be of the go /no -go type while others will yield quantitative results. Both tests are equally simple to make.
ever, this variation is normally small in comparison to the
specified test voltage and hence contributes negligible error.
In the case of severe overload, that is, if the leakage current is quite a bit higher than expected, neither the transistor
nor the meter will be damaged since the usual v.t.v.m. is
capable of standing rather high overvoltages without harm
and the measurement resistor serves to limit the current
flow through the device under test.
Where many transistors or diodes must be tested on a
go /no -go basis to a given specification, it is possible to use
a different arrangement which yields a minimum amount of
operator decision and hence requires much less test time. The
over -all reliability of the test results is also increased.
Fig. 1B illustrates the basic leakage current measurement
where a go /no -go test result is required. Voltage supply El
provides the required test voltage across the collector -base
diode (for the Icso case shown) . Another voltage source,
E2, in conjunction with resistor R1 produces a reference
current which is made equal to the current test limit. The
voltage across the d.c. null detector is assumed to be insignificant with respect to the voltages El and E2. The value of
R1 required is E2 divided by the limit test current.
The current flowing into the d.c. null detector is the net
difference between the unknown current, Ix (which for the
Leakage Currents
example shown is /rum ) and Is, the reference current. Thus,
Let us first consider the measurement of leakage current
as long as Le is less than the test limit, the net current,
since this one parameter is perhaps the most revealing with
Is. flowing into ti'e null detector will be negative. However,
regard to damage or deterioration. A voltage is applied to
as the value of I.v is increased, the net current approaches
zero until Lt is exactly equal to the set limit current. Above
two of the terminals and the resulting current is measured.
this value, the net current into the null detector becomes
One approach which gives a quantitative result is shown in
positive.
Fig. 1A.
Using the go /no -go approach, it is only necessary to note
Voltage source El represents the required test voltage to
which direction the null detector moves to determine whether
be applied between the collector and base terminals ( for the
the leakage current for the transistor under test is less than
case for /rum as shown). Actually, E1 should be set to about
or greater than the test limit.
0.7 v. higher than the required test value to allow some drop
The sensitivity of the null detector required depends on
across the current meter. A v.t.v.m. may be used to measure
the magnitude of the limit current. For example, the normal
current by placing a shunting resistor across its terminals
as shown. For example: R1 of 1000 ohms
v.t.v.m. with 11- megohm input resistFig. 1. (Al Basic quantitative leakage current
would give a full -scale current of 1.5 ma.
ance and a 1- or 1.5-v. range may be
(B) Basic "go/no-gomeasurements for
( using the 1.5 -v. scale on the meter) .
used for test currents down to about
leakage current measuremen for
Full -scale currents of 150 pa. and 15 pa. Improved "go/no-go" leakage current test. 15 na. For lower currents, a d.c. milli TRANSISTOR
TRANSISTOR
may be obtained using values of R1 of
voltmeter, such as the Dynamics Model
UNDER TEST
UNDER TEST Ica°
10,000 and 100,000 ohms respectively.
4472, or a sensitive current meter such
IN "Ill -IR
As we increase the sensitivity to 1.5 pa.
as the General Radio Type 1230-A or the
RI
and 150 nanoamperes (na.) , we must
Hewlett- Packard Model 4251, may be
+
also include the input resistance of the
used. The null detector current sensiv.t.v.m. ( usually around 11 megohms)
tivity should be better than one -tenth of
when we determine the value of R1.
the limit current.
NULL
DETECTOR
Thus, for 1.5 pa. full -scale, R1 should
Using electronic meters, the circuit is
be 1.1 megohm and for 150 na. R1
capable of withstanding a substantial
iBl
should be 110 megohms ( made up of five
overload as was true in the previous
22- megohm resistors in series) .
Ic.°
quantitative measurement. It may be
PRESS TO
SI
TEST
Since the value of leakage current
wise to place a momentary switch in
varies about 10 percent per degree centiseries with the unknown leakage current
grade, it serves little purpose to have a
path in such a manner that the null devery accurate means of measurement
tector is shunted to ground as shown in
TRANSISTOR
UNDER TEST
and the approach described above yields
Fig. 1C. After the transistor is inserted
adequate results. The actual test voltage
into the socket, switch Si is depressed
will vary somewhat depending upon the
and the circuit is as given in Fig. IB.
voltage drop across the v.t.v.m.; howThe improved circuit has several adD
36
ELECTRONICS WORLD
TRANSISTOR
TRANSISTOR
TRANSISTOR
UNDER TEST
UNDER TEST
vantages over the more basic circuit. UNDER TEST
R2
Zc
First, an overload will normally occur in
transistor
until
the
of
Fig.
lB
meter
the
_
is inserted and this may produce an
appreciable delay in the reading. The
D2
(C)
(e)
meter of Fig. 1C always starts out from
zero such that no overload is present
=cEB
ZCER
TRANSISTOR
TRANSISTOR
and any zero drift is immediately seen.
UNDER TEST
UNDER TEST
Furthermore, any severe overload proTRANSISTOR
EcE_
Ecc_
UNDER TEST
duced by a faulty component under test
(A)
Si
is
depressed
will be noticed as soon as
(E)
(D)
and hence may be removed rapidly (before the meter pins for most cases).
R2
RI
'Soo
DIODE
Finally, the sensitivity of detection is inUNDER
TRANSISTOR
NULL DETECTOR
TEST
TEST
UNDER
(OR COMPARATOR)
creased since the operator merely looks
r1
for a minor meter movement as a direct
EEc
result of depressing Si.
(G)
(F)
The basic circuits of Figs. lA and 1C
may be modified to measure any of the
Fig. 2. Simplified measurement circuits are
standard leakage currents illustrated in
used for various leakage current parameters.
Fig. 2. Although all examples show the
TRANSISTOR
testing of an n -p -n transistor, p -n -p
Fig. 3. (Al Quantitative VCE(Rat) measureUNDER TEST
(B),
transistors may likewise be tested merely
ment. (B) For "go /no -go" VCE(sat) readings.
by reversing all polarities.
The above circuits may also be used for measuring leakage
voltage E3 which is set to the desired rejection limit value.
currents of switches, printed circuits, or ceramic or paper
For value of VCE (sot) exactly equal to the limit value E3,
capacitors. Enough time must be allowed to charge the cathe null detector voltage will be zero. As Vrr: wit) is varied
pacitors before such a reading is taken.
above or below the limit value, the null detector voltage
will change from one polarity to another. Using a sensitive
Saturation Voltages
null detector, rapid testing of VrE (xnr) may be performed.
Saturation voltage of a transistor is measured with the
Clamping is accomplished as before for the transistor but
transistor driven by a constant collector current and a contwo germanium diodes, D3 and D4, limit the voltage across
stant b(,.,c current. The ratio of lc to la is made considerably
the detector when Vrr: (.,) is excessively high or very low.
lower than the natural d.c. current gain of the common
The reference voltage, E3, may be derived from E2 as
emitter stage. In some switching applications, VrE ())i,n is a
shown, or from the main supply El as shown by the dotted
very important parameter.
lines. It should be adjusted with a resistor equal to the ratio
Measuring Vrr: (..0) is very simple in its basic form since it
of the limit saturation voltage to the value of II, or with the
is only necessary to provide two current sources with an outnull detector and clamps removed.
put voltage variation of only a volt or so. This means that a
The forward voltage of a diode may be measured in a test
100 -volt source used with appropriate resistors will yield
configuration very similar to that of Fig. 3, with the base
excellent results. The value of Vc (.ut is then the collector -tocurrent supply and clamping diode removed.
emitter voltage under this bias condition.
D.C. Current Gain
To prevent the possibility of transistor damage which
for
a
might result from an increase in power dissipation
The d.c. current gain, or more properly, the d.c. current
transistor which does not fully saturate, and for operator
transfer ratio, is another very important parameter not only
protection against electrical shock, a sampling arrangement
for d.c. switching and control circuits, but also for the proper
should be used. One complete arrangement is given in Fig.
biasing of small -signal a.c. circuits. In addition, the a.c.
3A for the quantitative measurement of Vrr:
current transfer ratio and its d.c. counterpart have some fair
El in conjunction with resistors R1 and R2 provides the
amount of correlation and, since a.c. current gains are more
two constant- current biases Ir and la respectively. The redifficult to measure, a simple d.c. measurement may be
sistor values are determined from the following:
used to test the transistor. By far the more common parameEl /Ic
(1)
R1 = (El -Vrr; (,N,) 1./Iit)/ 1r
ter is hFE, the d.c. current transfer ratio of the transistor in
(2)
(El - 0.5) /Ia E1//E
R2 = (E1 -Vita) fin
the common- emitter configuration.
By definition hIE is merely the direct ratio of the collector
Diode D2 serves to limit the collector voltage to about
current, Ir, to the base current, In, for a given set of bias
0.7 v. if a silicon diode is used. Below about 0.5 v., where
many saturation voltage measurements are specified, the diconditions (normally a fixed VrE and Ir). It would, at first
ode conducts practically no current at all, but as the collector
thought, seem the natural procedure to set up the bias arvoltage rises above this value, the diode will conduct. For
rangement and then measure le and Irr by means of milli ammeters and then taking the required ratio. The resulting
VrE (xnr) measurements above 0.5 v., it may be necessary to
test accuracy is very poor, and two rather expensive meters
add a second diode, D3, in series with D2.
Silicon diode D1 prevents the base from going more posiare required for precision better than ± 20%. There are sevtive than the collector by more than 0.7 volt. Since the coleral methods that yield much better results with less costly
equipment and without the necessary calculations. It is poslector is clamped, then the base will also be held to a voltage
sible to design a production go /no -go arrangement which
of about 1.4 volts or so. In some cases, it may be necessary
to use two diodes in place of D1 if the difference between
even eliminates the necessary individual adjustment of the
VJ E and Vrr: (x(() should be greater than about 0.5 v.
bias. We will now consider several of these approaches.
The simple arrangement of Fig. 4A illustrates a test cirA test arrangement to yield attribute or go /no -go operacuit which will allow the quantitative measurement of hir:.
tion is shown in Fig. 3B. It is the same as the quantitative
E2 supplies the base current and El supplies the bias for
approach except for a modification in the readout circuitry.
the collector circuit. E2 is adjusted until the meter reads
The v.t.v.m. is replaced by a null detector or comparator
full scale. This sets the collector current by using the meter
which is used to compare the actual VCE (.xat) with a reference
RI
ECB
-
EEB
EcE
r
(A)
DI
L
)
December, 1963
37
scale reading is obtained for the circuit
shown, this indicates that the actual
value of hFE is higher than the set value.
+
On the other hand, if the reading is
E
liv.=
E2
E' V.
down- scale, this indicates that the actual
IOI
0 -150V.
value of hFE is less than the value of the
RI
test limit.
IK
A word of caution should be injected
WITH
100K
DIAL
here concerning some hFE specifications
4.7K
in which the conditions call for a pulsed
TRANSISTOR
UNDER TEST
measurement. This is a difficult test to
R5
perform and while the measurement
KR2
might be attempted on a straight d.c.
hrE' RI
hFE ' R3 +I
basis, we must be absolutely certain that
(A)
(8)
the power rating of the transistor is not
exceeded. The value of hFE obtained in
Fig. 4. (Al Simplified quantitative FIFE measurement circuit while the test set
circuit of MI can be used for quantitative or "go /no -go" live measurements.
the straight d.c. manner will be somethat
obtained from the pulse measurement.
higher
than
what
value,
constant
to
a
E1
set
with
and,
R1
as a voltmeter across
the collector -emitter voltage must also be fixed at a value
Breakdown Voltages
equal to the difference between El and the measured drop
Measurement of the various breakdown voltages of tranacross RI. For the circuit of Fig. 4A, the bias point is 10 ma.
sistors
and diodes may be accomplished in one of two ways.
volt.
collector current and VCE of 1
A simple voltage supply and meter arrangement, as shown in
Switch S1 is now depressed and potentiometer R2 adjusted
Fig. 5A, may be used to give approximate results if El is very
until the meter indicates a null or zero- current reading. The
much larger than the breakdown voltage of the transistor unvalue of hPE is then read off the multi-turn dial of R2. This
der test. Resistor R1 is chosen to limit the maximum amount
technique is capable of very high accuracy.
of current which may flow in the transistor. For many breakA second circuit which may be used for either quantitative
down voltage measurements, particularly for silicon devices,
voltor attribute testing of hr is shown in Fig. 4B. A single
a current level may be varied somewhat without changing
age supply is used with two resistor networks to provide the
the resulting breakdown voltage appreciably.
will
be
base and collector currents. The collector current
A second method of measuring the breakdown voltage is
determined by the ratio of (E1 VeE) to R3. The meter acts
observing the voltage- current electrical characteristics on
by
as a d.c. null detector to compare VCE with a reference voltage
curve
tracer. Fig. 5B illustrates a very simple circuit which
a
The
operating
R5.
R4
and
voltage
divider
by
determined
can be used for this purpose. A self -limiting circuit has been
conditions for the particular circuit of Fig. 4B are again 10
included to control the maximum amount of current that
ma. for lc and 1 volt for Ver,.
may flow. For the circuit values shown, limiting will begin
The base current is provided by the resistor network conto occur at 150 p.a. If Rl is reduced to 100,000 ohms, then
(R1
+
VBE/
to
(El
be
equal
R2
will
and
sisting of R1 and
limiting will begin to occur at roughly 1.5 ma. The brightR2) . For silicon transistors, the value of VBE will be in the
ness of the trace on the oscilloscope screen will not be uniform
to
VCE.
equal
volt,
approximately
or
neighborhood of 0.8 to 1
because of the nature of the sweep, but an indication of the
Under this condition, the value of hFE will be equal to (R1 +
sharpness of the breakdown characteristic may be observed
to
hFE
is
equal
made
equal,
R2) /R3 and since R1 and R3 are
as well as measuring the breakdown voltage for a given value
(R2 /R3) + 1. Furthermore, hFE will be directly available from
ohms,
of current.
100,000
of
A
resistance
the dial of the decade resistor.
Specific breakdown voltages are much like the leakage curfor example, will indicate an hFE of 10 + 1 or il. If the reparameters indicated in Fig. 2. For example, we might
then
rent
ohms,
is
900,000
sistance required to cause a meter null
measure BVCEo by connecting the breakdown measurement
IIPE is 90 + 1 or 91. This circuit has the advantage over the
terminals between the collector and the emitter, leaving the
previous one in that the same adjustment that sets the bias
base terminal open.
condition is also the one that provides the answer. Actually,
In this article, we have considered simple ways to measure
resistor R1 is not required in the circuit from a theoretical
several of the more important, or at least
standpoint and, in fact, the readout proFig. 5. (Al Measurem ent of BVCBI breakmore revealing parameters of transiscedure would be much simpler if it were
down voltages. (B) Cu rye tracer for display tors and diodes. While basic in nature,
ing breakdown volta ges on oscilloscope.
not present (hFE: would then be merely
the techniques presented here yield acR2 /R3). R1 has been inserted as a
curacies equal to or better than many of
means of protecting the transistor under
the much more expensive commercial
test, the power supply, and the decade
test sets available and require very little
box should the resistance value of R2
time to set up in the usual electronics
accidentally be made too low. It seems TRANSISTOR
laboratory or even service shop. We have
much easier to add the extra unit onto UNDER TEST
not covered every possible detail but inthe value of hFE than to replace the tranformation has been presented which,
sistor or decade box.
when mixed with a small amount of
The circuit of Fig. 4B may be used to
(A)
STANCOR
thought and common sense, will allow
provide a quantitative answer of the
1N538
PS-8415
I:I
valuable quantitative measurements to
value of hFE by adjusting R2 until the
HORIZONTAL
(VOLTAGE)
be taken, the economical testing of semiminimum
readindicates
a
null
or
meter
conductor devices on an incoming ining, then reading the value of hFE from
spection basis, or the determination of
the
sure
to
add
the dial of R2 (being
--0 (CURRENT)
VERTICAL
possible damage to either a transistor or
extra 1).
diode.
as
a
used
The same circuitry may be
All of the circuits shown in this article
go/no -go test set by setting R2 to the
have been bread -boarded and have been
proper value and then merely noting the
IN538
used many times with good results.
(8)
position of the meter pointer. If an upTRANSISTOR
UNDER TEST
100K
-
-
-
38
ELECTRONICS
WORLD
QUANTUM DEVICES/how they work
By JOHN
R.
COLLINS
When certain molecules are excited by electromagnetic radiations, they
change energy levels. When they drop back to their previous levels,
they give up energy. This is basis for masers, lasers, atomic clocks.
SEVERAL striking developments in the past few years
have advanced electronics in a sort of quantum jump
-to use an expression that is becoming commonplace. It
is especially appropriate here because many new devices
are outgrowths of the quantum theory, which, although more
than half a century old, is just beginning to be exploited.
The most familiar of the new quantum devices are the
maser and laser, which embody entirely new principles of
amplification for microwaves and light rays. In addition,
there are molecular and atomic clocks with accuracies better
than 1 second in 40 years, the tunnel diode which can amplify or oscillate in the gigacycle region, and certain spectrometers capable of making detailed chemical analysis of compounds by electronic means.
Much of the quantum theory is hard to visualize or to
represent with mechanical models. Electronics has come a
long way since water tanks represented voltage, narrow pipes
portrayed resistors, and walking on a garden hose illustrated
modulation of d.c. with a.c. Moreover, the quantum theory
is not a single rule like Ohm's Law, but an accumulation of
information about the atom that fills many volumes. While
the theory is definitely an area for specialists, its impact on
modern electronics has been so great that no technician who
wants to understand the newest equipment can afford to remain ignorant of this phenomenon.
Energy Levels
Conventional electron devices, such as electron tubes,
function by means of the effect of an electrostatic field on
the movement of charged particles, usually electrons. Quantum devices, however, utilize changes that take place inside
particles owing to the effect of an electromagnetic field on
their internal structure. The particles may be either molecules, atoms, or ions. In the following discussion, the term
December, 1963
molecule is used to denote any of the three kinds of particles.
Molecules are made up of electrons and atomic nuclei
which, according to the quantum theory, can assume only
certain fixed motions and orientations. Each set of motions
or orientations is associated with a discrete amount of internal energy called the "energy level" ( Fig. 1) At any given
instant, a molecule may be at any one of a number of possible energy levels. It cannot exist anywhere in between. The
fact that it jumps from one level to another is the origin of
the so- called quantum jump. When a molecule jumps from
a lower to a higher energy level, it absorbs energy and is said
to become excited. When it drops to a lower level, it gives
up energy.
A natural question is, "What takes place inside the molecule when energy is absorbed or emitted ?"
There is no simple answer to explain all changes in energy
levels. In some instances, the absorption of energy is accompanied by the transition of an electron from its usual orbit
to a new orbit more remote from the nucleus. An equal
amount of energy is emitted when the electron returns to its
original orbit.
A second type of transition involves atoms having unpaired
electrons. Each individual electron may be viewed as a small,
spinning magnet with a north and south pole. In most substances, electrons are paired off with their poles opposite to
each other, so that their magnetic fields are cancelled. In a
few substances, however, cancellation is incomplete, leaving
an unpaired electron in each atom.
When such substances are placed in a magnetic field, the
unpaired electrons can have just one of two positions -a
lower energy state in which the electron's north pole points
in the direction of the magnetic field, or a higher energy
state in which its south pole is in the direction of the field.
The frequency at which energy is absorbed or emitted in
.
39
this kind of transition is directly proportional to the strength
of the external magnetic field.
In a third case, energy transitions may be accompanied
by changes in the relative positions of elements making up
a molecule. The ammonia molecule (NH3), for example, is
shaped like a pyramid, with an atom of nitrogen at the apex
and a hydrogen atom at each of the three corners of the base.
When excited, the nitrogen atom apparently drops through
the base to the other side, inverting the pyramid.
Regardless of the reasons, however, the important point
is that molecules will absorb and emit energy in fixed
amounts, and the transition from one level to another is not
smooth, but takes on the appearance of a jump.
Planck's Constant
Although the absorption and emission of energy by various substances had been observed for some time, it was not
until 1900 that Max Planck made the important discovery
that a fixed relationship exists between the energy and the
frequency of the radiation. At the time Planck was studying
LEVEL 3
1
f23
LEVEL
fl3
2
i
f12
LEVEL
I
Fig. 1. Among the three energy levels in a molecule, the
energy difference between each level is related to characteristic frequency. For example, f23 is the frequency
corresponding to energy difference between levels 3 and 2.
Fig. 2. Rules for the interaction of molecules with photons.
BEFORE
AFTER
O O
PHOTON OF INCORRECT
ENERGY
STRIKES MOLECULE AT LOWER
NO
EFFECT
AJo.
LEVEL
Spontaneous and Stimulated Emission
Under ordinary circumstances, some of the particles in
any substance will be at a higher energy level and some at a
lower level at any given tune. Particles are raised to a higher
level by heat, light, electron bombardment, etc. They will
naturally revert to a lower level after a period of time, and
in doing so spontaneously release photons. These photons
may strike other molecules and cause them to jump to a
higher level in turn.
Fig. 1 shows, in diagram form, the energy levels that
might be found in a molecule. Each transition from one level
to another would be accompanied by absorption or emission
of radiant energy of a characteristic frequency. If f23 represents the frequency of the radiation absorbed or emitted in
a transition between levels 2 and 3, we can determine the
energy E23 involved from the relation: E23 =hf23. Similarly, if we know the energy of the photons emitted, we can
find the frequency by re- arranging Planck's formula to:
f23 =
LEVEL
PHOTON OF CORRECT ENERGY
STRIKES MOLECULE AT LOWER
radiation of energy from a hot object. He noted that the
amount of radiant energy emitted at each wavelength from
the ultraviolet to the infrared could be obtained by multiplying the frequency of the radiation by a constant amount
of h, equal to 4.13 x 10 -" electron -volt- second. His discovery
is expressed by the formula E = hf where E in this case
stands for energy, not voltage, and f is frequency.
Just as Einstein found a way of expressing energy in terms
of mass, Planck's formula provides a means of expressing
energy in terms of frequency. Although the theory started
with Planck, its further development was carried out by many
of the greatest scientists and physicists of this century, including Einstein, Pauli, Rutherford, and Heisenberg. It was
soon found that Planck's formula applies not only to energy
emitted from a hot object, but to the entire electromagnetic
spectrum. It should be noted that Planck's constant is exceedingly small and therefore the amount of energy involved
becomes appreciable only at the upper end of the spectrum
-that is, in the region of microwaves, x-rays, and light.
Since h is a constant, Planck's formula implies that energy
E is always absorbed or emitted in discrete packets or quanta
which are called photons. A photon is equal to the product
of its characteristic frequency f and the constant h. Since
frequency may vary over a wide range, all photons are obviously not of equal energy. However, in no case is energy
emitted or absorbed in a fraction of a photon.
PHOTON IS ABSORBED, MOLECULE
JUMPS TO HIGHER LEVEL
PHOTON OF CORRECT ENERGY
STRIKES MOLECULE AT HIGHER
LEVEL
MOLECULE DROPS TO LOWER
LEVEL AND EMITS 2 PHOTONS
E23/ h.
The time required for a molecule in a higher state to revert
spontaneously to a lower state depends on the kind of molecule and the type of transition involved. The probability of
a transition taking place may be greatly increased or stimulated by the presence of radiation of the required characteristic frequency. The greater the density of this radiation, the
greater the probability that a transition will occur.
Fig. 2 shows how molecules react with electromagnetic
radiation of the characteristic frequency. It is important to
note that a photon of the correct frequency (or energy)
striking a molecule at the lower energy level will cause it to
jump to a higher level. However, if a photon of the sane
energy strikes a molecule already in the higher energy state,
the molecule will revert to the lower state and two photons
will be emitted. It is this characteristic that makes possible
the amplification of microwaves and light by masers and
by both solid -state and gas lasers.
The Ammonia Clock
PHOTON
MOLECULE AT LOWER LEVEL
MOLECULE AT HIGHER
40
LEVEL
One of the first practical applications of the above principles was the molecular clock using the ammonia molecule.
This molecule has two energy levels separated by a gap corresponding to 23,870 mc. Ammonia has the unusual property
that at the lower level the molecule is attracted by an electrostatic field, while at the higher level it is repelled.
ELECTRONICS WORLD
- EXCITED
NH3
Q- UNEXCITED
MOLECULE
NH3 MOLECULE
CHARGED CONDUCTORS
0
O
0
O
O
0
0
RESONANT
CAVITY
Fig. 3. Excited ammonia molecules are separated from unexcited molecules to form the basis of an ammonia frequency standard.
Fig. 3 shows how this characteristic is used to separate
high-energy molecules from a mixture. Ammonia gas containing both excited and unexcited molecules is emitted from
a source at high pressure and is passed in a narrow stream
through a focuser. The focuser is made up of a system of
charged conductors that provide a strong electrostatic field.
The low- energy molecules are attracted by the conductors
and are thus dispersed along the sides of the focuser. The
high -energy molecules, however, are repelled by the conductors and are therefore concentrated in a narrow beam at
the very center of the focuser. They are thus directed into
the narrow port of a resonant cavity while the low- energy
types are deflected aside.
The dimensions of the cavity are exactly proportioned to
make it resonant at precisely 23,870 mc. This tends to reinforce the oscillations which occur at that frequency as the
molecules drop to the lower energy level, so that a strong
signal is generated. This signal is conducted from the cavity
by a waveguide. The flow of energized ammonia molecules
into the cavity is regulated at the level necessary to make
up for losses and sustain oscillations. The output is a frequency of 23,870 mc. of the utmost purity, with no sidebands
or noise and serves as a precise frequency or time standard.
Masers and Lasers
It was pointed out previously that if radiation of the proper
frequency strikes a molecule in the excited state, the output
will be two photons of the same frequency. Therefore, if
enough molecules are in an excited state when struck by
these photons, the result will be the amplification at the
characteristic frequency. The apparatus for accomplishing
this is the maser -an acronym standing for microwave amplification by stimulated emission of radiation.
Solids are usually employed for masers since their molecules are more concentrated than those of gases. Early masers
were two -level devices in which molecules were excited by
"pumping" with radiation corresponding to the transition
frequency. Such masers could amplify a signal only during
the interval between pumping and spontaneous relaxation.
This difficulty was solved by the three -level maser (Fig. 4).
Normally, most molecules are at the lowest level, the fewest
at the highest level. The pumping frequency corresponds to
the energy difference between levels 1 and 3, so that molecules are transferred from the lowest to the highest level.
During the relaxation period they drop in about equal numbers to levels 2 and L
If the pumping radiation is strong enough, more molecules
can be kept in level 2 than in level 1, and the frequency
corresponding to the energy difference between levels 1 and
2 can be used for amplification. Since this frequency is different from the pump frequency, the apparatus can 'be operated as a continuous amplifier.
A resonant cavity is used in the case of the ammonia clock,
and cryogenic equipment is employed to rechicc noise. Noise
level is extremely low, so that masers may be used to amplify
December, 1963
very weak signals, such as those encountered in radio telescopes and long -distance radar.
The laser (light amplification by stimulated emission of
radiation) is closely related to the maser and requires little
additional comment. It was recognized that light could be
amplified in the same way as microwaves, provided that the
energy difference between two energy levels corresponds to
a frequency in the light region of the spectrum. Because of
the short wavelength of light, the problem of devising a resonant cavity was formidable. This difficulty was overcome,
LEVEL
LEVEL
2
B
LEVEL
1)
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0
(A)
cB)
Fig. 4. Distribution
of molecules in a 3- energy level maser.
(Al shows normal distribution before pumping where most molecules are in the lowest energy level and fewest in the highest level. In (B), molecules pumped from level
to level 3
fall back to either level 1 or level 2 so that the total numin
level
exceeds
the
number
that
ber
2
are present in level 1.
1
RUBY ROD
WITH
SILVERED ENDS
OUTPUT
BEAM
Fig. 5. When a chromium -doped ruby rod is excited by the intense light from a flashlamp, it emits a red, coherent light.
however, by using mirrored surfaces at the end of the laser
crystal.
The test setup is shown in Fig. S. A ruby crystal, composed
of aluminum oxide and containing a small percent of chromium oxide which causes its red color, is formed in a rod
several inches long. One end is completely silvered to give
full reflection, the other with a very thin coating so that some
light will pass through it.
A brilliant flash lamp pumps the chromium atoms to a
higher energy level. Laser action begins when one of the
energized atoms spontaneously emits a photon in the direction of one of the mirrored
(Continued on page 84)
41
By ROBERT W. WINFREE
Construction of adapter, to be used
with an FM tuner, that will respond to the
67 -kc. "storecast" transmissions.
FVERY FM- multiplex buff knows about that mysterious
SCA service that may be a source of annoyance in FM
J stereo reception. This Subsidiary Communications
Authorization (SCA) provision for background music, or
"storecast," dates from 1955 and antedates by several years
compatible FM- stereo broadcasting. Although of greater significance to broadcasters than to the public, this multiplexing was welcomed at that time by nearly two hundred stations
as a means of supplementing their incomes through this private point -to -point service.
Prior to FM-stereo broadcasting, the FCC permitted SCA
channels to be located anywhere between 25 and 75 kc. Popular frequencies for multiplexing were 37, 41, 42, 57, and 67
kc., with only the last being sufficiently separated in frequency from the present 23- to 53 -kc. stereo passband to be
interference free. Since stations are not required to move
Over -all view of adapter built by author on 4" x
42
6'
x
2" chassis.
their SCA to 67 kc. until they convert to stereo, some of
the other frequencies may be around for a long time. Any
discussion of equipment here assumes operation on the 67-kc.
channel although minor changes in multiplexer design will
make its use possible on other frequencies.
Although the SCA service is completely analogous to the
stereo multiplex transmission, there are several important
points of difference to be considered. While the stereo difference information ( L -R) is transmitted as amplitude modulated sidebands on a 38 -kc. suppressed subcarrier at 80 to
90% modulation, the background music is frequency modulated on a 67-kc. subcarrier at a maximum of 10% of the
total modulation. Besides this technical difference, the stereo
program is "broadcast" while the background music is "transmitted," this difference being clearly distinguished by the
FCC. While unauthorized reception and use for profit ( such
as playing it in a place of business) is not allowed, reception
of and listening to an SCA transmission in one's own home
apparently does not constitute "reception and use for profit."
While program quality may not meet hi -fi standards (most
stations play tapes at 3.75 ips or slower), the program content
of uninterrupted, easy -to- listen -to music is most attractive
to the home listener.
Since most FM service areas have at least one station providing background music, the addition of a multiplexer will
enable the owner of the average FM tuner, either with or
without stereo multiplex facilities, to receive the SCA programs in the home.
The connection necessary between the FM tuner and the
multiplex converter is to the output of the discriminator or
ratio detector at a point ahead of the usual de- emphasis network. This is exactly where a stereo multiplexer would be
connected and if the tuner has a "MPX Jack" not in use, this
may do. Since the converter to be described has a relatively
low impedance input circuit so as to be tolerant of connecting cable lengths, the addition of a simple one -transistor
emitter -follower output circuit in the tuner will improve the
operation for both stereo MPX and background -music use
by isolating the tuner high -impedance detector circuitry from
a multiplex converter.
Since the background music is transmitted on a 67 -kc. frequency- modulated subcarrier, all that is needed to listen to
ELECTRONICS
WORLD
it is a suitable FM receiver operating on this frequency and
plugged into the MPX jack on the tuner. Since this proves to
be a scarce item on the market, a little construction work
on your part will be necessary here. There are several approaches to this problem and each must meet the several
requirements of such a unit. Selectivity or filtering must adequately attenuate stereo subcarrier sidebands and noise below
60 kc. and above 74 kc., and amplification and limiting circuits must pass a suitably tailored FM signal to the frequency -sensitive detector while rejecting AM noise and signal
components in the passband. Of course, no tuning adjustments should be necessary since the operation is on a fixed
frequency.
Of the several basic designs for such a unit, the one to
be described has the important advantage of not requiring
complex tuned circuits or filters operating at the subcarrier
frequency. By using a crystal oscillator with conventional
superheterodyne circuitry and a standard intermediate frequency, no special, hard -to-find, or home -made components
are required in the equipment and no tuning adjustments
are needed during use. In fact, aside from the 388.888 -kc.
crystal and the 455 -kc. discriminator transformer, most parts
can be found in the experimenter's junk box or are easily obtained at the parts house. The crystal is a surplus type available from, among others, Texas Crystals, Fort Myers, Fla., as
the Type 241 channel 280 crystal for 50 cents plus 5 cents
postage. The Type SSO -1 crystal socket is a good buy at 15
cents. The total cost of all parts if purchased new will be
around $20.00. The output of the converter is a high -quality
audio signal suitable for feeding the tuner or auxiliary inputs to a music -system power amplifier. An output level control allows setting to a level compatible with other program
sources of about 2 to 3 volts and a separate low- impedance
cathode -follower output at about one volt is provided to feed
remote distribution amplifiers in the author's hone.
allows better limiting in the i.f. stages. The interstage i.f.
transformer, T2, couples the converter stage to the 6BJ6 first
i.f., which provides most of the gain and some limiting due to
grid current. Most of the limiting action takes place in the
6BH6 second i.f. stage operating at very low plate voltage.
Grid rectification in this stage provides a d.c. voltage on the
order of - 25 volts at the grid which is brought out through
a 100,000 -ohm resistor as a test point, designated "T.P," for
alignment purposes.
The remainder of the circuit is unusual and worthy of
mention. The detector uses two germanium diodes in a balanced bridge discriminator which, at first glance, may appear
to be a type of ratio detector. This circuit, when properly
balanced, is capable of the high AM and noise rejection required here, as its electrical balance produces no output from
these sources. This circuit is similar to that used in the
"Dynatuner" and various industrial equipments. Loading of
the discriminator is optimized by the high input impedance
of the cathode -follower triode, 1_- 12AX7A. A low -impedance
loO pf
LIMITER
TUNER MPX
OUTPUT
EMITTER -FOLLOWER
CIRCUIT
68K
IOOK
IOOO
AUDIO
AMP
-
Pf
(A)
TO BE
ADDED IN TUNER
Circuit Description
Having read this far, you are probably interested enough
to take a look at the circuit diagram and parts list and follow a detailed circuit analysis. The composite input signal
as provided by the FM tuner will consist of frequencies from
a nominal 50 cps at the low end to at least 75 kc. at the upper
range, unmodulated, amplitude modulated, and frequency
modulated where the station provides all FM services. Where
this composite signal is supplied from a high -impedance detector output you will want to add, in the tuner, the simple
emitter -follower stage using one 2N508 transistor shown in
Fig. 1. When adding this MPX output isolation amplifier, the
diagram indicates where to tap off the signal for either this
background music converter or a commercial stereo adapter.
In fact both may be used at the same time if desired. Even if
your tuner does not have wide -band i.f. and discriminator
circuitry so desirable for F \I stereo, this background music
converter will give good results. Remember, we are working
with a frequency -modulated subcarrier here instead of the
amplitude -modulated subcarrier for stereo and a falling off
of the signal level at the higher frequencies due to tuner
shortcomings which is so disastrous in stereo, is easily made
up by amplification in the unit.
Referring to Fig. 2, the input tuned circuit, T1, a slug tuned TV horizontal width coil, tunes to 67 kc. with the
step -up provided by autotransformer action giving a signal
level of about 100 to 150 mv. at the mixer input grid. Grids
1 and 2 function in the oscillator circuit of the 388.888 -kc.
crystal oscillator with feedback controlled by the 82- and
100 -pf. capacitors. The mixer plate circuit contains the desired 455.888 -kc. i.f. signal as well as a strong component
of the oscillator frequency. This undesired component is
blocked by T5, a miniature 455 -kc. i.f. transformer which,
by the addition of a parallel 20 -pf. capacitor, tunes sharply
to the undesired 388.888 kc. signal. Elimination of this signal
December, 1963
-,
I.F. AMP.
TUNER
MPX OUT.
68
AUDIO
AMP
68K
loo
Pr
2N508
OR
T
2N324
I
T
l000
I
=
P}
MPX
OUTPUT TO
IOP1
T15V.
MULTIPLEXER
t5
+100+250V.
TO BE ADDED
IN
TUNER
J
(8)
Fig. 1. Addition of a transistor emitter -follower circuit
to (A) discriminator and (B) ratio detector in FM tuner.
output is tapped off here for remote audio lines. Then follows
the de- emphasis network and volume level control feeding
the - 12AX7A output stage operating with plate -to -grid
feedback. The maximum audio level available from this stage
is in the order of 3 volts.
The power supply is entirely conventional and need not
be built if suitable facilities are available in the tuner or
elsewhere. The transformer 6.3 -volt winding supplies all tube
heaters while the 125 -volt supply is half -wave rectified by
a silicon diode followed by adequate filtering and decoupling
circuits. The high resistance of the transformer winding obviates the use of the usual surge resistor in the rectifier circuit. The total d.c. current drain is under 20 ina. with no
signal. No a.c. switch is included since the unit normally
plugs into a controlled outlet on the author's tuner. Obviously
you may include a switch if you wish.
The emitter - follower transistor multiplex output stage
added to a typical FM tuner is diagrammed in Fig. 1. It is
most important to locate the proper point in the detector
circuit to pick off the multiplex signals. This must be before
',
43
68E6
I
68J6
I
V3
I
115
i - --I
L
I
TI
68H6
V2
Ò0-0-07d\-
J
r-
C8
12
85
R6
-! J
C
R
C9
11
C19
R
Ct0
R4
XTaL
T
RB
-VMANVR3
T
+40V
+140V.
J2U
R21
HIGH
OUTPUT
J3
n
LOW
+130v.
+140V.
D3
+I30V.
+ C2IA
+ C2IC
+ C218
CS -100 pf., 250 v. disc capacitor
C6
pf., 250 r. disc capacitor
-20
C7,C9,CIO,C12,C13,C76,C18-.0I ¡if., 250 v. disc
capacitor
C8,Cl1-50 pf., 250 v. disc capacitor
C14,CI5-250 pf., 250 v. disc capacitor
C17,C19-.0047 4., 250 v. disc capacitor
C20-10 pf., 15 v. elec. capacitor
C21-20/20/20 pf., 350/350/300 v. can type elec.
capacitor
11,12.13-RCA-type phono jack
.Ytal- 388.888 -kr. crystal with socket (see text)
TI- 0.5 -5.0 mhy. TV horiz. width coil (J. W.
.hiller 26323)
T2,T3- 455 -kc. i.f. trans. (3leissner
RI-150 ohm,
res.
R2- 18,000 ohm, 1/2 w. res.
R3,R5,R9,RIO,R19,R25,- 100,000 ohm,
R4- 560 ohm, 1/2 w. res.
R6 -47 ohm, 1/2 w. res.
R7- 22,000 ohm, 1/2 w. res.
R8,R16 -330 ohm, 1/2 w. res.
RII,R12 -- 47,000 ohm, 11z W. res.
R13,R14- 68,000 ohm, 1/z W. res.
R1 5-I megohm, 1/2 W. res.
1/2
w.
RI7-8200 ohm, í z'. res.
RI8- 24,000 ohm, I2 <ï. res.
R20 -1000 ohm, 1/2 w. res.
R21 -- 680,000 ohm, 1/2 w. res.
R22 -470 ohm, !/2 w. res.
R23 -2200 ohm, i.2 w. res.
R24- 500,000 ohm miniature audio -taper pot
CI,C2 -.001 µf., 250 v. disc capacitor
C3 -.05 µf., 250 v. disc capacitor
C4 -82 pf., 250 v. disc capacitor
!
1/2
w.
res.
sec. unused (Lafayette MS-7801
T6 -Power trans. 125 v. Pi 15 ma.; 6.3 v.
amp. (Lafayette TR -121 or equiv.)
44
C 0.8
DI,D2-1N34Á germanium diode
D3-1N2070 silicon
V1 -6BE6 tube
V2 -68J6 tube
diode
V3 -6BH6 tube
12A X7A tube
I'4-
Fig. 2. Adapter circuit. Output of crystal oscillator mixes with the 67-kc. SCA signal to produce the desired 455 -kc.
the de-emphasis filter, usually a series 68,000 -ohm resistor
and shunt .001 -pf. capacitor. The usual 10.7-mc. filter elements of 50- to 100 -pf. capacitors will help locate the right
place and corresponding locations for both a typical discriminator and a ratio detector are shown. The transistor socket
and other components may be hung by their leads under the
tuner chassis in a convenient location,- providing short connections, while the 150,000-ohm dropping resistor is adequate
for all tuner d.c. voltages from 100 to 250 volts. Be sure to
observe polarity when connecting the electrolytic capacitors.
In addition, for longest transistor life do not plug in or remove the 2N508 from its socket while the power is on.
It is most convenient to feed the new MPX output to an
RCA -type jack as usually provided for such connections. The
full mono program will be present at the jack as well as all
MPX subcarriers. Circuit values permit use of any type
16.67581
T4- 455-kc. disc. trans. (J. W. Miller 12 -C45)
TS- .liniature transistor -type 455 -ke. i.f. trans.,
i.f.
of multiplex adapter that the builder may desire to employ.
Construction
&
Alignment
A look at the photographs will show the logical layout of
components on the 4" x 6" x 2" aluminum chassis. At the
front edge are three jacks for MPX input, low audio output,
and high audio output, with the oscillator crystal socket just
to the rear of the input jack and the audio level control in
back of the high output jack. The three 455 -kc. i.f. transformers are mounted with the clips supplied and the filter can
by its twist tabs. The four shield base tube sockets are fastened with 4 -36 screws and shields are used on all tubes.
Orient the sockets to insure the best lead arrangement under
the chassis. Be sure to mount everything that fastens to the
chassis before beginning any wiring. A few suitably placed
lug strips will provide terminals for those resistors and caELECTRONICS WORLD
pacitors not soldered directly to the sockets and coil lugs.
A three -point strip, center ground, fastened on one of the
power transformer screws will mount the 1N2070 rectifier
and the limiter test point resistor and capacitor.
A strip xvith three insulated lugs, fastened in the center
of the chassis between the discriminator i.f. transformer and
the input i.f. transformer, provides distribution points for
the two d.e. voltages used in the i.i. amplifier and for the
common terminal of the discriminator 68,000 -ohm bridge
resistors and output capacitor. Another three -lug strip, center ground, between the discriminator can and the 12AX7A
socket, is used to tie the detector diodes to the bridge resistors
and bypass capacitors.
Follow the usual practice of putting in the heater and
power supply wiring first, then a bare wire bus connecting
the grounded points, and finally add the small components,
building from the chassis out. The small 24 -gauge solid hookup wire is a good size to use. The power transformer primary
leads are brought out through a rubber grommet and terminated in an a.c. plug: you may want to use a regular line cord
here. The resistors and capacitors are all supported by their
terminal leads in a point -to- point wiring arrangement, as is
the midget i.f. transformer 388 -kc. trap coil.
The tune -up requires at least a d.c. voltmeter, preferably
a 20,000 -ohms -per -volt V.0.111., and a station on the air with
an SCA signal.
A visual check of the wiring and parts values after the
wiring is completed may save considerable grief later. If no
trouble is found, plug the unit into the a.c. line before putting in the tubes, then check the "B +" d.c. voltages. They
should be around 200 volts with no load. Plug in all tubes
and check the voltages when they settle down, comparing
with the diagram values. Then with the v.o.to. on the 10 -volt
range, connect to the test point and chassis ground to measure
the 6BH6 limiter negative grid voltage. If this is about )_ volt,
plug in the channel 280 crystal. The leak- through signal from
the oscillator on 388.888 kc. will increase the negative grid
voltage to 5 to I O volts. Now carefully adjust the 388 -kc.
trap coil 'I'5 slug -tuning to dip this voltage to a minimum of
less than 1 volt.
Cable the unit up to the tuner NIPX output and adjust the
input coil tuning slug until it is out about '!ua" beyond the
end of the form. Now tune to a station providing SCA service
or tune over the band while watching the limiter grid voltage with the meter on the 50 -volt range. Adjust the input
coil slug and top and bottom slugs of the two i.f. transformers
to peak the meter reading at maximum. Be sure the F\l tuner
has been exactly centered on the channel with its a.f.c. turned
off vvhile doing this. If the tuner is off resonance, a spurious
indication may appear on a station without SCA. The voltage should be 20 volts or more when everything is peaked.
It is advisable to unplug the tuner and check the trap coil
adjustment again for best oscillator rejection. Now clip the
v.o.m. between the junction of the two 68.000 -ohm discriminator resistors and ground, using the 10 -volt range on the
meter, and carefully screw in the discriminator slug (top of
cam) to produce a maximum voltage, positive above ground,
of about 3 to 5 volts. After noting the voltage reading, screw
the tuning slug oust, watching the voltage decrease through
zero and increase with the opposite polarity. You will swap
the meter leads here and continue to screw the slug out until
a peak is reached. If this voltage is within 10 percent of that
previously noted, the primary tuning is satisfactory as is. If
not, adjust this tuning (bottom screw) by running it in about
one turn.
Now repeat the top tuning procedure, checking the balance of the peaks. If the positive and negative voltage readings are more nearly the same, the primary adjustment just
made was in the proper direction. If there is a greater discrepancy between the readings, the adjustment was in the
wrong direction and it should be reversed for the next atDecember, 1963
tempt. Continue this juggling until the voltage maximums,
positive and negative, produced by the secondary tuning are
about equal. This leaves the primary tuning on frequency.
Now adjust the secondary tuning to the zero voltage point
halfway between the peaks. A small correction may be made
later but this will leave the secondary very nearly correct.
All this can be done in less time than it takes to describe it.
For signal generator users, the discriminator peaks are about
30 -kc. apart and the characteristic is quite linear over the
-!-7 -kc. modulation swings.
Now connect the audio output jack to a power amplifier
and speaker and check the audio signal for music quality and
background hiss. During the silent period in the music, carefully adjust the discriminator secondary to minimize any
noise and modulation from the main program. Objectionable
hiss here will be due to weak signal level and poor signal-ton Dise ratio on the main carrier. As with stereo multiplex,
12
V2
C2I
TI
XTAL
VI
Top -chassis view showing the compact but uncrowded arrangement.
T5
Wiring
is
not too critical as frequencies involved are fairly low.
antenna improvements to boost signal levels will be helpful.
For average signals, the noise may be barely noticeable during pauses.
Stability of the oscillator and other components is very
good and no trouble will be experienced with the unit drifting off the center of the channel. Very accurate frequency
measurements of subcarrier signals reveal that not all SCA
subcarriers are exactly on 67 kc. A slight variation here,
within the range encountered in commercial operations, will
not cause tuning troubles since the discriminator will accept
signals as much as one kc. off center with no strain. If you
find that you prefer a particular station's programming, however, all adjustments may be optimized to it. Finally, while
enjoying the easy -to- listen -to music in your home, remember
that you are really intercepting point -to -point transmissions
intended for someone else.
45
CB RADIO- R'AF'F,
Discussion of ground and sky -wave signals for normal
and unusual conditions, and distances to be expected.
By R. L. CONHAIM, 19W7577
DURING the early days of CB, I was having a short
conversation one Sunday morning using my mobile.
There were skip signals coming in from the West
and South. Some locals were even trying to work the distant
stations. Being a law- abiding, FCC -fearing citizen. I ignored
the skip signals as best I could. When another 19W called me,
I answered immediately.
"How far are you from Akron?" he inquired.
"Oh, about 175 miles. Why ?"
"Well, that's too far" the voice on the other end said.
"I thought maybe you could telephone my Dad and tell him
where I am, but that would cost too much."
I began to get a little suspicious.
"Where are you ?" I inquired cautiously.
"Oh, driving along about sixty-miles -an -hour on a beautiful
highway in the Arizona Desert!"
I gulped when I heard that and ended the conversation
as quickly as I could without being rude. Here I'd been talking to a mobile almost 2000 miles away, just as though he'd
been down the street. His signal was loud and clear, never
wavering, and ten -over -nine for the duration of the conversation.
Here was one example of "skip," the kind of signal which
legally I should not have answered. But, it is something
which plagues the class D Citizens Band, especially during
the winter months. It's often the subject of lively arguments,
some of them quite inaccurate. But the subject is one that
CB users should understand so they know what to expect at
certain seasons of the year and from one year to the next.
Most explanations of radio -wave propagation are concerned with determining the best operating frequencies for
point -to -point communications. We on the class D Citizens
band are confined to one band of frequencies. Our interest
in skip signals is based upon either the interference they
cause or, out of curiosity, their reason for being. Some of us
are inclined to believe that the reception of signals from such
distant locations is clue to superior receivers or exceptionally
good antennas, or even the locations of our stations. In fact,
the reception of skip signals has little to do with the quality
of our equipment. We're all subject to receiving skip on
either base or mobile stations. Let's examine the mechanism
of 27 -mc. radio -wave propagation and see why this band
has its own peculiar characteristics.
Communication from one CB station to another is based on
one of two basic types of propagation. One is called the
ground wave. This is basically the wave we use in our daily
communications and the type referred to in the FCC regulations. The other is referred to as the .ski/ wave and is the one
that accounts for the reception of skip signals.
The Ground Wave
Although we think of the ground wave as being one particular type of wave always propagated in the same manner,
it is actually composed of four kinds of waves. These are
known as the direct wave, the ground -reflected wave, the
surface wave, and the tropospheric wave. These waves are
shown in Figs. 1 and 2. From the figures it is evident how
each type of wave travels. The direct wave is limited only
by line -of- sight, or distance to the horizon, plus a small distance caused by diffraction of the wave around the curvature
of the earth. The actual total distance can be approximated
quite closely by assuming that the earth's radius is actually
4/3 of its true value. This will take into consideration the
diffraction of the atmosphere. In other words, the radio line of -sight distance, is actually slightly greater than a visual one.
The direct wave could be very important in class D CB if
we could erect antennas as high as we would like, but since
we are limited by the 20 -foot regulation, the direct wave
can provide only limited distance communications. Assuming
both receiving and transmitting antennas are about 20 feet
off the ground, radio line-of -sight distance over even terrain
is 9 to 10 miles. If, for base -to- mobile operation, we assume
a 30 -foot house with a 20 -foot antenna or a total of 50 feet
above ground for one end and 10 feet above ground for the
mobile, we have a line -of -sight distance of about 11 miles.
Or suppose we are talking base -to -base, with one station's
Fig. 1. That portion of the ground wave that travels in contact with the surface of the earth is
called the surface wave.
SURFACE WAVE
46
ELECTRONICS WORLD
t'ROVI t ' ATION
Even thousands of miles can be covered by means of a
low- powered CB
transmitter because of sky -wave "skip"
antenna on a house, 50 feet above ground, and the other
on top of a tall office building, 500 feet above ground, then
the line -of -sight distance is about 40 miles. Conversations
from an airplane at 5000 feet with a base station at 50 feet
would cover a line -of -sight distance of about 110 miles.
The ground -reflected wave is relatively unimportant in CB
work because the reflected wave tends to be subject to phase
reversal which results in a cancellation effect between the
ground -reflected wave and the direct wave. This is especially
true when the antennas are located relatively close to the
ground, as is the case with the class D Citizens Band.
The most important part of the ground wave for our work
is the surface -wave component. The surface wave is not necessarily confined totally to the surface of the earth but may
extend to some height, diminishing sharply in intensity with
height. Part of the energy of a surface wave is absorbed by
the ground and the rate of attenuation or the distance we
can communicate is dependent upon the character of the surface over which communication takes place. If we rate the
various types of ground over which communication is to take
place, we find relative conductivity as shown in Table 1.
Over very good surfaces, distances up to 40 or 50 miles
can be worked with our 5 -watt transmitters, noise being one
of the limiting factors. When man -made noise is low, as is
the case late at night, working distances can be expected to
be greater.
Since the surface wave actually extends for some height
into the atmosphere, the condition of the air can affect
characteristics of reception. On rainy, foggy days we may
notice increased signal strength, due to greater conductivity
experienced by the surface -wave component. The types of
antennas we use, with relatively low angles of radiation, are
also important for good surface -wave propagation because
they concentrate more of their energy into a low angle of
radiation.
The tropospheric wave has little application in the 27 -mc.
CB band, but occasionally it accounts for reception of signals at somewhat longer than normal distances. It is caused
by relatively rapid changes in atmospheric moisture. density,
Fig. 2. Other
or temperature with respect to height. This results in refraction of the transmitted signal. One of the most common
causes of the tropospheric wave is temperature inversion.
This can result from a warm air mass overrunning a colder
mass, the sinking of an air mass heated by compression, rapid
cooling of surface air after sunset, or the heating of air above
a cloud layer by reflection of the sun's rays from the upper
surface of the clouds. Since tropospheric propagation is so
dependent upon weather conditions, it is an unreliable means
of 27 -mc. CB communications, but can account for some of
the effects which we have all noted. The greatest effects are
at higher frequencies -50 mc. and up.
The Sky Wave
The sky wave is the culprit in all long- distance 27 -mc.
reception. It is not by any means confined to the 27 -mc. Citizens Band and is used advantageously in other services where
long- distance communications are permitted. On the amateur
bands it is responsible for pea -power transmitters reaching
remote corners of the world and this is one of the exciting
and rewarding phases of amateur radio. The proud possessor
of a DX Century Club Award for having worked 100 countries can thank the sky wave, and his own hard work, for
this distinguished and cherished memento.
The sky wave is that portion of a radio wave which is reflected from the layers above the earth's surface. As shown
in Fig. :3, the atmosphere above the earth is more than one
homogeneous layer of air. It consists of a number of different
layers termed the troposphere, the stratosphere, and the ionosphere. It is the latter in which we are most interested. The
ionosphere derives its name from the fact that it contains,
instead of the stable gases of the lower atmosphere, a high
proportion of electrically un- neutral ions.
These ions are created largely by ultraviolet radiation
from the stun. In areas where gas molecules are few and far
between, ionization will become quite high because there are
relatively few positive ions with which the negative ions can
recombine. Although this sane phenomenon exists in the
louver atmosphere, the air is so dense that gas molecules
important components of the ground -wave signal that are responsible for Citizens Band communications.
TROPOSPHERIC PATH
DIRECT
PATH
O
R
PHASE REVERSAL OCCURS HERE
December,
1963
PART OR ALL CF ENERGY MAY BE REFRACTED
INTO EARTH
47
SURFACE OR TERRAIN RELATIVE CONDUCTIVITY
Sea water
Excellent
Large lake
Wet soil
Flat, loamy soil
Dry, rocky terrain
Desert
Very good
Good
radiation angles, we can get reflections from the ionosphere
when we could not if the angle of radiation from the antenna
were considerably greater.
Fair
Poor
Very poor
Changes in Ionization
Table 1. Relative conductiv'ty of various types of terrain.
collide with each other at the rate of four billion collisions
per molecule per second. Obviously, in such a dense atmosphere, an ion can have only a very short life- estimated to be
only a few millionths of a second. Such a dense atmosphere
tends to absorb rather than reflect radio waves, especially at
lower frequencies.
But in the sparse regions of the ionosphere where there are
relatively few gas molecules, the ions re- attach themselves
at fairly slow rates. hr the upper regions of the ionosphere,
called the F2 layer, recombination is so slow as to be relatively unimportant. The important thing about these ions is
that they make the atmosphere electrically conductive. Thus
the electromagnetic energy of a radio wave is partially transformed into kinetic energy represented by the motions of the
ions. If these ions do not recombine, this energy is converted
back to electromagnetic energy and the radio wave continues
to be propagated. If, on the other hand, the ions recombine,
absorption of the radio wave occurs and the wave is sharply
attenuated.
Now, one of the most important factors about this ionization is the fact that the greater the degree of ionization, the
higher the frequency that will be refracted and returned to
the surface of the earth. For any one frequency, there is a
degree of ionization that is required to refract the wave
sufficiently to return it to earth depending upon the angle
of radiation. Frequencies higher than this, for the same angle,
will not be sufficiently refracted and will not return to the
earth.
As far as the 27 -mc. band is concerned, the required degree of ionization occurs in the F2 layer of the ionosphere
which is the uppermost portion shown in Fig. 3. However,
ionization alone does not tell the story. In addition to the
factors of ionization and frequency, radio -wave propagation
is also dependent upon the angle at which the wave strikes a
particular layer of the ionosphere. At low angles of radiation,
Fig. 3. Sky -wave CB signal propagation via the ionosphere.
LTItAVIÓL'T 9AOtAT {ON
225
f{it
2
(IGO TO
220 MILES LOWER LIMIT)
COMBINE
ISO
OWER LMST
w
90 MILES)
125
ó
t
/iii ///
loo
IONIZED BLOB OR CLOUD
á
E
(55
LAYER
90 MILES)
TO
75
D LAYER
(30 TO 55 MILES
DISAPPEARS AT NIGHT)
STRATOSPHERE
50
25
SEVERAL HUNDRED MILES
}-f
48
Ionization of the atmosphere is not a constant thing. It
changes from day to day, hour to hour, season to season, and
from one year to the next. It tends to be greatest during
daylight hours, as in summer, and is further influenced by
sunspot activities, magnetic storms, the magnetic field of
the earth, the passage of meteors, and the presence of other
types of radiation such as cosmic rays.
Thus the ionosphere is undergoing changes in its ionization
constantly. At night, for example, the lower or D layer practically disappears with the setting of the sun. Thus, broadcast -band waves are absorbed in the daytime but not at night,
resulting in long-distance broadcast reception at night only.
At night, the height of the E layer is lowered and the F1 and
F2 layers combine into one layer somewhat closer to the
earth than during the day. Peculiarly, although the D and E
layers are less ionized in winter, the F2 layer is ionized more
so and this effect is thought to be due to the magnetic field
of the earth which seems to have a greater effect upon the
F2 layer than the mere ionization of gas molecules by the
ultraviolet rays of the sun. It is for this reason that we notice
skip signals on 27 megacycles during the winter months and
also because there is less attenuation of the signals in the
lower regions of the atmosphere due to their reduced ionization during winter months. Since sunspot activities increase
the ionization of the ionosphere, skip is more prevalent during
the more intense period of the 11 -year sunspot cycle.
Now, let us see what happens when some winter month
you are communicating with your mobile and your signals are
heard 2000 miles away. As you transmit, part of your signal
is radiated at a relatively low angle toward the ionosphere.
When the signal enters the ionosphere it is entering an area
of different density. At this point the wave is slowed down
and starts to be refracted or bent by the difference in densities. The same effect can be noted optically when you thrust
your arm into the waters of a lake. To your eye, it appears
that your arm is bent where it enters the water. This is due
to the different densities or different refractive indexes of air
and water.
As your radio wave continues into the ionosphere, it is
bent more and more until it reaches a degree of ionization
which is so high that it actually will reflect a 27 -mc. signal.
At this point the radio signal from your transmitter starts
downward toward the earth, returning to the surface of the
earth at the distant receiving station.
Skip Distances
175
iz
a lesser degree of ionization is required than at high angles.
And, since most of our CB antennas are designed for low
-
--+-,
1250 TO 2500 MILES
AT NIGHT
Now you may be wondering what determines the distance
at which your signal can be heard. It is determined by a great
many factors. The frequency is one factor, but we can ignore
it since we are limited to the 27 -mc. band. Other factors
are the angle of radiation, the height of the ionized layer
at which the 27 -mc. signal is reflected, the absorption of the
lower atmosphere, and the curvature of the earth. You must
remember that your signal is not all radiated at the same
angle and, consequently, you may be heard at several distant
points. Generally, for 2 7 -mc. CB, the minimum distance is
about 1250 miles, when the ionized reflecting layer is low,
with the maximum about 2500 miles when the ionized reflecting layer is high. Within this range your signal can be
heard at many different points. You should also bear in mind
that it is not the ionization over your own station or over
the receiving station which is important, but the ionospheric
conditions at a point midway between the two stations where
the reflection takes place.
(Continued on page 88)
ELECTRONIICS
WORLD
COLOR -TV in KIT FORM
Featuring a built -in dot generator, this color -TV
kit comes with a degaussing coil and with all
critical circuits factory assembled and tested.
any time he desires to check the CRT color convergence.
The circuit consists of a synchronized oscillator operating
design
to
that
felt
manufacturers of kit equipment,
at a multiple of the frame frequency and a ringing coil operatand market a color television set kit would be a
ing at a multiple of the line frequency. (If these two signals
have
form
in
kit
foolish venture. Black- and -white TV sets
were made visible on the CRT screen, they would form a
design
color
a
develop
to
but
marketed,
successfully
been
cross -hatch pattern.) The two signals are mixed in a diode
alignseemed to have been much too complicated, as far as
that produces an output pulse whenever the two signals
that
hope
to
concerned,
were
color
adjustments
ment and
coincide. This, of course, would be at each intersection
the consumer could construct one. The Heath Company, on
of the cross -hatch pattern, thus making the resulting output
because
viewpoint,
had
a
different
the other hand, apparently
signal a dot pattern.
they have just announced the availability of a 21 -inch color
The horizontal line generator is a neon -lamp relaxation
apparent
the
it
that
obvious
TV receiver in kit form making
oscillator whose output frequency is controlled by R1. When
difficulties in alignment and testing have been solved. This
the frequency is set and synchronized to some multiple of
does
in
itself,
new TV kit is basically an RCA design and,
the vertical rate, then the series of horizontal lines for the
not warrant much comment. There are, however, many incross -hatch pattern will be generated. This portion of the
novations in the original design that provide foolproof aligncircuit is synchronized to the set's vertical rate by applicament and color adjustment. This is the first kit, at least to
tion of a pulse, via Cl, from the vertical output tube.
the writer's knowledge, that has its own built -in test equipTo produce the series of vertical lines for the cross -hatch
simnot
only
that
major
four
points
are
there
Actually
ment.
a positive -going pulse is taken from the horizontal
pattern,
plify the alignment and color adjustment, but sufficient deand applied to a fairly high-"Q" coil tuned
transformer
output
of
fair
knowledge
with
a
so
that
anyone
tails are available
the line frequency. The frequency of
of
multiple
some
to
electronics can service and maintain the performance of
number of vertical lines.
the
determines
coil
the
set.
the unit for the life of the
switch is in the "Dots" position,
Dots"
"Normalthe
When
As an aid to the constructor who may not have access to
signal from the picture devideo
the
usually
certain items of test equipment
to ground by C2 and
is
bypassed
tector
TO GRID OF
required for color set adjustment, this
B+
FROM VERTICAL
VIDEO AMPLIFIER
signal is fed to
output
OUTPUT TUBE
the
dot
generator
275V.
new kit has a built -in dot generator, proWhen
the switch is
amplifier.
video
the
NO. OF
VIDEO
visions for shorting out the separate color
VERT.
SIGNAL
CI
the
output of
position,
in
the
"Normal"
DOTS
RI
FROM
20pí.
guns of the tube, is supplied complete IMEG.
DETECTOR
is bypassed to ground
the
dot
generator
incorporates
and
220pf.
CRT
degausser,
with a
2.2
and the video signal from the detector is
NORMAL
MEG.
an instruction manual that includes a
.0050f.
then allowed to pass to the amplifier.
service
220K
with
diagram
complete schematic
During the original adjustment, or
and maintenance information. It is, in
NE-2
when moving the set from one wall
even
yf.
.0
but,
manual
service
essence, not only a
200.
it is necessary to demagnetize
to
another,
in itself, an important educational tool
tube. Instead of decolor
picture
the
C2
more
for those interested in knowing
33pf.
having a debuilder
'Yf
pending
on
the
about the design and maintenance of a
Jn`
coil available, Heath has taken
gaussing
FROM HOR120NTALH
color -TV set.
OUTPUT XFMR.
the precaution of supplying a rather inHORIZONTAL PDOTS
The built -in dot generator, a unique
is esexpensive, small-sized coil, consisting of
generator
-in
dot
built
The
1.
Fig.
circuit in itself, is shown in Fig. 1. This
sentially a cross -hatch generator with only
30 turns of # 18 wire operated directly
circuit is used during the original conthe intersections of the vertical and horfrom the 6.3 -v., 13 -amp. filament supizontal line pattern showing up as a dot
vergence procedure and can be switched
ply.
tube
screen.
-ray
cathode
the
on
at
pattern
viewer
of
the
convenience
in at the
P to the present time, this writer and, in fact, many
01
mounted near the
Interior views of the color set showing the vertical chassis, with the convergence board
December, 1963
CRT
yoke assembly.
49
AN
1
\DOOR HORN
FOR TV-FM 1.1JGEPTIO\
By B. V. K. FRENCH
/
Avco Corp., Electronics and Ordnance Division
Scaled -up version of a broadband microwave horn makes
an excellent TV and FM antenna that can be mounted
in confined indoor areas such as attic crawl spaces.
M ONG the vicissitudes and occupational hazards off
professional existence in the electronic industry, is
the necessity of compromising a desire for high -qual-
ity, noise -free TV and FM reception with the rabbit ears
pick -up usually imposed by apartment -house regulations.
Having lived in apartments in five large metropolitan
areas, the writer has found that apartment rules prohibit the
use of an outdoor antenna, or at least one visible from outside the building; multiple ghosts are invariably present due
to reflections from the framework of nearby buildings, power
lines, or other metallic structures; commutator -type electrical appliances such as kitchen mixers, vacuum cleaners, and
electric razors cause a high intermittent noise level in multiple -unit apartments; and conditions are often aggravated
by nearby shopping centers or service stations with flashing
signs, animated displays, or other electrical noise -producers.
Single unit suburban dwellings on which an outside antenna is objectionable for aesthetic or other reasons are often
subject to the same restrictions as multiple unit urban apartment houses.
Under these conditions, the only possible solution lies in
using the attic of the single unit dwelling or the attic crawl
area of the apartment. Here, convincing the landlord or rental
agency that the installation will not damage the building or
constitute any greater fire or lightning hazard than is presented by the electrical wiring of the building itself, is the
only major problem. The lead -in from the antenna is routed
unobtrusively down the corner of a clothes closet and along
Fig. 1. Dominant mode cut-off frequency versus physical dimensions for the broadband equilateral horn antenna described.
10
8
2
7
3
-4--
TEEN
HORIZONTALLY
POLARIZED
WOVE FRONT
z
5
BRONZE SCREEN.
CHICKEN
Ñ
VHF
Lowy--
4
CHANNELS
OR
.{ -FM+i
WIRE
HARDWARE CLOTH
3
2 METER
AMATEUR
HAND
2
i`-
YHF
i
1
50
75
100
125
150
175
FREQUENCY IN MEGACYCLES
50
-
TV12131
NIGH
CHANNELS
200
1
225
250
the baseboard of the room to the receiver to provide a finished installation.
Elimination of ghosts and man -made noise dictate the use
of antenna structures which have extremely high front-toback ratios, high gain for horizontally polarized television
and FM transmission but with reduced pick -up of vertically
polarized radiation such as noise. Additional important requirements are broad frequency response and a good impedance match over the required frequency band. The last
two considerations are particularly important when the desired stations are widely separated in the TV band, or when
color reception is a requirement.
The choice of antenna type to fulfill these requirements
depends largely upon the receiver location with respect to:
number and frequency allocations of required TV broadcast
transmitters; angular relationship between the incident direct signal from the transmitter and the reflected signal causing tIle ghost; and adequate antenna gain to produce pictures with a sufficiently high signal -to -noise ratio.
If only a single broadcast station is involved, the use of a
multi- element yagi antenna array- consisting of a driven element, a reflector, and sufficient directors -will provide the
required pattern for the elimination of ghosts. Adequate response at video carrier, color sub- carrier, and sound frequencies dictate broader bandwidth parameters than are provided by a narrow-pattern yagi. A number of such arrays, as
would be required for multiple station reception, necessitate
the addition of multiple lead -in wires and cumbersome
switching arrangements either at the antennas or at the receiver. Thus the yagi array provides only a partial solution
to the problem.
The writer has found by experiments in urban multi -unit
apartments and suburban single -unit dwellings in a number
of large cities, that a scaled -up version of the familiar microwave horn admirably fulfills a majority of the requirements
for a broadband antenna.
No originality is claimed for this use of the microwave
horn for television reception since at least two references to
such possible use have appeared in the literature.1,3 However this application has received nowhere near the attention
it deserves.
The early investigators of the microwave horn radiator
(W. L. Barrow, F. D. Lewis, and L. J. Chu of Massachusetts
Institute of Technology) in the first published articles
(1939 )1,2 originally proposed its use as an aircraft blind
landing localizer radiator, but suggested, "This (broadband)
feature of the electromagnetic horn, which is perhaps not
equalled in any other type of ultra- high-frequency radiator,
fits it peculiarly to wideband applications like television...."
The first specific application of the sectoral horn to v.h.f.
television reception was proposed by D. O. Morgan (1951) .3
He described its use as a tower mounted, fringe -area outdoor
antenna for use with a rotator. In spite of its excellent performance characteristics it presents wind resistance problems and it is hardly a thing of beauty when exposed to public view. These considerations, of course, will not apply when
ELECTRONICS WORLD
11(
14
Eal
12
NM,'
=Or'
Air
00.wil-4
A Ar
50
75
100
125
150
175
200
225
zso
s
FREQUENCY IN MEGACYCLES
Fig. 2. Gain versus frequency for various sizes of antennas.
the antenna is secreted either in itn attic, or in some other
convenient out -of -sight place.
Theoretical l :onsiderations
The configuration chosen for this application is a bisectoral, equi- angular, pyramidal horn. The literature is
replete with pertinent theoretical and design informatiot .1.2,3,4,7 In reading these references, several items should
be noted:
L Vertically polarized transmissions (electric field lines
perpendicular to the earth's surface) are employed in all
radio services, except television and FBI broadcasting, therefore vertically polarized transmission is generally assumed
in the literature although not specifically so stated. For this
reason, illustrations should be rotated 90- degrees for application to horizontally polarized reception and the text interpreted accordingly.
2. Sectoral horn discussions are mainly concerned with
"flare" (inclined at an angle) in one plane only while
pyramidal horns are flared in both planes.
only
:3. The version considered here consists of two sides
of the pyramid (top and bottom omitted) since the desired
mode of reception is that for horizontally polarized waves.
In Fig. 1, dimension H determines the low frequency cutoff of the horn. When operating in the dominant mode, a
half -wavelength of the electric field occurs across this dimension. The electric field distribution, across the rectangular
aperture, when operating in the dominant mode is identical
to that in rectangular waveguides. See any standard text.
Dimensions of a 60- degree flare pyramidal horn versus cut-
off for various frequencies in the television bands are also
shown in Fig. 1.
As the flare angle varies, the gain of a pyramidal horn
referred to a half -wave dipole goes through a broad maximum between 40 and 60 degrees. The equilateral version
with a 60- degree angle is within 0.2 db of the maximum.
Such variation is negligible. The gain versus frequency characteristic of 60- degree bi- sectoral horns having apertures of
4, 6, and 8 feet are shown in Fig. 2. The reference base is a
normal 72 -ohm, resonant half -wave dipole.
The directional reception patterns of electromagnetic horn
antennas as a function of flare angle are shown in detail in
the literature.4 While flare angles of less than 60- degrees will
provide narrower reception patterns, this is accompanied by
a reduction in gain. The antenna polar pattern is sufficiently
narrow to accomplish its purpose of ghost elimination and
yet allow adequate gain over a 20° included angle. (It is of
interest to note that the bow -tie antenna for u.h.f. television
is a horn with a 180° angle.) For a perfect match, a lead -in
impedance of 377 ohms is required. deans of attaining a
satisfactory impedance match will be covered while discussing antenna construction later in this article.
Practical Construction
Many apartment houses have a slightly pitched roof construction with an attic crawl space provided for ventilation
and heat insulation purposes. Access to this space is usually
provided through a small trap door often located in the ceiling of a clothes closet or hallway and may be a scant three
feet or less in its diagonal dimension. To meet these cramped
conditions, as well as to make preliminary performance and
orientation tests before final installation, a design was
adopted which permitted ready disassembly. A screwdriver is all that is required for re- assembly in the attic.
Fig. 3 shows the assembled antenna which consists of two
equilateral triangular frames made from 1" x 2" pine furring,
and covered on the facing or interior surfaces with bronze
screen cloth. The frames are held together at the corners by
hardware mending plates ('é" x 1" x 2 ") fastened with
wood screws. The screen cloth is tacked to the upper and
lower side pieces and secured with screws and flat washers
at the vertical front piece. Thus, the front parts of the frame
can be removed and the entire antenna folded for passage
through the attic door.
Fig. 4 illustrates some of the constructional details at the
apex of the horn. The screen cloth is trimmed off at the
apex corner of both sides to prevent an accidental short circuit. The nose block or brace was made by gluing together
two of the :30- 60 -90- degree pieces of wood cut from the ends
in forming the sides of the frame. ( The nose block is shaped
like an equilateral triangle.) Assembly employs small angle
(Contiuucd on page 78)
brackets held to the sides
in any confined area such as an attic.
Fig. 3. The four -foot horn antenna can be disassemble d easily for installation
Dtctmbtr, 1963
51
CHOOSING A TWO-WAY RADIO S Y STEM
HOWARD
/
By
H. RICE
Technical Information Center, Motorola Inc.
PART 2 / Types of communications systems, simplex and duplex operation,
and various types of repeater systems are covered in concluding
part.
PART I of this series covered the design parameters of a
two -way radio system. This portion will cover types of
systems currently available.
The simplest, and undoubtedly the most prevalent type of
two -way radio system is of the one -frequency simplex design.
Each transmitter and receiver in the system is tuned to a common frequency and communications travels in one direction at
a time. For most business radio users, the one -frequency simplex system is completely adequate. Its chief benefit is simplicity, not only because of the equipment economy but also
because one -frequency simplex radios are easy to operate.
This type of system can be licensed in all three business radio
bands. (See Part 1.)
If the user can install an antenna tower on the roof of his
building or adjacent to the building, a locally controlled radio
set can be mounted on the dispatcher's desk and the transmis-
called a "multi- frequency option" since it is not truly a
two frequency system. Suppose, for example, a local police department wanted to contact its own mobiles as well as the mobiles
of a nearby police department, or perhaps state police
vehicles. A dual- frequency transmitter and receiver would
then
be installed at the base station. However, only one switch selected frequency would be used at a time, so the system
would still be, essentially, a one -frequency simplex system.
In other cases, the user might require this two -frequency
option for his mobile units as well as his base station -or instead
of it- depending on his needs.
A full step up from the one -frequency simplex system
is the
true two -frequency simplex system. This system is still a simplex system since communication still occurs in only one direction at a time. However, the system operates on two different
frequencies: the receiver on one and the transmitter on an-
T1
i
a
-____
il
R]
R7
Fig. 1. The radio circuit of the radio -controlled base
station (left) replaces the wire control lines in those systems
where the cost of leased landline may be prohibitively high. In
the mobile relay system (right), the base station dispatcher is connected to the repeater by a radio link. Both the dispatcher
and the mobiles are tuned to same frequency.
sion line run from the installation directly to the antenna. As
a rule -of- thumb, transmission line should not exceed 500 feet
in the 25 -50 mc. range, 250 feet in the 150 -174 mc. range,
and 125 feet in the 450 -470 mc. region. Therefore, if the
user's dispatching desk is some distance from his antenna site
or if he requires a higher powered transmitter, a remotely
controlled base station is necessary.
Remote control of a base station is usually achieved by
leased landlines. Most remote control consoles are compatible
with either 2 -wire lines (in which the d.c. control voltages
use the same pair of lines as the a.c. audio voltages) or with
4 -wire lines (in which the control lines are separate from the
audio lines ) The remote control console should also contain
a microphone preamplifier and a compression amplifier to
make certain that the input level to the line meets telephone
.
company specifications.
Additional dispatch points may be added to either locally
controlled or remotely controlled base stations. The dispatch
point might be only a telephone -type handset on the manager's desk or it might be another remote control console
installed in an alternate or emergency dispatching office. The
FCC insists, however, that the system be under the control
of the main dispatcher at the control point; he must be able
to monitor both sides of any conversation which originates
from an auxiliary dispatch point, unless some emergency situation has disabled the control point.
A variation of the one -frequency simplex system might be
52
other. If the base station transmitter operates on frequency 1,
the receiver operates on frequency 2. The mobile units are
set up in the opposite way, transmit on frequency 2, and
receive on frequency 1. The mobile units cannot communicate
directly with each other, since their transmitters and receivers are not tuned to the same frequency.
This arrangement is used most often by taxicab companies
and by large police departments. As a matter of fact, the taxicab radio service has been specifically divided into pairs of
channels so that two -frequency systems can be used. The advantage of the two-frequency system is that it permits rapid fire dispatching, such as that necessary for police or taxicab
operations. In such systems there is usually more traffic originating at the dispatcher's office than there is coming into the
dispatcher from the mobiles.
An expansion of the dual frequency idea is the two -frequency duplex network. This type of system differs from the
previous one in that communications can take place in both
directions at the same time. All radio sets in the system require two antennas, one for the transmitter and one for the
receiver. If the two frequencies are sufficiently separated from
each other, a single antenna can be used with a diplexer, a
band -reject filter which prevents the strong transmitter energy from entering the associated receiver. The full two -frequency duplex arrangement is rarely used in applications
other than mobile radiotelephone systems.
A modified two- frequency duplex system, in which
the
ELECTRONICS WORLD
base station is set up for duplex operation but the mobiles are
limited to simplex facilities, is often used in situations where
traffic from the dispatcher is extremely heavy. With such a
system, a transmitter dispatcher is responsible solely for outgoing messages. Because base station traffic can be transmitted and received simultaneously, a separate dispatcher is
on duty to receive all incoming messages. This type of system
is utilized for large metropolitan police departments and also
by users whose radio dispatching requirements are exceptionally heavy during most of the working day.
Repeater Systems
Repeater systems are, in essence, a more complex integration of several basic two -way communication system designs.
Repeater stations are used to take advantage of an exceptional
antenna tower site and are becoming more and more prevalent, not only in mountainous regions but also in large metropolitan centers. There are two types of repeater stations: the
radio -controlled base station repeater and the mobile relay
repeater shown in Fig. 1.
Consider the situation in which a nearby mountain or hill
provides an ideal location for the base station antenna site.
However, the cost of leasing telephone lines up to the base
station might be prohibitive. One successful solution to the
problem is a separate control circuit using radio instead of the
tion have two antennas since it is receiving and broadcasting
simultaneously.
The major benefit afforded by mobile relay operation is the
vastly extended coverage it affords; it actually gives each mobile station a range equivalent to the range of the mobile plus
the range of the repeater. Beside the improved range, the system is also important because it can be licensed to business
radio users in the 450 -470 mc. band.
The dispatcher can be connected into the system in one of
two ways. The headquarters can be equipped with a locally
controlled base station, tuned to the same pair of frequencies
as the mobile units, and a directional antenna beamed at the
repeater site. With this arrangement, the dispatcher's radio
operates as though it were a "tied- down" mobile unit; each
radio in the system has equal access to the repeater.
The other method used to link the dispatcher with the rest
of the system is a wire control line. When the repeater ( see
Fig. 2) is operated in this manner, the dispatcher has corn plete control of the system. For additional system flexibility,
the dispatcher's remote control console is often equipped with
a special "Repeater On /Off" switch. With the switch in the
"Off" position, the system is operated by the dispatcher as
though it were a simple two -frequency system. When the dispatcher goes off duty and the headquarters is left unattended,
the switch on the remote control console is thrown to the "Re-
Fig. 2. In the mobile relay system (left), base station dispatcher is connected to repeater through a wire
line. In the one -way talk -back repeater system (right), messages from dispatcher go directly to mobile units; messages from mobile units can go directly to base station; or over greater distances, can be relayed by repeater.
conventional wire lines. A low- powered control station is installed at the dispatcher's location (which we'll call "headquarters") with a directional antenna beaming the signal up
to the remote base station.
On the mountaintop, the signal is picked up by the receiver
in the repeater station. The audio portion is then used to mod ulate the base station transmitter which sends the message out
to the various mobile units in the system. Communication
from the mobile units operates in the same way. The message
is picked up by the base station receiver and is automatically
rebroadcast back down to headquarters by the repeater transmitter. Note that the mobile units can communicate directly
with each other.
Between the base station and the mobile units, we have a
one -frequency simplex system which can be operated on any
of the available two -way communications frequency bands.
The control circuit is a directional point -to -point system
which is usually operated on a pair of frequencies in the 450470 mc. or up in the 960 -mc. region.
There are several variations of the mobile relay concept and
we will explore each. The basic mobile relay system is exactly
what its name implies: a relay for expanded mobile-to- mobile
coverage. The relay station is usually located on a high hill or
mountain, or on a tall building in metropolitan areas. It is
completely unattended and is arranged in such a way that all
signals picked up by the receiver are automatically rebroadcast by the transmitter. This, of course, requires that the staDecember, 1963
peater On" position and the systems reverts to mobile relay
operation.
An example of this wire -line control mobile relay system
might be a county or state highway department. During the
day when many mobile stations are in operation, the system
is under the control of the headquarters dispatcher. At night,
a few vehicles are still operating. The dispatcher closes the
base station when he leaves for the day and the responsibility
of the system goes to a night supervisor who is operating one
(Continued on page 82)
of the vehicles. The next
Fig. 3. A tone -coded squelch is used in the shared or community repeater system so that each user heats only those messages originating within his portion of the over -all system.
53
1T HEN electronic flash units of the high -voltage
battery type perform in a faulty manner, the trou-
ble is often caused by bad storage capacitors. The
units described in this article were designed to fulfill a longstanding need for an instrument which could be used to
prevent storage capacitor deterioration by keeping the capacitors formed, determine the condition of the storage
capacitors, and act as a power source when a flash unit is
operated near a power line (for example, in a photo studio)
r
R
3
117V.
INPUT
.
Capacitor Deterioration
The first sign of storage capacitor deterioration is an increase in the electronic flash unit's recycling time. The
second sign is that the batteries do not last as long as usual.
The third sign, and this happens when the storage capacitors
are quite bad, is that the "Ready" light will not indicate
a ready condition. This is due to a lack of high voltage
at the storage capacitors because of the high leakage current causing a sizeable voltage drop across the de- ionizing
resistor in the flash unit. The de- ionizing resistor is usually
on the order of 500 to 1000 ohms. As a single bad storage
capacitor can easily draw 100 ma., and as some flash units
have two or more such capacitors, a voltage drop of 50 v. or
more can appear across the de- ionizing resistor. Most ready
lights are set to operate at from 80 to 100% of the intended
flash unit operating voltage, therefore a drop of 50 volts and
more would keep the ready light from operating. Some flash
units of the 450 -v. variety can have less than half voltage
at the storage capacitors because of high leakage currents
dropping an appreciable voltage across the de-ionizing resistor.
Electrolytic capacitors for electronic flash units are manufactured of the highest- quality materials under highly controlled conditions and have very -low leakage currents.
The storage capacitors become deformed in an electronic
flash unit which has not been used for some time. The degree
of deformation depends upon such things as length of idle
period, quality of the capacitors, prior condition of the ca-
RI-10 ohm, I
w. res.
R2-100 ohm, ,2 w. res.
C1 -10 µf., 450 v. elec.
C2 -12 µf., 250 v. elec.
C3 -20 uf., 600 v. elec.
PL1,PL2-250 v., IO w.
I -Neon lamp assembly
95408X or equiv.)
J-Socket
(Matto
(Cinch -Jones S -302 or
equiv.)
Isolation trans., 40 w. (UTC R -72
S- S.p.s.t. switch
or equiv.)
F-%-amp "Slo -Rlo" fuse
TPI,TP2 -Jack, (GC 33-240 or equiv.)
D1,D2,D3- 1N2071 diode
VR1,2,3, -0A2 tube
Fig. 1. The circuit and parts list for the 450 -v. flash unit
battery eliminator and capacitor former. The device is easy
to construct and features built -in, short- circuit protection.
T-
pacitors, temperature, and humidity. When a flash unit is
placed in service with deformed capacitors, even to a small
degree, the result is a greatly decreased battery life and a
definitely lessened watt- second output.
When flash units which are not in use, even for short periods of time, are subjected to a proper forming voltage, not
only will battery life be greatly extended, but these deforming troubles do not generally appear.
In designing a suitable forming unit, the following features
should be incorporated: it must have as great a degree of
safety as possible, therefore line isolation is required; the
unit must be simple to build and operate and have no controls to adjust; it must apply the correct voltage to the
flash unit over wide variations of line voltage; it must be
able to be used as a battery eliminator in addition to performing the function of capacitor forming; and it must be
entirely dependable.
The circuits for 450 -v. and 510-v, units are shown in
CAPACITOR FORMIER for
ELECTRONIC FLASH UNITS
By MELVIN S.
LIEBERMAN
Leaky storage capacitors in an electronic flash uni
can cost a lot of pictures. This device prevents
capacitor deterioration, determines leakage rate,
and can act as cr power source in lieu of batteries.
54
5%
capacitor
capacitor
capacitor
bulb
.
and 2 respectively. An underside view of the completed 450 -v. capacitor former is shown in Fig. 3.
Effects of Leakage Currents
Let us consider the effect of leakage currents in the storage capacitors of high -voltage, battery -type electronic flash
units. A typical 450 -v. flash unit, using two Burgess N150
or Evereadtj 492 batteries, will give approximately 1500
flashes when operated at 100 watt -seconds. (The actual number of flashes depends upon numerous conditions, such as
the amount of continuous or intermittent use, temperature,
age of the batteries, and storage conditions, to name a few.)
These units are in the very best of shape if the leakage current is no greater than 1 ma. per 100- watt -second rating. If
the storage capacitors had 10 -ma. leakage, the recycle time
of the flash unit would become slightly longer due to the IR
drop across the de- ionizing resistor, and this 10 ma. represents 4.5 watts (450 v. X 0.01 amp.) or in 10 minutes of
"on" time this would be 2700 watt- seconds (60 x 10 x 4.5)
Now just what does 2700 watt- seconds mean to us who use
these types of Hash units? It means that we will have lost
the equivalent of 27 flashes at 100- watt -second rating or 54
flashes at 50- watt -second rating with a unit whose storage
capacitor's leakage was 10 ma. In terms of economy, we
would lose 1.8 percent of our battery life (27/1500 or
54/3000) for an "on" (but unused) time of 10 minutes.
Now you can see the importance of keeping your capacitors
well formed. Better formed capacitors means less leakage and
less waste.
As a matter of interest let's consider the effect of having
accidentally left on, for 24 hours, a 450 -v., 100 -watt -second
flash unit that was in such excellent shape as to have only
1 ma. of leakage current. This leakage current represents
0.45 watt (450 v. x 0.001 amp.) and in 86,400 seconds
(24 hours) the leakage energy lost would be 38,880 watt seconds (86,400 x 0.45) This is equivalent to 776 flashes
at 50 watt- seconds (38,800/50) or 388 flashes at 100 watt seconds (38,800/100). And if this doesn't impress you then
let's look at it in terms of lost battery capacity on the basis
of 1500 flashes per 100 watt- seconds or 3000 flashes per 50
watt- seconds. You would lose 25.87 percent of your battery
capacity (388/1500 or 776/3000) As you can easily see now,
it is definitely to your advantage to have your flash unit off
when not in use and in top shape when in use.
In the opinion of the author, a 10 -ma. leakage current
in a 100 -watt -second flash unit is intolerable. Even though
a 100 -watt -second flash unit with this leakage current and a
500 -ohm de- ionizing resistor will charge up to 98.9 percent
of the battery voltage, this leakage current does represent
a substantial loss of battery capacity. A 10 -ma. leakage
Figs.
1
.
RI
JDID2,D
/PLi
Or
VRI
VR2
VR3
-kf P2
R2
TPI
PL2
CI
C3
C2
I
F
S
Fig. 3. Underchassis view of completed 450 -v. capacitor former.
loo
90
80
70
60
50
40
30
20
.
10
9
8
7
6
.
PLI
PL2
5
4
PL 3
O O
TPI
D6
VR 4
(RED)
çR2
CURRENT
TP2
(BLK)
Fig. 4
time,
Fig. 2. The circuit
and the parts list
for the 510 -v. unit.
R1 -10 ohm, 1 w. res.
R2-100 ohm, 1/2 w. res. + 5%
C4,C5-12 4., 250 v. elec. capacitor
C6,C7-12 4., 450 v. eler. capacitor
PLI,PL2,PL3 -250 v., 10 w. bulb
S- S.p.s.t.
switch
F-4/4-amp "Slo -Blo" fuse
I -Neon lamp assembly (Dialco
95408X or equiv.)
December. 1963
J- Socket (Cinch -Joncs S -302 or
equiv.)
T- Isolation
trans., 40 w. (UTC R -72
or equiv.)
D4,D5,D6,D7-1N2071 diode
TP1- Jack,red (GC 33.240 or equiv.)
TP2-Jack, black (GC 33.242 or
equiv.)
VR4 -0B3 tube
VRS,VR6,VR7,VR8 -0R2 tube
10
15
20 25
30 35 40 45 50
CONSECUTIVE DAYS NOT USED
If
electronic flash unit has not been used for some
this -c,raph shows forming time for storage capacitors.
0
LEAKAGE
5
a
amounts to a loss of 81 flashes in a 450 -v. flash unit and 90
flashes in a 510 -v. flash unit for every 30 minutes of flash
unit "on" time. If a typical photographic assignment lasted
30 minutes, then the loss of battery life would amount to
half of the battery capacity for ten such assignments.
If you do not use your flash unit several times weekly,
or do not find it practical to put it on "capacitor forming,"
or do not have a voltmeter to monitor the capacitor- forming
voltage to determine that the capacitors have been fully
formed when put on capacitor forming, then use the graph
of Fig. 4 to determine how long the unit should be placed on
forming. This is, however, only an approximate guide since
the forming time varies with the condition of the capacitors.
55
5o
Leaving the unit on for longer or indefinite periods of time
with the formers described here will in no way be harmful
to the flash unit or to the forming unit.
15
6
e
tv
Voltmeter Test Points
The finished units were constructed with two test points
(TP1 and TP2). These test points are connected to each side
of a 100 -ohm resistor, which is in series with the -positive side
of the high -voltage output lead. By connecting a voltmeter
(10,000 ohms /volt or better) to these two test points and
reading the voltage after the storage capacitors are charged,
you can determine the leakage current with the aid of the
graph of Fig. 5. The voltage at these test points will never
exceed 4.6 volts in either of these two units even with
FOR
LEAKAGE
CURRENT IN
MILLIAMPERES
450V
UNIT
(A)
20 25
52
P-or.
50
0 of
48
O
46
FOR
LEAKAGE
CURRENT IN
MILLIAMPERES
510V
UNIT
44
42
C
40
(B)
38
Fig. 7. These meter scales may be used for the leakage current
monitor. The meter face of (A) is to be used for the 450 -v.
unit, while the one at (B) is to be used for the 510 -v. unit.
36
34
32
30
28
26
24
22
20
18
16
-
14
12
Io
8
6
4
a.11111111111111
2
0.2 0.4 0.6 0.8
1.0
1.2
1.4
1.6
1.8
2.0 2.2 2.4 26 2.8 30
VOLTAGE AT TEST POINT (VOLTS)
Fig. 5. Leakage current can be determined using a 10,000 -ohm-
per-volt voltmeter at the leakage current monitoring
points.
6. Novel leakage current meter has automatic overload
protection because push- button must be held down on the sensitive ranges. Device is to be used with the capacitor former.
Fig.
S2, S3
NORMALLY
Meter and Meter Circuit
OPEN
AMMETER
RANGE
56
R5
SCALE
0 -50pA_
25K
0- IOOpA.
0 -IMA.
C
shorted storage capacitors. Fig. 6 shows the circuit of a
voltmeter that the author built to use with these units for
reading leakage current directly.
The circuit design of the battery eliminator and capacitor
former unit described here limits charge and leakage current
flow to a nominal 45 ma. If we were to read leakage currents
up to 400 and 500 ma., we would have to have a specially
calibrated meter scale. In other words, the available current
of 0 to 45 ma. from these units has to represent 0 to 500 ma.,
where 45 ma. must equal a short. We therefore make an
assumption that capacitors with given amounts of leakage
at 450 and 510 v. can be represented by some value of
resistance which remains constant with a change in voltage.
By connecting these different values of resistance, which
represents known values of leakage at 450 and 510 v., to the
two completed units, we can calibrate the new meter scale.
The results of this calibration are the meter scales of Fig.
7. The special scales may be cut out and glued on the original
meter scale. Since this scale is calibrated directly in leakage
current, there is no need to refer to the graph of Fig. 5 if
you build this companion meter.
Applying the rated voltage all at once to a capacitor
which has not been in use for some time, is actually hard on
the capacitor because of the high initial surge and leakage
currents. The very nature of the protective features of the
units described here prevents high surge or leakage currents
due to ballast action. As the capacitor charging and forming
currents decrease; the ballast circuits allow a higher voltage
to be applied to the capacitors. Thus, the capacitors are
formed in a very gentle fashion. As a matter of fact, these
units never allow more than a nominal 45 ma. of current
to flow into the capacitors even if they are shorted!
R4
SCALE
R3
B
SCALE
12.5K
I00K
50K
100K
50K
'.25K
2.5K
5K
A
This meter circuit is unique because the high range,
scale A, is always connected unless the push -button switch
for scale B or scale C is pressed. Thus, protection against
meter overload is automatic. The values for R3, R4, and R5
using three common ammeters, are shown in Fig. 6.
In addition to leakage current scales, the meter templates
have markings for using the meters to read 225 v., 450 v.,
and 510 v. with an external series resistor. The series resistor should be sufficient for converting whatever basic
meter movement is used to a 1000 -v. meter.
ELECTRONICS
WORLD
OUTPUT -TRANSFORMER CHART
Listing of output powers and required audio output
transformer primary impedances for over 200 tubes.
power given and should have a secondary winding that will
match the loudspeaker impedance. In most receivers, this
value is 3.2 ohms, while in amplifiers, common impedances
are 4, 8, and 16 ohms. Note that "S" stands for single -ended
and "P.P." means push -pull. All load resistances are given in
thousands of ohms. This chart was based on information supplied by Stancor Electronics, Inc.
THE following chart will be helpful in selecting the proper
output transformer as a replacement in radio receivers
or in the construction of audio amplifiers. To use the chart,
simply check in the first column for the tube type being used,
then read across for the applicable operating characteristics
and required output transformer primary impedance.
The transformer should be able to handle the amount of
--
_
-1
Tube
Use
1A5-GT
1AC5
1AG4
1B8-GT
1C5-GT
S
S
A
A
A
A
A
108-GT
1E7.6 (GT)
S
A
S
A
A
A
A
A
B
B
A
S
S
S
PP
1F4
1F5-G
155-G
1G6-GT
H4-G (GT)
1J5-G
1
S
S
S
PP
PP
S
Class
Ohms
.10
.05
25
25
0.035
.21
.24
.20
.29
12
14
8
12
16
.575
24
.31
.31
.55
.675
2.1
.45
Res.
in
K
(GX)
Q5-GT
1S4
1
1T5-GT
1V5
1W4
2A3
PP
S
S
S
S
S
S
S
S
2E24
2E26
2E30
3A4
3B5-GT
387/1291
3C5-GT
3D6
3E5
3LE4
3L F4
3Q4
305-GT
3S4
.27
.27
.17
.05
PP
AB
S
A
S
S
S
A
A
A
S
A
S
A
S
A
16
16
6B05
S
A
PP
AB1
9
68S5
6BU6
S
S
A
12
8
6BW6
S
A
A
6CA5
S
S
13.5
PP
AB2
S
A
.2
S
A
A
.26
A
A
A
A
A
A
A
A
A
.25
.325
PP
S
S
A
A
A
ABI
A
PP
15
3
4.8
18.5
3.9
4.0
4.5
7
ABI
A
.6
.4
.27
.4
.18
.27
.27
0.25
1.0
2.0
10.
21.5
5.5
7.5
ABI
A
A
PP
PP
A
15
B
S
A
10
1.4
PP
B
6AM5
6AN5
6AQ5-W
6AR5
6AS5
6B4-G
A
PP
AB1
S
S
S
10
5
S
S
S
S
S
5
5
5.4
6A4/LA
A
8
5
4.5
4.5
10.
10
2.5
15
1.4
3
3.75
8
3.6
3.2
9.5
3.8
8
2.5
3
8
10
7
3
10
A
10.8
4.2
1.0
28
A
1.1
A
3
10
10
A
6.5
1.4
2.5
PP
S
S
S
6V7-G
6W6-GT
6Y6-G (GT)
6Y7-G
6Z7-G
7A5
7B5
7C5
9DZ8
10
1105
12A5
12A6(GT)
12A7
12AB5
A
A
AB
A
S
A
A
A
S
A
PP
A
PP
PP
PP
PP
AB1
AB1
PP
ABI
S
A
PP
B
S
S
A
S
S
S
A82
AB2
A
A
A
AB1
S
A
PP
AB1
S
S
A
S
A
B
PP
PP
S
A
B
A
0.3
4.0
3.5
3.5
3.5
5.7
11.0
4.5
0.3
4.5
5.5
1.5
11.0
2.8
4.5
10.
3.8
2.3
5.4
21.5
1.4
3.8
3.8
3.6
2.0
1.6
1.4
3.8
4.8
18.5
10.5
6.5
10.8
17.5
26.5
18
31
47
3.9
9.4
4
10
0.3
0.3
5.5
4.5
10
5.5
10
0.35
3.8
6.0
8.0
4.2
1.5
4.5
A
A
5.5
8
A
A
S
A
A
19
S
A
A
5.7
11.0
2.0
1.6
1.5
3.4
3.4
.55
S
A
4.5
S
S
S
S
A
A
12BF6
S
A
12BK5
12BU6
S
A
A
3.5
0.3
S
S
A
1.3
2.5
A
S
A
A
4.5
3.4
2.2
3.2
12AL8
12895
5
'Triode- connected (Williamson Circuit).
PP
AB1
S
S
A
A
PP
AB1
S
10
12CS5
12CU5
7
6.5
12005
12118
7
5.6
4.5
8
12DM5
5
10
5
8.5
5
10
4
4
2.5
14
3
6
7
±Ultra- linear (Williamson Circuit)
12
2.5
4.2
5
6.6
3.8
6
3.8
7
7
7
3
5
10
5
10
20
5
2.6
14
12
2.5
9
10
8.5
A
A
PP
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1218
121(5
121.6-GT
12V6-GT
12W6-GT
14A5
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A
2.3
1.5
2.0
5.5
3.8
2.3
3.8
0.04
1.9
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0.005
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1.5
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0.02
0.04
5
S
A
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2.1
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4.5
2.2
.77
S
31
32ET5
32L7-GT
33
35A5
35B5
35C5
35028
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43
45
46
47
48
49
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50B5
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4.8
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2
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4.8
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18
20.0
2.7
2.5
0.17
4.6
3
6
2.5
4.5
2
3
4
4
4
5.7
2.8
2.6
6677
6945
6973
5
2.5
2.5
2.5
2.5
10
1614
5881
6146
6550
7027
7189
7212
5
7
1.5
11
EL-34
(6CA7)
EL-37
EL-84
(6BQ5)
KT-66
4.35
2.1
2
3.8
1.9
2.5
4
AB1
S
A
AB 1
5.5
1
2.0
10.0
3.8
4.5
9.3
1.4
0.375
4.5
10.0
2.8
0.8
15
20
6.6
2
10
3
27
20
9
1.7
1.7
8.5
3
5.5
10
4.5
6
8
16
10
5
10
7.5
3
5.5
7.5
5
7
4.6
3.2
5.8
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PP
PP
3
4
10
10
9
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S
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A
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A
4
.85
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1.0
1.25
1.0
.065
2.7
4.3
4.3
3.0
5
12
S
A
.85
1.2
High-Fidelity Applications
8.0
807/W
PP
A*
7061
6
2.5
S
PP
1.5
2.6
4
S
S
3.5
3
1.4
6
3.8
2
2.1
4
3.8
0.35
20
6
3.0
6
20.0
2.5
1.5
2
1.8
0.79
4.8
14
8.0
20
0.35
6.75
3.4
0.285 10.65
1.1
5902
6005
6095
6216
6287
B
A
A
S
S
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S
S
S
A
A
5871
5
5
PP
S
S
S
1632
1644
5640
5670
5672
5686
5812
5824
8.5
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42
4
7.5
A
A
2
50CA5
50EH5
M7-GT
117N7-GT
117P7-GT
1631
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A
3.6
117L7/
S
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2807
A
6.5
2.5
A
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7017-GT
71A
79
85
89
112A
6
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A
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S
55
59
3
10.0
3.8
2.8
5.5
S
S
S
2.5
2.7
1.25
2.5
4.5
Ohms
50BK5
5005
5006-G
50L6-GT
4
.8
Res.
in K
Class
2.5
A
19
25N6-G
25W6
26A7-GT
26E6-G
4
A81
2.3
1.5
2.3
3.8
25L6 (GT)
4.5
5.5
8.5
S
A
A
25F5
2.5
Pwr.
Out.
Watts
Use
Tube
PP
S
S
S
25C6-G
25CA5
25EH5
Ohms
10
17C5
17CA5
17CU5
17L6-GT
2586-G
25BK5
K
1.0
AB
2585
in
3.8
PP
19AQ5
25A6 (GT)
25A7-GT
25AC5-GT
Res.
.8
4
A
A
A
41
5
A
Pwr.
Out.
Watts
S
S
1405
38
10
10
A
S
S
8
10
.8
S
S
4.5
5
A
A
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10
2.5
10.2
2.5
3.3
7.5
13.5
S
S
S
8
10
10
A
S
4
8
S
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5
7.5
7.2
S
Al
Al
S
120Z8
12E05
12EH5
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2.5
S
120117
12DV8
12EM6
2
A
A
S
A
A
A
4.5
7.5
Class
Use
12C5
12CA5
12CM6
3
7
9
AB2
AB1
Tube
1.1
S
S
K
4.5
S
PP
Res.
in
10
10
PP
PP
8BQ5
A
A
A
2.5
4.5
2.5
4.8
December, 1963
A
A
S
S
15
4
1.9
7.6
ABI
A
A
A
Ohms
10.0
0.02
4.5
10.0
0.3
PP
S
S
6V6 (GT)
10
8.4
AB1
S
S
S
PP
3.5
A
A
6N6-G
6N7
6R8
6SR7
6U6-GT
6V5-GT
11
16
20
S
6M5
5
3.2
PP
S
PP
6L6(G) (GA)
8
10
5.5
S
A
A
A
PP
8
6
8
10
11
8
ABI.
S
PP
606-G
6K6-GT
A
A
4.5
16
8
10
14
ABI
S
6E6
6EH5
1.5
S
PP
S
PP
6028
6
6F6 (GT)
F
6A6
6AB8
6AC5-GT
6AC6-GT
6AD7-G
6AE7-GT
6AG6-G
6AG7
6AH5-G
6AJ5
6AK6
6AK7
6AL6-G
10
5.5
8
5
6A3
6A5-G
60G6-GT
6DS5
.7
.2
A
B
25
6085
A
S
S
6CS5
6CU5
6CZ5
605G
S
S
S
S
S
14
PP
S
12
A
S
S
S
8
8
Al
S
S
6CL6
6CM6
2.5
S
S
12
25
A
A
A
A
6C A7
.2
A
A
10
25
3.5
AB2
PP
i
A
A
A
A
A
S
S
5CZ5
5V6(GT)
.1
.2
PP
S
5CM6
A
.1
S
S
3V4
3W4
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A
AB1
A
S
PP
2A5
B
A
A
Class
Use
6B5
68F5
6BF6
6815
6BK5
6BM5
6BM8
116-G(GT)
1LA4
1164
1N6-G(GT)
Tube
Pwr.
Out.
Watts
Laud
Loud
Load
Load
Pwr.
Out.
Watts
KT-88
PP
PP
PP
PP
PP
PP
PP
PP
PP
PP
PP
PP
PP
PP
PP
PP
PP
PP
PP
PP
PP
PP
PP
A#
AB1
AB2
A*
AB1
A*
A#
AB1
A*
A
AB1#
AB1#
ABI
AB1
AB1
AB
ABI
AB1
TRI
ABI
AB1
AB1#
ABI
A
PP
AB1
PP
A*
PP
AB1#
PP
ABl#
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AB1
PP AB1#
S
25.0
15.0
55.0
10.0
26.5
8.0
25.0
26.5
18.0
55.0
60.0
100.0
31.5
34.0
50.0
24.0
24.0
16.5
22.0
37.0
37.0
60.0
7.6
3
3.2
10
6.6
10
7.6
6.6
10
3.5
4.3
5
4.5
6.6
6
8
8
11
8
6.6
6.6
4.3
69.0
3.25
5.7
17.0
10.0
20.0
5.2
25.0
60.0
7.6
4.3
100.00
8
10
10
5
Pentode Operation
57
Technical curiosity can reap some satisfying rewards even
when it just involves solving a case with freak symptoms.
CASE OF THE BAD BYPASS
"
GUESS this knocks the props from under those furon-the-wooly-worms forecasters who said we wouldn't
see any cold weather until after the first of the year,"
Barney remarked as he hung up his heavy coat and started
rubbing his half -frozen ears. "It took me twenty minutes to
get my car started this morning."
"Here's just the thing to warm you up," Mac suggested,
sliding a playing little radio down the bench toward his assistant. "It's one of your jobs that bounced.-The owner admits
it now takes longer for the noise to start up after the set is
turned on than it did before; but once it starts, it's just as
bad as ever. The ticket says you replaced a noisy 12BE6
tube."
"I remember that set, and I'll swear the 12BE6 was bad!"
Barney exclaimed. "It was one of those jobs in which you
could trigger the noise on or off by flipping the envelope of
the tube with your finger nail. After I put in a new tube, no
amount of jarring produced any noise; so I made out the
bill -"
He was interrupted by a great crackling, frying sound from
the little receiver. Quickly he removed the back and struck
each tube in turn with a tube tapper. The noise was unaffected. "Guess it must be a bad i.f. transformer," he hazarded, reluctantly starting to pull the flimsy printed- circuit
chassis from the case.
But when the noise- testing probes of the signal tracer were
placed across each winding and between the windings of the
i.f. transformers, there was no indication of defective coils
or of leakage from coil to coil through the plastic in which
the coil- tuning capacitors were embedded. Similar tests revealed nothing wrong with the oscillator coil. Even when
Barney tried gently flexing the printed circuit board to see
if a break in a printed circuit lead might be causing the
trouble, the noise kept merrily grinding away.
Mac, who was aligning a receiver on his end of the bench,
noticed the noise from Barney's receiver was heard almost
as loudly in the set he was aligning. When Barney's set was
turned off, the noise disappeared from Mac's set.
"Whatever is causing that noise must be pretty close circuit -wise to where the line enters the set," Mac suggested;
"otherwise it wouldn't be feeding back into the line so
strongly. Try removing the capacitor that connects directly
across the input when the set is turned on."
Barney did, and instantly the noise disappeared. When the
capacitor was returned to the circuit, the noise returned. A
new capacitor produced no noise.
"That's a new one on me," Barney admitted. "The defective
capacitor feels pretty warm. It must have an intermittent
high -resistance leakage path through the dielectric. Probably
lightning caused it. The erratic leakage current doesn't start
until the capacitor reaches a certain temperature. That's why
I didn't catch it before. I was looking for one, not two, sources
of noise. Having found the noisy tube, I looked no further."
"I can't honestly criticize you too much this time," Mac
admitted. "I had that set playing a good forty -five minutes
before you came in, and it was as quiet as you could wish.
58
Furthermore, I can't remember seeing more than two or
three cases like that in all the years I've been servicing. It's
not uncommon to find a line bypass that makes an intermittent noise when it is tapped simply because the poor
connection between foil and lead is disturbed by the vibration; but this capacitor was soldered firmly to the printed
circuit, and vibrating it had no effect whatever. The leakage
path is inside the capacitor. Ordinarily the heavy line current
follows across any leakage path there and literally blows the
capacitor apart. Let the defective capacitor cool down, and
then we'll run some checks on it as we gradually warm it up
with a lamp. I'd like to know what's peculiar about it."
"I used to think I got all the odd -ball cases," Barney remarked; "but the other day I was talking to a technician
over at the parts store, and he came up with a really wild
tale. A man who lives at the edge of Cantorville to the west
of here was sitting on his front porch one evening last fall
watching a neighbor's dog frisking about the yard. The dog
happened to brush against a downspout that came down
alongside the porch, and immediately let out a howl of
anguish and went yelping for home as hard as it could lope.
The man walked over to the downspout to investigate, and
when he touched it he was almost knocked flat by an electric
charge.
"He called the electric company, and the electrician found
a full 120 -volts a.c. between the downspout and ground; yet
neither spouting nor eavestroughs came anywhere near any
wiring about the house. The electrician methodically began
pulling fuses and he soon discovered one line in the house
that killed the charge when its fuse was pulled. Next he unplugged things from that line one at a time, and when he
unplugged the TV set, the charge on the downspout was gone.
"The electrician suggested a TV technician be called to
see what was wrong with the set, and that's where my friend
came in. It didn't take him long to discover lightning had
shorted a line bypass capacitor between the hot side of the
line and the chassis. When this was replaced, the charge
disappeared from the downspout, and the receiver seemed
to work normally. It was supper time when the job was completed; so my friend packed up his tools and left.
`But that night he couldn't sleep. He lay awake trying to
figure out how on earth the 120 -volt a.c. was getting from
the TV chassis to the downspout. He reasoned it must have
something to do with the owner -installed TV antenna, for
he had noticed on the diagram that the center -tap of the
antenna coil was grounded to the chassis and that there were
no capacitors in the antenna leads. What's more, the antenna mast had not been grounded. But the closest the antenna lead came to the downspout or eavestrough was right
where the lead went through the wall and connected to a
lightning arrester; and that arrester was at least a foot away
from the downspout, and both were fastened securely to the
painted wooden siding.
"The next morning he went back to the house and asked
permission to do some more investigating on his own time.
To simulate previous conditions, he disconnected the antenna
ELECTRONICS WORLD
"...like switching
Come to think of it, this is a pretty good
way to describe PHOTOFACT. We
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SEE YOUR SAMS DISTRIBUTOR FOR FULL DETAILS, OR MAIL COUPON
CIRCLE NO 135 ON READER SERVICE PAGE
December, 1963
Zone
State
J
59
Popular ScieNce
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60
LOADS OF BARGAINS!
Dept. 1273
Phone: CAlumet 5 -1281
lead from the receiver and connected
it to the hot side of the a.c. line through
a 10,000 -ohm resistor. Sure enough, the
voltmeter revealed almost 120 volts on
the downspout. Looking very closely at
the lightning arrester, my friend thought
he saw a faint dark line beneath the
paint going over to a metal clamp that
held the downspout. When he carefully
scraped away a bit of the paint, he revealed a carbonized path burned right
into the wood leading from the arrester
to the clamp. Checks with an ohmmeter
revealed only thirty ohms resistance in
this path. When the arrester was replaced with a new one mounted at a
slightly different spot on the siding, the
downspout was cool as a cucumber.
What's more, TV reception was improved because signal pickup by the
eavestrough and downspouting fed into
one side of the lead -in had been messing
up the directivity of the antenna.
"My friend reasons the same flash of
lightning that knocked out the line bypass must have jumped from the arrester
to the downspout and burned the carbonized path into the wood. Possibly
lead in the paint smeared over the case
of the arrester made this jump easier.
Anyway, my friend claims he slept like
a baby the next night."
Mac nodded in agreement. "I know
exactly how he felt, and I like this friend
of yours. He has that most important
characteristic of a good technician, a
good engineer, or a good scientist: technical curiosity; and he's not afraid to
spend time and effort, with no prospect
of immediate monetary return, to satisfy
it. You used the phrase `on his own time'
to describe the investigation your friend
made into the puzzling case of the hot
downspout. In my book, every technician
worth his salt puts out a lot of effort
`on his own time' in his daily work. When
he encounters a puzzling situation in his
servicing, he's not content with merely
restoring the set to operation through
lucky accident. For his own peace of
mind he must try to find out why the
defective component made the receiver
behave the way it did, if there was any
reason for the failure of the component
that could be corrected, and if there
was any best way to pinpoint the trouble
should it be encountered again."
"Yeah, but aren't you going to be
griping because I'm not turning out sets
instead of educating myself at your expense?"
"Have I ever criticized you for following through on a puzzling service job?
It's not that I'm just interested in seeing
you satisfy your curiosity. I know that
each time you do this you improve yourself as a technician, and a really smart
and alert technician is worth three times
as much to me as a half -baked one capable of doing routine servicing and nothing more. You don't get smart by doing
service work mechanically. You have to
think and to wonder and to check and
to double -check until you know. Out of
this knowledge comes diagnoses that are
quicker, surer, and more accurate."
Mac had been replacing an FP filter
capacitor with an under -the- chassis cartridge type as he talked. After all the
unanchored connections were carefully
taped, he bundled the leads together
and wrapped some sort of flexible white
strap around them and cut off the excess
length.
"Hey, what you doing there ?" Barney
demanded.
"I'm using a Ty -Rap' manufactured
by the Thomas & Betts Company of
Elizabeth, New Jersey, to hold the wires
in place," Mac answered, tossing one of
the objects to Barney. "As you can see,
it's sort of a long, flat needle of nylon
shaped something like an old- fashioned
cut nail. There's an `eye' running crossways in the flat head, and a piece of
metal is embedded in this eye so that
when the tapered tail of the `Ty -Rap' is
threaded through the eye and pulled
tight around a bunch of wires, the loop
is locked solidly in place and the excess
tail can be snipped off with the diagonal
cutters.
"They are used in cabling in place of
lacing. They come in a wide variety of
shapes and sizes. Some of them have
provision for fastening each unit to a
chassis or board after it has been
wrapped around the wires. In addition
to these hand -installed units that I think
will be most useful in onr work, there
is another group designed to be installed
with a tool that pulls the `Ty -Rap' tight
around a bunch of wires, locks it in place,
and snips off the tail all in one operation.
These would be fine in production, but
I believe the hand-installed units will
come in quite handy for us in making
neater auto- radio, custom hi-fi, and other
installations where keeping wires fastened securely together and out of sight
adds to the appearance."
"It sure beats taping wires together,"
Barney agreed.
CHASSIS -PUNCH HINT
By JAMES L. HARTLEY
INSTEAD of using a wrench with a
chassis punch, clamp the head of a
bolt tightly in a bench vise, with the bolt
standing vertically. Next place the die
section of the punch on the bolt. Put
the pilot hole in the chassis on the bolt,
then screw the cutter section down with
your fingers.
Rotate the chassis until the hole is
cut through. Spin the chassis in the
opposite direction to screw the cutter
section off the bolt. Lift the die section
on the bolt until the cut -out washer is
just clear of the top of the bolt. The
tip of a screwdriver inserted in the pilot
hole then permits the sut -out to be removed easily.
ELECTRONICS
WORLD
HiFi tereo Review MODEL
STEREO TESTRECORD,
211
AND
HOME
FOR
O0A0N9TRATgN
EXTRA:
OF THE HIGHEST POSSIBLE FIDELITY. THIS RECORD INCLUDES A
AS A
TAPE PROCESS
PROGRAM 0F MUSIC RECORDED DNECTLY ON TIE MASTERNMTN NO INTERVENP G
NOW...GET THE FINEST
STEREO TEST
RECO RD
for
ever produced
just...$4.98
Featuring Tests Never Before Available
Outside Of The Laboratory
,
Model 211
Why We Make the
Available Now
Although there are many stereo test records on the mar
ket today, most critical checks on existing test records
have to be made with expensive test equipment.
Realizing this, HiFi STEREO REVIEW decided to produce
a record that allows you to check your stereo rig, accurately and completely, just by listening! A record that
would be precise enough for technicians to use in the
laboratory -and versatile enough for you to use in your
home.
The result: the HiFi STEREO REVIEW Model 211 Stereo
Test Record!
Stereo Checks That Can Be
Made With the Model 211
Frequency response -a direct check of eighteen
sections of the frequency spectrum, from 20 to
20,000 cps.
the most sensitive tests ever
Pickup tracking
available on disc for checking cartridge, stylus,
and tone arm.
Hum and rumble -foolproof tests that help you
evaluate the actual audible levels of rumble and
-
hum in your system.
Flutter -a test to check whether your turntable's
flutter
r
/
is low, moderate, or high.
-
two white -noise signals that
Channel balance
allow you to match your sys:em's stereo channels
for level and tonal characteristics.
Separation -an ingenious means of checking the
stereo separation at seven different parts of the
musical spectrum -from mid -bass to high treble.
Stereo Spread
ALSO:
Speaker Phasing
Channel Identification
UNIQUE FEATURES OF
MODEL 211 STEREO TEST RECORD
acoustics
Warble tones to minimize the distorting effects of room
checks.
-response
when making frequency
db from 40 to
Warble tones used are recorded to the same level within It
20,000 cps, and within ± 3 db to 20 cps. For the first time you can measure
chamber. The frequency
the frequency response of a system without an anechoic
limits of each warble are within 5 % accuracy.
White -noise signals to allow the stereo channels to be matched in
1
level and in tonal characteristics.
Four specially designed tests to check distortion in stereo cartridges.
Open -air recording of moving snare drums to minimize reverberation
when checking stereo spread.
All Tests Can Be Made By Ear
will give you immediate answers
STEREO REVIEW's Model 211 Stereo Test Record
It's the most complete test
to all of the questions you have about your stereo system.
on one test
record of its kind-contains the widest range of check -points ever included
made by ear!
disc! And you need no expensive test equipment. All checks can be
efficient design and
Note to professionals: The Model 211 can be used as a highly
to very close
measurement tool. Recorded levels, frequencies, etc. have been controlled
with test instruments.
tolerances -affording accurate numerical evaluation when used
Hifi
DON'T MISS
FILL IN AND MAIL TODAY!
Stereo Test Record
Electronics World -Dept. SD
One Park Ave., New York 16, N.Y.
Please send me
order) for
test records at $4.98 each. My check (or money
understand that you will pay the postage
fully guaranteed. (Orders from outside the U.S.A. add
is enclosed.
I
50c to partially defray postage and handling costs.)
The non -test side of this record consists of music recorded directly on the master disc, without going through
the usual tape process. It's a superb demonstration of
Address
December, 1963
$
-_
and that each record is
Name
demonstration that will
flawless recording technique.
amaze and entertain you and your friends.
OUT- SUPPLY LIMITED
new standard for stereo
The Model 211 Stereo Test Record is a disc that has set the
only a limited number
test recording. Due to the overwhelming demand for this record,
WORLD on a
are still available thru this magazine. They will be sold by ELECTRONICS
want to
first come, first serve basis. At the low price of $4.98, this is a value you won't
check ($4.98 per
miss. Make sure you fill in and mail the coupon together with your
record) today.
PLUS SUPER FIDELITY MUSIC!
A
Hifi /STEREO REVIEW'S
City
(Please Print)
State
Zone
SORRY -No charges or C.O.D. orders!
EW-123
61
ANOTHER REASON WHY HEATHKIT
SOLID-STATE` STEREO
NEW! AR -13 STEREO RECEIVER... only $1950°
2.
1.
.rlÌ°
3.
'
-at
4.
ammo
1111
6.
7.
4.
2.
Al
a
CD
o
i0
21.
.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
15.
Preassembled FM Front End
Individual AM and FM Tuning
AM Rod Antenna
Regulated & Electronic Filtered Power Supply
Tuning Meter
Transformer Operated Power Supply
Stereo Indicator Light
Input Level Controls
Illuminated Slide Rule Dials
Phase Adjust Control
Converter Balance Control
* 43
62
10. 11. 12. 13. 14.
16.
17.
12.
13.
14.
15.
16.
17.
18.
19.
9.
18.
16.
20.
Stereo Separation Control
FM Squelch Control
Level Balance Control
Phase Adjust Switch
AFC Switch
Local- Distance Switch
SCA Filter Switch
Noise Fiilter Switch
20. Speaker Phase Switch
21. Hinged Lower Front Panel
(conceals secondary controls)
Transistor, 16 Diode Cïrcuitry
ELECTRONICS WORLD
LEADS IN TRANSISTOR STEREO
TUNER -AMPLIFIER
FIRST IN KIT FORM!
ALL -TRANSISTOR AM-FM & FM STEREO TUNER PLUS
ALL -TRANSISTOR 40 -WATT STEREO AMPLIFIER -ALL
IN ONE SMART WALNUT CABINET FOR JUST $195.00
Now in time for Christmas giving, Christmas listening! Two
20 -watt power amplifiers...two separate preamplifiers...plus
wide -band AM, FM, and FM Stereo...all beautifully housed
in this one, compact Heathkit All- Transistor Stereo Receiver. For Heathkit this means another first! For you it
means experiencing the uncompromising realism of "transistor sound" in a handsomely styled receiver that won't
overheat...just the coolest, fastest, most "hum- free" operation possible! Just the purest, most "solid sound" possible!
This is the why of transistor stereo. This is why you should
move up to the new AR -13 Receiver. And the traditional
Heathkit economy makes this advanced performer easy to
own ... just $195.00
All the electronics you need for a complete music system
are "Heath- Engineered" into this handsome unit... just add
two speakers and a phonograph or tape recorder! And there's
plenty of advanced features to match the advanced performance of the AR -13. You'll like the way this unit automatically
switches to stereo, thus eliminating any manual operation.
In addition the automatic stereo indicator light silently signals when stereo is being received. For versatility there's
three stereo inputs (mag. phono and two auxiliary) plus two
filtered tape recorder outputs for direct "off-the -air" beat -
free stereo recording. Dual- tandem controls provide simultaneous adjustment of volume, bass, and treble of both
channels. Balancing of both channels is accomplished by a
separate control. The AM tuner features a high -gain RF
stage and high-Q rod antenna.
Other quality features include a local- distance switch to
prevent overloading in strong signal areas; a squelch control
to eliminate between-station noise; AFC for drift -free reception; heavy die-cast flywheel for accurate, effortless tuning; pin -point tuning meter; and external antenna terminals
for long-distance reception. For added convenience the
secondary controls are "out -of-the-way" under the hinged
lower front panel to prevent accidental system changes.
Building the AR -13 is quick and easy with the pre- assembled FM "front -end" and 3 -stage AM -FM I.F. strip, plus
circuit board construction. Styled in Heathkit's new low silhouette design, the beautiful walnut cabinet accented with
the extruded gold -anodized aluminum front panel makes the
AR -13 a handsome addition to any home decor. This Christmas, move up to the better listening of "transistor sound"
with the new AR -13 Stereo Receiver...another example of
superb Heathkit quality at unmatched savings.
$195.00
Kit AR -13, 30 lbs., no money dn., $19 mo.
SPECIFICATIONS- Amplifier: Power
Control; Phase Switch; Input Level Controls (all inputs except Aux, 2); Push -Pull ON /OFF
Switch. FM: Tuning range: 88 mc to 108 mc. IF frequency: 10.7 mc. Antenna: 300 ohm
balanced (internal for local reception). Quieting sensitivity: 2% uy for 20 db of quieting,
3% se for 30 db of quieting. Bandwidth: 250 KC @ 6 db down (full quieting). Image
rejection: 30 db, IF refection: 70 db. AM suppression: 33 db. Harmonic distortion:
Less than %. Multiplex: bandpass: ±% db, 50 to 53,030 cps. Channel separation:
30 db, 50 to 2,030 cps; 25 db @ 10 KC. 19 KC suppression: 50 db down, from output
KC. SCA rejection: 30 db.
KC. 38 KC suppression: 45 db down, from output @
@
output per channel (Heath Rating):
watts /8 ohm load, 13.5 watts /16 ohm load. 9 watts /4 ohm load. (IHFM Music Power
Output): 33 watts /8 ohm load, 18 watts /16 ohm load, 16 watts /4 ohm load @ 0.7% THD,
1 KC. Power response: j1
db from 15 cps to 30 KC @ rated output; ±3 db from 10 cps
to 60 KC ® rated output. Harmonic distortion (at rated output): Less than 1%
20
KC; less than 1% ® 20 KC. Intermodulation distortion (at
6,000 cps signal mixed 4:1. Hum & noise: Mag.
phono, 50 db below rated output; Aux. inputs, 65 db below rated output. Channel sepiaration: 40 db @ 20 KC, 60 db (d} KC, 40 db (d} 20 cps. Input sensitivity (for 20 watts
output per channel, 8 ohm load): Mag. phono, 6 MV; Aux. 1, .25 v; Aux. 2, .25 v.
Input Impedance: Mag phono, 35 K ohm; Aux. 1, 100 K ohm; Aux. 2, 130 K ohm.
Outputs: 4, 8, & 16 ohm and low impedance tape recorder outputs. Controls: 5- position
Selector; 3- position Mode: Dual Tandem Volume; Bass & Treble Controls; Balance
20 cps; less than 0.3°%,
®
t
rated output): Léss than
1°% 60 &
1
1
1
1
535 to 1620 KC. IF frequency: 455 kc. Sensitivity: 1430 KC, 3.5 uv;
1000 KC, 5 uy; 500 KC, 10
standard IRE dummy antenna. Bandwidth: 8 KC @ 6 db
down. Image rejection: 30 db @ 630 KC. IF rejection: 45 db @ 630 KC. Harmonic
distortion: Less than 1%. Overall dimensions: 17" L x 5%" H x 14 %," D.
AM: tuning range:
uy-
r
HEATHKIT-1964
NEW! FREE 1964 HEATH KIT CATfLOG. See the
latest new pr3ducts in
Heathkit's wide, wonderful line. Over 250 do-it yourself its for stereo/
hi -fi, ma-ine, TV, electronic organs, amateur
radio, test instruments,
educational, aid home
and hobty items that
will save yot. up to
50 %. Seni for your free
copy today!
HEATH COMPANY Benton Harbor 15,Michigan 49023
Li Enclosed is $195.00, plus postage. Please send Model No. AR -13.
Lip
Please send Free Copy of New 1964 Cataiog.
Name
Address
City
December,
1963
CIRCLE NO. 121 ON READER SERVICE PAGE
State
63
DUAL TRANSISTOR
IGNITION SYSTEM FOR
VOLKSWAGEN PORSCHE GHIA
MODELS FOR MOST OTHER CARS
AUDIO TRENDS
BRiTAIN
I\
By PATRICK HALLIDAY
PROVEN IN
50,000,000 MILES
OF DRIVING
BY OWNERS IN 50 STATES AND 14 COUNTRIES
THE
A rundown on some new high-fidelity
developments at the recent International
Audio Fair held in London.
RELIABLE
SYSTEM
Hermetically Sealed
Transistor Control Unit
Complete with
Bosch "Super" Coil.
$39.95 postpaid (U.S.)
GUARANTEED FOR LIFE
INCREASES: ACCELERATION
-
PASSING
ABILITY
EXTENDS: CONTACT POINT LIFE-USEFUL PLUG
LIFE -TUNE UP
INTERVALS
IMPROVES: COLD WEATHER STARTS
RELIABILITY
-
TECHNICAL DATA
Two High voltage heavy duty power transistors
Silicon diode plus suppression network
High impact epoxy resin sealed unit
DESIGNED FOR YOUR CAR!
Write for free data sheet
Specify make and model car
OFFERED FOR THE FIRST TIME ANYWHERE
SEND $1
FOR
SCHEMATIC PARTS LIST
& DO- IT- YOURSELF INSTRUCTIONS
ALL PARTS ARE AVAILABLE FROM AUTOTRONICS
AUTOTRONICS, INC.
43 Woodland Drive, Woodcliff Lake 7, N.J.
CIRCLE NO. 104 ON READER SERVICE PAGE
Converts home or car radios to receive Fire. Police, Aircraft. CB. SW.
etc. Excellent sensitivity on High
& Low Bands. High Band type adjusts to bracket 150 -160 MC. Low
Band type should be ordered for
33 -47 MC. 40 -52 MC. 26 -30 MC,
9 -12 MC. etc. Adaptable for tran-
sistorized car radios.
5-54 MC
$17.95
115-160 MC
18.95
Order today or sensi for free catalog on full line
of converters and receivers for every application.
315 -B
KUHN ELECTRONICS
CINCINNATI 17, OHIO
64
SOME 85 exhibitors from Britain, the
United States, Japan, and Continental Europe were represented at this
year's International Audio Fair in Loudon. Although relatively few completely
new ideas in hi -fi and tape equipment
were seen, a number of interesting
trends were noted.
The rooms in the average British
home are small by American standards
and the emphasis, except for the dyed in- the -wool audio enthusiast, is increasingly on fairly compact speaker units designed to provide a standard of audio
reproduction which a few years back
would have demanded bulky cabinets to
obtain.
Typical of this trend is the extremely
shallow Goodmans "Eleganzia" system
in a rectangular cabinet 27" high, 20"
wide, and only 63,1" in depth. This has a
12 -inch bass unit with a composite diaphragm using lightweight impermeable
cellular plastic, differing considerably
from the more familiar expanded polystyrene diaphragms. The voice coil is
unusually long to provide constant drive
conditions at high amplitude with a deep
roll center suspension. At 900 cps, a
crossover network transfers the audio to
an 8 -inch middle- and treble-range
speaker. Both speakers are sealed in the
enclosure so that the bass diaphragm
operates on an air cushion.
Wharfedale, the speaker firm founded
by Mr. G. A. Briggs, the well -known
writer on audio, also has a number of
slim cabinets. The firm has developed
roll surrounds which permit large cone
excursions and lower resonances which
are necessary as the cabinets are reduced
in size. The "Slimline 2" model is 25" x
20" x 7". Most of these speakers are
rated to handle 15 watts r.m.s.
Another miniature full -range speaker
system is the Kelly "Mini Enclosure,"
23" x 133&" x 7;ß", with bass and treble
speakers. This trend can be seen in the
lines of almost all speaker firms.
Transistor amplifiers are still rare in
Britain, but we listened with interest to
a good, fully transistorized integrated
stereo amplifier with 20 -25 watt music
rating (15 watts r.m.s.) per channel and
with no output transformer to impair
transient response. This particular unit
has been introduced by Pye, one of
Britain's largest radio firms, and sells
in Britain for about $185.00.
Lowther has similar master control
preamplifier units in both transistor and
tube versions, the transistor unit being
preferred for installations where space
and heat are important considerations.
An interesting feature of one of this
firm's massive power amplifiers (Model
LL15S) is the use of a cascode first
stage: this and the associated phase splitter are shown in Fig. 1. The low
noise and good linearity of the cascode
are often neglected in audio work, although we know of some tape recorders
using them. The low noise allows an
over-all hum and noise level of 85 db
to be achieved. Another unusual feature
in this amplifier is the use of -30 volts
of fixed bias on the output stage. The
same firm also features an FM tuner with
a zener diode automatic frequency control circuit.
A new type of phase -splitter was
noted in one of the Radford amplifiers. This circuit, Fig. 2, was developed recently by Mr. A. R. Bailey and
has attracted considerable attention
from British audio enthusiasts. It is a
modified form of the conventional directcoupled, long -tailed pair circuit with
plate -to -grid feedback reduced by the
use of a pentode in the first section.
-
Fig. 1. The cascode first -stage amplifier
and phase- splitter of Lowther amplifier.
22K
--vwwn--
-
NEGATIVE
FEEDBACK
ELECTRONICS WORLD
NEW! Low -Cost All- Transistor, All Mode
Stereo Tuner and Matching 40 -Watt
Stereo Amplifier
Cooler, faster operation .. lower power consumption ... longer life ...
.
and the clean, quick realism of "transistor sound." You'll enjoy all this
and more with Heathkit's newest All-Transistor Stereo "Twins." Compact, low -silhouette styling magnificently fashioned in rich walnut
cabinets neatly fits this handsome pair into a "proud place" in any
hi -fi stereo system. Add to this extruded brushed gold -anodized aluminum front panels that serve practically to conceal secondary controls
and decoratively to enhance over -all beauty. The AA -22 Amplifier provides 40 watts of continuous power at a-1 db from 15 to 30,000 cps with
no fading, no faltering ... just pure solid sound! The AJ -33 Tuner offers
selection of AM, FM, or FM Stereo to please any listening preference.
Check both unit's features and liscover why Heathkit leads in Transistor
Stereo. The price? A great value, you'll agree ... $99.95 each!
40 -watt Transistor
Stereo Ampli'Pr, 14 lbs.
$10 mo.
$99.95
AA -22
1Iillfli.
40 watts of pcver (20 per
5 stereo inputs
channel)
MiniaSpeaker phase sw
ture indicator light fir each posiTrans tion on mode swit :h
t
formerless
output
circuits
Brushed gold -anodized aluminum
front panel conceets secondary
controls
Walnu
cabinetry
Transistor AM -FM-
Ai -31
FM
$1.2
4
Stereo Tuner,
mo.
14 lbs.
$99.95
...
AutoStereo phase control
matic stereo indicator
AFC
Filtered stereo tape
and ACC
recorder outputs
Built -in
sterec iemodulator
Tuning
meter
Flywheel tuning
Prealigred FN
Slide -rule dial
tuner and circuit board con-
struction
Brushed gold -
anodized aluminum front panel
conceal; secondary controls
Walrut cabinet
r
NEW! FREE
1964 HEATNKIT CATALOG
latest new products in Heath kit's wide, wonderful line. Cver 250
do- it- yourself
kits for stereo /hi -fi,
marine, TV, electronic orgars, amateur radio, test instruments. educational, and hcme and hobby items that
will save you up to 50 %. Send for
your free cony today!
See the
HEATH COMPANY Benton Harborl5, Michigan 49023
__
plus postage. Please send model No
Enclosed is $
Please send Free Copy of New 1964 Catalog.
,
Name
Address
City
State_
-
L
December, 1963
CIRCLE NO. 121 ON READER SERVICE PAGE
65
Listening Tests Prove
220K
DYNACO BEST
Specifications are important, but present measurement standards do not fully define
how equipment sounds. High fidelity equipment has achieved its ultimate goal when it
delivers sound so realistic that skilled listeners cannot distinguish the difference between
"live" and "recorded" music in a side by side comparison. This test has been performed
dozens of times before thousands of people in programs sponsored by Dynaco, Inc.
and AR, Inc. with "live" portions performed by the Fine Arts Quartet. In these comparisons, Dynakit's superlative performance was amply demonstrated, since the vast
majority of the audiences readily admitted that they could not tell the difference
between the electronic reproduction using Dyna Mark III amplifiers and the PAS -2 preamplifier, and the "live" music by the Fine Arts Quartet.
Such perfection in reproduction means that listeners at home can have a degree
of fidelity which cannot be improved regardless of how much more money were to be
spent on the components used. All Dyna components are of a quality level which permits reproduction indistinguishable from the original. The unique engineering in all
Dynakits makes them fully reproducible, so that everyone can hear the full quality of
which the inherent design is capable. Dynakits are the easiest of all kits to build-yet
they provide the ultimate in sonic realism.
z
-An outstanding stereo FM tuner featuring
automatic transition to stereo with the visual
Stereocator. The FM-3 is a super -sensitive drift -free
tuner with less than 0.5% distortion at all useable signal levels, four IF stages, wide -band
balanced bridge discriminator, and time -switching
multiplex system.
FM -3 kit $109.95; assembled $169.95
-35- Combined stereo preamp and amplifier
with low noise, lower distortion, and 17.5 watts
continuous power per channel. Distortion less than
1% at full power from 20 to 20,000 cycles.
Unique feedback circuitry throughout.
SCA -35 kit $99.95; assembled $139.95
SCA
-The
famous "no distortion" PAS -2 stereo
preamplifier with a new look. Wide band, lowest
noise, with every necessary feature for superb
reproduction. Less than 0.1% distortion at any
frequency.
PAS -3 kit $69.95; assembled $109.95
-A
35
basic power amplifier similar to
that used in the SCA -35. Inaudible hum, superior
transient response, outstanding overload characteristic, and extremely low distortion at all
power levels. Fits behind PAS -3 or FM -3.
ST 35 kit $59.95; assembled $79.95
STEREO
-
70-A superlative power amplifier
continuous 35 watts per channel with unconditional stability and near -perfect transient response. Frequency response extends below 10
cps and above 40,000 cycles without loss of
STEREO
stability.
ST
70 kit $99.95; assembled $129.95
ASK YOUR DEALER FOR A DYNA DEMONSTRATION
Write for detailed specifications and descriptive literature
DYNACO INC.
3912 POWELTON AVE.
PHILA. 4. PA.
Cable: DYNACO Philadelphia
66
CIRCLE NO. 112 ON READER SERVICE PAGE
uT
Fig. 2. Triode- pentode phase splitter used
in Radford amplifier to reduce the feedback.
FM -3
PAS -3
--
8.2 K
i
A number of domestic tape recorders
using tubes have a low-noise transistor
as the first preamplifier stage; this is
partly because of their low noise and
partly because of the reduction in microphony. Our eye was also caught by a
neat and attractive all- transistor stereo
unit from Siemens Norge of Oslo, Norway. Equipment from such countries as
Germany and Switzerland is often outstanding in its clean modern cabinet
styling -Braun of Frankfurt /Main providing several notable examples.
Among the larger professional recorders for broadcasting was one by EMI
claimed to be world's first with a reversible head block to meet both the
British-American standard for tapes
wound with the oxide surface on the
inside and also the continental European standard which puts the oxide
surface on the outside.
Austrian engineers of A.K.G. have developed a special "polarscope" unit for
measuring the directional characteristics
of transducers such as microphones. A
turntable unit and the transducer are
placed in an anechoic chamber and remotely controlled from a cathode -ray
display unit which provides an immediate picture of the directional characteristics of wave emitting and receiving
transducers.
Multiplex stereo broadcasting, using
the Zenith -G -E system, has been tested
during recent months in Britain and in
a number of other European countries.
This technique is now known officially
as the "pilot- tone" system. Although the
trials have been favorable, there seems
little likelihood of any regular FM stereo
broadcasting in Europe in the near future. One of the main reasons advanced
for this reluctance to transmit stereo is
that in European countries the FM networks have usually been designed to
provide almost complete coverage of the
countries, and the reduction in transmitter range with "pilot- tone" stereo
would thus deprive some listeners of
programs during stereo transmissions. A
ELECTRONICS
WORLD
This New Feature - Packed 1964 Model Of The HEATHKIT
2 Keyboard "Transistor" Organ Costs Just $349.95.. .
AND YOU CAN BUILD IT!
What a delightful surprise on Christmas morning! And there's endless
hours of fun, relaxation, education and achievement ahead for the
whole family with Heathkit's 1964 version of the famous Thomas
Organ. You'll be saving big money too, by easily building it yourself! No
experience necessary! And you're assured long, faithful performance with
the full 5 -year warranty on tone generators. Can't play a note? Learn quickly
and easily with a complete 48-lesson self- teacher course on 4 LP records
it's yours for only $19.95! Like to
(GDA-232 -2) that's valued at $50
hear it perform? Send 50c to the address below, and ask for demonstration
record GDA-232 -5. Plan now to give your family the exciting dimension of
live music with the 1964 Heathkit Electronic Organ this Christmas!
...
Kit GD -232R, Organ,
160
lbs., no money dr., $23 mo
GDA- 232 -1, Matching walnut bench,
16
lbs., no money dn., $5 mo..
Attention Heathkit Organ Owners! Add Variable
$349.95
... $24.95
Repeat Percussion to your
Heathkit Organ with the easy -to- install kit.
GDA- 232 -4,
1
only
lb
HEATHKIT CATALOG
See all the latest products in
Heathkit's excrtiig line. Over
259 do- it- yoursdf electronic
kits in all ... by far tie world's
largest line! Ther's something for every nterest . . .
stereo /hi -fi . . . marine .
amateur radio .
test and lab
. television
. Some
and hobby. Seed for your free
copy today, and I ear how you
can save up to st %.
...
L
December, 1963
WITH UNITS COSTING
TWICE AS MUCH!
*
True Organ Voices; Trom-
10
bone, Reed, Flute, Oboe, Cornet,
Violin, Saxophone, Horn, Viola, DiaNew! Variable Repeat
pason
Percussion; produces effects of
banjo, marimba, mandolin, balalaika,
Variable Bass Pedal Voletc.
*
*
ume Control * Manual Balance
Control; adjusts volume of keyboards
Variin any degree for solo work
Standard Expresable Vibrato
sion Pedal; adjusts volume from soft
13 -Note Heel & Toe Bass
to full
Two Over -Hanging
Pedals
Keyboards; each with 37 notes,
Beautiful Walnut
range C thru C
Cabinet; modern styling, hand rubbed, hand -crafted * 20 -Watt
Peak -Power Amplifier & Speaker
Compact Size; 341/2" H x 39'/" W
Transistorized; for
x 21%" D
longer life, better tone, trouble -free
operation.
*
*
*
*
*
*
*
Ii3EDA.TI3;KZ,7*°
by D?4!aiw'e+r..
NEW! FREE
1964
$9.95
COMPARE THESE FEATURES
0
Enclosed is 5349.95, plus postage, please send my rleatrnit
Electronic Organ, model no.
GD -232 R.
HEATH COMPANY, Benton Harbor
Name
GDA-232 -1.
Address
Please send my tree copy of
the new 1964 catalog.
City
Michigan 49023
(please print)
Enclosed is $24.95, plus postage, please send matching
walnut bench, model no.
15,
Zone
State
J
CIRCLE NO. 121 ON READER
E
VICE
PAGE
67
TEST N
EQUIPMENT
111:ssr1iar
úÌÌÌi
j1Ì
%t1rl /ls
PRODUCT REPORT
la
neighborhood TV -audio service shop.
One of the most recent instruments
-the RCA WV-76A high- sensitivity
a.c. v.t.v.m.- symbolizes the design
trend toward higher performance and
lower cost. Because it is .a vacuum -tube
voltmeter, the WV -76A has many inherent advantages. Included are protection against meter burnout, high input
impedance to minimize test -circuit
loading, wide frequency response on
a.c.-voltage measurements, very high
sensitivity to low signal levels, excellent
stability, and -of primary importance
good over -all measurement accuracy.
These features enable the service
technician to troubleshoot and adjust
almost any audio component, such as
phono cartridges, tape heads, preamplifiers, power amplifiers, tone control and
mixer circuits, and audio networks of all
types. The instrument is also an invaluable aid in balancing stereo channels
and determining the frequency response
of circuits and systems.
Three basic functions are provided:
(1) a.c. voltage measurements from
0.0002 volt (lowest scale division) to
100 volts in nine overlapping ranges;
(2) direct decibel readings from -40 to
+40 db in nine ranges for measuring
stage or over -all amplifier gain; and (3)
an auxiliary amplifier function having
38 -db gain. This last feature makes the
WV -76A usable as a flat -response pre-
RCA WV -76A A.C. V.T.V.M.
For copy of manufacturer's brochure,
circle No. 58 on coupon (page 15)
.
-
FOR years, the audio voltmeter has
been restricted to the designer's
bench or sound studio by specialized
applications and "laboratory" prices.
Today's tremendous hi -fi market, however, has brought audio servicing -and
the audio voltmeter -right into the
8V
23
VIA
6BK7A
84
J1
1C2
4
INPUTI
)
/--5 -25
C6
SOME-.
I's
9
J3
R7
680
MEG.
330
¡CND.
RB
C9
R9
R501
OUT
C7
3.3K
-0
J2
6V.
RI
I
RS
6BK7A
?
R28
47K
V
C3
VI
B
V2A
SIC
2MF
130v.
15
V28
6AN8
1112
6AN8
68K
2
8.9MMP
WG
-3008
PT
RII
DIRECT/ LOW -
I
CAPACITANCE
PROBE
C10
2
HEG.
R13
SK
RIO
=110OM
RIT
3.24K
-
R14
ISO
R16
1020
130V.
RIB
10.26
CRI
IN876
87
40MF
REAR SECTIONS OF ALL SWITCHES ARE VIEWED
FROM FRONT WITH THE SWITCH SHAFT IN EXTREME COUNTERCLOCKWISE POSITION.
ALL VOLTAGES MEASURED TO GND. WITH A HIGH IMPEDENCE
VOLTMETER,
R2S
CR3
IK
3.3K
C118
o
CITA
-40MF
'
404F
200V.
o
CR4
RED
HU
MF B 1.0 B
0
3. FRONT B
68
I
4 CRC
ALL RESISTANCE VALUES ARE IN OHMS EXCEPT AS NOTED.
2. CAPACITANCE VALUES LESS THAN I.O ARE IN
ABOVE ARE IN MMF EXCEPT AS INDICATED.
4
CR2
150V 150V.t
NO:
TES
I.
R24
R23
3.3K.
R20
1.58
6BI:TA
GAN
g
ILK
¡it
amplifier for low -gain audio systems or
oscilloscopes. All readings are taken
from a 4i2" meter having only two basic
scales.
Frequency response-a limiting factor
with most a.c. voltmeters -is flat within
1 db from 10 cps to 1.5 megacycles.
Full -scale instrument accuracy on all 18
voltage and decibel ranges is ± 5% or
better -which is more than adequate
for general service and laboratory use.
A contributing factor to high performance is a switch -type direct /low-capacitance probe and shielded cable. In the
low-C position of the probe switch, the
WV -76A presents 10 megohns of input
resistance shunted by only 13 pf. of
capacitance. The low- capacitance function also extends the voltage and decibel
ranges to 500 volts and +56 db.
Four stages are used for maximum stability and sensitivity. The input signal
is fed into a cathode follower, VIA
(see figure) . Voltages from 3 to 100
volts are passed through a precision
attenuator ahead of VIA. On the 10millivolt to 1 -volt ranges, the signal is
attenuated between VIA and the first
amplifier stage, V1B. The a.c. output
from V1B is further amplified in V2A
and fed to the second cathode follower,
V2B. The output is then applied to a meter through a half- bridge circuit. A feedback loop from the meter circuit to the
first amplifier stage provides additional
stability and linearity. Heavy filtering in
the power supply and a hum- adjustment
potentiometer in the tube -heater circuit
effectively eliminate hum.
The optional user price for the factory -wired version of the instrument is
$79.95. It is also available in kit form
at an optional user price of $57.95.
Prices include the probe.
Simpson Model 261 V.O.M.
For copy of manufacturer's brochure,
circle No. 59 on coupon (page 15).
ANEW multi-range v.o.m., the Model
261, has been introduced by Simpson to answer the need for a more accurate, moderately priced instrument. The
meter has a sensitivity of 20,000 ohms
per volt on d.c. and 5000 ohms per volt
on a.c. Its accuracy is 1I% or better of
full scale for d.c., and 3% or better of
full scale for a.c. On the lowest current
range, the accuracy is that of the movement itself -1%. The accuracy of the
meter makes it more useful for design
work where exact values must be determined rather than just an indication
that the parameter under test is "about
normal." The instrument has the usual
a.c. and d.c. voltage ranges, as well as
d.c. current, decibel, and resistance
scales.
An interesting feature of the Model
261 is the built -in overload protection.
As shown in the schematic, the moveELECTRONICS
WORLD
Introducing The FIRST In A New Series of
Deluxe Heathkit SSB Amateur Radio Gear!
r
-J
Performance
New SB -300 SSB Receiver With Quality Features &
Found Previously On Units Costing Twice as Much ... Only $264.95!
Complete coverage of 80
Professional styling & features at 60% savings!
through 10 meter amateur bands with all crystals furnished, plus provision for
VHF converters
Prebuilt, calibrated linear master oscillator (LMO) 25 KC
per tuning knob revolution offers bandspread equal to 10 feet per megacycle
Stability of 100
2.1 KC crystal bandpass filter
Built -in crystal calibrator
cps after initial warmup Wiring harness & two heavy -duty circuit boards for
easy assembly
w
SPECIFICATIONS -Frequency range imeacycles):
3.5 to 4.0. 7.0 to 7,5, 14.0
to 14.5, 21.0 to 21.5, 28.0 to 28.5, 285 to 25.0, 24.0 to 29.5, 29.5 to 30. Intermediate
frequency: 3.395 megacycles. Frequency stability: 100 cps after warmup. Visual
dial accuracy: Within 200 cos on all bsndc. Electrical dial accuracy: Within 400
cps on all bands. Backlash: No more than 11 cp-.. Sensitivity: Less than microvolt
for 15 db signal plus noise.to.noise -etio 1, SSB operation. Modes of operation:
Switch selected: LSB, USB, CW, AtvM, Selectivity: SSB: 2.1 k.c at 6 db down, 5.0 kc
at 60 db down (crystal filter supplied;. AM: `".75 nc at 6 db der: n, 10 kc at CO db down
(crystal filter available as accessory). C W:440 c :s a" 6 db down. 2.5 I c at bd db down
(crystal filter available as acces-.<iv'. Spurious response:
rejection
better than 50 db. Internal sp..
-nut of
1
-
microvolt. Audio response: SSB:
Cps nominal at 6 db. CW: 800 to
pedance: 50 ohms nominal. Muting,
1
AM: ":. to 3500
Antenna input imrna. grourl :'
Crystal calibrator: 100 kc cy.tri Front panel controls: Main I-n'
aeon
switch; mode switch; !.(_,_0: AF gain control; RF pain control: pre$elector; phone j'.
Rear apror'. connections: Accessory power oleo: HF
antenna; VHF I/1 antenna, VIIIt; spare; antptrro: 500 ohm; F ohm
speaker; line cord socket: heterodyne os::3etcr output; LMO output; BFO output;
VHF converter switch. Tube complemerrt: (1) 68Z6 RF amplifier; (1) 6ÁU5 Heterodyne miner; (1) 6AB4 Heterodyne oecilatnr; (11 6AU6 LM ose.: (1) 6AÚ6 LMO mixer;
(2) 6BA6 IF amplifier: (1) 6AÚ6 Crysta, calibrator (1) 6HF8 1st audio, aucho output;
(1) 6AS11 Product detector. BFO, amotifio-. Power supply: Transformer operated
:with silicon diode rectifiers, Power regeirements: 120 volts AC, 50/60 cos. 50
palls. Dimensions: 1431,- W x 654' H 12'Ç D.
tnai
at
6 o:
The SB -300 SSB Receiver is the first in an exciting new series of Heathkit SSB
amateur gear designed to bring you the finest in communications facilities at
great savings. Its professional styling, quality and features offer performance
never before found in kit equipment.
Features include a crystal -controlled front -end for same rate tuning on all
bands; prebuilt, Linear Master Oscillator (LMO) for linear tuning with 1 kc dial
calibrations; built -in crystal calibrator; hermetically -sealed 2.1 kc crystal band pass filter; smooth, non -backlash vernier dial drive mechanism; optional AM
& CW filters; high frequency I.F.; AGC control; provision for transceive operation with matching transmitter available soon. This new deluxe Heathkit SSB
series is the greatest value ever announced in the Amateur Radio Industry! Send
for free specifications on the SB-300 today, or order now for early delivery!
Kit SB- 300...17 lbs....no money dn., $25 mo.
SBA -300 -1 CW Crystal Filter (400 cps)...1 lb.
SBA -300 -2 AM Crystal Filter (3.75 kc). .1 lb
$264.95
$ 19.95
$ 19.95
WATCH FOR ANNOUNCEMENT OF OTHER MODELS IN
THIS DELUXE HEATHKIT HAM SB SERIES I
X
r
FREE CATALOG!
HE rtTH,t1T-199.4
Send for your free copy
today! Fully describes
over 230 exciting Heath kits al sle,riegs of 50% or
morel' C-oese fr3m the
world's lirgestselectien
of quality hem gear .. .
"Mobie`
.
-
.
"Fixed"
and Accseories.
December, 1963
HEATH COMPANY, Benton Harborl5, Michigan
Please send FREE 1964 catalog. Q Enclosed is $
Please send model
49023
,
plus postage.
Name
Address
City
CIRCLE NO. 121 ON READER SERVICE PAGE
Zone
State
J
69
If you're willing
to pay anything for
professional quality
but would rather not
The Concertone 605 is for the one man in several who can't stand
less than perfection ... but can't see why professional quality should
cost so much. Never before have so many features and so much professional quality been available at this price. Read ahead carefully
and see: Precision plug -in head assembly... includes four precision
heads Separate microphone and line controls (input can be mixed)
Delay memory control circuit (never spill or break tape) ; Automatic
glasstape lifters, including electric cue feature; Sound on sound and
;
add sound; Solenoid operated brakes; Three motors, including
2 -speed hysteresis synchronous drive Automatic rewind; Exclusive
Reverse- O- Matic®. Learn all about the 605 in complete detail. Ask
your dealer for a demonstration or send for free literature today.
;
CONCERTONE 607
Broadcast version
The Concertone 607 with higher
impedance is for the true professional
or broadcaster. Remote control
optional. This superb tape recorder
is constructed to 19" x 14" dimensions,
permitting it to be used as
an exact replacement for old or
outdated tape recorders.
ment has a resistance of about 2000
ohms and a full -scale sensitivity of 50µa.
Therefore, at full -scale deflection, the
voltage drop across the movement will
be about 0.1 v. The movement overload
protection is provided by the diode
connected (in the forward direction)
in parallel with the movement. As shown
in the graph, essentially no forward
current will flow through the diode
when rated current passes through the
movement. If an overload of 2000 times
rated (100 ma. ) is applied to the metering circuit, most of the current will flow
through the diode. With 100 ma. of
diode current, the voltage drop across
the diode and across the movement will
be 1.02 volts. This means that the movement will have a current of 510 µa. flowing through it. Thus, with an applied
overload of about 2000 times, the movement is subjected to an overload of only
10 times rated. This small overload will
not cause damage to the movement even
if applied continuously.
The Model 261 also includes a mirror
scale and knife -edge pointer to insure
highest accuracy of reading. For example, because of parallax, it is quite
possible that the indicated reading
might be displaced 1/le" from the true
reading. This small reading error cor-
CONCERTONE 400 COSMOPOLITAN
COMMO^I
For people on the go...it's the Cosmopolitan
- Combination Tape Recorder with AM
Radio. A versatile companion and co-worker
for business or pleasure travels. 5" reel
capacity. Push -button operation. Amazing
fidelity. Remote mike. Foot-pedal control.
This all- transistorized recorder has big
recorder features in miniature form.
for further
information
write:
e
Export: J.
70
AMERICAN CONCERTONE, INC.
A
DIVISION OF ASTRO- SCIENCE CORP.
9449 W.
D. Marshall
JEFFERSON BLVD. CULVER CITY CALIF.
International, 170 W Washington, Chicago, Illinois
CIRCLE NO. 101 ON READER SERVICE PAGE
c-
ELECTRONICS WORLD
says
you can't
afford
Who
Color TV?
You Can With This New Heathkit
High Fidelity 21" Color TV Kit For As Little As
27 tube, 8 diode circuit
with optional UHF High
definition RCA 70° 21"
color tube with anti -glare,
bonded face safety glass
Built -in dot generator for
initial set -up adjustments
All critical circuits factory- builtand tested AuGated Automatic Gain Control for peak
tomatic Color Control
performance Hi -Fi sound with outputs for speaker and hi -fi amp
24,000 volt regulated picture power
Deluxe Nuvistor tuner with
"push -to- tune" fine tuning for individual channels 3 -stage high
Line thermistor for longer tube life and thermal
gain video I.F.
circuit breaker for component protection Can be custom mounted
Degaussing coil for
or installed in handsome walnut cabinet
demagnetising picture tube
SEND F31 FREE
HEA1HKIT CATALOG
I description and specifications 3f units above, plus 245
Test, Amateur Radio,
others
Hi -Fi, Maine, Educational and
1964
Gives fu
i
General H3bby fields of interest.
Send for y)ur free copy today and
get the c3rnplete story on money-
saving
l-
athkits.
$34900
The sharpest, clearest high fidelity picture and sound, plus the latest advanced
Color TV circuitry possible in the industry today! Unmatched savings . . .
compare it with sets costing $600 Easy
to build ... from parts to picture in just
25 hours and no experience needed
These are the reasons why you'll be
wise to choose the new Heathkit 21"
Color TV.
!
!
Kit GR -53, Chassis
& all
$349.00
$49.00
$20.00
tubes, 118 lbs., $23 mo.
GRA -53 -1, Walnut- finish cabinet,
70 lbs., $5 mo.
UHF Tuner, GRA -53 -2, 3 lbs...
HEATH COMPANY, Benton Harbor
Please enter my order for
a
15,
Mich. 49023
Heathkit Color TV Kit subject to condi-
tions below*
Please send FREE copy of 1964 Heathkit Catalog.
Name
Address
State
City
*Delivery Limited by tube availability send no money until we confirm shipping
date. Orders processed in sequence of receipt.
CL -164
December, 1963
CIRCLE NO. 121 ON READER SERVICE PAGE
-
_
71
Now you can get the
1964
PHOTOGRAPHY
DIRECTORY
& BUYING GUIDE
For up -to- the -minute news on virtually all the products on the photo
market, get the 1964 Photography
Directory & Buying Guide.
It covers: still cameras
flash equipment
movie cameras
still and movie projectors
still and movie films
lighting equipment
exposure meters
darkroom equipment
responds to a reading that is off by 1.71%
of full scale. Since 1.71% is greater than
the d.c. accuracy of 1.5 %, it is obvious
that it is essential that parallax errors
be minimized by use of a mirror scale.
Although generally not recognized,
the Model 261 (or any 20,000 ohms per
volt v.o.m. ) has a higher input impedance on the 1000 -volt d.c. range than
most v.t.v.m.'s. The input impedance on
this range is 20 meg., which allows reading voltages in very high impedance circuits. Since each division on the range
corresponds to 20 volts, it is possible
to read voltages as low as about 10 volts
on the 1000 -volt range with virtually no
circuit -loading effect.
In addition to the features mentioned
above, the meter uses a self -shielded
movement that is not affected by outside
magnetic materials or fields. Spring backed jewels are used so that the movement will withstand greater shock and
vibration without damage.
The Model 261 measures 5)I" x 7" x
3)á" and weighs 3)§ lbs. It is available at
$59.95 from electronic parts distributors.
tape recorders
The 1964 Photography Directory &
Buying Guide is only 75Q. Available at
your favorite newsstand and camera
store or enclose your payment (plus
15C postage and handling) and mail
to: Ziff -Davis Service Division, Dept.
PD, 589 Broadway, New York 12, N.Y.
(Add 4% sales tax if N.Y.C. resident.)
Eltec Model 600
Frequency Standard
For copy of manufacturer's brochure,
circle No. 60 on coupon (page 15).
NEW
Los Angeles Plant
Now Filling
West Coast
Orders
$215,4
EACH
Citizen Band
Class "D" Crystals
-
TEXAS
-
CITIZEN BAND CLASS "D" CRYSTALS
3rd overtone
.005. tolerance
to
meet all FCC requirements. Hermetically
sealed HC6 /L" holders. 12" pin =gracing.
.050 pins. (Add 15e per crystal for .003
ett /U
pins).
23
26.985,
27.075.
27.162,
All
megacycle frequencies in stock: 26.965, 26.9
27.005. ::.1115. _7.
2 7.11:35. 17.055. 27.0
27.085.
27.175.
2
Matched crystal sets for ALL CB units (Specify equipment
make and model numbers)
.$5.90 per set
.
RADIO CONTROL CRYSTALS
in HC6 /U HOLDERS -SIX FREQUENCIES
In .stork for immediate delivery (frequencies listed In
me^ncycles,: tolerance .005',. 1._" pin spacing.
.(t7,0 pin diameter (.003 pins available, add 15C per
ystal.i specify fremienry d,c
26.995, 27.045, 27.095, 27.145,
S
27.195, 27.255.........,.......
(add SC per crystal for postagehandling)
IF YOUR PARTS DEALER DOESN'T STOCK Texas Crystals.
order direct ami send us his name.
¡r.
RUSH
95
Z9á
TWO PLANTS TO SERVE YOU
YOUR ORDER NOW TO CLOSER PLANT
Y+TEXAS
CRYSTALS.V.
Div. of Whitehall Electronics Corp.
Dept. R -123
1000 Crystal Drive, Fort Myers, Florida Ph. WE 6 -2109
4117 W. Jefferson Blvd., Los Angeles, Calif.
Area 213 Phone 731-2258
FOR SHIPMENT VIA FIRST CLASS MAIL AT NO EXTRA
COST ATTACH THIS ADVT. TO YOUR ORDER!
72
order to take accurate measure of receiver and transmitter frequencies, some sort of frequency standard is required. The Eltec Model 600
combines the principles used in a heterodyne frequency meter and a highly
accurate crystal calibrator in order to
check frequencies in the 25- to 54 -mc.
range. Hence, the instrument can be
used to accurately set the frequency
of Citizens Band equipment and lowband equipment operating in the two way radio service. The accuracy of the
instrument is .0002 percent, exceeding
FCC requirements by five times. The
unit can also be used from 10 kc. upward
in amateur radio applications, such as
in checking 100 -kc. calibrators and spotchecking frequencies up to 54 mc.
Heart of the instrument is an accurate
100 -kc. crystal, which is mounted within a thermostatically controlled oven
to maintain its temperature and its operating frequency. Although highly stable,
it is suggested that the circuit be
checked against «'WV regularly to
make sure of its setting. A built -in audio
N
1 ments
detector, amplifier, and speaker are used
in order to respond to the beat note
generated by the instrument's oscillator
mixing with the output of a transmitter.
When receiver circuits are to be adjusted, it is common to use the receiver's
audio circuits for this purpose.
In addition to the 100 -kc. output of
the instrument, four other oscillator frequencies are available that are locked
to the 100 -kc. crystal oscillator. These
are 10 kc., 20 kc., 25 kc., and 50 kc. As
a result, harmonic frequencies are generated that are separated from each
other by 10, 20, 25, 50, or 100 kc. Since
all assigned frequencies in the 30 -50
mc. two -way radio band are exactly
divisible by 20 kc., all receivers and
transmitters in this band can be set and
aligned to their exact frequencies with
the Model 600 set to its 20 -kc. output.
Since the crystal trimmers in commercial
transmitters cannot vary the frequency
by more than about 5 kc., there is no
chance of reading the wrong harmonic.
In the Citizens Band, however, most
frequencies are not exactly divisible by
any of the above frequencies. To cover
these channels, the instrument's deviation control is adjusted. This permits
the user to select any frequency between two of the locked -oscillator harmonics. Deviation dial settings for these
intermediate frequencies are shown in
an individually hand -calibrated chart
supplied with the unit. Hence, it is not
necessary to use mathematics or interpolations.
The Model 600 is available from the
manufacturer at $349.95.
REVISED STANDARDS
THE Defense Electronics Supply Center has announced the availability of
nine new and revised specifications and
standards which received approval in
July. All of the documents listed below
can be obtained from the Naval Supply
Depot, 5801 Tabor Avenue, Philadelphia, Pa.
MIL -E -1/89 Revision C: Electron
Tube, Receiving, JAN- 5787WA (for
BuShips).
MIL -E- 1/1333 Revision C: Electron
Tube, Receiving JAN-7266 (for BuShips) .
MIL -E- 1/639, Revision C: Electron
Tube, Receiving JAN -12AY7 (for Buships).
MIL -E -1 /940, Revision E: Electron
Tube, Receiving JAN -OB2WA (Equivalent to JAN -6627) (for BuShips).
MIL -E- 1/1225, Revision A: Electron
Tube Receiving Pentode, Miniature
JAN-6688 (for BuShips).
MIL-E-1/1416, Revision A: Electron
Tube, Receiving JAN -6900 (for BuShips).
MS 24655, Revision B: Switch, Toggle, Miniature Aircraft, Single Pole, One
Hole Mounting (for USAF).
MS 24656, Revision B: Switch, Toggle, Miniature Aircraft, Double Pole,
One Hole Mounting (for USAF).
ELECTRONICS WORLD
,
BOOK
REVIEWS
..
yr,
,
.y4:z
;
i
ry
`--
TEST INSTRUMENTS" by Rufus P. Turner.
Published by Holt, Rinehart and Winston, Inc. 287 pages.
Price $5.95. Revised Edition.
Since the first edition of this book appeared in 1953, many
new pieces of test equipment have entered the repertoire
of the service technician while others have faded out of the
picture. In revamping his text, the author has acknowledged
the trend by eliminating obsolete units and adding the newer
instruments.
As was the case with the earlier volume and, in fact, with
all of this author's output, the presentation is clear, factual,
and easy to understand. He avoids the mathematical approach and eschews basic radio and electronic theory because
it is to be assumed that the reader is somewhat familiar with
the field.
The text is divided into 17 chapters dealing with simple
meters for current and voltage, ohmmeters and v.o.m.'s, electronic voltmeters, power meters, impedance checkers, capacitance checkers, inductance checkers, special -purpose
bridges and accessories, oscilloscopes and applications, r.f.
test oscillators and signal generators, audio test oscillators,
frequency -measuring devices for r.f. and a.f., audio- amplifier
testing devices, r.f. signal tracers, tube and semiconductor
testers, and miscellaneous instruments. Each type of test instrument is described in detail and commercial examples and
circuits are given.
NEW !
"BASIC ELECTRONIC
0
o
a
Tepper. Published by
John F. Rider Publisher, Inc. Two volumes. 204 pages total.
Price $5.30 (2 vols.)
The idea back of these two volumes is to present radio
servicing techniques as they would be practiced in a commercial radio shop. The first volume covers the test equipment most likely to be found in the non -specialized shop,
the various components encountered in radio receiver circuits,
servicing procedures, and the actual servicing of superhets,
portables, and auto sets using tubes.
The second volume is devoted to the servicing of FM receivers, transistorized receivers of various types, and transmitters.
In both volumes, line drawings, pictorials, cartoons, and
schematics have been included to illustrate basic points.
For the experienced hand at servicing, much of the material will be familiar but there are still some interesting shortcuts to servicing that might surprise even the oldest of
old- timers.
"BASIC RADIO REPAIR" by Marvin
.
o
0
16 -WATT HEATHKIT STEREO
OPERATES
AMPLIFIER
WITH MAGNETIC PHONOGRAPH CARTRIDGES; DE.
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LIVERS FULL POWER WITHIN
1 DB FROM 30 TO 30,000
CPS; HAS FULL -RANGE CONTROLS, 4 STEREO INPUTS,
2 FOUR -STAGE PREAMPLIFIERS, 2 PUSH -PULL POWER
OUTPUT STAGES; PLUS NEW
MOCHA BROWN, BLACK &
SILVER STYLING; AND IT
COSTS JUST $39.95! COMPARE AND ORDER NOW!
SPECIFICATIONS -Simultaneous power output per channel: 8 watts (16
watts total); IHFM music power output per channel; 10 watts (20 watts
total). Frequency response: ±1 db from 30 cps to 30,000 cps at rated
output. Harmonic distortion: (at rated output) 2% @ 20 cps, 0.7%
1000 cps, 2% @ 15,000 cps. Intermodulation distortion: (at rated output) Less than 3% using 60 and 6000 cps, mixed 4:1. Hum & noise:
Mag. phono input 48 db below rated output. Aux input, 65 db below
rated output. Channel separation: 42 db @ 30 cps, 45 db @ 1000 cps,
30 db @ 15,000 cps. Input sensitivity: Mag. phono, 6 mv; Ceramic
phono, 250 mv; Tuner, .25 V; Aux. .25 V. Input impedance: Mag. phono,
47 K ohm; Ceramic phono, 2.2 meg.; Tuner, 470 K ohm; Aux. 470 K
ohm. Outputs: 4, 8, and 16 ohm. Damping factor: 9. Feedback: 18 db.
Tube complement: 3-6EU7 and 4-ECL -86 (6GW8). Power requirements:
105 -125 V. 50.60 cps AC. 85 watts at 120 volts. Dimensions: 131/2" W
x4.11 /16 "Hx91/2 "D.
o
"ELECTRONICS IN BUSINESS MACHINES" by Tom Jaski. Published by A. S. J3arnc.xv Company. 306 pages. Price $5.95.
This book has been written for the layman and the student
of electronic data processing. It is not a service handbook nor
is it an operating instruction manual, rather it is an over -all
survey of the general operating principles of data -processing
machines in industrial automation.
The first chapter traces the history of calculating devices
of various types and deals with present -day applications of
these different types of computers. A second chapter covers
arithmetic and the common languages of business machines
and computers while the balance of the text covers the means,
December, 1963
.
HEATH COMPANY
Benton Harbor 15.Michigan 49023
Enclosed is $39.95 plus postage. Please send
model M -32 16 -Watt Stereo Amplifier (15 lbs.).
Please send my Free copy of the 1964 Heathkit
catalog.
FREE 1964
HEATHKIT CATALOG
See the entire exciting
array of the latest in do -it-
yourself electronic kits
from the world's largest
manufacturer ...Heathkit.
Over 250 In all!
Name
Address
City
State
Zip No
CIRCLE NO. 121 ON READER SERVICE PAGE
73
methods, and equipment involved in this important field.
Photographs and partial schematics of commercial units are
used throughout the book to point up specific details of the
text. For the layman weak in electronic theory, the author has
provided an appendix covering basic electronics and another
listing the basic glossary of computer technology.
Visit
the largest annual
worldwide exhibition
in the electronics field
from February 7th to 12th, 1964
Paris (Port de Versailles)
INTERNATIONAL
ELECTRONIC
"MORE ABOUT LOUDSPEAKERS" by G. A. Briggs.
Distributed
by Hernian Publishing Service, Inc., Stamford, Conn. 134
pages. Price $2.50.
This is an up -dated volume by the erudite and delightful
author of "Loudspeakers," "Sound Reproduction," among
many books in the hi -fi field.
Although he loudly proclaims that this is a book for the
music lover and layman, there are many professionals who
will benefit from his guided tour of the speaker world. As all
of Mr. Briggs' long -time readers know, instruction is painless
at his hands. Pixy humor, outrageous puns, and sly asides
pepper the text which nevertheless provides basic and vital
information about magnets, response and impedance curves,
transient response, distortion, load matching, outboard speakers, crossover networks, listening tests, stereo, enclosures,
grille cloths, various types of speakers and their performance,
plus a fine selection of reference material in tabular form.
"GETTING STARTED IN ELECTRONICS" by Allied Staff. Published by Allied Radio Corp. 109 pages. Price 50 cents.
Since many people who have no intention of making engineering their life work are still interested in certain phases of
electronics as an avocation, hobby, or as a means of keeping
the old homestead in tip -top shape, this little handbook is one
approach to a simple, clear, and easy understanding.
There are six chapters which provide not only basic theory
and information about components, but offer practical instruction on building ten everyday projects.
n
o
e
"HIGH -SPEED SWITCHING TRANSISTOR HANDBOOK" by Mo-
COMPONENTS SHOW
torola Staff. Published by Motorola Semiconductor Products
Inc. 346 pages. Price $2.50.
This handbook combines detailed design procedures for
saturated -mode, current -mode, and avalanche -mode switching circuits with complete device characterization and switching- transistor reliability.
This volume characterizes the behavior of transistors in
switching circuits and interprets device characteristics from
the standpoint of optimizing switching performance in
"worst- case" designs.
A separate chapter is devoted to reliability from the circuit
designer's viewpoint and explains methods of enhancing
over-all system reliability by proper circuit design.
o
All components, tubes and
semi -conductors. Measuring
and control apparatus,
electro- acoustics.
For information
and
literature contact
SDSA 23, rue de Lubeck
Paris 16e -Phone FAssy 0116
74
CIRCLE NO. 117
ON
READER SERVICE PAGE
e
e
"TV SERVICING METHODS GUIDEBOOK" by R. G. Middleton.
Published by Howard W. Sams & Co., Inc. 158 pages. Price
$2.95.
This volume is a collection of specially developed and
tested short cuts that the author has garnered in his many
years of practical experience with television receiver circuits.
He has dubbed his system "self-cheks" -and involve simple
yet efficient methods of using one section of a TV receiver to
check another. Thus by utilizing signals generated in one section of a receiver, visual or aural indications will help pinpoint defects in another section.
The book is made up of troubleshooting charts, step -bystep "self -chek" instructions, schematic diagrams, and photos
of the symptoms. The text material is merely supplementary
and has been held to a minimum in the belief that the technician at his bench doesn't have time to read lengthy explanatory material while the set cooks.
As a key to quick and easy television troubleshooting and
repair, this volume may do the trick for the busy electronics
service technician.
ELECTRONICS
WORLD
TECHNICAL
PERSONNEL
SHORTAGE
By 1970 we will need more than
2 million scientists and
engineers, up 90% from 1959.
ACCORDING to researchers for the
National Science Foundation, the
United States will not have enough technically trained personnel in the year
1970 to satisfy the expected needs of
industry and government. More than 2
million. scientists and engineers, for example, will be needed in 1970, an increase of 90 percent above 1959 employment levels, but the universities will
probably train only a little more than
700,000, the researchers predict.
A similar shortage is also predicted
for the other types of technically trained
personnel. These predictions are included in the "Proceedings of the Conference on Progress in Nuclear Education," recently published by the U.S.
Department of Commerce.
Demands for trained technical personnel in general have been rising at a
much more rapid rate than the increase
in the labor force, the researchers point
out. Our labor force has grown by 23
million workers, or approximately 50
percent since 1930, while the various
technical workers as a group have increased from 3.3 million to 7.4 million.
or more than double their number. The
demand for engineers alone increased
four-fold, while the demand for natural
scientists increased more than six times
by the end of the 30 -year period.
Present and future demands for scientists and engineers and other technical
workers are largely created by the Federal Government research and development programs, that is, for defense,
space, and atomic energy. About 65 percent of the estimated $15- billion expenditures for research and development in
1962 was financed by the Federal Government, requiring 65 percent of all the
technical personnel employed.
Currently more than 800,000 engineers are employed in the United States,
more than twice the number of scientists
employed. The demand for scientists,
however, has been growing more rapidly than the demand for engineers.
Eighty-three percent of the engineers
and 50 percent of the scientists are employed by industry, mostly in production
and research and development work.
Fourteen percent of the engineers and
20 percent of the scientists are employed
by the government. Most of the others
are employed in the universities.
December, 1963
CAVITY
GENERATED
SSPH
RIICCÄL
SOUND is Everywhere!
These people are enjoying an exciting new principle in sound reproduction.
Everyone is
receiving a uniform intensity of program material from this single Murray -Tone Cavity Generator
Spherical Sound System regardless of his relative position or distance from the instrument!
r
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True 360° spherical propagation is but one of the unique principles built into this quality
instrument and offered to the listener for the first time from a single sound source.
-
"CG's" spherical principle and compact design encourage complete flexibility of
placement
even under or behind furnishings
without disto'tion of performance in
either monaural or stereo application.
The use of a single driver in Murray -Tone "CG" systems produces balanced,
Sound with a new dimension of timbre, presence and response.
frrdurir,g
CAMILLE
full -range
í
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z
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rh.'
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Size: 11 "x8 "x41/4" -Full Frequency Range (without boom).
Power: 8 Watts (measured).
Propagation: 360 Spherical Degrees.
OPTIONAL FINISHES:
OILED WALNUT, HARVEST MAPLE OR LIMED OAK
Moderately Priced at $39.95
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INDIANA
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CIRCLE NO. 147 ON READER SERVICE PAGE
75
How
'
sq. ft. can speed up your picture -tube service:
10 versatile "Universal" picture-tube types from Sylvania's
SILVER SCREEN 85 line may be all you need to fill 52% of
your renewal needs! This fact, verified by a recent industry
survey, stems from a remarkable streamlining of the
Sylvania line- making fewer, more versatile types that can
be used as replacements for many others. Already 54
types can replace 217.
Think what the versatility of these 'Universal" tubes
can mean. An in-shop inventory of
a few popular types can
help you quickly take care of most of your renewal calls.
Ordering is simplified...and distributor calls for special
tubes can be cut way down.
Start profiting now from Sylvania's SILVER SCREEN 8.5
picture tubes. Call your Distributor and put an inventory in
your own shop -where it can enhance your reputation for
fast service and quality replacements.
SILVER SCREEN 85 Picture Tubes are made only from new parts and materials except for the
envelopes which, prior to reuse, are inspected and tested to the same standards as new envelopes.
76
ELECTRONICS WORLD
use
it for SILVER SCREEN
85., tubes...
(10 "Universal" types meet half of all renewal needs)
The "Big 10" Tubes that till
52% of all renewal needs:
21CBP4A)
21ZP4B
21ACP4A
21YP4A
21EP4B
21FP4C
24AEP4
21DFP4
21AUP4A
21DEP4A
December, 1963
24%
41%
52%
YLVAN
SVBSIO/'RY OF
fNEgA'L
(GENERAL
TELEPHONE & ELECTRON/CS
77
Indoor Horn Antenna
(Continued from page 51)
TWO -WAY RADI
and the nose block by 3/16 machine
screws, nuts, and washers. These provide contact for feed to the receiver.
Fig. 3 (left) shows the completed antenna in position in an attic area.
commun.icufione equipment
VHF-FM FURr
MOINE
RCRRE!
AMINE
VHF AEI FOR:
VHF
*MOAT
ANTENNAS
VENICLE{
GROUND SIANONl
REMOTE C
SO1N,T04O1Nr
AccusOEI
MOIORCICLE
PORTABLE
SASE
Transmission Line
COMCO
"ON GUARD" 24
HOURS A DAY
DEPENDABLE
COMCO
TWO -WAY RADIO
EQUIPMENT
USED EXCLUSIVELY
BY THE CITY OF
CORAL GABLES,
FLORIDA FOR
PAS- 15
YEARS
The 377 -ohm antenna impedance will
not be seriously mismatched if the usual
300 -ohm twin lead is used. The loss will
be about 1.3% in power or .06 db in
addition to the attenuation due to the
length of the line itself.
Reduction of interference due to manmade electrical noise will, in many instances, dictate the use of coaxial cable
for antenna to receiver connection. This
1P1 PINE FURRING
CARPET
o
TACKS
BRONZE SCREEN
MENDINE
PLATE
A SPECIALLY DESIGNED DISPATCHER'S CONSOLE
PROVIDES EFFICIENT, INSTANT CONTROL OVER
4 RADIO CIRCUITS.
BRACE
Police messages are dispatched to patrol cars,
motorcycles, police boats, and other vehicles over a
150 Mc mobile relay system of advanced design. A
310 ft. antenna height on relay transmitter provides
40 mile car-to -car communications. Two -way or
three-way versatility by selection at control console.
11
ELEVATOR
COILS
VERTICAL SUPPORT
2) A Local Government frequency for fire trucks,
rescue squads, electrical trucks, and other maintenance and official vehicles.
COAXIAL
The Inter -City circuit on 155.37 Mc has special
relay provisions permitting messages from other
communities in Dade County to be simultaneously
re- transmitted to Gables police vehicles enabling
each mobile unit to receive direct county -wide
broadcast.
CABLE
3)
4)
Fig. 4. Construction details of the
A completely independent stand -by base station
for Police and Local Government frequencies is located several miles
from main repeater station.
For MI details, write today!
This high performance system includes four base stations, 80.
mobile units. three portable base stations. Eleven new COIMCO
Model 900 mobiles with all- transistor receiver will soon be added.
ee
MT,
DESIGNERS
FOUNDED 1938
RADIO COMMUNICA TIONS EQUIPMENT
ND MANUFACTURERS OF
CO1IIaNI
Ub1ICATIONs
MIAMI 34, FLORIDA
CORAL
GABLES,
,
Inca
name
ND
ELECTRONICS WORLD
EVERY
HLTimiirs\01.1(1
address
city
zone
state
MONTH
Check one,
nCLri9ESTRUMENiarCS.831tr9L1AANN
3 years for $12
2 years for $9
I year for $5
In the U.S., and possessions.
Payment enclosed
Bill me
Foreign rates: Canada and Pan American Union
countries, add 500 per year; all other foreign countries, add $1.00 per year.
f]
New
Mail to:
Dept.
78
1
will require impedance matching at
both the antenna and the receiver. An
antenna -to -coax match, which is close to
ideal, can be obtained by using RG62/U cable with a characteristic impedance of 93 ohms and a four -to -one
matching network employing bifilar antenna matching coils. This transformer
network or balun is shown in Fig. 5.
The matching coils, also known as
elevator coils, are RCA Part No. 73591
or equivalent (Merit Coil and Transformer Corp. TV -172 or J. W. Miller
Co. No. 6104) . The match from cable
to receiver, 300 -ohm impedance, is accomplished by the use of an identical
network. In this case the mismatch 93
ohms to 300 ohms rather than 377 ohms
will be found to be negligible in effect.
The horn illustrated is currently being used for reception of channels 5, 9,
and 12. For cut -off below channel 5, the
dimensions should have been 7 feet on a
side. Attic dimensions limited the height
to 4 feet. A trial of this size of antenna
.
CIRCLE NO. 110 ON READER SERVICE PAGE
SE
apex.
Renewal
ELECTRONICS WORLD
-1211, 434 S. Wabash Ave.
Chicago 5, III.
at the receiver indicated that picture
quality was satisfactory on this channel
and that objectionable ghosts could be
eliminated on all channels. A similar
compromise of dimensions for reception
of low-frequency channels has also been
ELECTRONICS WORLD
APEX
by a simple two -pole, multiple- position
switch at the receiver. In many instances
the combination of a horn with a single channel yagi will suffice.
An alternative method of construction
which has been suggested involves the
use of overlapping strips of aluminum
cooking foil taped to large sheets of
wrapping paper for the triangular metallic sides.
If the antenna is to be mounted in an
attic or other place where it would not
be exposed to wind loading, then solid
metal sheets of either aluminum or copper flashing material could be used.
The author wishes to thank E. J. H.
Bussard of Aveo, E & O Division, for his
helpful advice in the preparation of this
article.
OF
BI- SECTORAL
HORN
ELEVATOR
COILS
SEE TEXT
-J
r-
RG62 /U
REFERENCES
COAX
Z
=93
OHMS
1.
Barrow, W. L.
Electromagnetic
Jan. 1939
&
The Sectoral
Horn," Proc. of the I.R.E.,
Lewis, F. D.:
Barrow, W. L. & Chu, L. J.: "Theory of the
Electromagnetic Horn," op. cit.
Morgan, D. O.: "Horn Antennas for Television," Electronics, October 1951
An Experimental Investiga4. Rhodes, D. R.:
tion Of the Radiation Patterns of Electromagnetic Horn Antennas," Proc. of the I. R. E.,
September 1948
5. Risser, J. R.: "Microwave Antenna Theory &
Design," Vol. 12, Radiation Laboratory Series,
McGraw -Hill Book Co., Inc., 1947
6. Kraus: "Antennas," McGraw -Hill Book Co.,
Inc., 1950
7. Schelkunoff, S. A. & Friis, H. T.: "Antennas,
Theory and Practice," John Wiley & Sons, Inc.,
2.
Fig. 5. The antenna -to- coaxial line matching network is a 4:1 balun transformer.
3.
previously discussed by D. O. Morgan.3
While the foregoing discussion has
been concerned with an application in
which all three desired stations were
within the 20- degree included angle of
the reception pattern of a single horn,
the use of two or more horns for complicated patterns can be accommodated
8.
-.
Fill in coupon for a FREE One Year Subscription to OLSON ELECTRONICS FanUnheard
tastic Bargain Packed Catalog
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If you have a friend interested in electronics
send his name and address for a FREE subscription also.
CITY
OLSON
ELECTRONICS,
INC.
642 Forge Street, Akron, Ohio 44308
1952
Terman F. E.: "Electronic and Radio EngineerCIRCLE NO. 131 ON READER SERVICE PAGE
ing," McGraw -Hill Book Co.. Inc., 1955
GREGORY ELECTRON ICS
Top Loaded Antenna
With Built In Rugged Efficiency
Spectacular Savings
THIS IS A PARTIAL LIST-WRITE FOR NEW 63 CATALOG
LINK 6000 NW SERIES
25 -50mc 20F3 Emission -Fully narrow
banded (Tx and Rx), 12
volt, 50 watt. Complete with all accessories, less crystals and
Loading coil embedded within the
antenna.
$168
Add $40 for crystals, tuning and brand new antenna -ready to go on your
fiberglass laminate
frequency.
30 -50mc MOBILES -GE
4ER6 -4ET5 30w 30.40mc
4ER6 -4ET6
Inner core of parallel glass
fibers
2 -Piece
-6
Unit
volt or
12
volt
$ 98
40 -50mc
60w 30 -40mc
40-50mc
$108
Complete with all accessories except antenna and crystals.
Equipment can be crystalled and tuned to any frequency in the 30 -50mc
band.
$ 198
volt or 12 volt
GE 2 -Piece Unit
4ER6 -4ET5 30w 30 -50 me
-6
$208
{
Outer core of
parallel glass fibers
Compare the Versatile VIP -Style 173
-with any other top loaded antenna.
There's no vinyl to crack or craze. The
exclusive Columbia Products fiberglass construction produces an antenna of superior strength that withstands impact and flexing, forms a
natural barrier to static precipitation,
won't corrode.
The VIP can easily be used for any
frequency between 27mc and 55mc
simply by trimming the tip with a fine
tooth hacksaw or triangular file.
COLUMBIA PRODUCTS COMPANY
STYLE 173
SHAKESPEARE CO.
CIRCLE NO.
December, 1963
SUBSIDIARY, COLUMBIA,
S. C.
4ER6-4ET6 60w 30- 50mc
Complete with all accessories including antenna and crystals. Fully narrow
(Tx A Rai and tuned to your frequency within the 30.50mc range.
MOTOROLA 30 -50mc T -51GGD or T -51AGD
6/12v 50 -60 watts -Fully narrow banded (TX and RX). Complete
with all accessories, less crystals and antenna
Same unit tuned to your frequency including brand new an.. ...
....
tenna, ready to be installed.
(This unit may also be bought without accessories for $198.1
........
RCA 25 -54mc CMF40
watts- Vibrator power supply. Fully narrow banded.
Complete with all accessories, less crystals and antenna.
Same unit tuned to your frequency including brand new an6/12v 40
..............................
(Same unit without accessories. $165.1
tenna, ready for installation
RCA 148 to 172 me
CMC30 (Vibrator Power Supply) -6/12 volt, 30
watt. Complete
with all accessories less crystals and antenna. Wide band
Fully narrow banded (transmitter and receiver)
$ 95
1
$235
$ 168
$198
Add $35.00 for crystals, tuning and antenna. Ready for Installation.
GE
150-170 LOW POWER INDUSTRIAL
$ 18
4ES20A2 -6/12 volt, 1 watt, complete with all accessories
WIDE BAND
Add $15.00 for crystals and tuning of the receiver only, thus making it a
compact and highly sensitive monitor receiver. Weatherproof cases for these
units are also available for $15.00.
OR reoaV
We Buy Late Model Equipment For Cash
Write; Wire or Phone!
-
GREGORY ELECTRONICS CORPORATION
Phone 773 -7550
Saddle Brook, N.
Area Code 201
rpl
109 ON READER SERVICE PAGE
........
$228
$268
249 Rt. 46
CIRCLE NO.
J.
151 ON READER SERVICE PAGE
79
HUM INTERFERENCE
CAR RADIOS
M cso
ELECTRON
I\
TUBE
FABULOUS LOW PRICES!
LARGE SELECT STOCKS!
DEPENDABLE, FAST SERVICE!
By DAVID T. GEISER
Nearby high- voltage power lines can sometimes
produce an a.c. hum in a car radio. An r.f. choke
across antenna input will usually cure trouble.
Each and every tube is tested In our
own laboratory for mutual conductance and life test.
We guarantee FREE replacement for
one year of any tube purchased from
IONALLY, power companies
received complaints of interference to auto radios, which on investigation have not been on radio frequencies. The car antenna has picked up a
strong 60 -cps field and carried it into
the a.v.c. system of the receiver, creating
severe hum. The usual cause of this difficulty is that the control grid of the radio
r.f. stage has a low 60 -cps impedance
to the car radio antenna and a high imOCCASOCCASIONALLY,
Which fails
under any or
tianS. Prompt
any defective
to function efficiently
all operating condirefunds are made on
merchandise The advertised tubes are not- necessarily new, but may be electrically
perfect factory seconds
or used
tubes -each is clearly so marked.
Us
H.V.
POWER LINE
GANG- TUNING
024
52e
10701 57307
303G7 5Y46
1H40 657
1N5GT 658
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6007
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SMs
203
6Á58
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3BC5
GAGS
31308 640701
3826 GARS
3CB6
6055
30F6
GA76
3C56
6478
3LF4
6AU407
304
640507
354
6AÚ6
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6640
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6C6
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6CF6
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6006
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627 6AN6
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6AX4GT 62607
5478 64X5GT 607
SAW4 6138
6113
6806
5807 6005
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6117
578
5U40
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5V40
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VBGT
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676
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6W407
6W6G7
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645
628
SISO
7A4 /%EL
705
724
1348
12AQ5
12A76
120T7
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12687
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707
748
704
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755
7B6
737
704
7C5
706
707
7E6
7E7
7F7
776
7147
757
2513Q6
25056
25L66T
25W4GT
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2526
26
35AS
3565
35C5
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3574
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39/44
42
45
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43
1216
1207
12547
5045
5085
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901pyf.
RI
470K
ANT.
TRIM
.05yf.
Fig. 1. Power line frequency can be capacitance- coupled to car radio antenna.
SOCS
5OLSCT
50X6
I35J7
125117
12555707
125G7
127607
12W607
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56
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75
76
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80
7X7 /XXFM 19
7Y4
19AU4GT
117234
11726
ALL TUBES SENT POSTAGE PAID. Please send 35C
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P.O.
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37
SEND FOR OUR FREE COMPLETE LIST OF TUBES
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MICRO
BODY
TO
GND.
pedance to the car frame. The first grid
usually has the a.v.c. voltage applied to
reduce strong signal levels, so when
60 -cps voltage appears on it, the received signal will be amplitude modulated by the 60 -cps frequency. This
amplitude modulation will appear as a
hum on a received signal, with the set
being quiet between stations. The actual
circuit existing in one such case of interference is shown in Fig. 1. The effective
power -frequency circuit is shown in Fig.
As the difficulty is caused by power
feeding into the car antenna through a
high -impedance circuit, the simplest
cure is to make the receiver input look
like a short circuit at power-line frequencies.
This may be done by shunting the
receiver input with an r.f. choke having
high impedance to broadcast frequencies but low impedance to power-line
frequencies. There is one precaution to
be taken when choosing the choke.
Every coil has inductance, capacitance,
and resistance. The inherent inductance
and capacitance of the coil will have a
tendency to misalign the receiver input
circuit. Ideally, a choke having a very
high inductance should be chosen to
minimize this effect, but the distributed
capacitance of this choke would be high
and the effective self-resonant frequency
would be lower in frequency than the
broadcast band. In this case, the choke
might look like a capacitance and reduce
the net sensitivity by reducing the signal level that the antenna can present
to the radio. If the resonant frequency
is higher than the broadcast band, the
CA
H.V.
POWER
LINE
ELECTRON TUBE CO.
Box 55 Park Station, Paterson
The reason that all power lines do
not cause this difficulty is that some
power line construction is such that
GET
nearly equal capacitance is presented to
INTO
the car antenna by each of the individual power lines and voltage reaching
V.T.I. training leads to success
as technicians. field engineers.
the antenna by capacity coupling from
specialists in communications,
guided missiles. computers. one line is cancelled out by the coupling
radar and automation. Basic & from the other line.
advanced courses in theory &
laboratory. Electronic EngiWhere this does not occur, there is
neering Technology. an ECPD
accredited Technical Institute a power -frequency voltage fed into the
curriculum. Assoc. degree in car radio. If the power line is
a high 29 mos. B.S. also obtainable.
G.I. approved. Graduates in all
voltage one (10,000 v.), and the car anbranches of electronics with
major companies. Start Feb., tenna is fully extended, more than a
Sept. Dorms, campus. High volt of the 60 -cps frequency may
be
school graduate or equivalent.
Write for catalog.
developed at the first grid with the car
located thirty feet away from the power
VALPARAISO TECHNICAL INSTITUTE
line. This will cause a hum to appear
Dept. RD, Valparaiso, Indiana
even on a strong local station.
3,
N.J.
Fig.
cuit
CIRCLE NO. 152 ON READER SERVICE PAGE
ELECTRONICS
l1
Effective power frequency cirappears like a signal generator.
2.
inductive effect will also misalign the
set. The best choice appears to be a
choke whose resonant frequency is at, or
slightly higher than, the broadcast band.
A National R- 100ST, a 10- millihenry
choke, has been successfully used by
the author and seems to be a natural
choice because of its small diameter.
Two mounting precautions must be
observed. The choke must be mounted
where it will not couple inductively into
other coils and it must be mounted with
lock washers. Thus installed, the r.f.
choke has completely cured receiver
power -line hum with minimum re -alignment and signal loss.
80
-
ELECTRONICS WORLD
CIRCLE NO.
136 ON READER SERVICE PAGE->
EXTRAVAGANCE?
Scott uses heaN.y, oversized output transformers
on their amplifiers and tuner /amplifiers. Most manufacturers settle for lightweights, as little as ha f the
iron found in Scot' equipment. Is this extravagEice?
Scott feels the Extra dollars put into jumbo output
transformers is an absolute necessity! Jusi listen
all
to the solid, clear bass response you get
Scott amplifiers and tuner /amplifiers. To obtain this
kind of bass you need power and lots of it in the
vital low frequency range. And to get this extra power
you must have big, heavy, oversized transformers
like the ones you find on all Scott
froi
amplifiers (even _he budget - priced
Model 200B.)
ycu find big transformers, conservatively rated components, and electrolytic aluminum chassis (for
coclest operation and low hum) on all Scott equip me- t.With Scott equipment you make an investment
in years of trouble -free listening Enjoyment.
Scott extravagances can be found in the powerful
80 -watt 299D and the modestly priced 48 -watt 222D,
as well as the previously mentioned 200B. They can
be found on all Scott Kits. Visit your favorite h -fi dealer for a demonstration or circle the number below on
the information card bound into the magazine, and
Scott will mail you complete information on all their quality products.
Scott never economizes on per formance or reliability. That's why
H. H. SCOTT,
INC.,111 POWDERMILL RD., MAYNARD, MASS.
299D 80-wait Stereo Amplifier $229.95
Price=_
sl ghtly higher west of Rockies
Export: Morhan Expcrting Corp., 458 Broadway, New tcrk, N. Y.
Canada: Atlas Radio Corp., 50 Wingold Avenue, Toronto.
Two -Way Radio
(Continued from page 53)
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CIRCLE NO. 116 ON READER SERVICE PAGE
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NAME
StATE
82
B
morning, the dispatcher opens the base
station again and regains control of the
system.
Another use for the basic mobile relay
system is for a one-way talk -back circuit.
Such an arrangement, shown in Fig. 2,
could be used where the base station is
in a high noise area (where reception
from distant mobiles is difficult) or
where the base station r.f. power has
been made considerably higher than that
of the mobiles to achieve wide area basestation coverage. In either case, a mobile relay repeater station can be used in
a one -way network to boost the signal
strength of mobile -to -base messages.
Three frequencies are usually used in
such a system with the mobile relay
transmitter operating on a point -to-point
frequency, beaming its energy back to
the base-station receiver. The base station is usually equipped with a second
receiver tuned to the mobile transmitter
frequency so that close-in mobiles can
talk directly to the base station without
having to go through the mobile relay
repeater station.
The final variation on the mobile relay
theme is the shared, or community repeater system. This type of system is
enjoying increased popularity with business radio users because each user has
the advantages of mobile relay operation
at a cost well below that of a privately
owned repeater network. It is used primarily in large cities in situations where
the user desires complete metropolitan
coverage including, possibly, reliable
suburban communications.
The basis for the shared repeater is a
system of tone -coded squelch discussed
in Part 1. Each user is assigned a different code tone and every radio set in his
sub- system is squelched until the proper
tone is received. The repeater station is
unsquelched by any of the code tones
operating in the system, but the individual radio receivers remain squelched until the correct tone is received. Because
of the tone-coded squelch system, each
user ordinarily hears only the messages
originating within his own portion of the
system, although several users are sharing a common repeater station. A typical
setup is shown in Fig. 3.
The dispatcher for each of the subsystems has a locally controlled, low powered base station that beams the
message to the repeater usually located
atop a tall building in the center of the
city. The code tone unmutes the repeater
receiver and automatically causes the encoder at the transmitter to remodulate
the outgoing signal with the same code
tone. The code tone is regenerated at
the repeater, rather than being fed directly through from the repeater receiver, to minimize distortion and there-
fore assure accurate unsquelching and
minimize "falsing" at the mobile or dispatcher receiver.
This discussion of the basic types of
radio systems by no means exhausts the
variety of networks possible. The various
systems can be still further combined
and their versatility can be increased
with the addition of other techniques
such as selective -signalling equipment,
multiple base -station antenna sites, and
so forth.
Remember, too, that a large variety of
highly reliable portable equipment is
available which can be combined with
the basic two -way radio systems to further enhance the services of a communications network. Each individual system
is a separate, highly interesting challenge. It can be made to do virtually any
communications job required by the
two -way radio user.
The Loudness Control
(Continued from page 35)
1 from one curve to the other.
It requires no compensation since it does
not change at various levels. )
Assuming we can build a control with
the characteristics of Fig. 2, how do we
use it? Simply set the level control so
that a program sounds as loud as the
original with the loudness control wide
open, after which we need adjust only
the loudness control to obtain natural
sounding reproduction at any level we
wish.
You may have been following along to
this point saying, "This is great for 80 -db
programs, but what happens when we
run into a program that is 60 decibels in
the orchestra? Supposing we are listening to a piece that we will call `Moderate
and Equal' which runs up and down the
60 -db contour, instead of 'Loud and
Equal' on the 80 -db contour then
what ?" There are no problems as long
as the broadcast or recording engineer
keeps his fingers off the controls so that
the modulation comes through at the
correct relative level. If we run our loudness control wide open, we will now hear
"Moderate and Equal" going up and
down the 60 -db contour at the 60 -db
level-just like the original. If we decide
we want to hear it at 40 db, we turn
down the loudness control to 20 db. It
won't be exactly right because the difference between the 80- and 60 -db
contours is not identical to the difference
between the 60- and 40 -db contours, but
it's close enough. "But," you may ask,
"What if I want to listen to 'Moderate
and Equal' at an 80 -db level ?" In that
case, you'll have to bring up the level
control and adjust the tone controls until
it sounds right.
A lack of understanding of the loudness phenomenon has in the past led to
some strange mores and way -out activi-
rise of Fig.
-
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a
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Tape. No. 290 is made to demanding stereo quality standards
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CIRCLE NO. 130 ON READER SERVICE PAGE
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CIRCLE NO. 133 ON READER SERVICE PAGE
TREMENDOUS NORELCO
HIGH FIDELITY SPEAKER SALE
AT McGEE
standard
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the loudness contour shift over a rangé
of about 40 db is the only satisfactory
solution.
Some loudness controls attenuate over
a greater than 40 db range. To accomplish this they either become quite complex or else do a rather poor job of
approximating the contour shift.
The simple control developed by the
author, shown schematically in Fig. 3,
covers the ample, if not ultimate, 40-db
range. More important, it never deviates
from the desired contours by more than
a couple of decibels over this range, as
its measured attenuation characteristic
( plotted in Fig. 4) clearly indicates. It
requires a low- impedance source (an
emitter or cathode -follower of not more
than 100 or 200 ohms ) and a high -impedance load ( about 300,000 ohms ) It
can be added to almost any preamplifier.
To use the control, set it wide open
and adjust the level control so that the
program sounds as loud as the original.
Next, set the tone controls for proper balance. These would be set flat if everything in the system from microphone to
room acoustics were perfectly balanced.
However, since this is never the case,
some tone -control trimming is almost always necessary. This done, we need not
touch the level control or the tone controls again unless the sound source is
shifted to a different power level or
tonal balance.
The loudness control may now be used
to achieve any listening level desired,
with the program remaining full and
natural sounding at any level.
.
alloy
magnet
McGEE
ties among audio enthusiasts who had
been misled by two mistaken postulates:
First, that only lowbrows enjoy the bass
turned way up and, second, that highbrows with golden ears ( like us) prefer
their music pure (i.e., tone controls flat).
This latter group play their rigs at full
concert level to make it sound right or
else sublimate their normal desire to hear
full, rich bass tones in favor of impressive highs.
Now that we recognize the need for
following the shift of the contours whenever we change levels, let us consider
some practical means of accomplishing
this action.
One way is simply to crank up the
bass tone -control knob on the amplifier
as we reduce level. This is better than
no compensation, but it has three basic
faults: First, the break frequency of most
bass controls does not follow the loudness shift break frequency very well;
second, every time we change level we
have to make some kind of guess as to
where to position the bass control; finally, and most serious, typical bass -boost
circuitry rarely exceeds 18 db of boost
wide open, and as we have seen, as much
as 30 db may be required to achieve the
desired compensation.
A separate control which will follow
900
SALE PRICE
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MATCHED PAIR
Model AD4877M, Nurelco 8" fuai range high -fidelity
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WRITE FOR McGEE'S 1964 176 PAGE CATALOG
WHICH INCLUDES A COMPLETE LINE OF
NORELCO SPEAKERS AT BARGAIN PRICES
McGEE RADIO CO.
1901 McGee St., Kansas City 8, Missouri
CIRCLE NO. 127 ON READER SERVICE PAGE
84
Quantum Devices
(Continued from page 41)
ends. Emission in other directions passes
through the side of the rod and has little
effect. However, emission in the direction of one of the mirrors sets up a chain
reaction as photons bounce back and
forth between the mirrored surfaces,
striking other energized atoms in the
process and causing each to emit two
photons.
When amplification is great enough,
a narrow beam of extremely intense red
light is emitted from the partially silvered end of the rod. The light is coherent, covering a single frequency, and
provides a striking demonstration of the
operation of the quantum theory.
The laser is finding wide use in medical, chemical, and biological research,
and may be the principal means of communications for space vehicles. Lasers
may also lead to the design of very -highresolution radar systems.
Spectrometers
The quantum theory has provided
two new kinds of spectrometers, called
the nuclear magnetic resonance (NMR)
and the electron paramagnetic resonance (EPR) spectrometer. The first
type uses the gyromagnetic properties
of atomic nuclei, the second the orientation of unpaired electrons. Electromagnetic radiation is provided by a
combination of an r.f. signal and a
strong magnetic field. The r.f. signal is
usually maintained at a constant level
while the magnetic field is usually increased.
Energy is absorbed from the system
at resonance points that correspond to
energy level transitions. Since these are
different for each kind of atom making
up the unknown sample, the composition can be determined by measuring
the density of the magnetic field at the
points where absorption occurs. The degree of energy absorption is related to
the number of atoms involved, so both
a qualitative and quantitative analysis
is provided.
An r.f. signal of about 10 kc. is usually
employed for NMR spectrometers. Since
EPR spectrometers are designed to take
advantage of fields associated with unpaired electrons which resonate at much
higher frequencies than atomic nuclei,
it is necessary to use microwave plumbing.
The above descriptions cover some of
the more important quantum devices.
The list is not exhaustive, as quantum
mechanics is influencing much current
developmental work. In view of the successes already attained, there is reason
to believe the quantum theory will be
a major factor in invention for many
years to come.
ELECTRONICS
WORLD
TRANSISTORS vs
TUBES for HI -FI
By RICHARD S. BURWEN
/
Consulting Electronics Engineer
Comments on "transistor sound," over -all performance,
and reliability of transistors in hi -fi power amplifiers.
Editor's Note: Following are some additional comments on our article "Transistors
for Hi-Fi: Panacea or Pandemonium ? ",
which appeared in our September and October issues. Mr. Burwen specializes in
audio and transistor circuitry and was responsible for the design of several high power transistorized hi-fi amplifiers and
other audio equipment.
views on transistors for hi -fi are
generally the same as those given
by the authors of the original article.
Here are some additional points not
covered previously.
One factor that can make a transistor
power amplifier sound cleaner than a
tube amplifier is its superior clipping action under overload conditions. Some
transistor amplifiers recover from an
overload much faster than vacuum -tube
amplifiers by virtue of d.c. coupling. This
makes the distortion produced by overloading much less objectionable and may
even be completely unnoticeable when
the amplifier is occasionally overloaded
as much as 5 db.
Another characteristic that can make
a very noticeable difference in the listening quality of the amplifier is the damping factor. Fig. 6 in Part 1 of the original
article showed that the acoustic response
of the speaker system did not change
much when the damping factor was
changed from 4 to 1 to infinity. Had the
impedance of the speaker system been
much lower than rated value at certain
frequencies, as is the case in some of the
more efficient systems, there would have
been a greater difference in the response
curves. This difference can be as much
as 3 or 4 db at certain frequencies and
does produce a very noticeable difference in the sound quality.
With either vacuum tubes or transistors the amount of distortion produced
depends primarily on the ingenuity of
the circuit designer in using negative
feedback. Both can produce very low
distortion if enough feedback is used.
On a performance -per -dollar basis,
transistors are still slightly behind tubes.
Silicon planar transistors, recently available at a low enough price, make practical preamplifiers which can provide
noise figures of 1 to 2 db over the audio
range without microphonics. They can
even perform well with source impedances up to 500,000 ohms.
The power transistors that really solve
MY
the problems of hi -fi, silicon planar types,
are too expensive, but prices are falling.
Transistors have been developed for
military equipment, for example the
"Minute Man" missile, which are so reliable that if 100,000 transistors were
operated for 1000 hours, not more than
one would fail. The same technology
which produces such high reliability is
being applied, although to a lesser degree, to the transistors now available for
hi -fi equipment. Since they lack the basic
wear -out mechanism of the tube, the
heater cathode, it can be assumed that
transistors will last many times longer in
hi -fi equipment provided that they are
properly applied.
It is true that transistors are very easily
destroyed, especially when someone unfamiliar with transistor circuitry reaches
into an amplifier with a test prod. Complete short -circuit protection for a d.c.coupled power stage is rather costly. One
compromise solution which the author
has used is to incorporate a fuse together
with an output coupling capacitor which
limits the low- frequency energy in the
transistors at a slight sacrifice in low -frequency power output.
Whether it is tubes or transistors, it
takes a lot of feedback and a lot of components to produce extremely high quality performance. In general, it takes
three to five transistors to accomplish the
job of a 12AX7, but there are some compensating savings on the power supply,
size, and the amount of heat produced.
A power amplifier using silicon alloy
power transistors has been built to deliver 25 -watts power output. This amplifier uses d.c. coupling, has only millivolts of d.c. offset across the loudspeaker
voice coil, recovers from overload instantly, incorporates complete overload
protection for both short circuits and reactive loads, delivers full power with less
than 0.05% total harmonic distortion up
to 5 kc., and does all this over a wide
temperature range with production transistors without matching and without
adjusting their bias currents. With planar
output transistors the same circuit will
produce full power to 20 kc. with similar
distortion characteristics. (Sorry, but we
cannot supply the circuit and construction details.- Editor)
Thus, transistors right now can produce higher quality than has generally
been available from tube amplifiers.
-
SPEAKER
SYSTEM
means the beat of
sound wizardry
Sound all around. Crystal clear.
Compelling. Mood setting...
such is the magic of Utah's
compact Sorcerer. This 2-
speaker system brings BIG, full,
distortion -free sound into reality. It performs this electronic
magic better than many larger
and more costly systems. Here
is wizardry developed from
Utah electronic ingenuity, and
found exclusively in the
Sorcerer.
-
fits Early American through
Modern decor.
Two Utah Speakers,
Components
an 8" Woofer, 5" Tweeter, Crossover.
Cabinet Hand -rubbed, oiled walnut
veneer, applied to th" plywood, a
standard for fine furniture.
Location Wall, bookshelf, floor,
Styling
-
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table -top.
Dimensions
-
20" in length, 12" high,
5" deep.
Power rating 12 watts.
Uses Hi -Fi or Stereo, as extension
speakers for record player, radio or TV.
-
-
$29.97
Net
SH4. W
85
December, 1963
CIRCLE NO. 146 ON READER SERVICE PAGE
H U N T
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,
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A NA
FOR SHARP,
CLEAR 2-WAY
RADIO
COMMUNICATION
TV NEWS
Fixed or mobile,
business or pleasure
THE x -ray warning note that all manufacturers of picture tubes include
in their data sheets, has caused many
inquiries as to the possibility of x -ray
radiation damage emanating from a typical picture tube.
The standard warning given in the
data sheets states that radiation shielding may be necessary if the picture tube
is operated at higher than manufacturer's ratings. A number cf magazine articles have appeared on this subject and
recently Sylvania passed along some information they had gleaned along these
fiel the new, low-cost
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Tunable receiver permits reception of all 23 C -B
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Name
Address
City
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?one
state
When a high -velocity electron beam
strikes a target, various types of energies
are released, some of it in the form of
x -rays. As TV picture tubes are usually
operated with anode voltage of 8 to
20 kv., mostly "soft" x -rays are formed.
Ordinary glass will pass soft x-rays only
with a substantial loss by absorption,
and since the face -plate of a CRT is
heavy glass, a considerable shielding effect is present.
Another reason for low x-ray output
is that the electron beam current is on
the order of tens of microamperes and
spread out over a large surface area
rather than the small target area of x -ray
tubes. In addition, the "target" in a CRT
is very inefficient in producing x-rays.
Thus, it becomes evident that an average TV picture tube, operated at its
rated voltage values, is being used in
such a manner that very weak, if any,
x -rays can be detected at a few inches
from its face-plate.
It is of interest to note that all -glass
picture tubes are even less subject to
radiating x-rays than the all metal type.
This is because the all -glass types have
a thicker face-plate made cf a glass that
absorbs x -rays to a greater extent than
the glass face-plate on the metal -glass
tubes.
To put some numbers to it, Sylvania
recently made measurements on several
typical all -glass and metal-glass picture
tubes and found that a typical 27 -inch,
all -glass tube, operated at above maximum second -anode voltage of 27 kv.,
produced no reading on a radiation detector held 3 inches in front of the faceplate. A 21 -inch, all -glass tube, operated
at above maximum second -anode voltage
of 24 kv., also produced no reading.
However, a 21 -inch, metal-glass tube:
operated at above maximum second anode voltage of 24 kv., produced 11,
26, and 68 mr- per -hour radiation when
operated at 20, 50, and 100 footlamberts
highlight brightness respectively. This is
far in excess of the 2.5 mr -per -hour allowable by Bulletin UL492 -10th Edition, of the Underwriters Laboratory. (A
limit of .5 mr- per -hour is under discussion by the International Commission of
Radiological Protection.) When a 34 -inch
safety glass was used with this CRT,
radiation level dropped down to a safe
.6 mr /hr. All measurements were taken
3 inches from the face -plate.
The same tube type (21 -inch, metalglass ) , operated at the same three
brightness levels as before, with above
maximum second -anode voltage of 22
kv., produced radiation levels of 3, 9,
and 16 mr- per-hour. However, with a
;4 -inch safety glass installed, radiation
dropped to well within the safe value.
Reducing the second anode voltage to
the maximum rated value of 18 kv., produced radiation levels of .6, .8, and 1
mr-per -hour, and all were reduced to
far within the safe value when the safety
glass was used.
The same metal -glass CRT types produced no measurable radiation when
they were operated at normal recom-
mended second -anode voltages.
The numerical values associated with
these tests illustrate some radiation levels that can be encountered whenever
picture tubes are operated with voltages
in excess of what the manufacturer specifies. The tests also point up the protection afforded by the normally used
safety glass. In many of the newer
CRT's, the safety glass is built -in at the
face -plate end of the tube.
The lessons to be learned are very
simple: never, but never, juggle the CRT
circuit to raise the voltages in the interests of a brighter or sharper picture;
and never operate a CRT without the
manufacturer's specified safety glass.
By the way, when are you going to
check the voltages and put a safety glass
on that cathode -ray tube that you use
as a bench tester?
ELECTRONICS WORLD
OVER 2000 COMPONENTS...
Amplifiers
STEREOL7 HIFI
Phono Equipment
F
DIRECTORY:'
Tuners
Tape Machines
Speakers & Cabinets
Accessories
are covered
inthe 1964
edition of the
STEREO/HI-Fl DIRECT
Complete listing of all Hi -Fi dealers
It's the world's most comprehensive
throughout
the,United States.
BUYERS' GUIDE to the hi -fi market.
Everything you need in sound is featured in the 180 product -packed pages
of the 1964 STEREO /HI -FI DIRECTORY. It gives you the vital statistics
-photos, prices, and performance data
-on over 2000 components from 177 different manufacturers. It's the best way
to see and compare speakers, enclosures, cartridges, changers, amplifiers,
tone arms, FM tuners, tape recor
and FM antennas before you buy.
Plus you get these special features:
How to select an FM tuner
Tips on buying Tape Recorders
Complete listing of all FM Stereo Multiple;
Stations broadcasting in the U.S. and Canada
(as of September 1963) .
..111b,1
196J
The 1964 STEREO /HI -FI DIRECTORY is
your indispensable guide to the total -sound
market. It goes on sale October 1st at your
favorite newsstand or hi -fi dealer's. Or fill in
this coupon and we'll send you a copy.
Price only $11
Ziff -Davis Service Division Dept. SD
EW123
Broadway, New York 12, New York
Please send me a copy of the 1964 STEREO /HI -FI
DIRECTORY. I enclose $1.00, the cost of the DIRECTORY, plus 15c to cover mailing and handling charges.
(Canada & Overseas: $1.25 plus 25c postage).
589
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87
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LETIDE BONUS #1
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4 SYLVANIA SILICON NPN, 2N333 transistors
2 SILICON "PLANAR" TRANSTRS, 4 watt, TOS, npn
6 RCA 2N408 TRANSISTORS, output, T01, pnp
"TEXAS" 2N1039 20W TRANSISTORS, T05 Case, pnp
4 RAYTHEON CK721 TRANSISTORS, pnp
10 30 MC. PHILCO TRANSISTORS, T01, pnp, MADT
4 SYLVANIA 2N219 TRANSISTORS, mixer, T022
2 SYLVANIA 2N296 25 WATT TRANSISTORS, T03
2 40 WATT TRANSISTORS, 2N174, 7036 case
IS GERMANIUM DIODES, 1N34, 1N48, 1N60 equals
5 GENERAL ELECTRIC 2N107 TRANSISTORS, pep
4 GENERAL ELECTRIC 2N170 RF, NPN TRANSISTORS
3-1 WATT ZENER DIODES, 6, 9, 12 volts
10 SWITCHING TRANSISTORS, npn, 2N440 equals
15 PNP TRANSISTORS, assorted types and casos
15 NPN TRANSISTORS, assorted types and cases
150 -WATT SILICON TRANSISTOR, 2N1015A, npn, stud
3 CBS 20 WATT TRANSISTORS, pnp, stud, 2N1320
3 CBS 20 WATT TRANSISTORS, npn, stud, 2N1321
25 -AMP SWITCHING TRANSISTOR, car ignition too
10 RAYTHEON CK722 TRANSISTORS, pnp, audio
15 RAYTHEON SILICON UPRIGHT DIODES
2 25 -AMP SILICON POWER RECTIFIERS, stud
10 TOP HAT RECTIFIERS, 750 ma, 400V, silicon
INFRA -RED PHOTO DETECTOR TRANSDUCER
INFRA -RED PARABOLIC REFLECTOR AND FILTER
10 "TINT" MICROSWITCHES, SPST, 115 VAC, 15A
100 PARTS SURPRISE, worth $50, prtd ckt tool
40 WORLD'S SMALLEST RESISTORS, 5% too, 1 /IOW
60 CERAMIC CONDENSERS, discs, npo's, to .05mf
SO TERMINAL STRIPS, 1 to 8 lugs, asstd styles
60 HI -Q RESISTORS, 1/2, 1, 2W. 5% and A.B.
100 HALF WATTERS, resistors, 5% too
35 ALLEN BRADLEY 2 WATT RESISTORS, asst, S %
SO COILS 8 CHOKES, if, rf, ose, parastic, peaking
10 TRANSISTOR ELECTROLYTICS, 8 to 100 mf
10 VOLUME CONTROLS, w /sw 8 duals too! To 3 meg
50 MICA CONDENSERS, postage stamp, silvers too
30 POWER RESISTORS, to 50W, to 24Kohms, S% too
id, encapsulated
4 TIME DELAYS, 1.2 micro_
10 TRANSISTOR SOCKETS, npn 8 pnp transistors
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40 PRECISION RESISTORS, /2, 1, 2W, (1/2 & 1%)
50 ALLEN BRADLEY ONE WAITERS, resistors, S% too
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CIRCLE NO. 150 ON READER SERVICE PAGE
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NYC 7, NY
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LOW -COST BUSINESS AIDS
FOR RADIO -TV SERVICE
Order books, invoice forms, job ticket
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statement books for use with your rubber stamp. Customer file systems, bookkeeping systems, many others. Write for
FREE 32 PAGE CATALOG now.
OELRICH PUBLICATIONS
6556 Higgins Rd., Chicago, III. 60656
88
CB Radio -Wave Propagation
(Continued fron page 48)
The basic conditions of the ionosphere
are reasonably predictable; so much so
that it has enabled predictions with a
fair degree of accuracy several months
in advance of the propagation characteristics at various points around the earth.
These are published by the National
Bureau of Standards in the form of
earth charts. By the use of these charts,
you can determine, if you are interested,
where you might be heard for any month
of any given year.
Up to now we've explained the mini mum distance for F2 skip, but what
about maximum distance. Greater distances than 2500 miles are due to multi hop transmissions, that is, those which
are reflected back to earth, bounced off
the earth and back into the ionosphere,
then returned to earth perhaps another
2500 miles away. This is a rare bird for
CB, due to the fact that with only 1 to 3h
watts output, the chances of multi -hop
transmissions are not very good. If the
signal bounces back to earth, the earth
itself will usually absorb most of the
energy so there is very little, if any,
which can be bounced back into the
ionosphere again. It does, however,
happen occasionally, especially where
the return to earth is at a place with
good reflecting properties.
Short Skip
Now that we've indicated that 1250
miles is about the minimum skip distance, you are apt to say, "OK, but what
about the short skip signals I've received
from only a few hundred miles away,
or even less ?"
Shorter distance skips are due to the
E layer, where the ionization becomes
quite high, especially during the summer
months or to so- called sporadic -E skip.
This latter condition is one in which
there are blobs or clouds of highly ionized gases in the E layer which may
persist for a few minutes or a few hours.
They occur quite often in early evening
hours and may persist even after the sun
has set, usually disappearing by midnight local time. These ionized clouds
occur quite often, especially in summer,
and can account for reception of signals
from transmitters only a few hundred
miles away from you.
The characteristics we have discussed
thus far account for most of the skip
signals in the 27 -mc. band. There are
some unusual conditions which can account for the sudden appearance of signals from almost any distance up to several hundred miles or even farther.
These include such effects as meteor
showers, tropospheric scatter, ionospheric scatter, back scatter, reflections
from satellites, and other causes -all of
which are relatively minor but which
may account for some of the bizarre results we sometimes get.
What To Do About Skip
The first thing, of course, is not to
answer skip signals, even though some
eager beaver calls your number from
2000 miles away. But, other than ignoring them, there is little you can do
about the interference they might cause.
Skip signals have one characteristic
which antenna manufacturers may use
some day to reduce the reception of CB
skip. Although your signal is vertically
polarized when it is transmitted, the polarization becomes circular or elliptical
when it is refracted by the ionosphere.
Such a signal has both horizontal and
vertical polarization. Now, if some antenna manufacturer can come up with
a device which reduces or cancels out
the horizontal component of a skip signal, he might be able to attenuate such
signals and so reduce interference.
The propagation of radio signals can
be an intensely interesting subject. Much
is known about it, and more is being
learned as we advance into the space age
with space probes capable of entering
or going through the ionosphere.
Oil Exploration
(Continued from page 30)
While most of the work of producing
data for the geophysicist is done in the
field, many times recordings are sent to
a central processing point. The processing center may do all or part of the filtering, mixing, and correcting usually necessary and, in addition, may handle the
work of several field crews. A typical
central processing unit is shown in Fig. 6.
Other Exploration Techniques
The exploration technique described
here is only one of a number of methods
used in finding oil and investigating the
interior of the earth. Others include refraction seismology, magnetic and gravity measurements, and well logging. Like
reflection seismology, most of them are
dependent upon electrical or electronic
instrumentation.
Refraction seismology is quite similar
to the reflection method in that it requires almost exactly the same equipment. The technique makes use of the
refracting properties of the subsurface
layers. This technique is generally inferior to the reflection method because
it does not give an exact picture of the
subsurface. It is useful in many instances, however, particularly where it
is desired to determine the velocity of
propagation in certain areas.
In well logging, a deep hole is drilled
in the earth and instruments are lowered
to the bottom. As the instruments are
pulled up, measurements are made on
the rock and soil and a chart or log is
ELECTRONICS WORLD
furi:
plotted as a function of depth. Among
the properties measured are acoustic velocity, electrical resistivity, density, self
potential, gamma -ray radiation, and others. Geologists have said that this is one
of the most useful of all of the various
exploratory techniques used.
NEW 1964 GIANT CATALOG
The Mohole and Vela 'Uniform
While a large percentage of the electronic instrumentation used in the geosciences is concerned with locating oil
and gas deposits, electronics is also helpful in other areas. Two recent interesting
uses of electronics in the geosciences are
the drilling of the Mohole and Vela Uniform.
The Mohole project is an attempt to
drill through the outer crust of the earth
into the mantle or inner earth. The mantle comprises about 80% of the earth's
volume, but little is known of its character. Knowing the nature of the inner
earth vi1l aid scientists in proving or
disproving theories and the history of
the earth.
The Mohole will be drilled at sea because the mantle is closer to the surface
under the sea than it is under land.
Naturally, this brings on many complications. The drilling ship must, at all
times, be accurately positioned over the
hole being drilled regardless of the condition of the weather and the sea. This
requires a special drilling ship as well
as an excellent positioning system. The
positioning system will make extensive
use of electronic techniques. Electronic
instruments will also be used to log the
hole as it is drilled. Reflection and refraction seismic tests have been run over
the water areas that are being considered as drilling sites. We can expect to
see some interesting results of the experiment.
Vela Uniform is part of the government's research project for the development of a satisfactory arms control in
the form of an underground nuclear
blast detection, identification, and location system. The entire program is
dependent upon electronic instrumentation. Seismological observatories or detection stations will be set up at carefully
chosen locations over the world. These
stations will be equipped with seismometers, amplifiers, processing and recording instruments, and other devices
necessary to the detection of nuclear
blasts and other seismic disturbances.
Underwater seismometers with telemetry equipment will also be used. Fig. 7
shows a typical detection station for nuclear explosions.
As advances are made in electronics,
so will advances be made in the geosciences. It is hard to predict what lies
ahead but it will no doubt be of considerable value to mankind -and much
of it because of the contributions made
by electronics.
December, 1963
100's of
new items
100's of
acked
listed for
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savings
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GUARANTEED
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FOR 37 YEARS THE
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Rush me the FREE
1964
B
BUYING GUIDE FOR:
Stereo
-A Catalog.
& Hi -Fi Systems and CompoTape Recorders
Electronic
Phonos & Rec.
Test Instruments
Cameras and Film
Public
and Kits
Address
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ords
Ham Gear
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NAME
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WANTED Transistors, Tubes all
types, Test Equip., Ground Equip.,
CRC, GRC, TS, URM, GPM. Air -
SAY YOU SAW IT IN
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raft Communications & Navigation
ELECTRONIC TUBES-Industrial, Special Purpose, Receiving-TV. Transistors -Diodes. LAB.
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89
NEW PRODUCTS
Sic LI'fERATi.'RE
TEST EQUIPMENT
TOOLS
COMPONENTS
COMPACT MULTITESTER
Lafayette Radio Electronics Corporation is
I
now offering a low -cost, compact 20,000ohms/volt multitester as the TE -58.
The 40 -µa. d'Arsonval meter has a 31/2"
1
scale in two colHigh input resistance is possible on
all ranges: 20,000 ohms /volt on d.c. and
10,000 -ohms /volt on
ors.
HI -FI
Additional information on the items
covered in this section is available
from the manufacturers. Each item
is identified by a code number. To
obtain further details, simply fill in
the coupon appearing on page 15.
AUDIO
EXPANDED -SCALE VOLTMETERS
ZGeneral Electric Company is now offering its
"Big Look" voltmeters with scales expanded
up to six times. Incorporating zener -diode references, these meters provide accuracy of ± 0.5%
and excellent narrow-range readability. Expanded -scale meters are available in 31/2" and
41/2" self- contained a.c. or d.c. models.
Standard a.c. ratings are 110 -130 and 105 -125
115
110
120
1
125
A-C VOLTS
30
CflkfiáELLmEtéC'-R.!'
sets of
quencies.
surfaces -from 1/4" stock down to .005 wire. Plastic parts are designed to withstand at least 10,000
volts d.c.
PELLET CAPACITORS
The Scionics Corporation is marketing pinhead-size pellet ceramic capacitors for use in
microelectronic programs. Values up to 1000 pf.
are available in thickness of .020" or greater, if
desired. Typical capacitor element size for .01
TRANSISTORIZED COUPLER
Winegard Company has just introduced a
3 transistorized two-set coupler which has been
designed to overcome splitter loss especially in
fringe or weak-signal areas.
With the model EC-230 Color -Coupler, it is
possible to operate two TV sets, or a TV and an
FM set simultaneously from a single antenna
and down -lead without loss of signal.
A high -gain transistor boosts the signal a minimum of +7 db to provide equal or better TV or
FM reception for two sets than was possible
for just one. In addition, 15 db isolation between
coupler outputs prevents interaction of sets
90
standard leads. Clips have swivel jaws
that clamp securely to Oat. square, or round
A
HI -FI
1
-
AUDIO PRODUCTS
PROFESSIONAL RECORDING TAPES
Eastman Kodak Company is now marketing
two professional -quality sound recording
tapes with a rugged, new Durol base.
The Type A303
µf.. 50 v. is .1" x .1" x .062" while a .1 µf., 50 v.
unit measures .2" x .2" x .062 ".
Larger capacitance values, higher voltage ratings, and special form factors are available on
request. The line is available with ribbon leads.
30 -gauge wire leads, solderable disc terminations,
and in micromodule wafers.
TEMPERATURE -MEASURING KIT
H. V. Hardman Co., Inc. is now marketing
a temperature- measuring kit that has been
specifically developed for the electronics industry.
The kit includes a selection of color -changing
"Thermochrom" crayons and "Detectotemp"
paints for indicating temperatures and heat distribution from 40 degrees C (104 °F) to 440 degrees C (824 °F.). Easy -to -see color changes, unaffected by ambients, clearly show surface
temperatures reached, not reached, or exceeded
to within ± 5 °C accuracy irrespective of range.
The kit can be used for checking out critical
temperatures on microminiature circuitry, transistors, diodes, breadboards, motors, generators,
bearings, transformers, and packaged equipment.
E
low -print tape with a
is a
signal -to-print- through ratio of 54 db. The Tspe
A304 is a high -output tape which is said to have
more than double the undistorted output of conventional tapes. The signal -to -noise ratio, as measured by zero signal to saturated output is 79 db.
Print -through has been held to a 49-db level.
The new Durol base virtually elminates stretching; residual elongation is held to less than one
percent. In case of recorder malfunction. however, the tape has a built-in "shear pin" effect
so that it will ultimately break clean rather than
stretching and snarling.
CABINETED TAPE RECORDERS
Allied Impex Corporation is now importing
8 two completely self -contained stereo tape recorders which are housed in teak cabinets.
The top recorder in the line is the "Sorrento"
which features solid -state circuitry with 21 transistors and 19 diodes in an OTL circuit and an
LI
U
e
volts. Standard d.c. ratings are 24 -30, 110 -130,
and 220 -260 volts. The d.c. meters are available
in either pivot and jewel or taut -band construction The d.c, d'Arsonval mechanisms are self shielded from stray magnetic fields and require
no special calibration for magnetic panels.
COMMUNICATIONS
which degrades reception, color in particular.
The unit features the same isolation at all fre-
a.c. In addition, 1%
precision resistors are
used for maximum
accuracy.
Full -scale ranges include: 0 -.6, 6, 30, 120,
600, and 1200 d.c. volts; 0 -6 30, 120, 600, and
1200 a.c. volts; 0 -60 µa., 0 -6, 60-600 ma. d.c.;
0- 10,000, 100,000, 1 megohm, and 10 megohms
resistance; -20 to +63 db; plus a special capacitance range of 200 pf. to 0.2 ¡if. The unit
operates on two standard 11/2-7olt batteries and
measures 3+;'i6" w. x 51/2" h. x 17A" d.
HAM
CB
CLIP -PROBE COMBINATION
Gator Probe Corporation has announced the
development of a combination test lead that
features an insulated alligator -type clip plus a
retractible probe.
The plug, at the end of a 52 -inch, 18-gauge
lead, will accommodate either banana tips or
pins. Both pairs of tips are included so the
combination can replace a minimum of three
all-electronic matrix -type push -button switching
system. Tape movement is controlled by three
separate motors; for capstan drive (7.5 and 3.75
ips), rewind, and fast forward. There are individual volume and tone controls for each channel, illuminated vu meters, and two built -in
4" x 6" speakers. The motor and power cut off
automatically at the end of the tape.
The "Nocturne" (photo) is a three -speed unit
with switch- controlled mono/stereo playback se-
lection.
INTEGRATED TUNER/AMP
Transwave Electronics Co. Ltd. is marketing
the
TW
-50, an integrated AM -FM stereo sysn
tem incorporating the compam's Model TW -2
AM -FM tuner, a comprehensive stereo control
center, and a stereo amplifier capable of delivering 50 watts of power. FM- stereo facilities
are built in and only the connection of two
speakers is required for a complete system.
The FM tuner section features stereo channel
separation of 40 db at kc., and 1.25 µv. sensitivity for 2(1 db quieting or 3 µv. IHF. AM
sensitivity is 5 µc. for 20 db signal -to-noise ratio.
Audio frequency response of the amplifier is
1
ELECTRONICS WORLD
18- 22.000 cps ±1
is 16 watts
db at rated output. Power
music power per channel and
25 watts peak power per channel.
output
FM- STEREO TUNER SEMI -KIT
Eico tile( (sonic Instrument Co. Inc. is now
10 offering the Model O200 "Classic Series" FMstereo tuner in semi -kit forni.
The Iront -end :nul the i.f. strip are pre -assembled and pre -aligned at the factory. A circuit
board is provided for the stereo demodulator
circuit and the coils supplied are pre- aligned.
The Model 220n features at precise rotary tuning dial with illtnnin;ted readout. Isar-type
RCA BRINGS YOU
TWO IMPORTANT NEW TEST INSTRUMENTS
TO GENERATE
RF SIGNALS
TO PROVIDE STEREO
FM SIGNALS_
electron -ray tuning indicator, and a stereo defeat
switch. 111F usable sensitivity is 3µy. for 30 db
quieting, signal-to-noise ratio 55 db, and harmonic distortion )))V;. Channel separation is
30 db.
The unit measures )1/2" h. x 151" w. x 111/2"
d. and weighs I2 pounds. A wired version of the
tuner is also available.
EQUIPMENT /SPEAKER CABINETS
RCA WR 51A FM
Lalaene Nadio Electronics Corporation is
11 now marketing the ncty "Liitrrion" line of
hi -fi cabinetry. The complete stem, ensemble
consists of one equipment cabinet and two
speaker cabinets. Both types of cabinets are
asailable in walnut, oiled walnut. or mahogany.
The equipment cabinet, which measures 44"
w. x 32ts/2" h. x 18" cl.. has four compartments
which will house a turntable or changer, amplifier, wiser. plus ruons for record .storage.
The speaker cabinets are designed to handle
any 12" speaker. :\ specially designed elliptical
port with diffracting ring
response, increases transient
inates cancellation effects
rear radiation. Dimensions
broadens frequency
response, and elimbetween front and
are 16" w x 3211"
h. x 18" cl.
SOLID -STATE STEREO
AMP
llarutan- óardun, Inc. has previewed its
12 Model .A- II)UIII stereo amplifier, an integrated solid -state unit rated at 70 watts, mono.
ac'r'oss the entire audio band.
Frequency response is 10- 100.000 cps ± tom, db.
Using no output transformers, the A -1000T
employs computer -grade silicon output transistors
which yield high power output with virtually
immeasurable distortion. The circuit employs 28
transistors plus lì diodes.
PORTABLE SOUND
olin
SYSTEM
Wm. A. Hnt Corporation is now arket3 ing a self -powered. self -contained public address system as the Model 300.
The unit contes in a compact, attache -type
portable case which sets up as a p.a. system in
seconds. A single "on -off' switch and volante
.
m
STEREO SIGNAL SIMULATOR
RCA WR -50A RF SIGNAL GENERFTOR
Generates continuous wave or amplitude modulated rf signals of sinusoidal waveform from 85 Kc to 40 Mc. Particularly
useful for aligning and signal tracing in
AM and FM radio receivers and Citizens'
Band transceivers -and for aligning if
amplifiers, and for signal tracing in TV
receivers.
Wide frequency range- continuous coverage 85 Kc to 40 Mc in 6 overlapping
ranges
Built -in crystal-calibrating oscillator circuit with front panel crystal socket
Permanently attached, shielded output
cables prevent errors, minimize time
loss and inconvenience. Built -in DC
blocking capacitors
Internal 400 cycle audio oscillator
Individual inductance and capacitance
adjustments for each range
Two -step rf attenuator switch plus a
continuously variable attenuator control
Easy -to -read dial scale -vernier tuning
Readily portable -weighs only 5 pounds
$5995 *
Generates signals necessary to service
and maintain stereo multiplex FM receivers and adapters.
GENERATES:
Four FM signals: Left stereo, right stereo, special phase test, monophonic FM
Eight sine -wave frequencies: 400 cps,
1 Kc, 5 Kc, 19 Kc, 28 Kc, 38 Kc, 48 Kc,
67 Kc- available separately or for mod-
ulating FM signals.
100 Mc carrier signal tuneable ± 0.8
Mc to permit selection of a quiet point
in the FM band
19 Kc subcarrier signal crystal -controlled within ± 2 cps
100 Mc sweep signal adjustable from
0 -750 Kc at 60 cps sweep rate
Choice of three composite stereo output signals: left stereo, right stereo, and
special phase test
ALSO features crystal- controlled markers
for receiver rf and if alignment. Zero -center meter for checking the balance of
stereo amplifier output. Portable and compact: weighs only 14 pounds.
$24950*
*User price (optional)
See them at your Authorized RCA Test Equipment
Distributor
RCA ELECTRONIC COMPONENTS AND DEVICES, HARRISON, N. J.
The Most Trusted Name in Electronics
December, 1963
91
control are at the microphone which the user
LAMPKIN METERS
can operate even as he talks to suit coverage and
acoustics. Transistorized, it requires no electrical
outlets. The system includes a microphone which
can be worn as a lavalier, used on a desk stand,
or hand -held. The microphone itself rejects feedback whines and other noises.
The entire unit measures 414" x 15" x 1714"
can mEan monEY
In YOUR POCHET!
and weighs only
15
pounds.
AM -FM -FM STEREO TUNER
Heath Company has added a deluxe all 14 transistor AM- FM -FM- stereo tuner to its line
of audio equipment in kit form.
The AJ -43 is completely transistorized and uses
25 transistors and 9 diodes. The circuit features
automatic stereo switching, automatic stereo indicator light, pre- assembled FM tuning unit and
four-stage FM U. circuit board, separate AM
and FM tuning meters, filtered stereo tape recorder outputs, a.f.c. and a.g.c.. and stereo phase
control for maximum separation and minimum
THE AMAZING EXPLOSION IN MOBILE RADIO CONTINUES. RIGHT NOW OVER 2,788.000 TRANSMITTERS
(PLUS 47,000 NEW INSTALLATIONS EACH MONTH',
MUST HAVE PERIODIC MAINTENANCE AND CHECKS ON
FREQUENCY AND MODULATION.
Frequency measurements and adjustments can only be made
by properly equipped-and licensed -servicemen. Quite often
maintenance is done on a term contract basis -assuring steady,
competition-free income.
radio tower or an-
distortion.
The tuner is designed to match the company's
AA -21 amplifier kit.
Almost every two -way
tenna in your area can mean money to
ANTENNAS FOR FM
you-
Jerrold Electronics Corporation has added
J three FM antennas to its "Paralog" line of
E
1
TO LEARN HOW YOU CAN CASH
ON THIS OPPORTUNITY
television units.
All three antennas provide a front -to-hack
ratio of 18 db for the smallest model to 23 db
for the largest model. The v.s.w.r. is rated at
1:1.2 to 1:1.8. Paralog gain is 12 db. The flat
response means that the antennas respond to all
signals in the FM band with an equal amount of
IN
MAIL COUPON TODAY!
LAMPKIN LABORATORIES, INC.
MFM Division, Bradenton, Florida
At no obligation to me, please send free
booklet "HOW TO MAKE MONEY IN
MOBILE -RADIO MAINTENANCE" and data
on Lampkin meters.
1
I
LAMPKIN 205 -A FM Modulation Meter. Tunes 25 to 500
105.8 Frequency
Meter. 0.1 to 175 MC and up.
$260.00. Accessary PPM Meter for 0.0001% accuracy on
split -cha i nels. 0141.00.
LAMPKIN
With four modulation
scales, 0 -1.25, 2.5, 12.5, and
MC.
amplification.
25.0 KC. 1310.
LAMPKIN LABORATORIES, Inc.
NAME
MFM Division
ADDRESS
BRADENTON, FLORIDA
STATE
CITY
CIRCLE NO. 126 ON READER SERVICE PAGE
MINIATURE TAPE RECORDER
Ricoh Industries, U.S.A., Inc.. is introducing
16 a Japanese -built miniature tape recorder
which features two speeds and operates on batteries or from house current with an adapter.
The tape recorder. which weighs under 5
jobber boxed tubes at 65% discount off current RCA price list. Send your trial
order NOW. Free catalog listing thousands of
parts, needles, crystals, tubes, kits etc. "Arctur. Send for catalog.
us" tubes at 78% di
RCA, G.E. etc.
TRANSISTOR
IGNITION
READY -TO- INSTALL
HEADLINE BUYS FROM OUR CATALOG
YOU can get TOP MILEAGE, HIGHEST PERFORMANCE, LONGER POINT & PLUG LIFE, BETTER WINTER STARTING, and MANY OTHER ADVANTAGES with
one of our INEXPENSIVE TRANSFIRE systems.
These include HERMETICALLY- SEALED AMPLIFIER,
HIGH -RATIO COIL, BALLASTS, Leads & hardware.
MODEL T
6 or 12v. neg. grd.
MODEL T2 TWO TRANSISTORS,
$39.95
$44.95
250:1 coil
$54.95
$59.95
MODEL TS
Special, 40kv system
TWO TRANSISTORS,
MODEL TS2
$49.95
400:1 coil
Everything needed to build
conversion. Includes transistors, coil, ballasts,
heat sink, decal, etc.
KT2 with TX250 coil for 30kv output . $34.95
$39.95
KTS2 with T400 coil for 40kv output
$27.95
KT1 one transistor with 400:1 coil
6 or 12v. Negative- ground only. Point insulation
kit adapts to positive ground, $2.50 pp.
1 oz. Epoxy potting plastic in mixing bag $1.95 pp.
TWO- TRANSISTOR KITS
.
.
HIGH -RATIO IGNITION COILS with free circuit diagram.
$ 9.95
TX250 Heavy duty coil 250:1 ratio
T400 HIGH EFFICIENCY 400:1 coil for
HIGHER OUTPUT and /or LOWER
$11.95
TRANSISTOR VOLTAGE
FULL LINE of PARTS at NET PRICES.
Free lists. Marine models available. When ordering,
specify voltage and car. Add postage for 4 lbs. on
kits and conv's; 3 lbs. on coils. $5.00 deposit with
COD's. Dealer & Distributor Opportunities.
LABORATORIES Inc.
617 -AL 6 -2626
CIRCLE NO. 132 ON READER SERVICE PAGE
92
Worth $30.00
KIT
PRICE
-2
late -type flyback transformers.
Kit ;501- Motorola
late -type flyback transformers.
Kit _502 -RCA
late -type flyback transformers.
Kit :503 -CBS
Kit :504-Zenith-2 late type flyback transformers.
late -type flyback transformers.
Kit _505- Emerson
late -type flyback transformers.
Kit ;50.i- Sylvania
lote -type flyback transformers.
KSt :507 -Philco
late -type flyback transformKit "508- Westinghouse
-2
-2
-2
-2
-2
ers.
direct
installation wo. insulating points
MODEL TP 6 or 12v. pos. grd.
PALMER ELECTRONICS
CARLISLE 1, MASS.
FLYBACK TRANSFORMER KITS
YOUR 299 PER
CONVERSIONS
Kit
;509- Dumont -2
-2
late-type flyback transformers.
TV YOKE KITS
70' and 90 °, a once -in -while buy. The six
yokes listed can be used directly or adapted
for use in almost every TV set ever built,
except 110- types. Their average cost to you
is ordinarily about $15.00 each. Our price
S1.99í.= individually boxed, and in perfect
condition. Your savings per kit; $26.00 approximately. Your cost per kit; $3.99.
Unit #Y-1 -One 90° Zenith and one 70°
$3.99
G.E. yoke. both for
Unit #Y -2 -One 90' Motorola and one 70°
$3.99
Westinghouse yoke, both for
Unit -..t.`Y -3-One 90' Muntz and one 90°
$3.99
Philco yoke, both for
7" TV
TEST TUBE
699
YOUR
COST
WORTH $25.00
Bench Te.t l'i.ture Tube: New -Not Rebuilt
(Uses
-
7" TV
(7BP7) -Flat Face- Electro- Magnett Focus,
focus coil of set under tests -no ion trap needed
Hand;es all currently used TV anode voltages -works
in any TV set except 110. Angle -Complete with
socket adapter harness. Ready to use at onceGuaranteed 1 year against alt defects
Pre -paid.
shipped post -paid, if order
in
ARCTURUS ELECTRONICS CORP.
D ZPD
502 -22nd ST., UNION CITY, NEW JERSEY 07087
CIRCLE NO. 102 ON READER SERVICE PAGE
pounds without accessories, measures 5" x 9" x 3"
and has a 2" x 4" oval dynamic speaker. It has
a volume control and sound -level indicator which
also shows battery condition.
The recording is 2 -track on 3V4" reels with
tape speeds of 3.75 or 17/s ips. The circuit uses
7 transistors and has a.c. bias.
FM- STEREO RECEIVER KITS
Merrell Electronics Inc. is marketing two
11 FM receiver kits, one completely equipped
for FM- stereo reception and the other with multiplex facilities.
Both the Model SR -436K and the SR -400K feature 10 front -panel controls, a pre-wired front
end, a.f.c., pre -aligned i.f. transformers, output
of 20 watts total (10 watts each channel), frequency response of 20- 20,000 cps for the tuner
and 20- 18,000 cps for the amplifier.
STEREO
AMPLIFIER
H. H. Scott, ILic. has oddest the Model 299D,
18 an 80 -watt stereo amplifier, to its "299 Series."
The new unit features switched front -panel
headphone output for private listening without
the use of loudspeakers, powered center -channel
output for driving an independent speaker system without need for a separate power amplifier,
and an 80 -watt output stage for low distortion.
ELECTRONICS WORLD
IHF power rating is 40 watts per channel, the
power band width is 18-25,000 cps + db, THD
is 0.8 %, and hunn level -80 db. Power rating
(steady -state) is 32 watts per channel.
1
SPEAKER
SYSTEM KIT
Electro- Voice, Inc. has added another loud19 speaker system in kit form to its line as the
stop /start switch, built -in amplifier and speaker,
plus a vu meter which indicates accurate record
level or battery condition. The unit also features
a variable back- spacing lever which when activated provides instant repetition of a word,
phrase, or entire paragraph.
The unit measures about 13" w, x 11" d. x 4" h.
It weighs 13 pounds.
forward motor, and one rewind motor. Tape
speeds (7.5 and 3.75 ips) arc stabilized and both
fast -forward and rewind can be performed in
approximately 50 seconds for a 1200 -foot tape.
The unit has a three-head system for recording,
playback, and erasing. It also features pushbutton control for easier operation. Frequency
response is 30- 15,000 cps Cr 7.5 ips and 30- s500
cps ,t 3.75 ips. The entire unit measures 191'Z' x
It;'
x 9" and weigh: 55 pounds.
"Coronct..,
Designed around the company's "Wolverine"
and "Michigan" eight -inch extended -range speakers. the enclosure is of the phase -inverter type to
pro, ide full frequency coverage. Of the high-efficiency type, the system can be used with any
CABINET FOR DYNA UNITS
Ruxton Electronics
is note offering an attrac22 tive oiled -walnut wood cahiuct desiguted tu
house the Dyna PAS -3 preamp nd l-M -3 tuner.
This complete stereo outer control center has the
CB- HAM -COMMUNICATIONS
:
ant plihem'.
The pre -finished enclostnr
AMATEUR ROTOR SYSTEM
Cornell- Dubilier Electronics Division is note
2 offering an amateur rotor system. the 'IR -44.
which supplies increased torque, braking, and
accuracy necessary for large v.h.f. antenna arrays
and small h.f. combination antennas. 'Typical
applications include amateur, mobile and Cit
radio, TV, FM, and FM- stereo.
The rotator is enclosed in an all -weather bell shaped casting which allows the unit to "free"
itself from ice and protects the mechanism front
rain and snow. An "end -of- rotation" electrical
motor cut -off stops the rotator 5 degrees before
the mechanical stop. A 30 ball- bearing movement
increases ability to carry weight and absorbs
wind forces. The TR -44 can be mounted on
masts up to 2" in diameter or on a flat plate
for interior totter mounting.
designed to be
used on a shelf or table. It conies in walnut
finish.
is
AM- FM /FM- STEREO UNIT
Radio Corporation of America has recently
20 unveiled the MX -7. a stereo hi -fi receiver dust
requires only the addition of speakers to provide
reception of ANI and F \I programs as well as
FM- stereo offerings.
The instrument combines a high-performance
tuner, 30- watt stereo
amplifier, plus input receptacles for tape recorder connections, phono turntable and changer,
microphone, or TV set.
he unit. which measures tit/n" h. x 173/5" w.
x 121/2" ci., features keyboard -type function con trols. dual volume controls, separate balance
control, visual tuning indicator, and an FMstereo signal indicator.
FM- stereo tuner, an AM
I
appearance of a single unit while retaining all
the virtues of independent components with full
ventilation.
The cabinet measures 141/2" wide by 9" high
MULTI -PURPOSE CB UNIT
Pearce-Simpson, Inc. is now marketing the
25 "Escort," a multipurpose too -way unit for
the Citizens Band service. Designed for both land
and marine applications, the unit is housed in
a heavy -duty enclosure which is rust- and corrosion- proof. A dual transistorized power supply
permits 12 -volt d.c. and 115 -volt a.c. operation.
The circuit features 8 channels plus an accessory crystal socket for use on any channel, 8
illuminated channel markers that are synchro-
by 8" deep.
PORTABLE TAPE RECORDER
Superseope Inc_ has added the Sony Model
21 801 -A portable tape recorder to its line of
products distributed in the C.S.A. This batterypowered, two-speed, dual -track mono recorder
has a full 5" reel capacity.
The Model 801 -A features all push -button
operation, self -storing microphone will[ remote
FOUR -TRACK STEREO RECORDER
Inter -Mark Corp. has added the "Cipher
23 Denon 800" professional four -track stereo
unit to its line of tape recorders.
The new stereo/mono tape recorder and playback unit has three hysteresis synchronous motors; one
4- pole /8 -pole 2 -speed
motor, one fast
NOW! THE FIRST "UNIVERSAL["
SHIELDING KIT FOR AUTOMOTIVE
IGNITION SYSTEMS!
Back Issues Available
Use
Break the strangle -hold ignition noise
puts on two-way communications
improve AM, FM broadcast receiver performance! NOT A SUPPRESSION KIT
but a complete ignition shielding kit to
control both radiated and conducted interference. Easy to install utilizes
shielding techniques and materials used
in "customized" systems by police,
taxi and other operators of two -way
radio equipped fleets.
this coupon to order back issues of
.
fill
in the coupon below, enclose
your remittance in the amount of
65 and mail.
$2995
Cylinder
Kit
6
NET
E.
Cylinder
Kit
8
SERVICE DIVISION
$3850
NET
F.JUHN150'h CD.
1106 10th Ave. S.W.
Waseca, Minn.
O
Dept. BC, 589 Broadway
New
.
-
We have a limited supply of back
issues that can be ordered on a
first-come, first -served basis. Just
ZIFF -DAVIS
.
-
ELECTRONICS WORLD
York 12, New York
Please send the following back issues of ELECTRONICS WORLD.
am enclosing
shipping and handling.
to cover the cost of the magazine,
Month
Yt'ar
Month
Year
Month
Year
I
A
TRADEMARK
HALLETT MFG. CO.
OF
1
Name
Address
City
Zone
State
No charge or C.O.D. orders please.
December, 1963
CIRCLE NO.
148
ON
READER SERVICE
PAGE
93
The transceiver comes complete with a channel 15 transmitting crystal, push-to -talk ceramic
microphone, and mounting brackets. It measures
111" w. x 5" h. x 6H" d. The power receptacle
in the rear is for the 117-volt line with a connection for an optional external 6. or 12 -volt d.c.
power supply.
A NEW
COLOR CODES
CHART IS
nized with the channel -selector switch and in-
dicate operating channel, squelch circuit for
quiet standby operation, low power drain, preset noise limiter, plus universal mounting
bracket.
Dimensions are 111/2" w. x 4W h. x 91112" d.
AVAILABLE
A
colorful, authoritative
fold -out wall chart (originally appearing in the
pages of EW) can now be
yours, and for only 25C.
This Color Codes Chart
gives you complete identification of color codes. You
can use it to identify spe-
cific value of ceramic,
MOBILE ANTENNA
ge The
GARAGE -DOOR
CONTROL
Alliance Manufacturing Co., Inc. is now
Lu n production on a palm -sized high -frequency
radio transmitter that will operate garage doors
by remote control. Known as the "Genie Model
AT -10," the transistorized transmitter offers a
range up to 125 feet and provides 21 channels
instead of 9 formerly available.
Housed in a black and white case of high impact plastic, the 344" x 234" x 114" transmitter
weighs only 9 ounces. It is powered by a single
low -cost 221/2 -volt battery.
Both the transmitter and its companion receiver, Model AC -10, meet FCC specifications.
The receiver operates on 117 volts a.c.
HOSPITAL INTERCOM SYSTEM
Executone, Inc. is now offering a complete
LI hospital communications system which provides a wide range of features and benefits.
The new system provides two -way voice Com-
pa-
per and mica capacitors;
transistor bases; semi -conand transformer wiring.
Ziff -Davis Reprint Service
Department EW
589 Broadway
HI -FI COMPONENTS
TAPE RECORDERS
SLEEP LEARN KITS
high quality
Low
tape, cost,
in boxes or cans.
recording
SEND FOR FREE CATALOG
DRESSNER
\"12y
munications between nurse and patient, two -way
communications between nurses and ancillary
department, remote infusion monitoring, remote
beil occupancy monitoring, provision for remote
physiological monitoring, pillow speakers for
individually controlled radio and television programming, announcement and alarm facilities,
and an administrative intercom network.
Polytronics Laboratories, Inc. is currently in30 troducing a 24- channel, crystal -controlled
transmitter and tunable receiver which features
precision selectivity.
The "Pro" operates on all channels in the
Citizens Band service and has an additional
channel for CAP, government. or county frequencies. The circuit features an all -nuvistor front
end including cascode r.f. amplifier, nuvistor
CB TRANSCEIVER
New York 12, New York
MERITAPE
Ilse vehicle is replaced, a standard rear-clew mirror can be mounted in the same location.
The antenna itself operates in the 150 -174 -mc.
range and is factory tuned to the exact frequency
required by the user. The v.s.w.r. is less than
1.5:1 at design frequency while the antenna's
efficiency, according to the company, is equal
or greater than that of a quarter-wave whip
mounted in the same location.
24- CHANNEL TRANSCEIVER
ductor diodes; resistors
Enclose 25 for each chart
and mail to:
Sinclair Radio Laboratories, Inc. has devel29 oped an omnidirectional v.h.f. communications antenna, housed in a fender -mounted
rear -view mirror, which defies detection, prevents
vandalism, and eliminates unsightly attachments
to the vehicle.
The Model 50037 consists of a ruggedly constructed mirror that requires no unusual mounting procedures -just two bolt holes to hold the
mirror and connection of the antenna. When
1523 JERICHO TPKE.
NEW HYDE PARK 16 N.Y.
Lafayette Radio Electronics Corporation has
28 added the HB -115 push -to -talk transceiver to
its line of CB equipment.
The new unit features eight crystal- controlled
transmitting channels operating at the maximum
legal power of 5 watts fully modulated; a pinetwork output which matches 30 -100-ohm antennas for maximum output; an r.f. stage in
the transceiver section; and a superhet receiver
tunable on all 23 channels with over 2 watts audio
output.
There is a.v.e. and a full -wave variable noise
limiter, accurate planetary vernier tuning, separate "on -off" power switch, external speaker /earphone jack, and electronic push -to -talk switching.
first mixer, nuvistor crystal oscillator, and tun-
able oscillator.
Other features include a tunable receiver with
6:1 vernier dial, 6 -mc. 1st i.f., 455 -kc. second i.f.,
and separate peak and null controls.
MANUFACTURERS' LITERATURE
INDUSTRIAL D.C. GROWTH
EARN
Engineering
You can earn an A.S.E.E.
level HOME STUDY courses
stand them. Continue your
the highly paid electronics
DEGREE
degree at home. College
undertaught so you c
education, earn more In
industry. Missiles, com-
puters, transistors, automation, complete electronics.
Over 27.000 graduates now employed. Resident
school available at our Chicago campus -Founded
1934. Send for free catalog.
American Institute of Engineering & Technology
1141 West Fullerton Parkway, Chicago 14, III.
94
Amprobe Instrument Corporation has just
31 published a I6 -page information bulletin entitled "D.C. Growth in Industry."
Written in easy -to- understand language, this
manual is being released in conjunction with the
firm's new line of d.c. current recorders and
50 -mv. shunts. The booklet provides the reader
with such useful background information as:
reasons behind the rapid growth in d.c. current,
ELECTRONICS
WORLD
cch tic. current has become so popular, the advantages of d.c. plus details on the company's
products for this service.
EMI GLOSSARY
Ace Engineering & Machine Co., Inc. is now
charge copies of a 12 -page
offering
without
32
booklet entitled "A Short Glossary of EM!
"Perms."
The publication lists some of the more fre-
quently encountered terms in electromagnetic
interference work. It covers such terms as attenuation. cell-type enclosure. hash. T \'I. RFI,
EMI, spectrum signature analysis, and others.
SOUND MEASURING EQUIPMENT
General Radio Company has published a
-page,
20
illustrated brochure which describes
33
its line of sound and vibration measuring instruments and associated apparatus. Among the insttnnents included are two new analyzers, one
with constant -percentage bandwidths and one
with constant -frequency bandwidths; a new microphone reciprocity calibrator, and stroboscopic
equipment adaptable to vibration measurements.
REPLACEMENT TRANSFORMERS
has issued a
24 -page catalogue covering ils entire line of
Triad Dist' ibutnr hisision
34
replacement transformers. Prices, application
data, specifications, and dimensions are given for
nuire than 735 transformers, yokes, tiybacks, and
filter chokes.
All of the items listed
distributors.
are stocked by the firm's
INDICATOR -LIGHT DATA
Drake Manufacturing Company has an35 nounced availability of its Catalogue 44-6302
which covers complete details on the firm's line
of indicator lights. lampholders. and lenses.
Halftone illustrations and tabulated data cover
main features of the different units.
IGNITRON SELECTION CHART
has made available
two-page "Ignitron Selection Chart," No.
National Electronics, Inc.
36
a
SB -21.
The chart shows the demand current vs percent duty rating of all welder ignitrons (size A
to size E) on a single chart. This makes it ctsv
to select the correct ignitron for an application
as soon as the current and ditty requirements
arc determined.
3'
RECORDING INSTRUMENT
LINE
Esterlins Angus Instrument Co., Inc. has
published a Ili -page catalogue covering its
new line of "GraphLine Series "S" " recorders.
In addition the new publication carries information on the firm's line of servo recorders, single
and two -channel recorders, inkless and ink -type
r
L
BENJAMIN
MIRACCORD
shown with new
INTEGRATED COVER /BASE
Model
Attractive as it is protective, the new Integrated Cover /Base keeps your
Miracord dust -free at all times
rest and during play. Consists of clear
plexiglass cover hinged to handsome, oiled walnut base. Cover need not be
removed or kept open while in use, even when playing records automatically
with long spindle. Yet, slip-hinge design permits removal of cover, where
desired. Measures 183/8" wide x 143/4" deep x 9" high with cover closed.
Complete Cover /Base price is $19.95. Miracord prices, less base and
cartridge: Model 10 (4 -pole induction), $89.50; Model 10H (hysteresis),
$99.50. See them at your hi -fi dealer. For literature, write to:
-at
BENJAMIN ELECTRONIC SOUND CORP.
80 SWALM STREET WESTBURY, N. Y.
U.S. distributor for Miracord turntables, Elac cartridges and Truvox tape recorders.
CIRCLE NO. 107 ON READER SERVICE PAGE
HI -FI BUYERS!
Want to
save yourself
a sack of
money?
GET IT from GOODHEART!
GOODHEART's new advertising policy:
1. We have the choicest selections in surpiuseiectronies bargains.
2. But we can't describe them adequately in these
ads, so we got up a FREE CATALOG. Please ask
for it.
3. Inasmuch as we wi new awards all the time.
no catalog can keep n up with incoming mdse, so
ALSO please ask for your specific needs.
4. The following heads from some f o r previous
ads indicate the scope of o
ehoieeui entore:
CHOICE BARGAINS IN COMMUN. RECEIVERS
2 -METER
RECEIVER
2/6/10
&
METER
XMTR
PWR SPLY FOR ART -13 & OTHER XMTRS:
ARC -3, ARC -27, ART -13 MANUALS!
FIND TREASURE & PIPES w /MINE DETECTOR
-
REGULATED DC SUPPLIES AT NEW LOW PRICES
event recorders, among others. Specifications and
selection data are provided.
BEST TEST SCOPE FOR TRANSISTOR WORK
BEST TEST SCOPE FOR
LUCKY -BUY SCOOP!
LABORATORY TEST EQUIPMENT
-
MEASURE
complete line of X -Y recorders, T -Y recorders.
and laboratory test equipment. The catalogue
provides complete technical descriptions of all
instruments.
TAPE RECORDING
PRECISION INSTRUMENTS
Kerr Corporation has announced
of a lì-page, 2-color catalogue
describing its complete line of quality instrument
for a variety of measurements and types of
analysis and control.
Wayne
40 publication
December, 1963
E
-A RECORDER
R
TO 0.1
%,
E
AND
I
TO
0.01%
LEEDS & NORTHRUP VOLTAGE- DIVIDER BOX
LEEDS & NORTHRUP'S K -2
POTENTIOMETER
$49.50 LM FRED METERS ARE $42.50
IN CHURCH
church occasions.
MA
CALIBRATED -OUTPUT SIGNAL GENERATORS
IImiston Instrument Corporation has pub
o ished a short -form catalogue covering its
38
The 3\I
mp any, is now
g cop ies of
39 its free bC000klet " he "Pae Recorder in
the Church." It outlines the uses of tape recordings to bring services to shut -ins, rehearse sermons. dramatize Bible stories. and create interest
in chair improvement. In addition, the booklet
outlines tc;iys to use taped music for various
VHF & TRANSISTORS
1
SEND US YOUR LIST OF
COMPONENTS FOR AN
UNBELIEVABLE QUOTATION
THAT CAN NOT & WILL NOT
BE BEAT. WRITE TODAY!
Send for our discount catalog, too.
0.1 % SORENSEN Line
-50005 r gut. against load
changes 0.5 kva & line
changes 95 -130 v. 1 ph
SO /60 cy; adj. output 110
120 v, holds to 0.1%.
Harm. less than 3 %. Recovery .15 sec. Regularly
5695.00 less spares. New.
fob'spares
orig.
pack.
r
285
$349.50
fob Utica
Also in FREE CATALOG.
Line Regulators: Sorensen
1
& 11/2 kva, Soda
&
2 kva. Super.
Elect. 6
kva. Also RECUL.
DC
SUPPLIES: Hewlett -Packand general purpose & for
r/
Klystrons;
HERE
Voltage Regulator
f-
..
.
Sorensen;
o ressen- Barnes;
E.R.A.
E.M.C.;
Ratings to 11/2
Amps dc. All variable!
KEY ELECTRONICS CO., INC.
518
E, 95 Si., B'klyn 12, N.Y.
Phone: Dickens 6 -4191
CIRCLE NO. 124 ON READER SERVICE PAGE
R. E. GOODHEART CO. INC.
Box 1220 -A, Beverly Hills, Calif. 90213
Phones: Area 213, office 272-5707, messages 275.5342
C
95
Included are ratio -arm bridges, self- balancing
capacitance bridge, bridge standards and adapters, transfer function computer, primary standards, plus various audio and video instruments.
equipment, test instruments, recorders and accessories, radios and phonographs, tubes, parts,
antennas, tools, and technical books.
MATHEMATICAL PUZZLERS
Adler Electronics, Inc. is now offering copies
45 of an address given by Stanley P. Lapin of
the company before the Third Annual Conference on Educational Television in which he
described an FCC -approved, economical 2500 megacycle closed- circuit service for instructional
television.
terchangeability guide and essential characteristics of 575 tube types now available.
The chart is printed on heavy stock and measures 28" x 30" for ease in wall mounting to
serve as a ready reference in television service
work. The new chart is No. ETR -702H.
EDUCATIONAL TV DATA
Al Litton Industries is again offering copies
of its popular "Problematical Recreations"
-41 illustrated mathematical puzzles and their
answers.
The Fifth Edition carries an interesting assortment of brain teasers ranging from those
involving simple reasoning to posers that may
stump the professional mathematician.
MAGNETRON APPLICATIONS
5oSylvania Electric Products Inc. is now offer-
ing a free brochure entitled "Magnetron Application Notes" which has been prepared by
the Microwave Devices Division of the company.
The 21 -page booklet is divided in seven sections which include chapters on test specificadons, essential tube information, measurement
of system and tubes as a unit, and application
notes for testing.
TV -FM ANTENNA CATALOGUE
Jerrold Electronics Corporation has issued
46 a 7 -page, 2 -color catalogue describing i:s
new line of Paralog TV -FM antennas. Catalogue
DS -CS -518.1 includes an explanation of the
modular parasitic element concept, plus specifications on both non -amplified and amplified
antenna types.
ELECTRIC SOLDERING EQUIPMENT
Electric Soldering Iron Co., Inc. is now
42 offering copies of its Catalogue No. 763, a
complete listing of its entire line of electric
soldering equipment.
Pictured and described is an extensive line
of solder pots, industrial soldering irons, miniature irons, soldering tips, and soldering guns.
Complete specifications are included.
INDUSTRIAL PARTS LISTING
Semiconductor Specialists Inc., distributor
51 of industrial components, has issued a 20page listing of a comprehensive line of diodes/
rectifiers, transistors, zener diodes, silicon controlled rectifiers, field -effect transistors, 4 -layer
diodes, diode assemblies, multiple -chip circuits,
micro -logic circuits, and accessories.
The listings are presented in tabular form for
easy identification of specific components.
INTEGRATED CIRCUITS
Signetics Corp. has issued an
8 -page
con-
41 densed catalogue which carries data on
25
integrated circuits available off -the -shelf. The
publication includes data on the firm's SE115
dual "nand /nor" gate which also provides "exclusive-or" function. Special -order products and
"CORDLESS POWER" REPRINT
Sonotone Corporation's Battery Division is
offering copies of an illustrated reprint of
the article "Cordless Battery Power" by Robert
J. McCarthy.
-I he four -page folder covers the firm's complete line of commercial, rechargeable sintered plate, nickel- cadmium battery cells. Included are
cross -section views, operational curves, packaging
concepts. charts, and tables on physical and
electrical characteristics, plus photos.
43
packages are also described.
PRINTED -CIRCUIT DATA
Centralab has announced publication of the
52 Seventh Edition of its popular "Packaged
Electronic Circuit Guide." The guide contains
information on how to select, test, and replace
PEC circuits used in radio, television, and high fidelity equipment.
The 8 -page booklet contains a complete listing of over 200 of the firm's packaged electronic
circuits, as well as complete replacement data.
TV TUBE REBUILDING
Windsor Electronics, Inc. has published a
48 booklet entitled "The Open Door to TV
Profits" which describes the rebuilding of TV
picture tubes by TV dealers and service technicians. Details on the company's rebuilding
equipment are also included in the compact,
pocket-sized manual.
ELECTRONICS CATALOGUE
Allied Radio Corporation has made "Elec44 tronics for Everyone" the theme of its new
444 -page 1964 catalogue.
The new publication lists the latest in hi -fi
components, "Knight- Kits" in all categories, CB
and amateur radio units, p.a. and intercom
PICTURE -TUBE
REPLACEMENTS
CAPACITOR RELIABILITY FACTORS
General Electric Company has announced
An Publication of its new "Television Picture
Tube Replacement Chart" which includes an in-
The Electro Motive Mfg. Co., Inc. has pre53 pared a special treatise entitled "Reliability
la
Jobs look for YOU
in ELECTRONICS
Factors Affecting the Selection of Mylar -Paper
TUBES
1
CORNELL'
1
Learn FAST -EARN FAST with
MTI's Unique Exclusive
Mutual Conductance Lab -tested, Individually
Boxed, Branded and Code dated
Training.
...................
Whether it's a BIG PAY JOB you
want or the chance to be YOUR
OWN BOSS -your big opportunity today is WAITI-NG for YOU
183
1H5
1L4
1T4
1U4
1X2
in ELECTRONICS! MTI's unique
SELECT-A -SKILL method quickly,
2A5
3CB6
5U4
5V4
easily qualifies you for the type of
electronic work that's exactly right
for YOU
COMMUNICATIONS
-
PER
TUBE
ELECTRONICS, INDUSTRIAL
ELECTRONICS, or RADIO & TV
SERVICING. Previous experience SKILLS PAY BILLS
proved unnecessary. Age no obstacle. With millions unemRight at home or through resident ployed
there is NO
classes in Jacksonville you learn by
doing, using your hands as well as
your head-building electronic equipment, testing and experimenting with
SEVEN BIG MASTER ELEC-
-
WIMP
Dept. 7- AX -02, Jacksonville 6, Florida
ACCREDITED Member, National Home Study Council
MAIL COUPON TODAY for FREE BOOK
and MTI's unique SELECT -A -SKILL
Opportunity Finder that can take the guesswork out of YOUR FUTURE!
World of Opportunity
in Electronics" PLUS
your SELECT -A-
SKILL Opportunity
Finder.
96
CIRCLE NO.
am interested in:
Home Training D Classroom Training
Name
Address
Zone.... State
City
I
0
/Weal.
6AG5
6AL5
6AN8
6AQ5
6AS5
6AT6
6AT8
6AU4
6AU5
6AU6
6AV6
6AW8
6AX4
6BA5
6BC5
68D6
6BG6
6BH6
68.16
6BL7
6BN4
6BN6
6BQ6
6BZ6
6C4
6C86
6CD6
6CF6
6CG7
6CG8
6 CM 7
6CZ5
6D6
6DA4
6SH7
T86
6SJ7
6SK7
768
6DE6
6DQ6
6EM5
6SL7
7C5
6F6
6SR7
6SN7
6507
7Y4
12AD6
12AE6
i
YOUR ORDER
If
noi shipped
24 hrs
FREE!
6H6
6J5
616
6K7
6L6
6Q7
6S4
6SA7
6SC7
6U7
6U8
"2AF6
12AT7
6V6
6W4
6W6
6X4
6X5
7A7
7A8
112AU7
12AX7
112046
1128 D6
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1Z6H7
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24
27
41
45
47
75
77
78
80
84/6Z4
LIVE IN THE EAST?
WAITED MONTHS FOR DELIVERY FROM OTHERS?
per tube
AIR MAIL AN ORDER TO CORNELL
AND RECEIVE DELIVERY TO THE EAST COAST
IN AS LITTLE AS 72 HOURS!!!
1
NO SUBSTITUTIONS WITHOUT YOUR PERMISSIO
(No Limit) from
TERMS:
6SN7024
6AG5
6AU6
6CG7
this lust. 0 Tubes are new, seconds or used and
616
6K6
6V6
6W4
FREE POSTAGE
ON
so marked.
PREPAID
USA ORDERS. Under
Send 25% deposit on COD
$5.00 add 50c for handling.
orders. No Canadian or foreign COD's- include postage.
No 24 Hr. Free Offer on personal check orders. 5 -DAY
MONEY BACK OFFER!
ORNELL ELECTRONICS CO.
Dept. EW12 4217 University Ave., San Diego 5, Calif.
Phone: ATI -9792
-
128 ON READER SERVICE PAGE
12BL6
128Y7
iB7
Other tubes and CRT's at low prices_ send for free list
%With every $10 Order
o
MASSEY TECHNICAL INSTITUTE
Dept. 7- AX -02, Jacksonville 6, Florida
6AC7
TUBE
rrr11
you NEED to insure
your future!
Massey Technical Institute
Please rush to me,
without obligation
your FREE BOOK
Pick Your New
3Oc
PER
5Y3
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100 TUBES OR MORE
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special skills! Let MTI
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TRONIC KITS! And you can earn
while you learn!
r
Ilt.t1UAli,AI,171,1)
CIRCLE
NO.
145 ON READER SERVICE PAGE
to military
Dipped, Paper Dipped, or Nlvlar- Dipped Capacitor" as a service
and industrial users of capacitors.
life
The publication provides the latest data and reports covering the
capacitors.
of
line
Menco"
"Elfirm's
the
of
characteristics
1964 KIT CATALOGUE
Heath Company has published the 1964 edition of its electronic kits
a wide selection of kits
54 catalogue. The 100 -page publication includes
infor all ages and interests. Products illustrated and described in detail
'[V. elecclude all types of audio equipment, color and black -and -white
tronic organ, tape recorders, radio receivers of all types, CB equipment.
and
ham and short -wave gear, marine equipment, automotive accessories,
test and lab instruments.
No
VARIABLE ATTENUATORS
offering an illustrated catalogue which contains design and
information, and
55 application data, dimensions, specifications, ordering
With
prices on four basic continuously variable attenuators in combination
various connectors.
Microlab
is
DX CIRCULAR
Buchanan, Michigan.
similarly
priced
SLIDE RULE
for
Electro- Voice, Inc. is now offering an ingenious circular slide -rule
hams as the "\\'9IOP Second Op."
Priced at $1.00. the device provides complete DX operating information
including prefix; great circle beam heading; tinte and data at DX location:
coupon exchange
air- mail. first class. and QSL card postage rates; IRC
table: continent; I)X zone; prefix -to- country translation: and QSL bureau
addresses. Also included is a log to indicate contact and receipt of QSL
cards for each country.
Orders for the "Second Op" should be sent direct to the company at
BELL
Li=
CARDIOID
measures up to the'fUß6f;R
EDUCATIONAL AID
Bell Telephone Laboratories has announced the availability of a new
teaching axid for use in high schools.
The new unit. which is entitled "Speech Chain," consists of material for
use in physics and biology classroom and an experiment that an advanced
student can do on his own.
The classroom material is based on the book "The Speech Chain: The
Physics and Biology of Spoken Language" by Drs. Peter Doles and Elliot
Pinson. a motion picture, a phonograph record, and a group of demonstra-
500
tion devices.
The entire package will be made available to high schools and science
teachers through local Bell Telephone business offices.
HI -FI /STEREO GUIDEBOOK
The Institute of High Fidelity, Inc. has issued "An Introduction to Hi -Fi
on selectR Stereo" designed to provide the layman with basic information
ing and setting up a component hi -fi system.
The booklet carries a number of photographs showing how audio equipment can be installed in various room settings without being obtrusive or
detracting from the decor, then the various components comprising a hi -fi
system are discussed individually with emphasis on performance standards.
listing of
A glossary of hi -fi terms, a hi -fi equipment planning guide, and a
audio specialists completes this attractive 64 -page booklet.
Copies are available for 25 cents each from The Institute of High Fidel-
Q840ó
LIST
ity, Inc., 516 Fifth Avenue, New York, N.Y. 10036.
HOBBY MANUAL OF SCR CIRCUITS
General Electric Company has published a "do-it-yourself" manual for
hobbyists interested in constructing circuits using silicon controlled rectifiers.
This 76 -page handbook contains a variety of practical home. workshop,
and industrial circuits using low -cost SCR's, rectifiers, and associated semiconductor components.
In addition to its use as a build -it- yourself book, this manual can serve
as a valuable introduction to solid -state devices for engineers and technicians not already familiar with power semiconductors.
All fifteen of the circuits included have been tested in the laboratory and
arc ready for breadboarding. Copies of the "SCR Hobby Manual" are SI.1)1
each. They may he ordered by writing direct to Hobby Manual, Box A.
You can buy microphones as good as the
Model 500, but they cost more money.
That's why it's wise to buy or specify Turner for top value in a cardioid. The Model
500 is ideal for any application where high
quality is necessary, calling for elimination
of extraneous noises -recording, broadcast,
P.A. and communications use. Matched
for stereo, unmatched for value. Ask for
. insist on today's big value in cardioid
microphones the Turner 500. Available
from electronic parts distributors, or write
direct for complete specifications.
A
Auburn, N.Y. 13022.
CHOOSING TOOL SIZE
By ELWOOD
C.
-
THOMPSON
SELECTING the proper wrench or nut driver for a nut,
bolt, or other such hardware item is not much of a problem ordinarily. However when the hardware is sunder a chassis
or otherwise hidden from view, although accessible, determining the correct tool size can be a nuisance. Several may
have to be tried, with reliance on an uncertain sense of touch,
before the right combination is obtained.
Use of the fingertip provides a "handy" shortcut. The finger
is pressed against the nut or other part, leaving a clear, if temporary, impression on the tip. The appropriate tool can genA
erally be matched up to this impression on the first try.
December, 1963
THE
MICROPHONE COMPANY
900 17th Street N.E.
Cedar Rapids, Iowa
IN CANADA: Tri -Tel Associates, Ltd., 81 Sheppard Ave. West
Willowdale, Ontario
CIRCLE NO. 141 ON READER SERVICE PAGE
97
Read Why the . . .
uu
r\\\V 1111unI u u nu uiUil////
-7/
__--
1963 INDEX
=
VOLUMES
TRANSISTOR IGNITION
with 30,000 Volts gives your car
peak ignition performance
69-70
drops from 28,000 volts to
13,000 volts as speeds increase to 50 mph. This
results in a weak spark
causing incomplete combustion, fouled plugs, burned
COMMUNICATIONS
points, loss of engine
power and- poor gas mileage, as unburned gasoline
goes out the exhaust. AEC -77 increases and maintains high voltage at all speed with no high voltage
fall -off, guarantees more complete combustion, stops
wasting unburned gasoline, releases all the power
your engine can develop to give you extra miles
per gallon.
----s"
POINTS
f
PLUGS
COIL'S 30,000 VOLTS: delivered to the plugs exceeds S.A.E. to t standards for performance. Its
regulated high voltage protects ignition wiring and
bakelite parts from insulation breakdown.
POINTS: high current charge now passes through
the transistor instead of the points, eliminates
burning and pitting
points last over 75,000 miles.
.
-
PLUGS: fire clean as higher voltage keeps carbon
and lead deposits from building up, eliminates
fouled plugs and high speed miss
plugs last over
50,000 miles.
-
3 Year Guarantee!
Proven in over 2,000,000 miles of testing
voltage transistors type .##2N1358A
are used in every AEC -77
while others use two unmarked low
voltage transistors in series that
can cause synchronization problems
and transistor failures.
50 WATT ZENER DIODES,
Motorola
type #1N2836B regulate high voltage and protect the transistor from
failure
while others use two 1
watt zener diodes or none at all.
400:1 COIL: epoxy -oil impregnated,
epoxy sealing holds component parts
firmly, cannot vibrate loose to cause
internal shorting,
oil filled and
hermetically sealed for superior cooling and insulation, while others use
inferior tar filled coils that cannot
handle the power loads AEC -77
delivers.
...
.-
Letters From Owner's Report
...
...
What
IN
...
AEC -77
AEC K4
Transistor 77 (400:1) Ignition Coil
Ballast Resistor, 250 watt .3-.9 ohm vari
AEC -77 Positive Ground
(British Cars)
6/12 volt
...
AEC
New Connectors and Techniques
(Buchsbaum)
Parts Improvement (Frye)
$39.95
387 PARK AVE., SO. NEW YORK 16, N.Y.
Commercial & Dealer Inquiries Invited
!ADDRESS
I
ID
ZONE
STATE
ground 6/12v
$39.95
ground 6/12 e
$39.95
400:1 Coil $11.95 El Ballast $1.95
AEC -77 For Negative
AEC -77P For Positive
Kit $32.95
FREE BROCHURE ON AEC 77 SYSTEMS.
EW12
CIRCLE NO. 103 ON READER SERVICE PAGE
98
July
52
43
67
41
69
26
27
8
48
32
41
36
62
48
listing
of
all
feature
41
52
46
79
33
July 48
Jan.
Oct.
June
July
Sept.
Nov.
Oct.
I
I
1963. We suggest you keep
this for reference.
Diodes Regulate Power Supply (Re) ....Oct.
14 -Watt Transistor Hi -Fi Amplifier
(Rehberger)
May
High- Performance Transistor Ignition
System (Mayfield)
June
Home -Made Printed Circuits (Barmore) ..May
Hybrid Bridge Power Supplies
(Marshall, WA4EPY)
June
Low -Cost Solid -State Power Supply
(Lehmann)
Oct.
Making Etched Circuit Boards (Bailey) .June
New Light- Operated Switch
(Whateley)
Nov.
9 -Watt Transistorized Hi -Fi Amplifier
( Bammel)
Mar.
Regulated Transistorized Power Supplies
(Collins)
Mar.
Silk- Screen Printing for Panels (Bailey)..July
Simple Transistor Checker (Molinara)... Feb.
Solid -State 3- Channel Color Organ
(Lancaster)
Apr.
Stereo Indicator Light Circuit (Blaser) ..May
Tape -Slide Synchronizer (Todd)
Sept.
Transient Evaluator (Ives)
May
Transistorized Tachometer (Todd)
Nov.
Transistorized Wireless Intercom
(Dezettel)
Feb.
Transistor Voltage Regulator (Gyorki)..July
Tunable Phase -Shift Audio Filter (Ives) ..May
Unijunction Metronome (Cleary)
Feb.
Simple Hum -Bucking Circuit (Gilbert) ..Aug.
53
49
94
80
May
76
44
96
34
42
July
80
Apr. 60
CONSTRUC d [email protected]!
I NAME
CITY
"Skin Effect "? (Tusinski)
Making Special Resistors (Jones)
Modern Batteries (Collins)
Modern Capacitors (Collins)
$39.95
$32.95
$11.95
$1.95
rAUTOMOTIVE ELECTRONICS CO.
1
387 Park Ave. South, N. Y. 16, N. Y
I
is
Effects of Radiation on Electronic
Components (Tromanhauser)
Fixed Resistors (Collins)
ORDER NOW!
(Regular list price $49.951
Transistor Ignition ... 6/12 volt
Do It Yourself Kit ... 6/12 volt
Dec.
COMPONENTS
last over 75,000 miles
plugs last 5 times longer
. installs in 20 minutes
eliminates 3 out of
4 tune -ups...pays for itself in 10,000 miles usage.
SAVE $10.00
(Part 2) (Rice)
Compact 6 -Meter Transceiver (Leibowitz,
W3KET & Pappas, W3TND)
Apr.
Emergency Call System for Highways
Jan.
FCC Answers our Questions on
Business Radio
Jan.
FCC Establishes Fees for Radio Licenses.Aug.
How Tough Are the Proposed CB
Regulations? (Conhaim)
May
Jet Transport Communications
(Conhaim)
Nov.
New CB Regulations (Editorial)
Feb.
New Citizens Band Circuits
(Buckwalter)
Apr.
New Citizens Band Circuits
(Buckwalter)
June
New Citizens Band Circuits
(Buckwalter)
Sept.
New Citizens Band Circuits
(Buckwalter)
Nov.
19 -Kc. Filter (Reamer)
Feb.
Proposal to the FCC
Citizens Radio
Technician License (Conhaim,
19W7577)
Mar.
R.F. Power Output Measurements
(Conhaim)
Oct.
Selective Calling for Two -Way Radio
(Golden)
June
Single Sideband Simplified
(Baird, W7CSD)
Feb.
Solid -State 3 -Watt CB -Ham Transmitter
(Barmore)
Oct.
Technical Manuals for Surplus Equipment
(Kelley)
June
Upgrade from CB to Business Radio
(Sands)
V.H.F. Marine Radiotelephony (Sands)
V.L.F. Loop Antenna (Genaille)
What is "Q "? (Tusinski)
15% extra miles per gallon
increases top speed
by 10% . . faster warmups
instant starting in
sub -zero weather
smoother idling
. points
... ...
Antennas for Business Radio (Rice) ....Mar. 33
CB Radio -Wave Propagation (Conhaim). Dec. 46
Choosing a Two -Way Radio System
(Part 1) (Rice)
Nov. 50
Choosing a Two -Way Radio System
-A
GENERAL MOTORS 15 AMPERE high
.
plete
articles which appeared in
ELECTRONICS WORLD daring
In any ignition, high voltage at the spark plugs
COIL
As a service to our readers we
are again presenting a com-
A.C. Voltage Calibrator (Bethany) ....June 56
Add a TV D.C. Restorer (Cohn)
Oct. 78
Burned -Out Pilot -Lamp Indicators (Ives). June 40
Capacitor Former for Electronic Flash
Unit (Leiberman)
Dec. 54
Chassis Design for Labs (Essex)
Sept. 91
Crystal -Controlled Time Standard
(Phillips)
June 34
D.C. to A.C. Transistor Powe- Supply
(Diehl)
June 66
66
46
30
64
82
92
38
47
46
40
73
94
55
72
50
45
66
76
74
48
78
77
HIGH- FIDELITY & AUDIO
Accurate Audio Frequency Measurement
(Edwards)
Aug.
Another Numbers Game (Editorial)
Sept.
Checking Speakers By Ear (Cohen)
Jan.
Checking Stereo Separation and Phase
(Glasgal)
Oct.
Column Loudspeaker Systems
(Augspurger)
June
Constant -Voltage Sound -Distribution
Systems (Cohen)
July
Decibel Table
Aug.
EIA Defines "High Fidelity" (Editorial).. Mar.
14 -Watt Transistor Hi -Fi Amplifier
(Rehberger)
May
Hi -Fi Loudspeaker Cones (McShane)
Feb.
Loudness Control (Jacobs, Jr.)
Dec.
Low -Pass Audio Filters for Increased
"Talk- Power" (Genaille)
Sept.
Microphone Volume Control (Trauffer) ..Apr
Music /Speech Discriminator (Gross) ....Apr.
Must Stereo Discs Sound Bad? (Cooper)..July
9 -Watt
Transistorized
Hi -Fi
46
8
57
37
25
29
38
6
46
38
34
47
72
36
42
Amplifier
(Bammel)
Phasemeter for Audio Frequencies
(Reamer)
Quarter-Track Mono Crosstalk Remedy
(Corn)
SCA Background -Music Multiple:.er
(Winfree)
Mar.
46
Nov.
43
May
83
Dec.
42
Apr.
50
Simplified Audio Impedance Matching
(Pugh, Jr.)
Solid -State 3- Channel Color Organ
(Lancaster)
Stereo Indicator Light Circuit (Blaser)
Tape -Deck Preamp (Wherry)
Tape -Slide Synchronizer (Todd)
Thin Loudspeaker Systems
(Augspurger)
Apr. 55
...May
Feb.
72
90
Sept. 50
Sept. 30
ELECTRONICS WORLD
TOOLS IN ONE!
FOR HOME
CAR SHOP
HOBBIES SPORTS
Transistorized Wireless Intercom
(Dezettel)
Transistors for Hi -Fi: Panacea or
Pandemonium? (Part 1) (von
Recklinghausen, Under & Mason)
Transistors for Hi -Fi: Panacea or
Feb.
Sept. 37
Pandemonium? (Part 2) (von
Oct.
Recklinghausen, Under & Mason)
Transistors vs Tubes for Hi -Fi
Nov.
(Miller, Grodinsky & Westra)
Transistors vs Tubes for Hi -Fi (Burwen) Dec.
Tunable Phase -Shift Audio Filter (Ives) May
Mar.
Turntable Testing at Home (Villchur)
Twin -T Oscillators: Design & Application
(Maynard)
Upgrading Simple
-
Offers Unlimited versatility
handles popular sizes of nuts, bolts
and screws with slotted, recessed,
square or hex heads!
Features fast action speedy 3 -way
ratchet handle that operates in
either direction or locks; regular
and recessed -head screwdrivers;
straight and offset adapters; eight
hex and square sockets from % "
to % ". Does the work of 18 tools
-8 straight and 8 offset wrenches,
plus 2 screwdrivers, yet fits in a
5%" x 4 %" case.
ONLY
complete with case -attractively
packed in gift sleeve upon request.
FULLY GUARANTEED!
MAIL COUPON TODAY!
EW -123
Ziff -Davis Publishing Company
Consumer Service Division
One Park Avenue, New York 16, New York
SOCKETOOL sets at
Please send me
$2.95 each. (N.Y.C. residents please add 4%
Sales Tax). My check (or money order)
is enclosed.
for
I understand that you will pay the postage
and that each SOCKETOOL is fully guaranteed.
D Check here for gift sleeve packing.
Name
Address
lone State
City
(SORRY -No Charges or C.O.D. Orders)
December,
1963
48
85
48
29
May 40
(Cassaday)
SOCKETOOL
BY SHELTON
38
FM Tuners
Which Tape to Use? (Burstein)
Wireless Stereo Converter (Pugh, Jr.)
RATCHET ACTION
76
May 80
Nov. 34
Jan. 53
use" your>''1
EW LAB TESTED
Nov.
"Acoustech I" Power Amplifier
May
Acoustic Research Turntable /Arm
Audio Dynamics ADC -1 "Mark II" Phono
Mar.
Cartridge
Audio Dynamics ADC -3 Phono
July
Cartridge
Audio Dynamics ADC -14 Speaker
Nov.
System
Audio Dynamics ADC -18 Speaker
Sept.
System
June
Audiotex Model B -206 Microphone
Bell RT -360 "Professional" Tape
Oct.
Recorder
Feb.
Citroen Model 660 Tape Recorder
Dyna FM Tuner FM -1 & Multiplex
Jan.
Adapter FMX -3
June
Eico ST70 Integrated Stereo Amplifier
July
Eico Model ST97 FM-Multiplex Tuner
Apr.
Fisher FM -200B Stereo Tuner
Mar.
Fisher KM -60 FM- Multiplex Tuner
Heath AA -21 Transistorized Stereo
Amplifier
Dec.
22
12
20
96
System
Koss
Leak
"PRO-4" Stereo Headphones
"Sandwich" Speaker System
Scott 333 AM- FM -MPX Tuner
Scott Model 340 Integrated
Tuner /Amp
Scott 350 -B Stereo Tuner
Shure 545S "Unidyne Ill" Microphone
Shure Model 560 Lavalier Microphone
20
May
24
22
24
14
Feb.
16
Aug.
12
Dec.
20
Aug.
12
A.C. Negative- Resistance Devices
July 50
(Turner)
Alternators: Selection and Installation
June 70
(Hector)
Are You a Potential Electronics Technical
May 58
Writer? (Glickstein)
Binary Numbers & Boolean Algebra
Mar. 72
(Andariese)
Mar. 25
Bionic Computers (Gilmore)
Jan. 88
British Electronics Research (Halliday)
Calibration
Aug. 28
Aug. 35
June
CREI can help you
make this profitable move
24
INDUSTRIAL ELECTRONICS
& Repair Technician
(Gedney & Winterburg)
Color Codes Chart
Controlled -Rectifier Gate Circuits
"Delcotronic" Transistor Ignition
System (Norris)
Digital Readouts (Buchsbaum)
Down -to -Earth Discussion (Frye)
Electromagnetic Delay Lines (Silver)
Electronic Instrumentation for Oil
Exploration (Frenzel, Jr )
Electronics Field Engineers Around
the World (Olson)
Electronics in Banking (Gilmore)
Electronics Lab Technician: His Role in
Industry ( Glickstein)
Ford Transistor Ignition System
(Oldham)
Hall Effect (Collins)
Instrumentation
12
14
Apr. 24
Sept.
Oct.
Jan.
field of Nuclear
22
16
AP
gtiuiôhe new
16
24
ectrobia experience to
N
16
Heathkit AS -22 "Profile" Speaker
"Knight" KN -3050 Public- Address
Amplifier
eI
22
16
Industrial use of nuclear energy is
creating new careers, right in your own
field of electronics. Men are needed to
design, build, operate and maintain
electronic instrumentation for practical
application of nuclear energy. You can
earn more money -with your present
employer or with another company-if
you supplement your electronics experience with specialized knowledge of
the nuclear field.
OUR FREE BOOK tells you how you
can do it -in your spare time -through
CREI's unique Home Study Program
Nuclear Engineering Technology.
or your copy, mai
coupon or write:
in
CREI, Dept. 1112 -A1,
3224 Sixteenth St.,
N. W., Washington
10, D. C.
FREE BOOK
84
July 39
CREI ATOMICS
CREI
Division of The Capitol2adio
Dept.
Engineering Institute,
1112-Al, 3224 Sixteenth St.,
N. W., Washington 10, D. C.
A
Feb.
33
Oct.
58
Feb.
46
Dec.
27
Please send me FREE BOOK describing the CREI Home
Study Program in Nuclear Engineering Technology.
have a technical background and a high school education.
Sept.
42
Name
Apr.
29
Nov.
40
Age
Address
City
Apr. 46
Apr. 39
Zone
State
A-61
99
latest Advances in Touch Control
(Atkins)
Many Uses of Solder (Entrican)
Microelectronics (Hamlin)
Naval Observatory Time Signals
(Wood)
May 34
July 65
Jan.
31
Aug. 30
Novel Electrometer Tube (Atkins)
On Our Cover
Operational Amplifier (Part 1)
(Frecker)
Operational Amplifier (Part 2)
( Frecker)
Oscilloscope Photography in Industry
(Shiver)
Quantum Devices (Collins)
RC Coupling Networks: A Practical
Viewpoint (Heller)
Scaler Measures Distances from Aerial
Oct.
Aug.
44
27
July 52
Aug. 48
Mar.
53
Dec.
39
Jan.
46
Photos (Hiliard)
Jan. 40
Sceptron
Sound -Operated Fiber -Optic
"Brain Cell" (Balandis)
Mar. 36
SCR: Silicon Controlled Rectifiers -New
Applications in the Home (Sterni
Oct. 27
Selecting a Suitable Heat Sink (Gyorki) June 46
Semiconductor Strain Gages (Renné)
July 36
Taming Transients (Frye)
July 56
Variable Electronic Gain Control
(Shields)
Oct. 101
-A
MEDICAL ELECTRONICS
Advances in Electron Microscopy
(Gilmore)
July
Bionics -Its Meaning, Promise &
Danger (Frye)
June
Caduceus & the Electron (Frye)
Mar.
Electric Shock -On Purpose (Bukstein) Feb.
Electronic Anesthesia (Buchsbaum)
Sept.
21
50
58
29
27
NOMOGRAMS
NEW SONY CITIZENS BAND TRANSCEIVER
WITH SEPARATE HEADSET AND MICROPHONE
The new SONY CB -106 transceiver is unique in the Citizens Band
field. With 10 transistors for extreme reliability and sensitivity,
it includes a transceiver chassis and separate foam cushioned
headset with adjustable microphone. Your hands are always completely free, since the set is keyed with a fingertip cable release.
The chassis is out of the way, too, suspended in a shoulder case
and belted around the waist. Battery operated and with a range
of up to 6 miles, the CB -106 includes chassis, headset-microphone, microphone cable release, shoulder case, batteries.
$199.95 per pair. $99.95 each
SONY CORPORATION OF AMERICA
580 Fifth Avenue, New York 38, N.Y.
Regional Offices
Western: 500 West Florence Avenue. Inglewood. Calif.
Central: 4959 W. Belmont Ave., Chicago 41, III.
Gentlemen:
Ew -12l
Please rush me full details on the new
SONY CB -106 Citizens Band transceiver.
Name
Address
City
Zone
_S -ate
SONY Corporation of America 58C 5th Ave., N.Y. 36, N.Y.
CIRCLE NO.
138 ON READER SERVICE PAGE
ERRELL KITS
HAS THIS AMPLIFIER
Small collego
four -quarter year permits coni plat ion
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Engin Cerino: Electrical
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$4995
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STEREO AMPLIFIER W /PREAMPS
Complete line from $19.95. 5: higher W. of Rotkies
Detailed Instructions, Diagrams. Covers extra.
Write for Brochure, Nome of Nearest Dealer
MERRELL KITS, 519.W Hendrix St., Brooklyn 7, N. Y.
100
.
Sept.
Apr.
33
33
Aug.
37
Dec.
31
Nov.
31
Jan.
July
June
Oct.
38
25
37
31
May 25
TELEVISION & RADIO
------
Add a TV D. C. Restorer (Cohn)
Oct.
Additions to Japanese Radio Listing ..Sept.
AM -FM Car Radio (Prewitt)
Mar.
Brain Vacations (Frye)
Jan
Color -TV in Kit Form
Dec.
Directory of Importers and Manufacturers
of Japanese Transistor Radios
May
Electronic Antenna -Pros & Cons
78
(EW Symposium) (Tepfer)
European Color -TV Developments
41
Feb.
(Halliday)
82
44
64
49
38
July 66
How Britain Tracks TV "Pirates"
year -round program
.
Cathode -Follower Nomogram
(Teubner)
Coil- Winding Nomogram (Teubner)
Meter Range- Extension Nomogram
(Teubner)
Negative Feedback Nomogram
(Teubner)
Parallel- Resistor Chart (Brindley)
RC Charging Circuit Nomograms
(Moffat)
RC Filter Chart (Re)
Resistor Power Calculator (Re)
Ripple -Filter Design Chart (Teubner)
Tolerance Calculator (Re)
.
(Halliday)
June 68
How to Select a Closed Circuit TV
Camera (Sander)
Oct. 41
How Will U.H.F. TV Affect You? (Silver) June 21
Indoor Horn for TV -FM Reception
(French)
Dec. 50
Interference Stopper for AM Sets
(Amorose)
MPATI
Problems & Solutions (Frye)
Shrunken Raster: A Puzzler
-Its
June
May
(Widmann)
Nov.
Television Waveform Quiz (Balm)
Nov.
U.H.F. Reception: Practices and Equipment
(Beever)
Nov.
Understanding Color TV Demodulators
(Buchsbaum)
July
73
52
92
95
37
44
t11-1.11
TEST EQUIPMENT
'
16123 College Averse
Angola. Ind.
A.C. Voltage Calibrator (Bethany)
Audio Output Power Meter (Berry)
....June
ELECTRONICS
56
Oct. 48
WORLD
GREAT SUBJECTS,
GREAT PICTURES
IN
PHOTOGRAPHY
ANNUAL 19°..:.
,.+..,..
r ,w ,.w, aw sMw+W ..w+ n
doe
rm.. 4 rw..u.
Audio Tone -Burst Generator (Reamer)...Oct.
Calibrating Test Equipment
(Buchsbaum)
Cathode -Ray Oscilloscopes (Marrie)
Color- Pattern Generators (Cerveny)
Crystal -Controlled Time Standard
(Phillips)
D.C. to A.C. Transistor Power Supply
(Diehl)
Diodes Regulate Power Supply (Re)
Direct- Reading Instruments (Van Veen)
FM Multiplex Signal Generator
(Kolbe)
FM Multiplex Signal Generator
captured by Concord
50
Aug. 43
Aug. 50
Mar. 50
June
34
June
Oct.
66
66
THE
INTERGALACTIC
FORMULA
FOR
Aug. 23
Jan.
34
Feb.
(Reamer)
Frequency Multiplication & Division
Sept.
(Frenzel)
Sept.
How Much Accuracy? (Frye)
Hybrid Bridge Power Supplies
June
(Marshall, WA4EPY)
May
Hysteresis -Loop Plotter (Faso!)
Nov.
Inside a Digital Voltmeter (Messin)
Low -Cost Solid -State Power Supply
Oct.
(Lehmann)
Nov.
"New Look" in V.O.M.'s (Frye)
Aug.
1963 Directory of Kit Test Equipment
Regulated Transistorized Power Supplies
Mar.
(Collins)
Signal- Generating Equipment (Roberts) Aug.
Feb.
Simple Transistor Checker (Molinaro)
May
Transient Evaluator (Ives)
Nov.
Transistorized Tachometer (Todd)
Transistor Voltage Regulator (Gyorki) ...July
Tunnel Diode High- Resistance Checker
June
(Todd)
55
AUDIOSONIC
CALCULATION
53
58
82
29
53
92
60
54
40
31
94
45
66
74
86
PRODUCT REPORTS
The editors of Popular Photography
have gathered the year's outstanding examples of the art of the camera
for the 1964 Edition of Photography
Annual. It features: 5 personal portfolios, a forecast on next year's Pulitzer Prize -winning picture, excerpts
from the outstanding photo books of
the year, selections from photography exhibits and a famous International Portfolio of fine pictures. You
won't want to miss
PHOTOGRAPHY
ANNUAL 1964
It's now on sale at newsstands and
camera stores. Be sure to get your
copy today -or send in this coupon
and we'll mail your copy to you.
Only $1.25
Associated Research 2850
Megohmmeter
Ballantine Model 314A Video V.T.V.M
Don Bosco PHD -100 Universal
Signal-Tracer Lab Set
Delta 01B-2 R.F. Impedance Bridge
DeVry Transistorized Meter
Dynascan Ill Digital Voltmeter
Eico Model 430 Oscilloscope
Eico Model 722 V.F.O.
Eico 902 Distortion Meter
Eltec Model 600 Frequency Standard
Fisher 300 Multiplex Generator
GC Electronics 36 -616 CRT Tester &
Rejuvenator
Keithley Model 121 Wide -Bond R.M.S.
Voltmeter
Pioneer Model 36 Photo Tachometer
RCA WE -95A V.O.M. Dynamic
Demonstrator
RCA Model WR -51A FM Stereo Signal
Generator
RCA WV -76A A.C. V.T.V.M.
Seco 212 Electronics Thermometer
Seco Model 600 SCR Analyzer
Sencore 8E124 Battery Eliminator
Sencore CA122 Color- Circuit Analyzer
Sencore CR125 Cathode -Ray
Tube Tester
Simpson Model 261 V.O.M.
Triplett Model 630 -NS Volt -Ohm-
Microammeter
Ziff-Davis Service Division
EW-123
Dept. PA, 589 Broadway
New York 12, New York
Please send me a copy of PHOTOGRAPHY
ANNUAL 1964. enclose $1.25, the cost of
the ANNUAL, plus 15¢ to cover mailing
and handling charges. (Canada & Overseas: $1.25 plus 25¢ postage.)
I
NAME
ADDRESS
CITY
ZONE
STATE
-
(Add 4% sales tax if N.Y.C. resident)
t.
December, 1963
Aug.
78
Oct.
71
Feb.
20
Nov. 87
July 70
Sept.
75
Nov. 86
Mar. 70
Sept.
74
Dec.
72
Apr.
66
Oct.
70
July 71
Nov. 88
Apr.
68
Aug.
Dec.
78
68
Sept.
June
June
Oct.
76
60
60
70
Aug. 79
Dec.
68
July
70
4
3
track stereo record
and playback
speeds:
2
separated 6" speakers.
2 dynamic microphones
3a,1%
1 low price
good reasons why
you should own a
Concord 550 -4 with exclusive
Trans -A-Track priced under $320
Concord's 550 -4's transistorized operation assures greatest reliability with
freedom from noise, heat and hum.
Exclusive "Trans-A- Track" for education and fun is one of many fine features
10
including automatic reel -end shutoff,
pushbutton controls, sound -on -sound
and 2 VU meters. Uses amplifiers and
speakers of hi-fi system or completely
self -contained. (550 -D tape deck version available, less than $230 )
Prices slightly higher in Canada
TRANSISTORIZED
Detection of Nuclear Radiation by
Semiconductors (Renné)
Domestic Replacements for Foreign
Semiconductors (Eimbinder)
European Receiving -Tube Numbering
System (Elizondo)
Field- Effect Transistor (Green)
Kobe ( "Ten ") Transistor Substitution
Directory
Nippon Electric Co. Transistor
Substitution Directory
Power Transistor Specifications
(Gyorki)
550 -4
CONCORD
TUBES & TRANSISTORS
own'
of
Aug.
39
July
26
Mail coupon to:
Nov. 74
Sept. 66
CONCORD ()ELECTRONICS CORPORATION
Dept. 24, 809 N. Cahuenga Blvd.
for Concord's free booklet
full story on the 550 -4.
,
"All
Los Angeles 38, Calif.
The Facts" and the
NAME
Mar.
43
June
45
Jan. 44
ADDRESS
CITY
In
STATE
Canada/ Regal Industries Ltd., Montreal.Toronto
CIRCLE NO. 149 ON READER SERVICE PAGE
101
Problems of Tube Short Testing
(Overstrom)
Jan. 56
Receiving Tube Grid Current
(Szilasi)
Feb. 50
Recording -Storage Tubes and Their
Applications (Luftman)
May 21
Replacements for Non -Standard Domestic
Transistors (Eimbinder)
Sept. 36
Seminconductor Seminar (Frye)
Aug. 66
Simple Tests for Semiconductors (Todd) Dec. 36
Toshiba Transistor Substitution
Directory
Apr. 52
Transistors for Hi -Fi; Panacea or
Pandemonium? (Part 1) (von
Recklinghausen, Linder & Mason)
Sept. 37
Transistors for Hi -Fi: Panacea or
Pandemonium? (Part 2) (von
Recklinghausen, Linder & Mason)
Oct. 38
Transistor Substitution Directory (Sony
Your 1964
copy is
waiting
For fun and pride in assembly, for long years of pleasure
and performance, for new adventures in creative electronics
mail the coupon below and get Conar's new 1964 catalog of quality doit- yourself and assembled kits and equipment. Read about items from
TV set kits to transistor radios
from VTVM's to scopes
from
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FREE,
...
1111.UI MAIL THIS
...
COUPON
NOW111111111111111111U
C®NA
.
& Hitachi)
Transistors vs Tubes for Hi -Fi (Miller,
Grodinsky, & Westra)
NB3C
3939 Wisconsin Ave., Washington 16, D.C.
Please send me your 1964 catalog.
Name
II Address
City
Zone
State
SILICON CONTROLLED
PRV 7 AMP 25 AMP
70
1.50
2.75
140
2.00
3.25
NEW! LAFAYETTE
12- TRANSISTOR 2 -WAY
200
250
300
2.25
2.75
3.00
RECTIFIERS TESTED!
PRV 7 AMP 25 AMP
350
400
450
500
600
3.50
3.75
4.00
3.50
4.00
4.40
4.75
5.50
NPN- Germanium MESA Transistors F max
" WALKIE
4.40
4.65
5.00
5.25
6.00
-250
VARIACS
11/4 AMP
13/4 AMP
2 AMP
3 AMP
10 AMP
20 AMP
20 AMP (Cased)
ESTERLINE -ANGUS RECORDER
1 Ma Excellent Cond. W /Pen; ink; paper.
$229.50
VARIAN FOCUS MAGNETS
«1504 -A New
$1195.00 Pair
CAPACITOR
I Mfd. 12. SK Volts OIL
$14.95 ea.
SOLENOID
Guardian No. 16ÁC 115 VAC
Ib. pull.. 1.89 ea.
12 for 20.00
TRANSFORMERS
Pri 115 V or 230 V Sec
x 6.3 V 8 A, Ea. 230 V
450 Ma Epoxy Encapsulated
$6.95 ea.
Pri 115 V Sec 12.6 VCT @ 4 A& 15 V e LA
2.95 ea.
Stancor rPM8418 460 VCT @ 50 Ma & 6.3 V @
-2
-3
............
2.5
.........
A
2 95 ea.
6 95 ea.
6 49 ea.
PANEL METERS
4" SQUARE
AC- VOLTS
-0.2; 3;
5
10; 15; 25;
50
.3.95 ea.
0-71/3 & 15 5.95 ea.
AMPS-
0 -1; 2; 3..5.95 ea.
DC-MA0-50;
100..5.95
-300;
600
VOLTS
4"
500:
ea.
5 95 ea.
ROUND
AC- VOLTS0.50
3 50 ea.
-0.150
MA
ea.
DC- VOLTS -0-25;3.50
300;
500
3 50 ea.
3" RD-AC
0.100
0.5 AMPS (marked 150
A)
3"
0 -150 V &
RD
3 95 ea.
-DC
300 V (Dual
Scale) Weston 5.25 ea.
3" SQ. -AC
0-150V (Spread Bet. -90120) G.E. No. AO 72
Converts 117VAC to 9V
Plugs into HE -100.
4 95
3" SQ. -DC
0.5 MA
3 95 ea.
3" RD-DC
0-150; 200;
250 MA
4.25 ea.
10.0.6+ DB
4.50 ea.
2" RD -DC
Send
Cortlandt St., New York
7,
N.Y.
RE
2
-0270
CIRCLE NO. 100 ON READER SERVICE PAGE
102
me: Walkie
AC
28
30
52,
68
70
72
Talkie
(HE -100L)
Power Pack
OoenO)
mugeTw0m6s
//,,,,
INC.
1yu;
(HE-97),
I
I
I
TALKIES
27.52
enclosed.
$
I
Name
L
Shure Brothers, Inc.
Heath Company
(Fig. 1)
Sinclair Research, Inc.
(Fig. 2, left)
Hall- Sears, Inc.
(Fig. 2, right), (Fig. 3, left), 30 (Fig. 5)
Electro -Tech Division, Mandrel Industries, Inc.
(Fig. 3, right), 30 (Fig. 6)
Dresser Electronics, SIE Division
(Fig. 71
Geotechnical Corp.
53
Motorola Inc.
Radio Corporation of America
Simpson Electric Co.
Eltec Laboratories, Inc.
WALKI E
=---- - -- --I
Address
City
Credit
(left)
(right), 49
20
20
28
28
28
DC.
Shipping charges collect.
FOB NYC
ADVANCE ELECTRONICS
79
PHOTO CREDITS
Net 7.45
LAFAYETTE Radio ELECTRONICS
Dept. RL -3, P.O. Box 10,
Syosse :, L.I., N.Y.
-27
All Shipments
................
HE -97
0.1 MA
3 95 ea.
11/x" SQ. -DC
0.1 MA
3 75 ea.
-r22,
REFERRAL SERVICE
THE Library of Congress has established a National Referral Center for
Science and Technology which will serve
as a clearing house for information
sources available to scientists and engineers.
The Center's job is advisory, It is designed to make information resources
known to the country's scientists and
engineers and to assure the fulDest possible utilization of these resources. It does
not answer technical questions directly
but refers inquirers to the organizations,
institutions, or individuals -within and
Page
NEW! AC POWER PACK
MA
2 95 ea.
0 -130 VOLTS ..3.95 ea. 0 -100 MINA
3.95 ea.
TRANSISTOR CHARACTERISTIC PLOTTERS-Displays
r12
less Scope
$80.00 ea.
BLOWER Squirrel Cage type
V DC or 30 V
AC- Filtered. 7.000 RPM packed in reusable
can
$3.95 ea.
r12-
Nov. 48
.
Model d'AW
etc.
315 V Pri Sec. 6.3 VCT @ 30 Amp
Plate tsfmr. 1100 VCT 250 Ma
for 78.88
More fun ... better performance
greater
2
value, than ever. Superb
for fishing, hunting or
business use. No age restrictions or license requirements when used as
per Part 15 FCC regulations. Features: separate
microphone and speaker
for better sending and receiving, excellent noise
squelch; crystal controlled
receive and transmit, positive action push -to -talk
switch and 46" telescoping antenna. As a bonus
feature, the HE -100 may
be operated in the home
with an AC power pack.
(Optional see below) Saves
batteries too! Includes
crystals, earphone, leather
carrying case and batteries. Shpg. WT., 22 oz. Imported
HE -100L Walkie- Talkie
... Net 39.95
Pair for 78.88
14.95
18.95
24.95
29.95
71/1 AMP
5 50
6 25
7 50
8 95
39.95
only
MC-
BV-10V
10/4.00 100/35.00
Mixed Transistors
10/1.00
MADT Transistors
4/1.00
Germanium Diodes....
..Computer type-$8/1.00
UHF Diode 1N82A -LD128
10/2.50
WITH SQUELCH
TALKIE'
45
outside the Government.
Requests for referral service may be
made by visiting the Center between 9
a.n1. and 5 p.m., weekdays, on the fifth
floor of the Library of Congress Annex,
Second Street and Independence Avenue,
SE, or by calling STerling 3 -0400.
Written requests should be addressed
to National Referral Center for Science
and Technology, Library of Congress,
Washington 25, D.C.
11111111111111111M111111111111111111111111111111111M1
ADVANCE ELECTRONICS
Feb.
I
Zone
State
MIR
CIRCLE NO. 125 ON READER SERVICE PAGE
"Came in Ace Electronic Supply . .
What's
your best price on walkie- talkies ?"
.
ELECTRONICS WORLD
ND W 11' S A BREEZE
thing
every
All
to paint
with
-
p- acticatly
NO OVERSPRAI
-
IN OPERATION'
HO MISTING
CLOG
EVER
CAN'T
here
you see
-including
logs
theme
With the
WORLD'S FIRST
=PAINT
ROB
ONLY THE
SLOAN- ASHLAND
ROTARY ACTION
PAINT
GIIN...
Une
let's you paint dcan
so fine you
write your name
..
Delivers as much paint per minute
as a $200 industrial compressor
model. HANDLES WATER SOLUcover a full foot- and -ahalf swath with one pass ...
BLE, RUBBER BASE, OIL BASE,
FLAT, SEMI -GLOSS AND ENAMEL
INSECPAINTS. LIGHT OILS
. FLOOR WAXES,
TICIDES
POLISHES AND OTHER LIQUIDS.
...
No costly compressors
No nozzles, needles, strainers
to clog
No air hoses to drag
No flimsy vibrators
OPERATION for perfect control of light and heavy
liquids.
FINGER-TIP CONTROL OF
PAINT FLOW- trigger lets you
start and stop spraying instantly
ADJUSTABLE GATE FOR EXACT WIDTH OF SPRAY YOU
WANT- from '//" to 18" -can't
ever clog in operation.
2 -SPEED
paint within inches
.
CLAMP -ON CAN holds full
quart
PAINT VOLUME CONTROL
lets you deliver just the
amount of paint -desired to the
working surface
For 115V AC operation
Fully guaranteed
ALUMINUM DIE CAST
HOUSING for light weight and
rugged durability
CAN'T EVER CLOG
IN OPERATION
Powerful GE m:tor and rotary
action spin the paint at a
steady 17,000 RPM
actually makes the Sloan Ashland Paint Sun imposáible
to clog in operation!
Reduces misting and overs ray
to a minimum. Eliminates 90%
of usual masking! No more need
to cover everything in sight.
...
AMAZINGLY EASY
C$5,11"
TO
Powered by
GENERAL ELECTRIC
CLEAN OR CHANGE COLORS
Fill container with water or proper solveaL run gun for
two. That's all there is to it! No mess, no bother!
-
Now you can do 100 Sq. ft. of surface in minutes because you
cover three times as much area on each stroke, with the Sloan Ashland Rotary Paint Gun. You cover a full foot -and -a -half
inside or outswath with perfect control. Big job or small
whether you're spraying paint or other fluids- nothing
side
does the work as quickly, as easily as this amazing paint gun!
...
...
Typical Oval Pattern of
Ordinary Spray Gun.
minute or
TWO QUARTS OF
SPRED -SATIN PAINT
w
Covers 300% more width
in each stroke than a 6" brush or roller ...
a
American Products Division, 589 Broadway, New York 12, N.Y.
Send me your new Sloan -Ashland Rotary Paint Gun. I may use
it for seven days free, and return it at your expense if am
not fully satisfied.
Also -send me two free quarts of Spred Satin Paint (worth
agree to
may keep and ese whether or not
$4.30) which
buy the Sloan -Ashland Rotary Paint Gun.
I
I
I
If do agree to keep it, will pay only $8.50 a month until
I've paid the low price of just $59.95 (plus shipping and
handling..
I
I
"Straight Line" Pattern of
Sloan Ashland Paint Gun.
Name
(Please print)
Street
Zone
City
Oval spray and wide
feathering around edges
make precise work difficult,
requires extensive masking.
December, 1963
Straight line spray and
minimum of feathering gives
you perfect control for the
most precise painting.
State
Where employed
Home
phone number
EW1
103
r
\
ARC -3
RECEIVER!
=_
0
Will
II
Complete
th A ll
s Exc.
W
Used
1
IMPORTERS
50
....
unit for above tunes 100 to 156 MC on
any 8 pre-selected channels. 9 tubes. Crystal controlled. provides tone and voice modulation. 28V
DC Power Input. Complete with all
Q955
Tubes: 3 -6V6, 2.832A, 1.12SH7, 1 -6J5.
2 -6L6. Exc. Used
Only
Like new Condition
ARC -3 PUSHBUTTON CONTROL BOX
$5.95
LORAN APN -4
FINE QUALITY
NAVIGATIONAL EQUIPMENT
_
LATEST TYPE COMMAND
BROADCAST RECEIVER!
Like NEW,
with Tubes
INVERTER POWER SUPPLY for above APN -4. INPUT:
24 V DC. OUTPUT: 115 V AC, 800 cycles. Like
New
$22.50
--
$3450
-
,
12 -Volt Inverter Power Supply for above APN -4.
l'.U.I:.
a Complete line of replacement parts and
accessories for above.
like 'New.
We Carry
/APN -9 RECEIVER
& INDICATOR
CHANNELS
11
200 -1500 Kc
2 to 18.1 Mc
1
''
dition
a,
-
type 5CPI
only
p`
-r
.
,i
_
YY..
,,
`
D
.o O
Rw
TS -100AP 'SCOPE
EXC. USED (worth
OUR LOW PRICE
$750)
n
included. Also used
sweep as precision
$3950
,-an he U. ,,l with linear sweep or
general purpose
11
Q
O-(ß,1e !A
a,,
IDgelf't;j
l'
.
co
e
Brand New $69.50
test scope. Cables
with circular
range calibrator. Self- contained in metal
8" x 121/g" x 16" deep. For case
110
V .
to 1200 cycles AC. Excellent
used. like new, with li tubes including crystals and
Tube.
C.
EM FREQUENCY METER
Crystal calibrated modulated. Heterodyne, 125
Kc to 20,000 Kc With Calibration book
$69.50
Complete, Like New
BC -906 FREQ. METER -SPECIAL
Cavity type 145 to 235 Mc. Complete with antenna.
Manual and original calibration charts ineluded. BRAND NEW, OUR LOW PRICE..
$12.88
BC -221 FREQUENCY METER
SPECIAL BUY! This excellent frequency standard is
equipped with original Calibration Charts, and has
ranges from 125 KC to 20,000 KC with Crystal Check
points in all ranges. Excel. Used with original Calibration Book. Crystal, and all tables. CHECKED OUTI
rnmorlulaied
.
$79.50
Modulated .....P.U.R.
BC -221 1000 Kc Crystal !band New
p
BC -348 SUPERHET RECEIVER _Oil to 5'10 Re and 1.X
to 1800 Ale Voice T o
CW. S If
i i
1
i - ',
DC. Ene Lcd, Checked nut.
589 50
(
,
..
$0.5
If
`
ALL COMPLETE WITH TUBES
Type
Description
BC -453 Receiver 190 -550 KC
Used
$12.95
12.45
11.50
4
NEW
1.5 to
-4
$10.95
BC -696 TRANSMITTER 3 -4 Mc
Complete with
.Ml Tubes & Crystal. Like New
BC -456 Modulator
USED
ALL
.....
3.45
$7.95
$11.95
NEW 5.95
('t'1: usliRl FS AVAILABLE FOR ABOVE
ARC- 5/T -23 TRANSMITTER 100 -150 Mc.. includes tubes: 2 -832A, 2 -1625. BRAND
$21.50
NEW, with tubes
$5.95
Excellent Used. less tubes
ARC- 5 /R -28 RECEIVER, 2 -meter superhet, 100
to 156 Mc in 4 crystal channels, complete with
10 tubes
$24.95
'P
Excellent Used. with tubes
ó,rtñs Pegé0 Tnt 65(
include 25% Deposit with order -Balance
SCHEMATIC DIAGRAMS
Please
C.O.D., or Remittance in Full. 500 Handling Charges
on all orders under $5.00. All shipments F.O.B. Our
Warehouse, N.Y.C. All Merchandise subject to Prior
Sale and Price Change.
7 -4605
New York 13, N. Y.
Telephone: CO
St.
CIRCLE NO. 119 ON READER SERVICE PAGE
$9.95
BRAND
SCR -625
-
DYNAMOTOR VALUES:
Input
Type
SD
$2
2 950
Excellent BRAND
Output
250V .05A
575V .16A
28V 7A
540V .25A
0M -340 12V 2A
220V .080A
DM -36 28V 1.4A
220V .080A
DM -43 28V 23A
925V .220A
460V .185A
DM -53A 28V 1.4A
220V .080A
PE -73C 28V 20A
1000V .350A
PE -86 28V 1.25A
250V .050A
DM -37 DYNAMOTOR. Input 25.5 V DC
put 625 V DC
-
--
.;
MINE DETECTOR
DM -324 28V 1.1A
DM -33A 28V SA
Used
NEW
2.45
4.45
2.95
4.15
1.95
4.45
5.50
2.95
7.95
3.75
5.45
8.95 14.95
2.75
3.85
-
(d.
9.2 A. Out-
225 Ma. BRAND NEW. Each $3.25
MICROPHONES Checked Out. Perfect
EXC.
Model
Description
USED
T -170 ..Carbon Hand Mike.
.....$4.45
RS -38.. Navy Type Carbon Hand
BRAND
NEW
$7.95
Mike..3.55
HEADPHONES Checked Out, Perfect
Model
Description
EXC.
USED
-23 .. High Impedance
H5-33-Low Impedance
5.75
BRAND
NEW
$2.79.. $4.95
3.15.. 5.45
Imp. (featherwt.)
.90.. 1.65
Imp. (2 units)
3.75..
7.95
TELEPHONICS -600 ohm Low Impedance HEADSETS. BRAND NEW. PER PAIR
$3.95
CD -307A Cords. with PL55 plug and JK26 Jack
.99
Earphone Cushions for above -pair
.50
HS
HS-
30....Low
H-16/U. .High
.
2 VOLT BATTERY "PACKAGE"
-2V. 20 Amp. Hr. Willard Storage Battery.
Model _ 20.2. 3" x 4" x 51/2" high
$2.79
I -2V, 7 prong Synchronous Plug -in Vibrator.
1.49
-Quart
1.45
I
1
Bottle Electrolyte (for
2
cells)
ALL BRAND NEW! Combination PriCe
G & G RADIO SUPPLY CO.
77 Leonard
8,,,-..,--
Complete portable outfit in origi.
nal packing, With all accessories
Brand New
Like
NEW
$14.95
17.95
13.95
$17.95
1
all tubes and crystal.
BRAND NEW
Like New
'j
Like New, with tubes..$7.95
Like New, less tubes..$3.95
-454 Receiver 3.6 MC
-455 Receiver 6-9 MC..
3 MC. Receiver Brand New
110 Volt AC Power Supply Kit for all 274 -N
ARC -5 Receivers. Complete with metal
$.85
instructions
Factory wired. tested, ready to operate .$12.50
SPLINED TUNING KNOB for 274.N and ARC'',
RECEIVERS. Fits BC -453. BC 454 and
49(
others. Only
2.1 to 3 Mc Transmitter, Brand New
$12.95
BC -457 TRANSMITTER
-5.3 Mc. complete
$9 75
with all tubes and crystal. BRAND NEW
fV
J
Like New
.$7.95
BC 458 TRANSMITTER -5.3 to 7 Mc. Complete with
BC
BC
"
BC1206 -C BEACON RECEIVER
`
COMMAND EQUIPMENT
I
Hot Special! 2000 to 6(6/0 Ke AM Ile.
celver,
2 -hand,
complete with SII
tubes, 200 Kc Xtal Calibrators, and
12 V Dynamotor. Fine for 80
t ,^e
Ham band. Marine, etc. Provides fn.
(INV. MVC, AVC. Speaker Jack and two
Headphone Jacks. Shpg.
Qp
Wt. 50 lbs. Brand New, Onl439.50
195 to 420 KC. Made by
Setchel- Carlson. Works on 24
28 volts DC. 135 KC
IF.
Complete with S tubes Size
4" x 4" x 6 ". Wt.
lbs.
-if
SCR -274
I
/
_.
514.50'
BC -652A RECEIVER
k!j.
`)
s
..77
I
Sul
Supple
ACIPOwor
& G Radio maintains one of the largest stocks of
Government Electronic Surplus Equipment in America!
if the item you need is not shown here
you see
it listed elsewhere-write or call today for our LOW,
LOW PRICE and Speedy Delivery FROM STOCK!
APN -12 3 -INCH SCOPE
-
/APR4 RECEIVER only. 38 to 400G MC in 5 tuning unit ranges. High precision lab instrument. Input
115 V63 cy. Like New
$89.50
Tuning Units TN16, 17, 18 each
$39.50
Tuning Unit TN19. Brand New
$89.50
Tuning Unit TN54
$149.50
---°
[
1
AN
ELECTRONIC SURPLUS HEADQUARTERS!
I$14.95I
Has vertical and horizontal sweep
with focus and Intensity cOOtrOls.
coaxial antenna changeover motor.
Complete with 11 tubes and 3JP1
CR Tube. For 115 V. 400 Cycle AC
and 24 V DC. Circuit did.
gram included. LIKE NEW. $14.95
-
C
-TV service bench. LIKE
o-í radio
0 t--e
NEW! Supplied with 5" Scope,
ad
TRANSMITTER Companion unit to
-27.9
3C603 Receiver. Complete with all
tubes . BRAND NEW
$1095
. 5
ARB /CRY 46151 NAVY AIRCRAFT RADIO RECEIVER
190 to 9050 En in four bands. 6 -tube super communications. receiver with local and
-mote tun , .
band change. Complete with tubes and dyna
motor. LIKE NEW
$39.50
ER SUPPLY
FOR SCR522 $42.50
Transceiver. POW New
ti.,.
--PP
on
FIELD PHONES, Cheeked out. prfret working
Complete with all part.. Excellent $12.95
BC -604
Me FM
n
'
- "'°-r-..'
_
$29.50
t'ond.. Each
Collins Autotune Aircraft Transmitter. ASÍ
Quick change to any of ten preset channels
iv SICW.
manual tuning. Speech amplifier
uses
carbon or magnetic mike. Highly stable,!clipper
highly accurate VFO. Built in Xtal controlled calibrator.
PP81 Is modulate 813 in final up to 90% class °B."
A heal "HOT" Ham buy at our loss price!
AN /ART -13 XMTR, as above. In LIKE NEW $8fí.50
condition, with all tubes and Crystal
JJ
0.16 Low Freq. Osc. Coil for ART -13
7.95
24V Dynamotor for ART -13
11.95
We Carry a Complete line Of spare parts for above.
$29.50
LORAN APN /4
OSCILLOSCOPE
Easily converted for use
_,e14.)._
While Stocks Last
r
Famous
12-V. Power Supply for APN -9, like New P.U.R.
Shock Mount for above
$2.95
Circuit diagram and connecting plugs available.
We carry a Complete line Of replacement parts and
accessories for above.
104
USED
complete with Tubes
INVERTER POWER SUPPLY for above APN -9. INPUT:
24 V DC. OUTPUT: 115 V AC. 800 cy. Like New $22.50
-
$7950
$79.50
Used, with all parts, less tubes, crystal
and visor
Special
SPECIAL "PACKAGE" OFFER
Transceiver, Dynamotor and all accessories above. COMPLETE, BRAND NEW
order.
34
t
;
BC -645
EE8
5
I
Used
-7H7
1
AN /ART -I3 100 -WATT XMTR
R -65
4-
alone worth more than sale price!)
4
2 -7E6, 2 -6F6, 2 -955 and
-WE -3í6A. Now
covers 460 to 490 mc. Brand
new BC -645 with tubes, less power supply in
factory carton.
Shipping weight 25 lbs. SPECIAL!...I $1(f
9.50
PE -101C Dynamotor, 12/24V input
57.95
UHF Antenna Assembly
2.45
Complete Set of 10 Plugs
5.50
Control Box
2.25
7F7,
Model
Bzoe l
.ah r
ash Receiv er. hS . .,
too 1600 tc with c
1.I
t
,ot p28 VDC n1o>eratio,.
cable. G Tuts.110V í AC Power Supply for above: Kit $8.95; Wired $12.50
I
in ships and aircraft. Determines position by radio signals from
known xmitters. Accurate to within
1% of distance. Complete with
tubes and crystal. IN LIKE NEW Con -
vision experimental 470 -500 mc. 15 tubes
(tubes
COMED.
All packing and shipping is made directly
from our own warehouse in NYC to give
you substantial savings in handling costs!
NEW! APN -4A Receiver- Indicator as above, changed
to operate same as APN4-B for improved performance
NEW $88.50
Shock Mount for above
$2.95
LORAN
BRAND NEW! 15 Tubes 435 to 500 MC
Can be modified for 2 -way communication, voice
or code, on ham band 420 -450 roc. citizens
460 -470 mc. fixed and mobile 450 -460 mc. radio
tele-
ANYWHERE. INQUIRIES WEL-
Determine exact geographic position of your boat
or plane. Indicator and receiver complete with all
tubes and crystal.
INDICATOR ID -6B /APN -4, and RECEIVER R -9B/
APN -4, complete with tubes, Exc. Used.
$69.50
A,
jj
Many thousands of items in our huge
warehouse.
IF YOU DON'T SEE WHAT YOU
WANT HERE, WRITE US YOUR
NEEDS. LET US QUOTE ON ANY
GOV'T SURPLUS ELECTRONIC
EQUIPMENT YOU SEE ADVERTISED
....................$28.50
all.
°
later.
$jv
_
óná$9flct
All at LOWEST PREVAILING PRICES.
In addition to items shown on this page,
we have in stock or can obtain for export
customers, military electronic equipment
made for World War II, Korean War, and
ARC-3 TRANSMITTER
Companion
a..,
FAMOUS BC-645 TRANSCEIVER
EXPORTERS
of ELECTRONIC EQUIPMENT
We specialize in the export
of military surplus electronic
equipment:
Like NEW
533.50
Crystal -controlled 17 -tube su perhet. tunes from 100
to 156 MC., AM., on any 8 preseleC ed Channels.
28 -volt DC power input. Tubes: 1.9002, 6-6AK5.
1.125H7, 3- 12507. 1 -9001, 1 -12116, 2.12SN7.
1- 12SL7. 1.12A6.
110 V A.C. Power Supply Kit for above 15.00
Factory Wired and Tested
19.95
-9
s;wr,
-
WILLARD 6 -VOLT MIDGET
STORAGE BATTERY
Amp. Hour. BRAND NEW. 3%a"
13/ 16"
da/s ". Uses Standard
3
Electrolyte
'
6-
L 95J
Only $2
°'
$5.45
-
ELECTRONICS WORLD
ELECTRONICS MARKET PLACE
December 5th. Send order and
RATE: 60C per word. Minimum 10 words. February issue closes
ELECTRONICS
ENGINEERING
AND INSTRUCTION
Correspondence Courses and Books sold and
rented. Money back guarantee. Catalog Free. (Courses
Bought.) Lee Mountain, Pisgah, Alabama.
ELECTRONICS! Associate degree -29 months. Technicians, field engineers, specialists in communications,
missiles, computers, radar, automation. Start February,
September. Valparaiso Technical Institute, Dept. N,
Valparaiso, Indiana.
FCC LICENSE in six weeks. First class radio telephone.
Results guaranteed. Elkins Radio School, 2603C, Inwood, Dallas, Texas.
HIGHLY -effective home study review for FCC commercial phone exams. Free literature! Wallace Cook, Box
10634, Jackson 9, Miss.
RADIO course only $14.95. Includes all tubes, parts,
tools, instructions. Write for full information. Progressive "Edu- Kits" Inc., Dept. 93E, Hewlett, N.Y.
MATHEMATICS. Electronics. Pay as you learn. Free brochure. Indiana Home Study, 64 Memenway Road, Framingham, Massachusetts 01706.
ENGINEERING and Art Degrees earned through home
study. Electronics, mechanical, liberal arts, major accounting. When writing specify course desired. Pacific
International College of Arts & Sciences, primarily a
correspondence school. Resident classes also available.
5719 -C Santa Monica Blvd., Hollywood 38, California.
USED
FOR SALE
GOVERNMENT Surplus Receivers,
Transmitters, Snoop -
erscopes, Parabolic Reflectors, Picture Catalog 100.
Meshna, Nahant, Mass.
INVESTIGATORS, free brochure, latest subminiature
electronic listening devices, Ace Electronics, 11500J
NW 7th Ave., Miami 50, Florida.
MILITARY Discount -Name Brands Free Recording Tape
and Stereo Handbook. Include Rank and Serial Number. Electronics International, Inc., Box 3066, Char-
lottesville, Virginia.
radio, TV- tubes, parts at less than
manufacturer's cost. 100% guaranteed. No rebrands,
pulls. Request Bargain Bulletin. United Radio 1000 -W,
Newark, N.J.
CANADIANS -Giant Surplus Bargain Packed Catalogs.
Citizens
Electronics,
Rush $1.00 t(Refunded). ETCO.mDept. Z, 464 McGill,
Montreal, Canada.
TRANSISTORIZED Products importers catalog, $1.00.
Intercontinental. CPO 1717, Tokyo, Japan.
CONVERT any television to sensitive, big- screen oscilloscope. Only minor changes required. No electronic
experience necessary. Illustrated plans, $2.00. Relco,
Box 10563, Houston 18, Texas
JUST starting in TV service? Write for free 32 page
catalog of service order books, invoices, job tickets,
phone message books, statements and file systems.
Oelrich Publications, 6556 W. Higgins Rd. Chicago,
III. 60656.
SAVE Money -Free catalog: Photography, Tape Recorder, Hi Fidelity. Electronics tools, Wholesale Radio
& Camera Company, Box 3085, Phila. 50, Pennsylvania.
Save dollars
on
law never forgotten with copyrighted tool.
$2.00 Postpaid. Beck Radio, 6323 South Dale Mabry,
Tampa, Florida 33611.
OSCILLOSCOPE: DuMont 303AH Lab. Scope, 10MC Bandwidth, Excellent Condition. $245. Kretschmer, 807
Manhattan, San Diego 8, California.
IN San Diego, Calif. it's Alpha Electronics, 7077 UniOHM'S
versity,
prices.
for
everything
in
electronics at discount
Edison Cylinder Phonographs refrom storage. Write: Whitlock's, 114 State,
Brewer, Maine.
TEST Equipment. Frequency meters, signal generators,
scopes. Many other electronic components. Echols
Electronics, P.O. Box 5522, Arlington 5, Virginia.
SUPERSENSITIVE Listening -In- Device picks up any telephone conversation in vicinity. No connection to telephone necessary. Easily concealed. $2.98 complete.
Consolidated Acoustics, M1302 Washington St., Hoboken, N.J.
RESISTORS precision carbon -deposit. Guaranteed 1%
accuracy. 1/2 watt 8ç. 1 watt 12C 2 watt 150. Rock
Distributing Co., 902 Corwin Road, Rochester 10, New
York.
DIAGRAMS for repairing Radios $1.00. Television $2.50.
Give make model. Diagram Service, Box 1151 E, Manchester, Connecticut 06042.
TRANSISTOR
Ignition coils, components, kits. Advice
Free. Anderson Engineering, Wrentham 5, Mass.
N. Y. C.
16, N. Y.
all components and recorders. Hi-Fi,
LOW, LOW quotes:
Roslyn 9. Penna.
TUBES
"FM /Q" Metropolitan Broadband Antenna, the finest
compact yogi made, completely rustproof, only $14.95
prepaid. FM Book with station directory 30e. FM /Q,
Wethersfield, Connecticut.
STEREO Tape Club -All major labels, latest releases.
Fast service, worldwide membership, no minimum purchase. STC, Box 652, Santa Barbara, California.
PLAY Transistor radio on Hi -Fi amplifier. Converter
changes transistor radio into Hi -Fi tuner when plugged
into earphone jack. $9.95 postpaid. Box 583, Brandenburg, Kentucky.
TUBES -TV, Radio, Transmitting And industrial Types
At Sensibly Low Prices. New, Guaranteed, 1st Quality, Top Name Brands Only. Write For Free Catalog
REPAIRS AND
SERVICING
transmitters $6.00. Other bargains, send 10e for
list. Vanguard, 190 -48 99th Ave., Hollis 23, New York.
CB
fidelity, citizens band, test equipment,
all top brands, factory to you, write for prices on speDiscount Prices, Loville ElecWholesale
items.
cific
tronics, 547 S. Broadway, Hicksville, New York.
STEREO, high
or Call WAlker 5 -7000, Barry Electronics, 512 Broadway, New York N.Y. 10012
receiving tubes, test equipment, Hi -fi
components, kits, parts, etc.... send for your giant
free Zalytron current catalog, featuring Standard brand
tubes; RCA, GE, etc.-all brand new premium quality
individually boxed. One year guarantee -all at biggest
discounts in America! We serve professional servicemen, hobbyists, experimenters, engineers, technicians.
Why pay more? Zalytron Tube Corp., 461 Jericho TurnBEFORE you buy
pike, Mineola, N. Y.
-7"
TV test picture tube, perfect for
$30.00 value
70° and 90° sets, built-in ion trap -your cost $6.99.
Tubes-new, jobber -boxed RCA, G.E. etc.-65% off list
prices. Special: Tube #6146 -$2.95 each. Send your
order. We pay postage (you save 4 %). Immediate delivery. Write for Free Catalog listing thousands of
parts, phono needles, tubes, etc. Arcturus Electronics
Corp., Dept. ZD, 502 22nd St., Union City, New Jersey.
TV
Tuners Rebuilt and Aligned per manufacturers spe-
cification. Only $9.50. Any Make UHF or VHF. We ship
COD Ninety day written guarantee. Ship complete with
tubes or write for free mailing kit and dealer brochure.
Electronics, Box 51B. Bloomington. Indiana.
METERS- Multimeters Repaired and Calibrated. Free
estimates -Catalog. Bigelow Electronics, Box 71 -F,
Bluffton, Ohio.
TV Tuners Rebuilt and Aligned to Specifications.
JW
Guaranteed All Makes. One Price. $9.50 Complete.
Plus Shipping. Valley Tuners, 5641 -B Cahuenga, North
Hollywood, Calif.
RECORDS
RARE
78's.
State Category. Write Record -Lists, P.O.
Calif.
Box 2122, Riverside,
WANTED
PATENTS
QUICKSILVER. Platinum, Silver, Gold. Ores Analyzed.
Free Circular. Mercury Terminal, Norwood, Mass.
your surplus electronic tubes. Want
unused, Clean radio and TV receiving, transmitting special purpose. Magnetrons, Klystrons, broadcast types.
Want military and commercial lab /test equipment.
Want commercial Ham Receivers and Transmitters. For
a Fair Deal write: Barry Electronics, 512 Broadway,
New York, New York 10012 (Walker 5- 7000).
INVENTIONS: Ideas developed for Cash Royalty sales.
Raymond Lee, 2104G Bush Building, New York City 36.
CASH Paid! Sell
TAPE AND RECORDERS
BOOKS
Learn how to have your book published,
FREE booklet "ZD," Vantage,
120 West 31 St., New York 1.
WANTED: Short stories, books, articles, plays of all
descriptions for sale to publishers, producers. Free
literature! Literary Agent Mead, Dept. 39A, 915 Broadway, N. Y. C. 10.
AUTHORS!
promoted, distributed.
TAPE Recorders, HI -FI Components. Sleep Learning
Equipment, Tapes. Unusual Values. Free Catalog. Dress ner, 1523 EW Jericho Turnpike, New Hyde Park 10, N.Y.
-all
major
Stereo Tapes-over 2,500 Different
labels-free brochure. Stereo -Parti, 1616 -E. W. Terlace Way, Santa Rosa, California.
RENT
SELF -Hypnosis. New concept teaches you quickly by
tape or LP- record. Free literature. McKinley Publishers,
Dept. T6, Box 3038, San Bernardino, California.
30% Stereo music on tape. Free bargain catalog/
blank tape /recorders /norelco speakers. Saxitone, 1776
Columbia Road, Washington, D.C.
SAVE
RECORDING Tapes. Free sample. Mail 25C (Handling).
Towers, Lafayette Hill, Penna.
TAPE Recorder Sale. Latest models $10.00 above cost.
Arkay Sales, 22 -21 Riverside Avenue, Medford 55,
Massachusetts.
HIGH -FIDELITY
NOTICE -Antique
leased
December, 1963
remittance to: ELECTRONICS WORLD, One Park Ave.,
GOVERNMENT
SURPLUS
$111.68, Boats $6.18, Airplanes, Electronics
Equipment, Typewriters, thousands more, typically at
up to 98% savings. Complete information $1.00. Surplus Service, Box 820, Holland 11, Michigan.
JEEPS -$89.64, Typewriters -$4.15, Receivers -$5.65,
Televisions, Oscilloscopes, Multimeters, Typical Government Surplus Prices. Exciting Details Free. Enterprises, Box 402 -B6, Jamaica 30, New York.
JEEPS $178, Airplanes $159, Boats $7.88, generators,
$2.68, typewriters $8.79, are typical government surplus sale prices. Buy 10,001 items wholesale direct.
Full details, 607 locations, procedure only $1.00. Surplus, Box 177 -C1, Abbottstown, Penna.
JEEPS
STAMPS AND COINS
SURPRISE Collection! Exotic mint British Colonials,
absolutely free with approvals. Viking, Great Neck 50,
New York.
Components, tape recorders at guaranteed We
Will Not Be Undersold" prices. All brands in stock.
15 -day money back guarantee. 2 year warranty. Write
your requirements for quotation. No Catalog. HiFidelity Center 1797L 1st Ave., New York 28, N.Y.
HI -FI
Components! Free wholesale catalogue!
Carston, 125 -R, East 88, N.Y.C. 28.
RECORDERS,
DISGUSTED with "Hi" Hi -Fi Prices? Unusual Discounts On Your High Fidelity Requirements. Write.
Key Electronics, 120 Liberty St., New York 6, N. Y.
DI6 -4191.
WRITE for lowest quotations, components, recorders.
No Catalogs. Hi- Fidelity Supply, 2817 -GC Third, New
York City 55.
MISCELLANEOUS
effortlessly, or refund!
Thousands delighted! $2.00. Minter, Box 244 -D, Cedar burg, Wisconsin.
WILD Labels, bumper strips! Strange, startling, unconventional! Krazy Labels, Box 15 -H, Olympia, WashHYPNOTIZE Unnoticed, quickly,
ington.
SILK Screen Stencils, your specifications. Write, Tracey
Co., Groton, Massachusetts.
FREE pipe catalogue. Send stamped, self-addressed
envelope. von Hopke Meerschaum, P.O. Box 328, An-
nandale, Virginia.
105
-
PHOTOGRAPHY FILM,
EQUIPMENT, SERVICES
MEDICAL FILM -Adults only -"Childbirth" one reel.
8mm $7.50; 16mm $14.95. International W, Greenvale,
Long Island, New York.
SCIENCE Bargains- Request Free Giant Catalog "C1
144 pages -Astronomical Telescopes, Microscopes,
Lenses, Binoculars, Kits, Parts, War surplus bargains.
Edmund Scientific Co., Barrington, New Jersey.
PHOTOGRAPHERS Earn Part Time, Write: PCI Dept. 470,
ELECTRONICS WORLD DECEMBER 1963
ADVERTISERS INDEX
"-
Arlington 10,
Va.
WORLD'S Most Complete Photographic Buying Guide.
700 illustrations. Impossible Low Prices. Send 506
(deductible with order). Olden Camera, 1265 Broadway, New York City.
READER
100
Advance Electronics
American Concertone, Inc.
& Technology
Rilov~
123
Kedman Company
70
124
Key Electronics Co., Inc.
95
Kuhn Electronics
64
Lafayette Radio Electronics
102
Artisan Organs
82
126
Lampkin Laboratories, Inc.
92
103
Automotive Electronics Co.
98
104
Autotronics Inc.
64
127
McGee Radio
84
128
Massey Technical Institute
96
129
Merit Coil
Manufacturing Co.
105
B
106
Belden Manufacturing Company.
& K
9
Benjamin Electronic Sound Co-p...
95
108
Burstein -Applebee Co.
89
144
Cabinart Acoustical Dev. Corp..
...
Institute, The
..
......
Micro Electron Tube Co.
130
Minnesota Mining
147
Murray- Carson Corporation
109
Columbia Products Co.
110
Communications Company, Inc
SECOND COVER
79
...
78
131
Oelrich Publications
88
Olson Electronics, Inc.
79
Conar
102
149
Concord Electronics
101
132
Palmer Electronics Laboratories Inc.
92
145
Cornell Electronics Co.
96
133
Peak Electronics Co.
84
111
Crown International
6
150
Poly Paks
88
Dressner
94
Dynaco Inc.
66
RCA Electronic Components and
Devices
RCA
113
EICO Electronic Instrument Co., Inc.
114
Electro- Voice, Inc.
115
Electronic Chemical Corp.
If you've recently changed your address or
116
plan to in the near future, be sure to notify
us at once. Place magazine address label
118
82
Fisher Radio Corporation
G & G Radio Supply Co.
Goodheart Co., Inc.,
R.
CITY
11
Gregory Electronics Corporation ..
79
62, 63, 65, 67, 69,
have any other questions
about your subscription be sure to
include your magazine address label
when writing us.
Mail to: ELECTRONICS WORLD, 434 So.
Wabash Avenue, Chicago 5, Illinois
71
,
Sams & Co., Inc., Howard W.
136
Scott Inc., H. H.
138
Sony Corporation of America
139
Sprague Products Co.
140
Standard Kollsman Industries, Inc.
4
....
59
....
100
81
2
THIRD
Sylvania
COVER
76, 77
Texas Crystals
72
89
122
International Crystal Mfg. Co., Inc.
14
141
Turner Microphone Company, The
97
146
Utah Electronics
85
117
International Electronic
V & H
Components Show
Johnson Co.,
E. F.
74
93
Radio
89
Valparaiso Technical Institute
142
148
100
73
Henshaw Radio Supply
MAIL COPIES TO NEW ADDRESS STARTING
WITH
ISSUE.
106
Heath Company
STATE
If you
60
135
95
...
16, 17, 18, 19
Tri -State College
121
ZONE
....
W Electronics
Roberts Electronics, Inc.
PLEASE PRINT
ADDRESS
FOURTH COVER, 86, 91
104
E.
Grantham School of Electronics
151
21
....
Institutes, Inc.
134
8
Fair Radio Sales
119
R
26
22
158
NEW ADDRESS
NAME
83
75
Natioral Radio Institute
7
.
80
&
Manufacturing Co.
24, 25
Cleveland Institute of Electronics
100
152
5, 99
Channel Master Corp.
10
Merrell Kits
60
Capitol Radio Engineering
&
Transformer Corporation
1
107
112
here and print your new address below.
8
125
Made $40,000.00 Year by Mail Order! Helped others
make money! Start with $10.00 -Free Proof. Torrey,
Box 3566 -N. Oklahoma City 6, Oklahoma.
product, at substantial savings. Milles Engineering,
Las Marias, Puerto Rico.
HIGH income in your own wired -music business. Free
details! CSOE, Box 10634, Jackson 9, Miss.
DETECTIVE
Opportunities. Experience unnecessary.
Write, Wagzner. 125 West 86th, New York 10024.
102
94
I
PLEASANT Way To Earn At Home. Free Details. Hamilton Studios. Seaford 2, New York.
ELECTRONIC Facility, tax exempt, will produce your
PAGE NO.
92
EMPLOYMENT
INFORMATION
BUSINESS
OPPORTUNITIES
ADVERTISER
Arcturus Electronics Corp.
102
expenses. Write only Foreign Service Bureau, Dept. D.
Bradenton Beach, Florida
EMPLOYMENT Resumes. Earn more by presenting yourself to prospective employers more effectively. Send
only $2.00 (cash or money order) for complete Resume
Writing Instructions, including sample and instructions for letter of transmittal. J. Ross, 63-61 Yellowstone Blvd., Forest Hills 75, New York, Dept. 61 -EW.
SERVICE NO.
American Institute of Engineering
While Asleep, hypnotize with your recorder.
phonograph. Astonishing details, sensat onal catalog
free! Sleep- Learning Association, Box 24 70, Olympia,
Washington.
FOREIGN Employment. Construction, other work projects. Good paying overseas jobs with extra, travel
PAGE NO.
ADVERTISER
101
EDUCATIONAL
OPPORTUNITIES
LEARN
READER
SERVICE NO.
143
80
Warren Electronics Co.
88
Weller Electric Corp.
23
Winegard Antenna Systems
.
12, 13
Printed in U.S.A.
ELECTRONICS WORLD
STANDARD KOLLSMAN BRING
Beauty
PERFORMANCE
TO UHF CONVERTERS YOU CAN SEE
The Model "A ", the only UHF converter
you can show and sell with pride. Designer
styled in beige and tan to blend with today's
to harmonize with modern TV
decor
and
cabinet design. Standard waited
they
until
retested
and
analyzed,
tested,
could bring you the quality instrument you
and your customers have a right to expect
from the leading manufacturer of tuners. As
a result, you now have a converter which is
beautiful, profitable, and dependable.
.
.
.
.
.
.
Contact your Standard representative
New low- noise, shielded tuner
permits fine tuning for all 70 UHF
channels. Functions perfectly
with color or black and white sets.
Two simple controls: one for
the.
VHF, UHF, and "off"
other far channel selection and
fine tuning. The "SK" installs in
alaout a minute with just a screwdriver.
.
.
.
POWER IN
PROMOTIONAL
SUPPORT With a first
order of 12 units or more, Standard supplies 3 newspaper ad mats
ma3 radio spot scripts
terials for a powerful TV spot
a
2 -color catalog sheets
giant (3' x 6') 2 -color window
as
a counter card
banner
...
...
many pre -printed jumbo post
cards as you can use PLUS hard
hitting ads in TV Guide.
display carton
INDUSTRIES,
standard kolisman
/
CIRCLE NO.
...
...
Feature this exciting counter -top
... or write
Formerly Standard Coil Products Co., Inc., Melrose Park Illinois
...
...
INC.
WORLD'S LARGEST MANUFACTURFR OF TELEVISION TUNERS
140 ON !READER SERVICE CARD
r
BETTER
THAN
EVER!
rro
DI...41/10..01.00,
.....
_.
_..
:.
.
1
.
The latest edition of the famous
RCA RECEIVING TUBE
MANUAL... JUST OUT!
Each year we expand and improve our famous receiving tube
manual -to keen it the most popular and up -to -date tube
reference of its kind in elect-o,ics.
The latest edition- RC -22 -is the biggest and best ever...
almost 100 pages longer than the previous edition. It features:
Over 100 new tube types (1)
An expanded and completely detailed applications guide (2)
New circuit diagrams for:
Citizens' Banc Transceiver (3)
MR AM -FM Radio Receiver
FM Stereo MLItiplex Adapter (4)
Nuvistorized FM Tuner
All- Purpose Powe- Supply
...and much, much more!
NOW AVAILABLE
f:_
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...
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...,,...,......,,._.,......,.o.r.
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.<r
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4-.!'.:T
ROM YOUR AUTHORIZED RCA TUBE DISTRIBUTOR.
RCA Electronic Ccmponants and Devices, Harrison, N.J.
:
--...5'.. 177#2.t.
T...-
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