December - American Radio History

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December
1999.
Brightness
Control
To
Video
Detecta-
Sync Clipper
DC Restorer
Contrast
Control
To
Vert
Sweep
Osc
To
Pore- Trans (Primory)
Picture Tube
TV Signal -Strength
Indicating Circuit Featured
in
-Tube Model.
[See page 2]
21
THE TECHNICAL JOURNAL OF THE RADIO TRADE
www.americanradiohistory.com
NOW- you
can get all the
essential data on TV servicing
and other timely subjects
written for you each month
INTO ONE HOUR'S READING TIME!
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Want to know how you can keep up with
"Television Video Detectors"
"TV Picture -Tube Voltage and Signal Systems"
all the "down-to-earth" facts on TV
"Record Changer Speed Faults"
servicing without having to cut your
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"TV Interference ... Causes and Remedies"
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sending in the coupon on a penny postmoney - making TV servicing hints and
Do it now!
short cuts written for your specific day card.
to day needs. Here's material written in
Cornell-Dubilier Electric Corporation,
response to the thousands of requests we South Plain field, New Jersey. Other plants
get every month. Just glance at a few of in New Bedford, Brookline and Worcester,
the articles that have appeared in recent
Mass.; Providence, R. I.; Indianapolis,
months:
Ind., and Cleveland, Ohio.
-a
YOURS, FREE
1
-YEAR SUBSCRIPTION
TO THE C -D CAPACITOR
c9RyE<<-o
CONSISTENTLY
CLIP COUPON AND MAIL TODAY!
CORNELL-DURILIER ELECTRIC CORP., DEPT. S129
SOUTH PLAINFIELD, N. J.
*
CAPACITORS
*
.
You're on! Send me The Capacitor for the neat twelve
months, so that I can keep "my nose to the grindstone".
1910
ZONE
STATE
*
ANTENNAS
*
NAME
CITY
,
VIBRATORS
GENTLEMEN:
ADDRESS
DEPENDABLE
DEPENDABLE
1949
Reg. U. S. Poi. Off.
CONVERTERS
world's
largest manufacturer
of Capacitors
"NO BETTER TUBES SOLD
THAN KEN -RAD RUBES
-SALES PROVE IT!"
"Ken -Rad Tubes have been a steady
seller for us ever since we started in
business.
"Now, I don't pretend to be a merchandising expert-but when an item
satisfies customers and brings them
back for more, year after year, the
reason is simple.
"It's quality. Quality and value that
stand out.
"Ken -Rad Tubes sell fait, stay sold because you can't beat them on either
O. B. CONLEY and H. T. CONLEY, Conley
Radio and Electrical Shop, Corinth, Miss. like
thousands of servicemen, have increased turrover, boosted profit by pushing high -quality
Ken -Rad Tubes.
count."
i
ROBERT E. MOE, Division Engineer,
Ken -Rad plants, is one of many experts
who help direct the testing of Ken -Rad
"NO BETTER TUBES MADE
THAN KEN -RAD TUBES
-TESTS PROVE IT!"
Tubes. Besides noie and microphon cs,
these quality tubes are checked for
static characteristic;, life, shorts, appe prance, gas, air and hum.
"I h.alp make Ken -Rad Tubes. And I know-there are
no better tubes made!
"Ken -Rad Tubes have to prove their quality over and
over again at every stage of production.
"On the right, a Ken -Rad Tube is receiving the micro phonic and noise check, with the aid of an amplifier
hav:ng a known response and a specified gain..The..,
tube is tapped by a motor -driven tapper, and the
resulting audio output is checked on a standard VU
meter.
""This is only one ofOthe ¡>
tests
g,u
Rad Tubés must ass' before' ein shippé
Kent
u,
"Good? They've got to be good!"
e.
1132-1-I,,7
per
ye
J
,.zers
,
ThE SERVICEMAN'S TUBE
...
backed by profit-r^c'k
sales aids which your
Ken -Rad distributor will be
glad to show you. Phone or
write him today!
g
SEPtitcb,I`1isebnfi3Elt?1944.2
`
I
Vol. 18, No.
RADIO
12
minull1i11111111111i1116111111111111111111111111111111111111111111111111111111IIIIII01111111111IIIIIII
IIImIIIIIIIIIIIIIIIIIIIIIIIII II
TELEVISION
ELECTRONIC
December, 1949
Illllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll
I I I
SERVICE
LEWIS WINNER
Editorial Director
F.
WALEN
Assistant Editor
IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIImlllllllllulllulUl
ALFRED A. GHIRARDI
Advisory Editor
Page
Annual Index to SERVICE, 1949
Association News
Performance Diagnosis of Vacuum Tube Circuits. By Edward M. NoII
Frequency Rating
Phono Installation and Servicing (Stylus Factors
Dual Speed Changers). By Kenneth Stewart
Ser -Cuits (G. E. 12" Tube TV Models)
Servicing Helps. By M. A. Marwell
Signal -Strength TV Test Set (Cover)
Ten Years Ago in Associations
Tube News (Sweep -Circuit TV Tubes). By L. M. Allen
TV Receiver Line -Voltage Control -Checker. By Carl S. Cummings
TV Receiver Production Changes. By Donald Phillips
.
.
26
24
20
Systems
14
12
23
30
24
19
16
22
News and Views. By Lewis Winner
I
I
CIRCUITS
13
G. E. 817 and 821 TV Models (T and S Versions)
G. E. Discriminator Circuit
Horizontal Sweep System
Horizontal Deflection and Pulse Operated HV Supply for I0BP4 and I2LP4
Magnetic Deflecting Yoke Circuit
National Videometer (Cover)
6BQ6GT/25BQ6GT TV Circuit
TV Receiver Line -Voltage Control -Checker.
22
19
23
23
30
19
16
COVER
Signal -Strength TV Test Set (National Videometer)
30
SERVICING HELPS
Deflecting Yoke Applications
External Connection of Antennas to BC Sets
Horizontal Deflection Output and HV Transformer Application Notes
23
23
23
TV RECEIVER PRODUCTION CHANGES
Damping Tube Replacements
22
Discriminator Performance in G. E. Horizontal Sweep Generator and AFC System
Westinghouse Vertical Hold Improvements
22
22
48
Index to Advertisers
Manufacturers
48
Jots and Flashes
4543
News
New Parts
TV
... Accessories
Antennas ... Accessories.
40
Entire contents Copyright
S.
Davis Publishing Co., Inc.
Published monthly by Bryan Davis Publishing Co., Inc.
Telephone MUrray Hill 4-0170
Avenue, New York 17, N. Y.
Vanderbilt
52
<AB(
Bryan
1949, Bryan
Davis, President
Paul S.
Weil, Vice-Pres., Gen. Mgr.
EastCentral Representative: James
C.
F.
Munn, 2253 Delaware
Pacific Coast Representative: Brand & Brand, 1052
Walen, Secretary
Dr.. Cleveland
6,
Ohlo.
W. Sixth St., Los Angeles 14, Calif.
Suite 1204, Russ Building. San Francisco
4,
Calif.
AO>
A. Goebel, Circulation Manager
Telephone: Erievlew
Telephone: Michigan
1726
1732
Telephone: SUtter 1.2251
York, N. Y., under the Act of March 3, 1879. Subscription price:
Entered as second-class matter June 14, 1932, at the Post Office at New
$3.00 per year in foreign countries; 35 cents per copy.
year in the United States of America and Canada; 25 cents per copy.
2
SERVICE, DECEMBER,
1949
$2.00
per
Put This Proved Money -Making Service Data Library to Work
... in your shop
wow,/
NOW YOU CAN OWN
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11
le, FM,Changers, Tuners,
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Record
Na
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Includes your membership
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at
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Entitles you to
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NOW-you can afford to own the Service Data Library that is earning
extra profits every day for more than 25,000 successful Service Technicians! NOW-for the first time-the famous PHOTOFACT Library can
be Yours with this new "Pay -as -You -Profit" Plan! Here's all you have
to do: See your parts jobber. Order 4 or more PHOTOFACT Volumes.
Pay only $18.39 down. You get your Library immediately. You use it
now. It. earns for you-and you pay as you profit! If you're not already
a money -making PHOTOFACT user; here's your easy -pay chance to own
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using PHOTOFACT, here's your chance to complete your library by
filling in those missing volumes. Now that you can afford PHOTOFACT,
don't be without its time-saving, money -making advantages a single
day longer. See your parts jobber today!
pAt
nUTO
nNOA
HAVE COMPLETE, ACCURATE DATA ON
ALL POST-WAR SETS YOU SERVICE!
With the Easy -Pay Plan, you can boost your earnings
now, using proved superior PHOTOFACT. Have complete,
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the only Radio and TV service data based on actual
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PHOTOFACT is better in every way. You get: 1. Exclusive
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Changer service data. 10. Exclusive keyed data system
-all values right on the schematic. There's nothing like
PHOTOFACT! It pays for itself in saved time, bigger
work output and greater profits. To protect your future
in Radio-TV servicing, act now-own the PHOTOFACT
Library the Easy -Pay Way!
SEE
CURRENT PHOTOFACT BEST-SELLERS
YOUR PARTS JOBBER
OR WRITE DIRECT TODAY
The Recording and Reproduction of SOUND,
by Oliver Read. The complete, authoritative treatment of the entire subject of Sound, written
by the editor of Radio & Television News
$5.00
Photofa¢t Television Course. The book used by thousands; gives you a
clear understanding of TV principles, operation and practice .$3.00
Television Antennas. Shows you how to select and install the proper
antenna, and how to overcome antenna problems
$1.25
1948 Record Changer Manual. Covers 45 models made in 1948, including
new LP and dual-speed changers, plus leading wire recorders.
Based on actual analysis of the equipment
$6.75
Auto Radia Manual. Complete Photofact service data on more than
100 post-war auto radio models-a time-and -money -saver $4.95
.
HOWARD W.
SAMS
&
CO., INC.
INDIANAPOLIS
1,
IND.
HOWARD W. SAMS & CO., INC.
955 N. Rural St., Indianapolis 1, Ind.
D Send full Easy -Pay Details
Send FREE PHOTOFACT Cumulative Index
13 Send PHOTOFACT Folder for Set Model
(FREE to Service Technicians writing in on letterhead; 50c charge to Experimenters)
Name
Address
City
Zone
State
SERVICE, DECEMBER, 1949
.
3
r, e
every General Electric small -size
speaker you get from your distributor
or jobber! Adjustable up, down, or
sideways, these brackets save your
time and simplify tough jobs.
answer to- a
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Lateral mounting feature
of bracket saves fingers,
time and temper. Screws
hold bracket arms and
speaker securely and permanently in place.
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victigapAaaessent.
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This offer open only to radio and
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QENERPAL
1"
9HIelICEJEDECElea,
1949.
'4
a[.òx.....
di.f5TO1rL
tQ.A$
R
4E
General Electric Company, Bldg. 1, Room
Electronics Park, Syracuse, New York
1
9;
W.\
7ev
C'
''J6
o.
TV
servicetne i!
1S
Send me free sample bracket and all the facts on
Size Speakers.
G
-E
Small -
NAME
FIRMDDRESS
.ITY
STATE-
J
11 Ill
u.
The nenc, Du Mont Types 12RP4 and
15DP4 :rer lacing respectively Types
12JP4 and 1:API) fea ur? the exclusive Du
Mont bent -gun. This ion-trap design eliminates ion-spot blemishes while maintain.ng
an undistorted spot for maximum pictorial
resolution. Meanwhile, lead-free glass reduces tube weight considerably. Five -pin
duodecal base permits using the new half socket for a significant saving, although old type full-socke-. also accommodates these
new tubes wAhout moiif_cation.
-
Definitely "Your beet buy!" For initial equipment or replacement purposes
for
superlative performance and longest service
-
insist on Du Mont Teletrons!
iv
Abo.-e: Du Mont bent-7un prirciple, utilizing single iontrap magnet. Space saved ...Dy eliminating cloulo:e beambencing magnet results in sfiorer neck length. Focussed spot distortion elimicared by use of electrode parts designed to form symmetrizoi E le:erostatic fields ir. G, space.
Lower -cost magnet.
Below: Conventional straige-gicn design. Ion and electron
beam is twisted by slanting electrostatic field between
second grid and ano -e, recuirirg TWO bending magnetic
fields. More costly beam-b3ad3r. Longer neck. Focussed soot distortion.
0 Write for latest literature.
ALIEN B. DU MONT LA.BCRATORIEZ,
ALLEN B. DU MONT LABORATORIES. INC.
`TRADE MARK
TUBE DIVISION
PASSAI
SERVICE,
ERS ET
DECEMel,A429s.(35
TWO STANDOUTS
from the
OUTSTA. DING LINE
CHANNEL MASTER'S
FAN FLECTOR
This sensational
new preassembled antenna,
the Fan -Flector, a development of
Channel Master's research laboratories,
is the most sensitive all -channel antenna
developed to date.
No high band attachments.
No multiple lead in wires.
No wasted assembly time.
Dealer after dealer has made his most difficult
fringe installations stick
with the Fan -Flector,
America's fastest selling antenna.
List
.. 6
\
\
1
9
8
-%'
1
1
.
'.'
An
46..
F
~'' .
-
,
,
\
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CHANNE(
e
--
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°.
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4
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____
ACPED fAN-El CTOP
CONVEN IONAL STACKED CONICAI
5
.
(MANN
l
50
2
3
60
rPEOD[NCY-MCS.
4
6
5
70
80
7
90
9
8
190
180
10
11
200
12
13
210
'
GAIN CURVES
"Most popular" conventional stacked conical antenna
(broken lines) compared to the stacked Fan-FIector
(solid lines).
TO: CHANNEL MASTER CORP., ELLENVILLE, N.Y.
DEPT. S-12
Please send Ine:
Name of nearest Channel Master Distributor
Technical data and literature
YOUR NAME
COMPANY NAME
ADDRESS
CITY
\
\
ú
CHANNEt7
\\ \
i
7
HORIZONTAL POLAR DIAGRAMS
front -to -back ratios between 3 and 4 to 1.
Lobe width decreases on high band for ghost -free
reception. Yee -Beam engineering minimizes side lobes.
SERVICE, DECEMBER, 1949
\
o
Law band
6
i
29.30
63.25
w
:'43
....,',
/
41
g
,11
..., -' ,
13.75
Fan -Flector
Stacked Fan -Flector
Double Stacked Fan -Flector
BM312
BM312X2
BM312X4
STATE
CHANNEL MASTER'S
HIDEAWAY
ems,
THE
OF A
DISAPPEARANCE
THE
PERFORMANCE OF
BUILT-IN ANTENNA
AN OUT -DOOR ANTENNA
Channel Master's exclusive Multiflex Action*
enables this antenna to be hidden
away behind the set when not in use.
The elements can be arranged to
form a horizontal Vee for any channel in
any direction thus increasing the gain.
The hand rubbed hardwood surfaces,
nickel plated metal components and smart
design makes the Hideaway
the most attractive indoor antenna
on the market today.
LIST 975
'Pat. Pend.
available
in blond,
mahogany and
walnut
FIRST IN PREASSEMBLEt! ANTENNAS
~
...1.111OP`
SERVICE, DECEMBER,
1949
`
SOOo
i20©
30a
60 .f
V I2
D
11
AQJ
0
g000
OFF
-~"-..1 E O D
,...300
le
A
0
y
OUT
PUT
.-..3
and cle/iendaóle iush'ttu
MI
ONLY
8
$37.50
SERVICE, DECEMBER,
AT YOUR DISTRIBUTOR
1949
THE MAN
WHO TAKES PRIDE
IN HIS WORK
ANOTHER HYTRON FIRST
/
Y O
U'
L
BUYING SOON
BE
L
ANEW HYTRON
RECTANGULAR
all -glass 16RP4
Meet Hytron's space and money saver. The new Hytron 16RP4.
Re.oli.ionary 16-inch rectangular picture tube. Takes approximately
same cabinet space as 12LP4. Automatically sets the pace for more
tort-pr ct and economical TV set design. You'll be seeing it ... buying
it ..
.
S)Un.
The n3'v 16RP4 is latest in a long series of Hytron firsts. Including:
The GT tube. Over 50 GT types. The subminiature. Many new miniatures. Special low-cost TV deflection -circuit tubes: 1X2, 6BQ6GT,
5U4GT 25BQ6GT. Check the 16RP4's many features. Watch for it.
Buy the best by the leader. 3uy Hytron!
E9 OF REGEN\
Np E..EGZROvi\GS
GORD.
With oid-style round tube,
see the
you lose the corners.
transmitted.
picture
Features of HYTRON
4, you
just as
16RP4
1
Rectangular shape permits smaller, less costly
cabinets.
2
Also just as short as 12LP4.
3 Weight
is
approximately two-thirds that of
inch, all -glass round
4
tute.
16 -
Easy to mount. Can't rcll or twist.
5 No
high -voltage isolation of tube required.
... increases contrast ratio.
6
Neutral gray face
7
Large viewing screen. You get the entire transmitted picture; no lost corners. Gives picture (with
standard 3 by 4 aspect ratio) 10/s inches by
131/2 inches.
Write for Bulletin
E
147
giving complete data.
MAIN OFFICE: S?.LEM, MASSACHUSETTS
SERVICE, DECEMBER, 1949
9
5
NAVE
R
?ROOTED MpAIG NS
sy
ANIAES CA
SING
..and YOU can
do the same by
ACTING NOW:
Another of Sylvania's famous profit -building campaigns is getting under way!
The campaign runs through the months of January, February, March and
April-with half-page ads like this in LIFE, THE SATURDAY EVENING POST,
LOOK, COLLIER'S, and RADIO AND TELEVISION BEST. The ads tell your customers and prospects to come to you for radio and television service.
But that's just the start! THEN ... you tie in with this national advertising
by using Sylvania's complete kit of display and direct mail material-all built
around the ads-designed for you-and ready for you now!
Sylvania's previous campaigns paid off in a big way for thousands of dealers
and servicemen. Be ready to cash in on this latest big push!
AdRY l
"km son A swath No mud!
HERE'S WHAT YOU GET IN THE SYLVANIA KIT:
O POST CARDS. You get 4 sets o$
Postal Card Mailings-one for
each month in the campaign.
They're in 3 colors-imprinted
with your name and address!
You pay only the government
postage on each card-that's
all you pay for the entire kit!
EVERYTHING ELSE IS FREE.
We use and
tectmmend
T
SYLVANIA
Radio and
Television Tubes
©WINDOW
DISPLAYS.
You get
dimensional -4 colors -2 by
COUNTER CARDS, too, 12 by
let us
Pvt, ne
Auer Sui tone
in goer old radio
IOOR FOR THIS
SIGN OF OENENDARIE
SYLVANIA RADIO TUBES
Does your radio give out
©
You get 4 Newspaper
Ad Mats-two sizes for each 2 -
with squeals and grunts? Then
call the serviceman who displays the Sylvania sign. Became
your radio needs expert care, the kind this fellow is trained
to give. He has Sylvania test equipment to root out trouble
tpom ... high-quality Sylvania radio tuba to bring you the
crystal-clear reception you want. Hear your old set perform
as it did the day you bought it. Get it fixed at the Sylvania
sign of dependable service.
month period. Sizes are one
and two columns wide, 7 inches
deep. Easy way to tie your local
newspaper advertising in with
Sylvania's national ads!
SYLVANIA
RADIO TUBES
/RODUCT OF SYLVANIA
a.CT.IC
LOOUCTS INC,
You get as many
Decals as you need-in 8
DECALS.
or 12 inch diameter.
Your choice of wording-
SYLVANIA RADIO TUBES
Window
:
3
18
feet. 2
inches.
}
t.
AD MATS.
RADIO SERVKE
Amnmu.d Dealet
2
Displays-featuring the same illustrations as the Sylvania national ads. 3-
RADIO SERVICE or
RADIO TELEVISION
SERVICE. Sylvania's ads
make these Decals nationally known-cash In
on their familiarity!
SYLVANIA
O
You get 2 Window Streamers-in 2 colors -11 by 26 inches. Like
STREAMERS.
the other items in the campaign,
Streamers feature both radio and television service.
You get 4 booklets of Radio Spot
OAnnouncements-one for each
of the 4 months in the camRADIO SPOT ANNOUNCEMENTS.
paign. When you've planned your schedule, just hand the
spots to your local radio station-they're all ready to use!
Mail coupon today for full details on the complete campaign!
Sylvania Electric Products Inc.
Advertising Dept. R-1912, Emporium, Pa.
Please send full details of your new 1950 January, February,
March and April Service Dealer Campaigns.
NAME
COMPANY
ADDRESS
CITY
ZONE....
STATE
E LE CTRI C
RADIO TUBES; CATHODE RAY TUBES; ELECTRONIC DEVICES; FLUORESCENT LAMPS, FIXTURES, WIRING DEVICES, SIGN TUBING; LIGHT BULBS; PHOTOLAMPS
10
SERVICE, DECEMBER,
1949
IIIIIIIimIIIIldlllll IIIPiYIIIIIIIIIIIIhIIIIIIIIIII!IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII11IIIIIIINIIIIIIIIIIIIIIIIIIIIIIIIIII
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The Old and the New
\Viri-I
nearing
equally peppery series
the Service Man can
and forward with extoss about quite a few
healthy hurrahs for the healthy state
of his industry.
Yes, '49 has been
quite a year for the Service Man and
'50 looks even better, with TV again
at helm as an income builder.
With close to two -million television receivers in operation, and as
Victor Mucher of Clarostat said in a
recent report . . "the sets operating
many hours a night and night after
night, hundreds of hours of wear and
tear are piling up to the gratification
of the local Service Man."
In addition, declared Muckier, many
of these receivers are from one to two
years old and
.
"that means dimming picture tubes requiring early replacement. It also means occasional
replacement of other tubes, because
even ogle weak tube out of two or
three dozen can mar entertainment.
Resistors and capacitors are apt to
let go, while controls get noisy or
flickery. All of which is sweet music
to the Service Man."
Every Service Man can get his
share of the 1950 boom business,
Mucher pointed out, if he'll
"make
sure that every installation he makes
provides satisfactory performance, and
particularly if he equips himself with
the proper test equipment and adequate stock of replacements for
prompt servicing."
The Service Man can't help but
hit the bull's eye, with that kind of
a code in operation, Mucher declared.
There are tremendous dollar -building possibilities in TV replacements.
Commenting on this vital point, during an address at the Hotel Astor in
New York City recently, Robert
Sprague of Sprague Electric, said .. .
"there are an average of five to seven
parts in a TV set to every one in
a broadcast model. A typical radio
set may have around 130 parts, while
a typicali television set will have a
thousand parts and most of a very
special design and construction."
That's quite a market
Not only are the "prospects bright in
TV, but sound, too, with practically
a new era to explore, thanks to the
A
BUSTLING YEAR
its end and an
of days ahead,
look backward
citing glee and
.
.
.
...
!
slow -speed systems and the accelerated
development of tape and wire re-
corders.
The tape recorders have really
carved a sparkling niche for themselves. Today, there are nearly two
dozen top-notch recorders and playback units available for a variety of
installations. The equipment is finding its way into schools, offices, homes
and studios where it is being used for
public speaking and dramatic training, speech correction, speech research, educational broadcasting, rerecording of platter music or airlane
tunes, etc.
Recorders have been made for from
half-hour to four-hour applications.
One four-hour unit, using a dual track
idea, operates at 7%" per second on
a 132" reel, and is said to have a
frequency response of 40 to 10,000 ±
2 db. There is also a dual -track recorder operating at 7/" per second
with a built-in three -tube tuner, which
affords a half hour of continuous recording on a 5" reel and one hour of
recording on a 7" reel. For basic
voice work there's a single-track type
unit with a tape speed of 7%" per
second using a 7" reel, the frequency
response being 100 to 5,000 cycles.
In servicing these units, familiarity
with the designs and frequency response is extremely important, for
such knowledge makes it possible to
evaluate the type of instrument requiring repair. According to audio expert
C. J. LeBel, vice prexy of Audio Devices, frequency response generally falls
into four categories Top professional,
with a uniform response to 15 kc, at 15"
or 30'' per second speed; portable and
economy professional, with a uniform
response to 7.5 kc at 7.5" per second;
good home type, with a uniform response to 5 kc at 7.5" per second;
and poor home with a uniform response to 3 kc at 3.75" or 7.5" per second. The latter is usually only employed for utility or very general work.
A knowledge of the motors used is
also important in servicing. LeBel
reports that inexpensive machines use
one motor for all drives, and use friction clutches for takeup and supplytension adjustment. If these clutches
ar improperly adjusted, the sound
qu1ity may suffer (if tension is light)
and the tape may be ruined if the
tension is excessive. There are other
clutch problems to consider, too. For
:
IIII
IIIIIIIIIIIIIIIIIIIII
instance, some clutches automatically
change their friction as the amount
of tape on the reel changes and some
do not. The former type is usually
preferred, since it has been found
to maintain the tape tension very
nearly constant from empty to full
reel.
Response tests are also important'
in tape -instrument servicing. Some
makes of home recorders have heads
which wear rapidly, resulting in a very
poor high -frequency response. Such
heads must be checked frequently and
carefully.
On the schedule of profit -making
activities, we also find the TV antenna installation, which has' and will
continue to play a stellar role in the
Service Man's busy day. We have
had an invasion of the built-in antennas, but in the bulk of installations
an antenna, particularly of the outdoor type, is still the medium required
to provide that sharp, interference free picture from all the stations in
the area.
Speaking about antennas, the multiple -antenna multiple -receiver feed
idea is becoming increasingly popular
and is destined to become a major installation factor in '50, offering the
Service Man an unusual opportunity
to serve a new highly lucrative field.
An enlightening discussion of this
phase of installation will appear in the
January issue of SERVICE. Watch for
it
!
The enterprising Service Man lias
found and will continue to find new
fields to conquer. There's the case
of the Service shop in the far west
who displayed what could be done with
a bit of vision. A highway service
agency wanted to cover miles of its
difficult roads with a comparatively
inexpensive communications system.
Handie-talkies were suggested, "'and
they worked so well, that a complete
system covering a dozen sites was installed, with a yearly servicing arrangement set up to assure continuous
service, on the spot, so essential to the
emergency facilities provided by the
portable units. With the expanding
use of these handie-talkies in the commercial world, and the expected
growth of the citizens service and the
walkie-talkies, the Service Man has
another profit-bearing field to add to
his lively prospect calendar for the
bright new year.-L. W.
-
SERVICE, DECEMBER,
1949
II
Circuit Analysis of
G.
E.
12" Tube TV Models and Admiral TV Receivers
With FM/AM Tuners.
THE 10" TV models, long a favored
type in the home and commercial installations, are surrendering their firm
position to the 12" variety. As a result set makers have been processing
more of the expanded -view picture tube receivers than ever. While in
the main, the 10" design patterns have
been employed for the 12" types,
larger -tube models with quite a few
circuit alterations have come off the
line.
In Fig. 1 appears the circuit of one
such model G. E. 817 and 821, T and
S version.
The front end is quite standard, with
1<he rf unit featuring two stages, a converter and local oscillator, constructed
asua self-contained sub -assembly, which
tali be demounted readily from the
rrlitin chassis. The tube complement
Gtessists of two 6AU6s used as rf amûers and a twin triode 12AT7, one
section of which is the converter and
the ,other section the local oscillator.
The first rf amplifier is connected as
as'triode amplifier.
-r.The antenna input circuit provides
a 300 -ohm balanced input. To obtain
the antenna input is coupled betnLthe grid and cathode sections of
the:.itube so that both of these tube
etfintzrols perform as signal input elenibntsH. The Gm of a 6AU6 connected
+fit ode is adjusted so that the input
iliipdetertce to the cathode is approxitelyv000 ohms, the grid input being
uttittleequivalent to it by shunting its
eet ltrrpedance by a 1,000 -ohm resilftbifft give a balance. The addition
ofri a'st+eríter-tapped choke, L., from
tíß gliìthin the cathode provides a bah
ätt itdfkt-0und and, at the same time,
Mleileek'tíhe cathode and grid impediiiceAdels to give a total of 300 ohms
srrtlie choke terminals, the point
offal
ifl¡ut. The inductance of the
?s such that it will resonate
Mate 1WYi the capacity in the grid
Aid ce d2ocircuits providing a unilerrlitim(4i<dkkce for all the lower chanr9M.1e118 g L. and L. have been
shunted across the choke L. on the
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SLICE,
DECEMBER, 1949
high -frequency channels for the same
reason. A pair of 5,100 -ohm resistors
serve to drain static charges from the
antenna to ground. Two capacitors,
CoZi and C. (510 mmfd), keep the line
voltage away from the antenna and
form a high-pass filter with LZo1, Lam,;,
and L 204 to remove any low -frequency
interference.
Tuning of the rf amplifier is provided by a shunt -tuned circuit in the
plate circuit of each of the rf amplifier tubes. Bandwidth is acquired on
the low-frequency channels by stagger
tuning these two tuned circuits so that
the first rf amplifier tunes to a lower
frequency than that of the second rf
amplifier plate circuit. On the upper
channels, tube loading provides a
rounded top of sufficient bandwidth.
The suppressor grid of the 6AU6 rf
tube is connected directly to the control grid of the 6AG5 second rf tube.
Since the suppressor grid is in the
tube plate electron stream and has interelectrode capacity with the plate, it
provides an efficient coupling device.
The rf choke coils in the output of
these tubes are used as a high-pass filter to shunt out any rf interference of
a low frequency which may be passed
from the first rf amplifier. A bias derived from the contrast control circuit
is applied to the second rf amplifier
grid circuit.
The triode tube section is connected
in a modified Colpitts oscillator circuit
which operates on the high frequency
side of the rf channel frequencies far
all channels. Oscillation is provided
by a split capacity across the inductance, L.2, consisting of the cathode to -grid and cathode -to -plate interelectrode and distributed capacities. The
choke, L., provides a dc ground path
to the cathode of the tube and maintains the cathode off ground at the rf
frequencies.
Video and Audio IF Amplifiers
Three 6AU6 pentodes are used in
the video if in a stagger -tuned hand -
A single -tuned
pass arrangement.
choke is included in each stage, each
tuned to a different frequency and then
loaded with suitable resistance to give
an adequate over-all hand -pass frequency characteristic. The choke inductance in conjunction with the tube
and distributed circuit capacity are
tuned to approximate frequencies by
the variable core adjustments in the
chokes.
Intercarrier sound is used in these
receivers, and therefore the sound if of
21.8 mc formed at the converter is
passed through the entire video if amplifier to the detector. It is attenuated
in passage through the video if to give
the proper ratio of sound if to video
if signal at the detector. At the detector, the video modulation components
are detected from the 26.3 -mc video if
and, also, a 4.5 -mc frequency -modulated sound if results from the beat
between the 21.8 -mc sound if and the
26.3 -mc video if. This 4.5 -mc signal
is amplified by the video amplifier tube
sections of the 12AU7 and then applied
to a 6AU6 limiter -amplifier tube. Detection of the 4.5 -mc signal is accomplished by a 6AL5 ratio detector.
No trap circuits are used in the
video if amplifier. Shaping of the
skirts of the if response is accomplished by a choice of frequencies to
which each tuned if choke resonates
and by the loading across this tuned
circuit. At the output of the video
amplifier, a 4.5 -mc series -tuned circuit, consisting of a 2-mmfd capacitor
(0341) and L2,,, is used to attenuate the
4.5 -mc FM if prior to application of
the video signal to the picture tube.
Taking voltage across the inductive
element of this trap, provides a means
of obtaining a slug-tuned input to the
limiter stage at the sound if of 4.5 mc.
Contrast control bias is applied to
the first video if amplifier as well as
the second rf amplifier. On early production receivers -(T versions), the
contrast control obtained its bias from
(Continued on page 32)
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Circuit of the G. E. models 817 and 821 (T and S versions) TV receiver.
SERVICE, DECEMBER,
1949
13
Pio'
phono player, there is
one accessory which requires particularly close attention. It is that small
item the stylus, and there appear to be
many variables which determine its
operational effectiveness.
One of the factors, for instance,
which determine how many satisfactory plays can be obtained from a given
stylus are the type of record most commonly played and the condition of
these records.
Records vary in degree of abrasive
action. In general, the higher quality
classical records are the best in this
respect, but unfortunately, the amount
of distortion due to stylus wear which
can be tolerated on a classical recording is generally less than that which
can be tolerated on a popular recording. The degree of groove modulation
is also a factor in record wear, the
heavier modulated recordings causing
more rapid wear than those which are
less highly modulated.
Stylus pressure is another important
consideration. Too much or too little
stylus pressure both will cause more
rapid wear of the stylus and the record.
In any reasonably good tone arm, using
a cartridge of the variable reluctance
type, one ounce should be considered
the maximum pressure to be used. The
stylus pressure should be adjusted to
between one-half and one ounce. For
professional type arms, specifically designed for the variable reluctance
cartridge, 12 grams have been found
sufficient.
The type of equipment with which
the cartridge is used is quite related
to the wear problem and merits an
analysis. Probably the largest number
of phono users utilize what might be
This
termed average equipment.
means that the amplifier and loudspeaker are of good quality, but are not
high fidelity in the generally accepted
sense of the term. Such equipment
probably does not place emphasis on
reproduction of frequencies above 7,000
or 8,000 cycles, and, although it provides excellent reproduction there is a
tendency to attenuate those frequencies
in which the most disagreeable distortion components are found.
There are, however, a large number
of users who utilize either the finest or
Ix
14
Oinstallation
SERVICING a
SERVICE, DECEMBER, 1949
FR
Rating
2
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Hearing
Typical
References
Uses
Audibility Liait
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Instonotions
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Minimum&mimesis
Roes For Musk
Comport Rodios
ILimlt.d .r Cbcul.I
Frequency -range rating system developed by
Jensen. Instead of stating frequency limits of
speakers in cycles, the hj region between the
minimum useful limit for music and maximum
limit for hearing has been divided into eight
steps, each of which is distinguishable from
the next as an audible difference for music. The
rating of the speaker is determined from the
highest interval at which loudness is maintained
at a significantly high percentage of normal.
reasonably priced wide -range audio
equipment in the reproduction of their
When the amplifier and
records.
speakers are capable of reproducing
the entire range to 10,000 cycles or beyond, the requirements of the entire
system with regard to distortion content become very strict, since the disagreeable distortion components will
be reproduced fully.
The degree to which the listener is
critical ties in quite closely with the
foregoing item since, generally speaking, the person who has taken the
trouble to provide himself with the
finest of equipment will also be the
most critical of the results. A critical listener will not tolerate as much
distortion as the average listener, nor
will he be willing, in most cases, to
reduce the high -frequency output by
means of a tone control to lesson the
effects of distortion when it is present.
The definition of a critical listener
is not restricted to engineers or experienced musicians who listen expertly for definite manifestations of
improper reproduction, but includes
those who enjoy and appreciate good
*
Based on data prepared by G.E.
Jensen Mfg. Co.
**
and
service
music, and find excessive distortion
very noticeable and disagreeable.
With these factors taken into consideration it is difficult to specify in
exact terms the number of satisfactory
plays which can be expected from, let
us say, a sapphire stylus. An average
listener using average equipment can
obtain approximately 1,500 satisfactory
plays before the stylus will need replacement, a play being defined as one
side of a512" record. A critical listener
using wide -range equipment may notice distortion due to stylus wear at as
low as 200-300 plays, and, although
this distortion does not seem to become a great deal worse between the
300 and 1,000 play mark, it is sufficiently objectionable to some listeners
to warrant stylus replacement at 300
plays.
The best way to judge whether or
not stylus replacement is necessary is
to listen for distortion to develop, particularly on heavily modulated inner grooves, i.e., grooves near the center
of the record. It should be borne in
mind that many recordings have distortion which .will be reproduced by
either a new or old stylus, and only a
record known to have low distortion
should be used in tests of stylus wear.
New Frequency Rating System
In a recent evaluation of the practice of assigning to loudspeakers frequency range values in cycles, it was
found that the use of cycles to define
the frequency limit appeared to be inadequate and unsatisfactory. The
sound engineers** who made this study
declared that in the first place frequency figures do not convey any information as to the ability of the
listener to hear differences in frequency range. Secondly, there are no
accepted standards for specifying freqency limits and therefore different
manufacturers could rate the same
speaker quite differently. Some rating
practices have been based on cut-off
limits which are actually far below the
threshold of hearing, thereby implying
performance at much higher frequen-
Variable Reluctance Stylus Wear Factors. Highlights of New Frequency
Range Rating System. Features of Westinghouse Two -Speed Changer
Needle Control.
by KENNETH STEWART
cies than are made available acoustically to the listener.
To solve the problem a new system
for rating was evolved. The system
employs liminal units (abbreviated
lim), one lim being the listener's sensation corresponding to a just-noticeable
change in frequency range.
Interval Constants
In ' deriving the new system, the
high -frequency region between 3,000
and 20,000 cycles was divided into
intervals which authoritative tests
have shown constitute just -perceptible
changes in frequency range to the ear
when reproducing music.*** The intervals are numbered from +1 to +8
The system provides for the assignment of a rating number of the
hig:est interval for a speaker, in
which the loudness is maintained at a
significantly high percentage of normal
as determined from objective measurements in connection with loudness
data and checked by means of listening
tests.
Since 3,000 cycles is approximately
the minimum range which is tolerable
for music (representative, for example, of the overall performance of
small inexpensive receivers), a par -
High -frequency
tweeter featuring
diffuser.
a
patented
(Courtesy Mark Simpson Manufacturing Co.)
ticular rating may be thought of as the
number of perceptible steps above this
minimum quality due to frequency
range extension. Thus, +5 lim and
±6 him represent the maximum perceivable ranges established by noise
and hearing for average and especially favorable home listening conditions ; loudspeakers with +5 or +6
lim ratings or higher will therefore
deliver as wide a range as is useful
for normal home listening. Loudspeakers with higher ratings are useful
at higher reproduction levels than normal, in the most critical technical applications where sound -effects, noises
and percussion instruments must be reproduced with utmost accuracy, and
where weight is attached to other performance advantages due to the use of
low- and high -frequency units handling their respective portions of the
tofal bandwidth.
The highest interval (+8 lim) is
that in which hearing cut-off occurs
for the best ears. This rating, therefore, is suggested as the maximum
which can be applied to any loudspeaker intended for listening purposes.
Westinghouse 2 -Speed Automatic
Record Changer
Dual -speed record changers for 78
and 33/ rpm are now being made to
accommodate twelve ten -inch records
or ten twelve -inch records in one loading; all records loaded together must
be rated to operate at the same speed.
In one model**** a unique twoposition needle control is used to provide the correct needle pressures.
The dual -tip needle extends through
the crystal cartridge in such a manner
that the standard tip is on one side of
the cartridge and the fine tip is on the
other side. By turning the needle control, the cartridge is rotated so that the
desired needle tip is brought into play.
At the same time, a chain and spring
arrangement in the pickup arm changes
the needle pressure to correspond with
the needle tip now in use. When the
needle control is turned *to bring the
fine tip into play (slow position), a
chain winds around the hub on the
cartridge swivel and applies tension
to a wire spring which extends along
the pickup arm to a bracket on the
pickup arm hinge pin. The tension of
the spring then lightens the needle
pressure. If necessary, the spring tension can be varied by bending the
metal bracket on the hinge pin to obtain the required needle pressure of 8
grams. With the needle control in
the standard position, the chain is not
wound around the cartridge swivel
hub, and there is no tension on the
spring; thus, the necessary 1 -ounce
needle pressure results.
The fine needle tip is identified by a
color, and the side of the cartridge
through which the fine tip protrudes
is identified in a like manner.
A speed control governs the position
of an idler drive wheel through a link
assembly. In one position, the drive
wheel bears against the larger diameter portion of the motor armature
shaft; this results in a turntable speed
of 78 rpm. In the other position, the
drive wheel is elevated so as to bear
against the small diameter portion of
the armature shaft, and a turntable
speed of 331j-'á rpm results.
Coaxial -type speaker* with a low -resonance
woofer and tweeter.
(Courtesy Utah)
"** Jensen Technical Monograph No. 3, Frenuauey Range and Power Considerations in
Music Reproduction.
Westinghouse V-6235.
-'"
SERVICE, DECEMBER, K949
15
TV RECEIVER
Line -Voltage
Control -Checker
Front view of the voltage
checker.
Novel Instrument Provides Means of Determining
and Correcting Line Voltage Variations Which
Cause Picture Flicker.
by CARL S. CUMMINGS
Television Service Supervisor
Goodman's, Inc., Jersey City, N. J.
Rear view showing the line -cord connections.
Circuit diagram of the setup.
ONE
of the most annoying problems in
TV servicing is picture flicker. The
most prominent causes are external to
the TV receiver, and have been traced
to either an improper antenna position
meters incorporated in popular testing
equipment were highly damped and
very slow in reacting to voltage fluctuations, and unless the change was
considerable, would fail to respond at
or line voltage fluctuation.
The line voltage is the most frequent
offender and therefore merits first consideration. When the voltage is extremely variable or low, a poor picture and picture flicker are sure to
result.
In analyzing the trouble, it was felt
that a means of checking the voltage
and then controlling it, should provide
a solution. As a result of this study,
a unit providing such detection and
control possibilities was evolved.
Our first construction problem was
in the selection of an ac voltmeter. It
was found that most of the ac volt-
all.
n,e
InDet Voltage
+"
of Output
An ac voltmeter that was only
slightly damped was therefore selected.
It was found to respond immediately
and report the line voltage condition
accurately.
In designing the unit it was decided
to include another feature, a breakdown test circuit. With the aid of a
variac the line voltage can be increased to 130, thus exerting additional
stress on all the components in the
receiver, which prompts weak or faulty
parts to break down and therefore
show up as defective.
For voltage variation, we included a
selector switch on the panel permitting control from 25 to 130 volts, all
at 500 watts.
Voltage
Operation
von«
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2116.
vgARV10E, DECEMBER, 1949
A toggle switch beneath the jewel
on the lower right of the control panel
was installed to turn the instrument
on and off. When the switch is off,
(Continued on page 39)
it
MORNING,
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1-94c.;
SN YD ER MAKES
WITHAMAZINGPRICE
Added Line
Construction
Tighten"
"Insert and
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caned
+
'
LIST
Complete
Hi & Lo Arrays
Genuine Bakelite insulator
1 -inch
aluminum elements
Cadmium plated hardware
Universal mast bracket
Quick and Easy Installation
ATTENTION
Jobbers. Distributors
Write for '50 catalog and
protected territories plan.
SNYDER MFG. CO.
Export: Roburn Agencies, Inc., N. Y.
New York Area Distributor: H. L. Dalis, Inc.
Phila. Area Distributor: Almo Radio Co.
SERVICE, DECEMBER, 1949
17
FIELD TESTED
Installation Information on
TV and FM
RECEIVING ANTENNAS
TV...
FM Antenna Installation
by IRA KAMEN
Manager, Antenaplex and TV Dept., Commercial Radio Sound Corp.
and LEWIS WINNER
Editorial Director. Bryan Davis Pub. Co., Inc.; Editor, SERVICE and COMMUNICATIONS
...
based entirely on actual
all-important item in TV and FM reception
experiences in the most active TV and FM areas in the country.... Over 35,000 words of vital data with
over 130 photos and drawings.
The only practical book on the
TEN CHAPTERS COVERING:
Installation Tools
Antenna Installation Procedures
Securing 72 -Channel Coverage
HF Antenna Installations
TY Interference
Fringe Reception
Master Antenna Systems
FM Antennas
Installation Business Practices
Tricks of the Trade
The first book in which you'll find complete design and installation information on every type of TV and FM
receiving antenna.... Contains detailed illustration and subject index for rapid reference.
VV "The best book on the market at this time
dealing with the problem of television antennas
and antenna installation
.
If more Service
Men would read this book, it would help them
considerably in making better installations and
providing better television reception for their
customers."-M. J. Shapp, President, Jerrold
VV
Electronics Corp.
VV
VV
"Will recommend it to all the Service Men
and technical people I meet."-Charles Cahn,
Feld Service Engineer, Rendis Radio.
"Well organized and illustrated, very complete and up-to-date, carefully detailed. It will
definitely improve the ability of the man who
studies it and therefore is mighty useful to a
firm like ours."-Hamilton Hoge, President,
United States Television Mfg. Corp.
...
.
Television Receiver Sales Div.
Allen R. DuMont Laboratories, Inc.
eral Manager,
VV
D. C.
Engineering, WJR, WGAR, KMPC.
a copy of TV
FM Antenna Installation, postwhich
paid, for
am enclosing $2.00.
I
thorough -going compendium of the in
art
. . Going to recommend it highly
Service Control Department and our
organizations."-Ernest A. Mars, Gen
"Will certainly fill a long -felt need for some
practical information
. sincerest congratulations."-George P. Adair, Former Chief Engineer, FCC, and now Consultant in Washington,
BRYAN DAVIS PUBLISHING CO., INC., Book Dept.
52 Vanderbilt Avenue, New York 17, N. Y.
Send me
"A
stalling
to our
service
VV
"Informative and extremely well written."-
R. Morris Pierce, Vice President in charge o!
AT YOUR JOBBER
OR ORDER DIRECT
(Please print)
NAME
Price $2 Post Paid
ADDRESS
CITY AND STATE
18
SERVICE, DECEMBER,
1949
i.
1 v
'.-
_1111r11111i
I
"
,
1111.''
>>/!1
11111
)tçws
by
L.
M. ALLEN
p31M1E
6B06GT
cC
E.,
THE CCENT ON TV receiver development land production, too, in many
plants has prompted intense studies of
tube -type improvements which might
be provided for these. receivers. The
result lof one such probe has led to the
processing of a series of tubes for horizontal sweep circuits. These tubes,'
the 1X2, 6BQ6GT, 6U4GT, 6W4GT,
25BQ6GT and 25W4GT, were designed for magnetically -deflected receivers, utilizing either a filament
transformer or series -string heaters
directly connected to the line.
The 6BQ6GT and 25BQ6GT, identical except for heater ratings, were
produced specifically as deflection amplifiers using either direct -coupled,
high -impedance deflection yokes or
lower -impedance yokes with coupling
transformers. With suitable components and circuits, the tubes have been
found capable of oversweeping TV
picture tubes up to and including the
16" size. Picture -tube anode voltage
is provided by the auto -winding of the
usual horizontal transformer. In the
case of the direct -coupled, high impedance circuit, the voltage is supplied
through a charging choke having a
step-up winding.
The 1X2, a high -voltage rectifier,
designed specifically for supplying
anode) voltage to the TV picture tube,
has a T-6/ bulb and a 9 -pin miniature
base which is arranged to permit
mounting of the filament dropping -resistor and high -voltage filter resistor
on the unused socket connections.
Types 6W4GT and 25W4GT are
high-lberveance diodes designed specifically for use as damping tubes in
(Continued on page 37)
ri"
!1
hvEwá,m
s
258066T
21eVa'â
IY.2
3.3 M.V
30Mn
°I/0'7r6
WI
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I
Yoke
Id
moot
ohm.
o
RO,
6U4GT
6W4GT
MrE
6waG.
Co. n.crion
OB
Fig. 1. Circuit for the 6BQ6GT/25BQ6GT direct -coupling system used in the Motorola chassis,
models TS14 and TS23. The control -grid resistance (Ro) is a .47-megohm unit. The cathode -bias
resistor (Ro) is a .47 -ohm resistor, and the screen -dropping resistor (Ro) is a 10,000 -ohm unit.
C, is equivalent to the capacity formed by the coating on the picture tube. The filament transformer
is a low capacitance type.
2..
Circuit of a conventional horizontal -sweep system using a standard 8.3-mh yoke and coupling
transformer. In this circuit both the damper diode -load resistor and the linearity control have been
removed. The control-grid resistance for this system (Ro) has the same value as the resistance
used lin Fig. 1 or .47 megohm. However, the screen dropping resistor, Ro, and the cathode -bias
resistor, Ro, are different in value. The screen -dropping resistor value is dependent en the transformer used and can be 24,000, 16,000, or 67,000 ohms. Variations in the cathode -bias resistor (R1.)
are also predicated on the transformer employed and may be 100, 43, or 47 ohms.
Fig.
X2
E,00r.
6/25BQ6GT
z
3 3
M.p
T
e
^^^,v`
aimr
amm
o
Conrlol
6W4GT
25WGT
Ebb
t$yttlon.
SERVICE, DECEMBER,
1949
19
Performance Diagnosis
Of Vacuum -Tube Circuits
Part 11 . . . Finding Gain and Grid Bias Values
of 6L6 Amplifiers By Way of Characteristic
Curves. Cathode -Follower Calculation Procedure.
by EDWARD M. NOLL
200,
Instructor
Et =6.3 Volts
x
xy
ir
150
2
Y
Eo
_ 100
eoo
.'
O
, ¿
M,a`I
N
1050
h
1165 Ro.
R
+eao
,
_
N
A
X
in Television
Temple University
6L6
Ph
'.-
x' 400
300y.
200
loo
; el
600
500
02H
700
Plate Volts
Figs.
1
Basic circuit of a 6L6 amplifier and the curves for the tube when connected in triode
fashion.
and 2.
Figs. 3 and 4.
Circuit of
triode connected as
a cathode follower and
the cathode -follower load lines.
a 6L6
a
plot of the curves for
IN APPLYING tube plot curves to study
circuit problems, it was pointed out
last month that the curves could reveal
such factors as power output, decoupling, plate loads, etc.
Let us now see how these plots can
be used to find the gain and grid bias
applied to a 6L6 amplifier; Fig. 1.
In the first step, we must find the
total resistance of the three resistors
which because of the presence of plate
current, affect the plate voltage of the
stage. This total is 4,000 ohms. Then
we can draw a 4,000-ohm load line,
with the supply voltage -zero plate current as one point.
Assuming that we have a plate -voltage change of 360 and 360/4000 locates
another point of the load line at 90 ma
on the plate current axis, the line XX'
can be drawn.
Then we can draw the loci of possible
bias points for a 150-ohm cathode resistor. To find two points on the line
bias, values of -7.5 and 15 were
selected for this example.
Point A:
2
6L6
Ef=6.3Volts
3000
le=
Ajg
N UAV
d
á
+.ow
550
e0
Ó1
-
ram"Aa,
5
7n
o
100
SERVICE,
D
200
I
DECEMBER,
,9
^y
I
a
.o
_._4.-'`.1..-..4i.'_"
400
300
Plate Volts
h
^
100 ma
150
7.5
Io=-=
50 ma
150
Now a line is drawn through points
A and B. Where this line crosses the
plate line, we have the operating point
or, at -E0 of 7.5 volts, E, of 160 volts,
and I. of 50 ma. To check this point
we have to multiply I, Rk and obtain
7.5 volts. Another check is to subtract
the supply voltage 360 from the suns of
the resistor voltage drops, I, (R5 plus
eq
ti
E
01
20
o
15
RK
Point B:
,i
-E,
-_-=
RL plus R0) or
Ep=360-50 ma (1050+2800
=360-200= 160
1y
-I-
150)
The true dynamic load line can now
Y
00
600
700
1949
www.americanradiohistory.com
be drawn with a slope of 2,800 ohms
(Continued on page 38)
3 New Time-Saving,
G -E
Profit -Building
TELEVISION SERVICE INSTRUMENTS
Now
- you can check
- with this new G -E equipment
varying from fringe
TV receivers under conditions
areas to "under the tower" and predict operation of
the sets anywhere in the service area at a glance!
-
Permeability Sweep Generator! Crystal Controlled Marker Generator! Cathode Ray
Oscilloscope! Put them all together in one group
arid you have what manufacturers and servicing
dealers have acclaimed the fastest, most accurate
answer to television receiver testing problems ever
offered!
VARIABLE
Here's whyVariable Permeability Sweep Generator can be
set quickly to any desired frequency, supplying high
output and exceptionally wide linear sweep-
0;.Z
ea/A
e2dpei
et9
4Aee
o Because of low leakage, complete over-all response from antenna terminals to picture detector
can be viewed with contrast at maximum settings.
All desired markers for complete alignment are
obtained by one initial setting of the master dial on
the marker generator.
High quality general purpose oscilloscope presents accurate picture of wide range of phenomena from response
curves to composite
signal.
`
General Electric Company-Room
1070
Electronics Park
Syracuse, New York
IL
Send me specifications, pictures, and prices on the
new G -E Television Test Equipment Package.
GENERAL(9I ELECTRIC IL``
NAME_
ADDRESS
CITY
STATE
SERVICE, DECEMBER,
1949
21
T
Receiver Production Changes
With the sync pulse positioning itself
Discriminator Performance in the G. E. Horizontal
Sweep Generator and AFC System. Changes for
Vertical Hold Improvement in Westinghouse TV
Models. Damping Tube Replacements.
by DONALD PHILLIPS
IN THE DISCUSSION' of the sweep generator and afc circuit used in the latest
G. E. TV models, it was pointed out
that the discriminator, consisting of
tube sections, Vaa, and VIIB, and allied
components, is used to develop a dc
correcting voltage by comparing the
phase between the output sawtooth
waveform and the incoming horizontal
sync pulses.
In Fig. 2 appear discriminator waveforms which illustrate the action taking place. The polarity of the saw tooth wave on each diode is represented as the same, while the polarity
of the sync pulses is inverted, with the
polarity of the pulse on Vaa, being positive and that on Vaa, negative. The
dc voltage represented by Em and E02
is thus equal to the difference between
the ac axis (dotted line) of the composite waveform and the peak of the
sync pulses. Stable operation of the
discriminator is obtained as long as the
sync pulse rides on the steep slope of
the sawtooth waveshape.
In A, it has been assumed that the
sweep generator is operating at exactly
SERVICE,
the same phase as the incoming sync
pulses. This condition requires that
no voltage be derived from the discriminator so that the sweep generator
will continue to operate at this same
frequency. This condition will only be
fulfilled when the sync pulse falls on
the steep slope of the sawtooth wave shape at the ac axis crossover, for each
succeeding cycle as indicated. At this
condition, Elm will be equal to Epp, and
from Fig. 1, since ED, + EDa is equal
to the do output voltage and EDl has
opposite polarity to EDa, then the resulting correction voltage applied to
the reactance afc tube will be zero.
A condition which calls for a correction voltage appears when the sync
pulse frequency is higher than the
sweep generator frequency. This is
exemplified by the pulse-sawtooth relationship where the sweep generator
is lagging in phase, as shown in B.
1.
fi
Eo2
Discriminator circuit.
1`32
Eo
1
}oI
.
Sweep Gen. In Phase
D
22
SERVICE, DECEMBER, 1949
the ac axis, the composite sync pulse
and sawtooth waveshapes cause E02 to
be greater in amplitude than that of
E,I, resulting in ED1 + Elm, providing
a negative polarity correction voltage.
This negative voltage, applied to the
grid of the sine-wave tube, will cause
the sweep generator to operate at
higher frequency 'than in A. This
higher frequency thus maintains this
new phase relation with time, resulting
in an identical frequency for the sweep
generator and incoming sync pulses.
In other words, the correcting voltage
formed by the sync pulses having a
higher frequency than the 15,750 cps
frequency of the sawtooth generator,
causes the generator to run at a new
frequency (higher), which corresponds
to that of the sync pulses.
The opposite condition of B, which
calls for a correcting voltage also, is
when the sync pulse frequency is lower
than the sweep generator mean frequency of 15,750 cps. This is the condition shown in C, where the sweep
generator is leading in phase. In this
case, the pulse positions itself below
the ac axis of the sawtooth waveshape,
with the result that EDa will be smaller
in magnitude than ED1. Thus, when
Elm is added to Elm, we have a resultant positive polarity voltage which
(Continued on page 29)
Fig. 2. Discriminator wave forms. These plots illustrate the addition of the sync and sawtooth
waveshapes when they are at different phase relations to each other and the resulting dc voltage
derivation.
November, 1949.
Fig.
on the steep retrace slope of the saw tooth waveshape so that it falls above
1
EA'
£07E
Sweep Gen. Logging
Sweep Gen. Leoding
EA
-------
o
Ea. ECM Eo2
-
Eoi*Eo2
Sca'iciiqïfíclps
THERE ARE
a variety of unusual com-
ponentsn every TV receiver, particularly in the picture -tube circuit. There
is, for instance, the magnetic deflecting
yoke, processed for the specific size
picture tubes. One model' has been
designed for use with picture tubes
having neck diameters of 1 ire" and deflection angles up to about 60°. Designed for use with the 10BP4 and
12LP4, it has a molded spool and a
molded -iron core. The start and finish
of each of four coils are brought out to
terminals, as shown in Fig. 1. This
yoke will be found installed with its
capped end toward the base of the picture tube.
Herizonral-Deflection-Output and
H g4 -Voltage Transformer
Another extremely interesting and
vital picture -tube component is the
horizontal -deflection-output and high voltage transformer' designed for use
in pulse -operated power supplies with
no-load picture -tube anode potentials
up to 12 kv. This unit can provide
full deflection for either a 10BP4 or a
12LP4 with a single driver tube (such
as a 6AU5GT) and requires about 15
watts in a typical deflection circuit for
a 10BP4, as shown in Fig. 2. To
assure quiet operation a powdered -iron
core is used. The windings are impregnated with a moisture-resistant
compound which does not support combustion. Leads and filament windings
are insulated with polyethylene plus
polyvinyl chloride compound to minimize fire hazard.
Autotransformer action of the unit
provides high voltage to two 1V2 recMagnetic deflecting yoke circuit..
Application Notes on Deflecting Yokes and
Horizontal -Deflection Output and High -Voltage
Transformers. How to Make External Antenna
Connections to BC Loops.
by M. A. MARWELL
Two methods have been found quite
effective for such applications. The
first involves winding of primary turns
around the present loop.
One or two turns of wire such as
No. 18 insulated bell wire are wound
around the loop antenna along the outer surface, near the outside turn, to
provide a suitable means for coupling
from an outside antenna. One end of
this two-turn loop antenna should be
connected to the outside antenna while
the opposite of starting end should be
connected to the receiver chassis or
ground. Additional turns will generally not show too much improvement over the use of two turns and
in addition may require retuning the
antenna circuit by adjustment of the
trimmer capacitor. When using this
method the loop antenna is still effec(Continued on page 36)
tifiers connected in a voltage -doubling
circuit. Two windings provide filament power to these tubes. On the
transformer is a terminal board with
two sockets for mounting the high voltage 1 V2s. In addition, the transformer has holes for mounting three
high -voltage capacitors on the terminal
board, and terminals are also provided for connecting a width' and a
linearity control.`
BC External Antennas*
NEED for the use of an external
antenna for the broadcast band is so
infrequent that this provision is omitted on most receivers.
However, there are occasions when
an external antenna is necessary.
THE
8RCA-205 Dl.
2 RCA 217T1.
° RCA 206R1.
*From RCA service notes.
r
RCA 207R1.
Hor Output
GT
64U5
Hoc. Dafteet. Output
and HV Tronstormer
MVRect.
HV Rect
iV2
500 Mmtd
IV2
a
Horizontal deflection
circuit
and
pulse operated high -voltage
supply for the 10BP4
and 12LP4.
Leads
from terminals 8 and
ha
must be
s
7
wiring. In equipment
where it is impractical
to maintain this lead
dress, the temperature
at point of lead contact
must never be more
than 80° C for any
condition of operation.
5
500
9
Mmld
110
Mld
dressed
awe. from each other,
the chassis, and other
a
1a
a
Control
6 =
Meg
a
eerie.
Lineority
25
rd
6
1
NIT
O/
Wid h
Mt
25
Control
ODO
Ohms
11
6W4 GT
Oomper Diode
o
DC Output
To Kinescope
Boosted Voltage
i3.
B-
To Vertical Output
and Discharge Circuits
SERVICE, DECEMBER, 1949
23
AUITIO
At a recent ARTSNY TV lecture, at the Central
Commercial High School in New York City,
which featured a talk by John Meagher of RCA.
Left to right: Arthur Silverberg, association
recording secretary; Gerard Nierenberg of the
association's legal staff; Hal Bersche, RCA;
Max Liebowitz, ARTSNY prexy, and John
Meagher.
David Leibowitz, son of Max Leibowitz,
ARTSNY prexy, presenting the ESFETA plaque
(right) to John F. Rider during a banquet held
at Locust Lawn, Ionia, New York.
W. England; A. Roy; W. G. Sousa
and J. Santos.
ESFETA
JoHN F. RIDER received an award recently, for his efforts on behalf of
radio -TV Service Men of the country,
from the Empire State Federation of
Electronic Technicians' Associations
at a banquet of the Radio Technicians'
Guild of Rochester, New York, at
Locust Lawn, Ionia, New York.
Rider was instrumental in inaugurating the current ESFETA lecture
series.
FRSAP
PAUL W. SMITH, program chairman
of a speakers' schedule for 1950 for the
Federation of Radio Servicemen's Associations of Pennsylvania, has reported that manufacturers are now
being contacted requesting speakers on
topics of interest to all Service Men.
Smith suggests that any manufacturer who would like to be represented
on the program should write him at
306 Chestnut Street, Harrisburg, Pa.
RTG
AT THE
ANNUAL
MEETING
of the
Whaling City chapter (New Bedford,
Mass.) of the Radio Technicians'
Guild of New England, John Tavares
was named president.
Al Gagnon was elected vice president; J. L. Shepley, secretary; J.
Sumner, treasurer; Louis Senra, sergeant -at -arms and Frank Cambra,
librarian.
Six were named to the board of
directors ; Ted Gurgan ; M. F. Correia
;
24
SERVICE, DECEMBER, 1949
ART of BC
THE ASSOCIATED RADIO TECHNICIANS
of the Vancouver chapter held a conventipn recently at the Stanley Park
Pavilion, which featured several lectures by outstanding Canadian authorities.
Miles Green, assistant radio engineer of the B. C. Laboratories Co.,
Ltd., provided a report on the telephony, FM, and microwave technique
practices in British Columbia. Don
Hinges of Electronic Laboratories of
TEN YEARS AGO
From the Association News Page of
SERVICE, December, 1939
at the Los
Angeles chapter and presented one of
his cross-country series of service lectures sponsored by RCA. . . . RSA
announced chapters in Amsterdam,
New York; Marinette, Wisconsin;
and Minneapolis, Minnesota. . . .
PRSMA announced that their weekly
classes on television were an outstanding success. Frequency modulation
and facsimile were subjects of special
talks during the month. . . . NAB RSA program was in full swing, NAB
member stations carrying a consistent
schedule of spot announcements advising listeners to improve their listening by keeping their receivers repaired.
JOHN F. RIDER appeared
Canada, presented a talk on the general
television conditions in Vancouver and
TV receiver design characteristics.
Nick Foster of the Edison Vocational Schools of Seattle, presented a
spirited talk on TV installation and
servicing.
PRSMA
has received special consideration in a revised edition of the
constitution and by-laws of the Philadelphia Radio Service Men's Association. In two amendments, two classes
of members have been established
television electronic technician and
television installation specialist.
In an amendment of the by-laws,
covering the requirements of eligibility
for these classifications, the passing of
special examinations are described as a
TELEVISION
:
requisite.
AR7SNY
THE TV LECTURES recently initiated
by the Associated Radio -Television
Servicemen of New York have become
extremely popular and attracted large
audiences.
Members of Westinghouse and
Emerson appeared to discuss video if
and sound circuits, respectively. At
subsequent meetings, representatives
of RCA and Allen B. DuMont covered detector and video amplifiers, and
picture tubes.
All lectures, which are incidentally
presented in cooperation with the Empire State Federation of Electronics
Technicians' Associations, are well
illustrated and, in most instances, accompanied by demonstrations.
Television Arithmetic
$200 Television Set + $5 Antenna = $5 Picture
$200 Television Set + $25 Antenna = $225 Picture
Yes... it's
as simple and basic as that. Just like 2 plus 2 equals 4. Let all
of us square up our thinking and recognize OPENLY that in a great,
great majority of cases, the television buyer can get the full value from
his set ONLY with a good outdoor antenna properly installed.
Certainly, there is great value for the indoor antenna. We make them
ourselves, and good ones, too, BUT ...
We'll be the first to admit that the best indoor antenna cannot compare
with even the poorest outdoor antenna for picture quality. In certain
"ideal" conditions, an indoor antenna will perform satisfactorily, BUT...
Let us not abuse this "condition" by recommending indoor or "builtin" antennas where they will not give the customer his full dollar's
worth. It is up to the Television Industry to see that the American
Public gets its money's worth in television and that means simply ... A
GOOD OUTDOOR ANTENNA SHOULD BE INSTALLED
WHEREVER POSSIBLE.
The indoor antenna is a good short cut to quick consumer sales, BUT
DOES NOT GIVE THE CUSTOMER THE PICTURE HE IS
PAYING FOR! This is the truth about television antennas ... as
related to picture quality. Tell it to your customers, let them decide
for themselves.
THE MAKERS OF THE
COMPLETE LINE OF GOOD TELEVISION ANTENNAS
THAT MAKE GOOD TV SETS EVEN BETTER!
THE RADZART CORPORATION
CLEVELAND 2, OHIO
Reprints of this advertisement
available upon request.
SERVICE, DECEMBER,
1949
25
INDEX
ANNUAL
JANUARY -DECEMBER, 1949
ANTENNAS
Antenna Installation Tricks of the Trade,
Feb.
TV; Ira Kamen
Apr.
Antenna Installation Hints, TV
May
Antennas, TV (Editorial)
Oct.
Coax Fitting Problems
Ira
Line Installation
Coax
Sept.
Kamen
Coax Line Installation Practices (Part II)
Oct.
Ira Kamen
Construction of Attenuation Pads for 72;
Feb.
300 -Ohm I.ines
Sept.
End Termination Problems at 200 Mc
Fringe Area Reception, Aligning the TV
Apr.
Receiver for; J. F. Bigelow
Jumper Link Assemblies for Folded Dipoles
Feb.
and Broadband Straight Dipoles
Practical Hints on Installation of Auto Antennas
May
Rhombic TV Antenna Installation; Ira
Aug.
Kamen
Oct.
Shielded -Line Variables
Sept.
Splicing Techniques for Coax
Oct.
Tap
-On
Splice
Technique
The
The Philco Built -In TV Antenna System.Sept.
Feb.
Those TV Antennas (Editorial)
TV Antenna Divider and Decoupling NetFeb.
works
TV Antenna Tower Installations; Ira
Kamen
July
Sept.
TV Tunable Built-1n Antenna System
AUTO RECEIVERS
.
Auto Power Supply Testing With a
May
'Scope
May
Auto Radio Antennas
Auto Radio Custom Designs
May
Auto Radio Extension Speaker Installation May
May
Auto Radio Installation; Lewis Martin
Auto Radio Service Aids; P. M. Randolph
Sept.
Auto Radio Servicing; Jack Darr
May
Auto Radio Speaker Installation
May
May
Auto Voltage Testing
Sept.
Basic Cures for Dead Receivers
Eliminating Noise Originating in Ignition of
May
Generator and Wheels
Eliminating Noise Rattles, Pickup Noise
Sept.
and Wheel Static
How to Build and Apply Special Types of
May
Auto Test Accessories
Improving Control Shaft Fittings
Sept.
Remedying Pushbutton Sticking
Sept.
Jan.
Taxicab Radio (Editorial)
Testing Car Sets on the Bench
May
May
Underdash and Firewall Mount Data
CIRCUITS
Aug.
Admiral 119-1 TV Filter Circuit
Admiral 21A1 TV and 4K1 FM and AM
Nov.
Tuner
May
Admiral 3 -Way Player
Amplifier Which Can Be Adapted to TV
Receivers to Improve Fidelity
June
Sept.
Approved Electronic A-400 (Cover)
May
Anchor ARC -101-50 (Cover)
May
Audio Demonstration Board
Audio Peak Limiter Circuit
June
Ballast Tube in a Circuit Using Too Large
Apr.
a Current
Bendix 1524, 1525 With Hush-O-Matic
System
Aug.
Bendix 235 (TV)
Jan.
Bendix 2,000-3,000 Series
Oct.
Bendix TV Receiver IF Alignment Setup Mar.
Browning RV -l0 (FM Tuner)
Jan.
Apr.
Capacitor Checker
Circuit With a Ballast Where the Current
Is Too Small
Apr.
Coax Line Parallel Setups
Feb.
Coax Switch Attenuation Control System Feb.
of
Ballast
Tube
DC
Connection
in AC or
Apr.
Circuits
ECA FM/TV Signal Generator
Mar.
DuMont RA 105
Aug.
DuMont RA 105 Power Supply
Sept,
DuMont RA 105 TV Receiver
Sept.
Espey 513 (FM/AM Tuner and AF Amplifier; Cover)
Feb.
Flexible TV Signal T.evel Pads
Feb.
FM IF Limiter and Discriminator Stages Mar.
Jan.
G. E. SPX -001 (Preamp. Equalizer)
G. E. Table Model Clock Mechanism
Oct.
G.E. 12" TV Models
Dec.
G. E. Variable Reluctance Phono Preamp June
Hallicrafters T -61/T-67 (Push-Button TV
Model)
Jan.
26
SERVICE, DECEMBER,
1949
510
(Circle July
Ang.
High Fidelity TV Amplifier
Horizontal -Deflection and Pulse-Operated
Dec HV Supply for 10BP4 and 12 LP4
Dec.
Horizontal Sweep Circuit
How to Connect a Ballast Tube in Circuit
Apr.
Using Transformer
Inverse Feedback Circuit in a Single -Ended
June
Amplifier
Feb.
LF Compensation Circuit
Feb.
Magnavox TV Horizontal AFC System
..Dec.
Magnetic Deflecting Yoke Circuit
Mallory Converter Circuits (Inductance
Jan.
Tuning)
Jan.
Meissner 8C (FM Tuner)
NC-TV-7/NC-TV-7M (Cover; Complete
Jan.
Circuit)
Aug.
National TVB-1 Booster (Cover)
Dec.
National Videometer (Cover)
Jan.
Olympic RTU-3 (TV Duplicator)
June
_Otarion Hearing-Aid Analyzer (Cover)
Sept.
Philco Built-in TV Antenna System
Mar.
Philco 41-609 LP Adapter Switch Kit
Nov.
Philco 48-700 Width Control
Mar.
Philco 48-1001 TV
Nov.
Philco 48-1000 Width Control
Nov.
Philco 49-1040 Width Control
Sept.
Philco 50-T1630 (Input)
Sept.
Picture -Tube Conversion Circuit
Jan.
Pilotuner (Capacity -Tuned FM Unit)
RCA 8T270, 8TC270, 8TC271 (16" Metal
July
Receiver)
Picture -Tube
Aug.
RCA 8V112 Magic Monitor Circuit
June
RCA 9EY3 45 -RPM Amplifier
Rock -Ola Crystal Pickup Adapter Circuit June
June
Rock -Ola Input Circuit
June
Rock -Ola Quick-Heater Relay System
Sept.
'Scope Using 3RP1
Nov.
Selenium Cell Doubler Circuits
Selenium Forward Voltage Drop Test CirNov.
cuit
Nov.
Selenium Rectifier Half -Wave Circuits
Nov.
Circuits
Selenium Reverse Testing
Dec.
6BQ6GT/25BQ6GT Sweep Circuit
Sola Constant -Voltage Transformer Circuit June
Mar.
Sparton AVC1/AVC2 (Cover)
Feb.
Sparton 4939TV/4940TV/4941TV
Speaker Transformer Primary Measurement
System
June
Oct.
Supreme 665 (Cover)
Supreme 665 (Dot Signal Channel Circuit) .Oct.
Oct.
Supreme 665 (Timer Section)
Apr.
Supreme 660 TV 'Scope
Feb.
72 -ohm Coax Line Pads
Oct.
TV Alignment Bias Box System
Sept.
TV Antenna Insertion Circuits
Nov.
Tech -Master BC -1223 (Cover)
Feb.
300 -ohm Selector Switch System
Feb.
TV Divider and Decoupling Networks
TV Receiver Line -Voltage Control -Checker;
Dec.
Carl S. Cummings
Oct.
UHF Antenna Installation Layout
Videola VS 160, 165
Sept.
Vision Research Model 20-20 (Cover)
Apr.
Voltage -Doubler Picture -Tube Conversion
Circuit
Sept.
Westinghouse H-196
Oct.
H196
Aug.
Westinghouse
TV Sound Circuit
Westinghouse H196 Sweep Circuit
Aug.
Westinghouse H196 TV Receiver
Apr.
Westinghouse 223, 242, 251, 231 and 226
Oct.
(Circuit to Eliminate Blooming)
Westinghouse 242 (Improved Horizontal
Multivibrator Circuit)
Oct.
Westinghouse 242 (Improved Vertical
Multivibrator Circuit)
Oct.
Zenith 28F20, 28F21 and 28F22 (Circular
Mar.
Screen TV)
Hallicrafters T64, 50,
Standard Screen TV)
COVER DIAGRAMS
Anchor ARC 101-50 (1 -Tube TV Pre May.
amp.)
Approved Electronic A-400 (TV and FM
Oct.
Sweep Signal Generator)
Espey 513 (AM/FM Tuner and AF AmpliFeb.
fier)
Hallicrafters T64 509, 510 (Circle-StandJuly
ard Screen TV)
Aug.
National TVB-1 (Two -Tube Booster)
National Videometer (Signal Strength TV
Dec.
.Test Set)
NC-TV-7/NC-TV-7M (Rotary Switch 7"
Jan.
TV)
June
Otarion Hearing Aid Analyzer
Supreme 665 (Composite Video Signal GenOct.
erator)
Stewart Warner, AVC1 and AVC2 (ReModel)
Mar.
flector System TV
Tech -Master BC -1223 (Keyed AGC TV
Nov.
Model)
Vision Research 20-20 (20-Tube 12%" TV
Apr.
Model)
EDITORIALS
AM and TV Circuitry
A Report on Sound
Broadcaster and the Service Man
Broadcasters and Service Men
Choice of UHF IF
Compensation for Your Knowledge
Just What the Doctor Ordered
Long -Playing Records
Loudspeakers
Preventive Maintenance
Preventive Maintenance
Preventive Maintenance Campaign,
Harrisburg
Oct.
June
May
July
Nov.
Feb.
June
Jan.
Mar.
July
Aug.
The
Preventive Maintenance Control
Preventive Maintenance Now a Headliner
Production Changes
Selling Your Service
Taxicab Radio
Telephone, Mail and the Doorbell
The Eyes and TV
The TV Surge
The TV Swing
The Ultrahighs
TV Antennas
TV Demonstration Boards
TV, FM and Sound
TV in '49
TV Safety Rules
The TV Service Operation
TV Servicing
TV Servicing
TV Servicing Pitfalls
UHF Design Study
Ultrahighs and the Service Man
Viewing Distances
Apr.
Sept.
Oct.
Jan.
Mar.
Jan.
July
Sept.
Mar.
Sept.
Aug.
May
Mar.
Jan.
Feb.
June
Aug.
Apr.
May
Nov.
Nov.
Nov.
Mar.
FEATURES
Alignment of FM Receivers; R. D. Hickok
Mar.
and W. A. Weiss
Aligning the TV Receiver for Fringe Area
Apr.
Reception; J. F. Bigelow
Aligning the Westinghouse H-196; Irving
Oct.
Silberg
AM/FM Tuner and AF Amplifier (Cover).Feb.
Dec.
Annual Index, SERVICE, 1949
Jan.
Association News
Feb.
Association News
Mar.
Association News
Apr.
Association News
May
Association News
June
Association News
July
Association News
Aug.
Association News
Sept.
Association News
Oct.
Association News
Nov.
Association News
Dec.
Association News
May
Auto Radio Installations; Lewis Martin
Auto Radio Service Aids; P. M. Randolph Sept.
May
Auto Radio Servicing; Jack Darr
Capacitor Checker Design and Application;
Apr.
P. M. Randolph
Coax Line Installation Practices; Ira
Sept.
Kamen
Coax Line Installation Practices (Part II);
Oct.
Ira Kamen
Coin-Operated Automatic Phono Servicing;
June
Jack Darr
Composite Video Signal Generator; Allan
Lytel
Oct.
Constant Voltage Sources for TV Receivers; Hans U. Hjermstad
June
Custom Audio Installations; Irving Greene May
Custom Audio Installations; Irving Greene June
Custom -Built Cabinets; Martin W. Elliott Feb.
July
Custom TV Installations
Design, Application and Servicing of
Nov.
Selenium Rectifiers; Irwin Wolf
Design and Construction of a Custom
June
Cabinet; Clifford .Stubbs
Jan.
FM Tuner Design; John B. Ledbetter
Hearing -Aid Servicing; Clifford W. Carlson
June
Horizontal AFC System in Magnavox TV
Feb.
Receivers; J. F. Bigelow
Preamp. (Cover)
May
1 -Tube TV
Performance Diagnosis of Vacuum -Tube
Nov.
Circuits; Edward M. Noll
Performance Diagnosis of Vacuum Tube
Dee.
Circuits; Edward M. Noll
Phono Installation and Service; Kenneth
Stewart
May
Phono Installation and Service; Kenneth
Stewart
June
and Service; Kenneth
Stewart
July
Phono Installation and Service; Kenneth
Aug.
Stewart
Phono Installation and Service; Kenneth
Stewart
Sept.
Phono Installation
Phone Installation and Service;
Stewart
Kenneth
Oct.
Phone Installation and Service; Kenneth
Stewart
Nov.
Stewart
Dec.
Phone Installation and Service; Kenneth
Reflector System TV Model (Cover)
Rhombic TV Antenna Installation;
Ira
Mar.
Kamen
Aug.
Rotary Switch 7" TV Model (Cover)
Jan.
Jan.
Ser-Cuii s
Feb.
Ser-Cuits
Mar.
Ser -Cuits
Apr.
Ser-Cuits
May
Ser-Cuits
Ser-Cuits
July
Ser -Cuits
Sept.
Ser -Cuits
Oct.
Nov.
Ser-Cuits
Dec.
Ser -Cuits
Servicing 45 -RPM Changers; Thomas Y.
Flythe
June
Jan.
Servicing Helps; P. M. Randolph
Servicing Helps; P. M. Randolph
Feb.
Mar.
Servicing Helps; P. M. Randolph.
Servicing Helps; P. M. Randolph
Apr.
Servicing Helps; M. A. Marwell
Sept.
Servicing Helps; M. A. Marwell
Oct.
Serving Helps; M. A. Marwell
Nov.
Servicing Helps; M. A. Marwell
Dec.
Signal Strength TV Test Set (Cover)
Dec.
Solder and The Service Man; Franklin S
Hagman
May
Sound Installation Servicing Helps; Ira
Ka new
June
Stepping Up Your TV Service Income;
R. J. Guilfoyle
May
Stepping Up Your TV Service Income;
R. J. Guilfoyle
June
Sweep Generator Operating Hints; Victor
I. Robinson
Sept.
Ten Years Ago in Associations
Jan.
Ten Years Ago in Associations
Feb.
Ten Years Ago in Associations
Mar.
Ten Years Ago in Associations
Apr.
Ten Years Ago in Associations
May
Ten Years Ago in Associations
June
Ten Years Ago in Associations
July
Ten Years Ago in Associations
Sept.
Ten Years Ago in Associations
Oct.
Ten Years Ago in Associations
Nov.
Ten Years go in Associations
Dec.
The Business Aspects of TV Installations;
Ira Kamen
Jan.
The Harrisburg Preventive Maintenance
Campaign
Apr.
The Philco Built -In TV Antenna System Sept.
Those TV Controls and Adjustments;
Align Lytel
Mar.
Tube News; I.. E. Stewart
Apr.
Tube News; L. M. Allen
Sept.
Tube News; L. M. Allen
Dec.
TV Antenna Installation Tricks of the
Trade;; Ira Kamen
Feb.
TV Antenna Tower Installations; Ira
Kaman
July
TV and FM Sweep Signal Generator
(Cover)
Sept.
TV Hi-Fi Audio Installations; Irving
Greene
Aug.
TV Model With Keyed AGC System;
Walter H. Buchsbaum
Nov.
TV 'Picture Tube Safety Rules
July
TV Receiver Line -Voltage Control -Checker;
Carl S. Cummings
Dec.
TV Receiver Production Changes; Donald
Phillips
Jan.
TV Receiver Production Changes; Donald
Phillips
Mar.
TV Receiver Production Changes; Donald
Phillips
Apr.
TV Receiver Production Changes; Donald
Phillips
Aug.
TV Receiver Production Changes; Donald
Phillips
Oct.
TV Receiver Production Changes; Donald
Phillips
Nov.
TV Receiver Production Changes; Donald
Phills
Dec.
TV Receiver Servicing; Carl Quirk
Aug.
TV Receiver Servicing; Carl Quirk
Sept.
TV Receiver Visual Alignment Techniques;
Letter L. Libby
Jan.
TV Receiver Visual Alignment Techniques;
Lester L. Libby
Mar.
TV Receiver Visual Alignment Techniques;
Letter L. Libby
Apr.
20 -Tabe 12,A" TV Model (Cover); Walter
H. Buchsbaum
Apr.
Two -Tube TV Boster (Cover)
Aug.
Viewing Areas of TV Receivers; Robert P.
Wakeman
Feb.
Visual TV Alignment Procedures; Victor
I. Robinson
July
Visual TV Alignment Procedures; Victor
I. Robinson
Aug.
FM
Admiral Receiver With FM/AM Tuner Dec.
ECA FM/TV Signal Generator
Mar.
Espey 513 AM/FM Tuner and Amplifier
(Cover)
Feb.
FM Receivers, Aligment of; R. D. Hickok
Mar.
and W. A. Weiss
FM and Sountd, TV (Editorial)
Jan.
Jan.
FM Tuner Design; John Ledbetter
'Scope and FM Signal Generator Limiter
and Discriminator Stages and Ratio Detector Alignment
Mar.
TV and FM Sweep Signal Generator
(Cover)
Sept.
Tuner Design, FM; John B. Ledbetter
Jan.
MANAGEMENT
Broadcasters and Service Men (Editorial). July
Just What the Doctor Ordered (Editorial) June
Preventive Maintenance (Editorial)
July
Preventive Maintenance (Editorial)
Aug.
Preventive Maintenance Control
(Editorial)
Sept.
Preventive Maintenance Now a Headliner
(Editorial)
Oct.
Selling Your Service (Editorial)
Mar.
Stepping Up Your TV Service Income;
R. J. Guilfoyle
May
Stepping Up Your TV Service Income;
R. J. Guilfoyle
June
The Broadcaster and The Service Man
(Editorial)
May
The Business Aspects of TV Installations;
Ira Kamen
Jan.
The Harrisburg Preventive Maintenance
Campaign (Editorial)
Apr.
The TV Service Operation (Editorial)
Aug.
Telephone, Mail and the Doorbell (Editorial)
July
TV Servicing (Editorial)
May
PRODUCTION CHANGES
Adding AFC to Motorola VT71
Jan.
Addition of Bias to Converter Grid of
G. E. 810, 811 and 814
Apr.
Addition of Power Transformer Fuse to
Admiral TV Sets
Oct.
Admiral 19A1 Revised Horizontal Sync
Filter System
Aug.
Admiral 30A, B. C and D Audio Output
Change to Increase Gain
Aug.
Alternate Audio IF Transformer for Admiral 30A1
Mar.
Bendix 235 Changes (Codes D and E)
Jan.
Changes for Vertical Hold Improvement in
Westinghouse Models
Dec.
Damping Tube Replacements
Dec.
Discriminator Performance in the G.E.
Horizontal Sweep Generator and AGC
System
Dec.
Eliminating AF IF Regeneration in G. E.
810, 814, 820, 830 and 835
Apr.
Eliminating Blooming in Westinghouse TV
Sets
Oct.
Eliminating Vertical Bars and Horizontal
Line Humps in Westinghouse TV
Models
Oct.
Horizontal Sweep Generator and AFC Circuit for G. E. Receivers
Nov.
Improving Audio IF Selectivity and Brightness Control and Removing Howl in
G. E. 810
Jan.
Improving Tube Focusing in G. E. 901 and
910
Mar.
Improvement of Picture Definition in
Westinghouse TV Models
Oct.
Installation of AGC and Improved Horizontal Oscillator in Admiral Receivers
Oct.
New String Tuning Drive for G. E. 810 Jan.
Picture Tube Interchange in G. E. 801,
802, 803
Mar.
Picture Tube Mask Change in G. E. 801
and 802
Mar.
Removing Microphonics in Admiral 30A1 Mar.
Removing Raster Wiggle in G. E. 814
Apr.
Removal of Vertical Retrace Lines in G. E.
810, 811, 814
Apr.
Substituting 6AU6s for 6AG5s in Admiral
30A 1
Jan.
Transmission Line Wave Traps
Apr.
Westinghouse H196 Audio Circuit Revision
for Removal of Hum
Aug.
Westinghouse H196 Altered Sweep Circuit Aug.
Westinghouse H196 Horizontal Oscillator
Modification to Curb Drift
Aug.
Westinghouse H196 Revamped Sound Circuit
Aug.
Westinghouse H196, H2O7 and H217 Revised Picture Circuit to Eliminate Picture Foldover
Aug.
Westinghouse H196 Sync System Change Aug.
Westinghouse Receiver Vertical Hold Improvement
Dec.
SERVICING HELPS
Adjusting RF Transformers in G.E. TV
Sets
Sept.
Admiral 20 and 30 Series Service Notes...Oct.
Application Notes on Deflection Yokes
Dec.
Auto Antenna Installation Hints
May
Auto Control Head Installation Notes
May
Auto Extension -Type Speakers
May
Auto Underdash and Firewall Mount
Notes
May
Avoiding Picture -Tube Damage Caused by
Incorrect Adjustment of Ion Trap
Oct.
Basic Cures for Dead Auto Receivers
Sept.
How to Disconnect Dynamic Limiters in
Belmont Chassis
Oct.
Nov.
Black Line-White Line Problems
Apr.
Capacitor Checker
Dec.
Cathode Follower Calculation Procedure
Connecting LP Adapter to Philco Receivers
Mar.
Using Beam -of -Light Reproducers
Converting 630 TS Chassis for 12%, 15, 16
and 20 -Inch Picture Tubes
Sept.
Eliminating Noise Originating in Ignition
May
or Generator Systems and Wheels
Eliminating Noise Rattles, Pickup Noise
and Wheel Static in Auto Installations Sept.
Eliminating Picture Distortion in Metal
Oct.
Tubes Due to Magnetism
Eliminating Tube Failures in AC/DC
Sept.
Chassis
Nov.
Eliminating Sync Troubles
Dec.
External Antennas for BC Sets
Amplifiers
Via
Values
6L6
Finding Gain
of
Dec.
Tube Curves
G. E. 64 and 65 Sleep-Receiv,r Clock Oct.
Booster Springs
Oct.
G. E. 805 Detent Index Button
Horizontal Deflection Output and High Dec.
Voltage Transformers
Improving Auto -Set Control -Shaft Fitting Sept.
Minimizing Bass Response in Westinghouse
Receivers
Sept.
Nov.
Philco Picture Width -Control Circuits
Preamp Equalization, Variable Reluctance Jan.
Feb.
Preamp Equalization
Oct.
Ratio -Detector Alignment Notes
Sept.
Reducing Hum Level in Bendix Models
Sept.
Remedying Pushbutton Sticking
Feb.
Selecting Coax Cables
June
Sound Installation Circuit Aids
June
Sound Installation Formulas
Nov.
Tuning Drift in TV Models
Apr.
TV Installation Hints
Sept.
TV Receiver RF Amplifier Circuits
Variable Reluctance Preamp Equalization Jan.
SOUND
May
Admiral RC210 and RC211
Mar.
Admiral 30A1 TV Audio IF
June
A Report on Sound (Editorial)
Automatic Phono Servicing, Coin -Operated;
June
Jack Darr
Aug.
Bendix Hush-O-Matic
May
Bendix V800D 2 -Speed Systems
July
Checking 3 -Speed Changers
Custom Audio Installations; Irving Greene May
Greene
June
Custom Audio Installations; Irving
Design and Construction of
Custom
June
Cabinet; Clifford Stubbs
Oct.
Duo -Cone Hi-Fi Speaker Design
Features of 3 -Speed Changers, Record
June
Players and Assemblies
Sept.
45 RPM Replacement Cartridges
G. E. 811, 814, 820, 830 and 835 Modifications to Curb Audio IF Regeneration.Apr.
Gram Scale Application to Check Tone
Arm Needle Pressure and Vertical
Oct.
Friction
Hearing -Aid, Servicing; Clifford W. Carl-
June
son
Sept.
Hi-Fi Amplifiers
How to Curb Groove Skipping and Minimize Hum -to -Signal Noise Ratios on
June
Microgroove Players
Feb.
LF Compensation Circuit
LP Adapter -Switch Kit, Beam -of-Light
Mar.
System
Sept.
LP Player Attachments
Jan.
Long-Playing Records (Editorial)
Mar.
Loudspeakers (Editorial)
Magnetic Tape Recorder-Playback Systems
Needle
Changer
Mechanisms
Playing Combination Changers
New Frequency Rating System
Phono Installation and Service;
Stewart
Phono- Installation and Service;
Stewart
Phono Installation
Stewart
Phono Installation and Service;
Stewart
Phono Installation and Service;
Stewart
Phono Installation
Stewart
Phono Installation and Service;
Stewart
Phono Installation and Service;
Stewart
Phono Systems Using 2 and
Record Changers
Long -
of
Nov.
June
Dec.
Kenneth
May
Kenneth
June
Kenneth
July
Kenneth
Kenneth
Kenneth
Kenneth
Aug.
Sept.
Oct.
Nov.
Kenneth
3
-Speed
Dec.
May
Mar.
Philco 41-609 Audio Circuit..
Philco Three -Speed Unit Employing a
Six -Gram High -Compliance C r y s t a l
Pickup
Sept.
Aug.
Philco Two -Arm Standard-LP Setup
Feb.
Preamp Equalization
Remedies for Too Slow or Too Fast Turntable Speeds
July
Aug.
RCA Magic Monitor
Servicing 45 -RPM Changers; Thomas Y.
Flythe
Sound, TV, FM and (Editorial)
Sound Installation Servicing Helps;
Kamen
Ju
Jail.
Ira
June
(Continued on page 28)
SERVICE, DECEMBER,
1949
27
INDEX
WHAT MEDICAL TEXTS
ARE TO THE PHYSICIAN
RIDER BOOKS
ARE TO THE
ELECTRONIC TECHNICIAN
RADIO OPERATOR'S LICENSE
Q AND
A MANUAL
by Milton Kaufman
prehensive treatment of the subject and
should prove especially valuable as a
quick review of essential theory, as well
as a refresher for advancement in the
field. It lists all the QUESTIONS and
ANSWERS for the FCC examinations.
However, the outstanding feature of this
volume is its thorough FOLLOWTHROUGH ...a carefully simplified discussion of the answer to the technical
question ... so necessary for a complete
and absolute understanding of the question. Useful appendices, which include
Small Vessel Direction Finders and Automatic Alarm, not ordinarily available in
a book of this type, provide a valuable
"extra". An indispensable reference volume for the student and operator. 608
pages. 193 explanatory diagrams.
$6.00
FM TRANSMISSION and RECEPTION
by John F. Rider and Seymour D. Uslan
A "must" book for the radio serviceman who
looks to FM and television as an important part
of his future earnings. Covers all types of frequency modulation systems employed in TV,
radio, amateur radio, railroad, aviation, marine,
police, point-to-point and mobile receivers. 416
pages, profusely illustrated
$3.60
TV PICTURE PROJECTION
and ENLARGEMENT
by Allan Lytel
Timely... Complete... Authoriative
Combines theory with practice, and offers a
clear and well -organized explanation of the
fundamentals of light, optics and optical systems as employed in home television receivers,
with emphasis on proiection types and front
tions, charts.
192 pages; 119 illustra-
$3.30
BUSINESS HELPER
by Leslie C. Rucker
(Rucker Radio Wholesalers)
Written
by
a
successful
business
man
who
started from scratch and worked his way up to
a chain of 3 stores. Any one of his many
worthwhile ideas can mean fifty times the cost
of this book in your pocket. 144 pages; 22
chapters.
OTHER RIDER
$2.00
BOOKS
Oscillator at Work. 254 pages
Broadcast Operator's Handbook
The
278 pages
Inside the Vacuum Tube. 420 pages
Servicing by Signal Tracing. 370 pages
Understanding Microwaves. 396 pages
A -C Calculation Charts. 168 pages
Vacuum Tube Voltmeters. 188 pages
Radio Amateur's Beam Pointer Guide
$2.50
$3.30
$4.50
$4.00
$6.00
$7.50
$2.50
32 pages
$1.00
Automatic Frequency Control
Systems. 154 pages
$1.75
Installation and Servicing of Low
Power Public Address Systems
208 pages
$1.89
Understanding Vectors and Phase
158 pages
Cloth Cover.. $1.89
Paper Cover..$ .99
Radar-What It Is. 80 pages
$1.00
RIDER BOOKS
JOHN F. RIDER PUBLISHER, INC.
480 Canal Street, New York 13, N.Y.
28
Stylus Pressure Gauge Design and Operation
July
Three -Way Player -Converter
Aug.
Two -Speed Record Changers for 7" Records
Oct.
TV Hi-Fi Audio Installations; Irving
Greene
Aug.
Variable Reluctance Preamp Equalization Feb.
Variable Reluctance Stylus Factors
Dec.
Vinylite Record Static -Discharge Liquid Sept.
Westinghouse 2 -Speed Changer Needle
Control
Dec.
TELEVISION
Addition of Power Transformer -Fuse to
This book is a most complete and com-
lens enlargement.
(Continued from page 27)
SERVICE, DECEMBER,
1949
Admiral TV Sets
Oct.
Admiral AM/FM Tuner and 16" Tube TV
Chassis
Nov.
Admiral TV Receiver With FM/AM
Tuner
Dec.
Adjusting RF Transformers in G. E. T\'
Sets
Sept.
Alignment Techniques, TV Receiver Visual; Lester L. Libby
Jan.
Aligning the Westinghouse H -I96; Irving
Sitberg
Analyzing TV Circuits
Application Notes on Deflecting Yokes
Bendix 235
Bendix 16 -Tube TV Chassis
Choice of UHF
IF (Editorial)
Oct.
Sept.
Dec.
Jan.
Oct.
Nov.
Circle-Standard Screen TV (Hallicrafters
T64, 509, 510)
July
Coax Line Installation Practices; Ira Kamen
Sept.
Coax Line Installation Practices (Part II);
Ira Kamen
Oct.
Feb,
Coax Switch Attenuation Control System
Coax Line Parallel Setups
Feb.
Constant Voltage Sources, TV Receivers;
June
Hans U. Hjermstad
Composite Video Signal Generator; Allan
Lytel
Oct.
Converting 630TS Chassis for 12", 15",
16" and 20" Picture Tubes
Sept.
July
Custom TV Installations
DuMont RA 105
Sept.
Eliminating Blooming in Westinghouse TV
Sets
Oct.
Eliminating Vertical Bars and Horizontal
Line Humps in Westinghouse TV Sets Oct.
End Termination Problems at 200 Mc
Sept.
Farnsworth GV 260 Differentiation and
Horizontal Control System
Jan.
Flexible TV Signal -Level Pads
Feb.
G.E. 817 and 821 (T and S Versions)
Dec.
Hallicrafters T -61/T-67 (Push -Button TV) .Jan.
horizontal AFC System in Magnavox
TV Receivers; J. F. Bigelow
Feb.
Horizontal -Deflection Output and High Voltage Transformers
Dec.
Installation of AGC and Improved Horizontal Oscillator in Admiral TV Receivers
Oct.
1 -Tube TV
Preamp
May
Picture -Tube Conversion
Sept.
Feb.
Picture -Tube Rasters
Probing Picture Tube Patterns
Sept.
Reflector System TV Chassis
Mar.
Rhombic TV Antenna Installation; Ira
Ira Kamen
Jan.
RCA 16" Metal Picture-Tube Receiver
(8T270 8TC270, 8TC271)
July
72 -ohm Gfoax Line Pads
Feb.
Jan.
7" TV Model, Rotary Switch (Cover)
Signal Strength TV Test Set (Cover)
Dec.
Sound and Picture IF Carriers
Oct.
Sparton Indirect Viewing TV Models
Feb.
Splicing Techniques for Coax
Sept.
Stepping Up Your TV Service Income;
R. J. Guilfoyle
May
Stepping Up Your T\' Service Income;
R. J. Guilfoyle
June
Sweep Circuit TV Tube Design and Application
Dec.
Sweep Generator Operating Hints; Victor
I. Robinson
Sept.
Motorola VT -71 (AFC Revision)
Jan.
National Videometer (Cover)
Dec.
NC-TV-7/NC-TV-7M (Cover)
Jan.
Olympic RTU-3 (TV Duplicator)
Jan.
The Business Aspects of TV Installations;
Ira Kannen
Jan.
Eyes and TV (Editorial)
Sept.
Philco Built-In TV Antenna System Sept.
TV Surge (Editorial)
Mar.
TV Swing (Editorial)
Sept.
.300 -Ohm Selector Switch System
Feb.
TV Antennas (Editorial)
May
Feb.
TV Antennas, Those (Editorial)
TV Antenna Insertion Circuits
Sept.
Apr.
TV Antenna Installation Hints
TV Antenna Installation Tricks of the
Feb.
Trade; Ira Kamen
TV Antenna Tower Installations; Ira
Kamen
July
TV Amplifier
June
Sept.
TV Built -In Tunable Antenna System
Oct.
TV Circuitry, AM and (Editorial)
T\' Controls and Adjustments; Allan
Mar.
Lytel
The
The
The
The
TV Demonstration Boards (Editorial).,..Mar.
TV Divider and Decoupling Networks.... Feb.
TV, FM and Sound (Editorial)
Jan.
TV and FM Sweep Signal Generator
(Cover)
Sept.
TV Hi-F)i Audio Installations; Irving
Greene
Aug.
TV in '49 (Editorial)
Feb.
TV Installations, The Business Aspects
of; Ira Kamen
Jan.
TV Model With Keyed AGC System,
Walter H. Buchsbaum
Nov.
TV Picture Tube Safety Rules
July
TV Picture Pattern Observation Practices Mar.
TV Preamp (Anchor ARC -101-50)
May
TV Receiver for Fringe Area Reception,
Aligning the; J. F. Bigelow
Apr.
TV Receiver IF Variations
Sept.
TV Receiver Line -Voltage Control -Checker;
Carl S. Cummings
Dec.
TV Receiver Production Changes; Donald
Phillips
Jan.
T Receiver Production Changes; Donald
Phillips
Mar.
TV Receiver Production Changes
Apr.
TV Receiver Production Changes; Donald
Phillips
Aug.
T\' Receiver Production Changes; Donald
Phillips
Oct.
TV Receiver Production Changes, Donald
Phillips
Nov.
TV Rece
Phillips
Dec.
TV Receiver RF Amplifier Circuits
Sept.
TV Receiver Servicing; Carl Quirk
Aug.
TV Receiver Servicing; Carl Quirk
Sept.
TV Receiver Visual Alignment Techniques;
Lester L. Libby
Jan.
TV Receivers, Viewing Areas of; Robert P
Wakennen
Feb.
TV Receiver Visual Alignment Techniques;
Lester L. Libby
Mar.
TV Receiver Visual Alignment Techniques;
Lester L. Libby
Apr.
TV Safety Rules (Editorial)
June
TV 'Scope
Apr.
TV Servicing Pitfalls (Editorial)
Nov.
TV Servicing (Editorial)
Apr.
20 -Tube 12'" TV Model; Walter H.
Buchsbaum
Apr.
Two -Tube Booster (National TVB-1)
Aug.
Ultrahighs and the Service Man (EdiNov.
torial)
Oct.
UHF Antenna Installation Layout
Nov.
UHF Design Study (Editorial)
Videola TV Models
Sept.
Viewing Distances (Editorial)
Mar.
Visual Alignment Techniques, TV Receiver;
Lester L. Libby
Jan.
Visual TV Alignment Procedures; Victor 1.
Robinson
July
Visual TV Alignment Procedures; f'ictor I.
Aug.
Robinson
Apr.
Westinghouse H196 Model
Westinghouse 242 Multivibrator Circuits...Oct.
Mar.
Zenith Circular Screen TV Models
Apr.
Zenith Circular Screen TV Receivers
TEST EQUIPMENT
Approved Electronic Instrument A-400
(TV and FM Sweep Signal Generator) .Sept.
Auto Power Supply Testing With a 'Scope May
Auto Voltage Testing
May
Alignment Procedure for Westinghouse
H-196 Sound and IF Sections
Sept.
Capacitor Design and Application
Apr.
Mar.
ECA FM/TV Signal Generator
How To Build and Apply Special Types of
Accessories
Auto Test
May
IF Marker, Sweep Generator and 'Scope
Sept.
Alignment Setup
Interpreting TV Alignment 'Scope Pictures.July
Aug.
RCA 630TS Aligment Techniques
'Scope and FM Signal Generator for Alignment of FM Receivers With Limiter and
Discriminator Stages and Ratio Detectors
Mar.
'Scope Type Alignment of 630TS
July
Signal Strength TV Test Set (National
Videometer)
Dec.
Supreme 665 (Composite Vides Signal
Oct.
Generator)
Sweep Generator Operating Hints; Victor
Robinson
Sept.
I.
Sweep and Marker Equipment for Alignment
Jan.
Sweep and Marker Setups for Alignment Mar.
May
Testing Car Sets on the Bench
TV Alignment Procedures, Visual; Victor
July
I. Robinson
TV Receiver Visual Alignment Techniques;
Jan.
Lester L. Libby
TV Receiver Visual Alignment Techniques;
Mar.
Lester L. Libby
Visual TV Alignment Procedures, Victor I
Aug.
Robinson
TUBE NEWS
Ballast Tubes
Apr.
Design and Application Feature of 3RP1
Three -Inch CRT
Sept.
Sweep Circuit TV Tube Design and Application
Dec.
TV Production Changes
WHAT A BASIC MEDICAL REFERENCE
LIBRARY IS TO THE PHYSICIAN...
Continued from page 22)
RIDERELECTRONIC
MANUALS
TECHNICIAN
serves as correction voltage for the reactance tube. This causes the sweep
generator frequency to run at a lower
frequency, which is the desired resultant for a sync -pulse frequency, which
is less than the mean of 15,750 cps.
Since correction takes place from
either direction, it is only necessary to
set the horizontal -hold control for a
mean sync condition, and when any
change takes place, such as :ine-voltage fluctuations which would tend to
change the sweep -generator frequency,
a correcting action takes place.
The ability of this circuit to work
in the presence of noise is partially due
to the fact that the discriminator acts
as a balanced input device. Furthermore, the RC filter circuit in the grid
of the control circuit consisting of Cs.,
Cagg, and Rmn, is a low-pass filter, with
a relatively long-time constant. Thus,
random noise pulses are absorbed without any affect on the bias.
ARE To THE
His answer
probably would
Westinghouse H-217
be-
"Electronic science grows more complex each day. And while no men
can be expected to retain the millions of details in his mind, he
plex every day. And while no man
can be expected to retain the mil.
lions of details in his mind, he
MUST hove them AT HIS FINGERTIPS. My library furnishes me with
MUST have them AT HIS FINGERTIPS. My RIDER MANUALS furnish
me with COMPLETE, ACCURATE
and AUTHORIZED MANUFAC-
ACCURATE and
AUTHENTIC DATA. It gives me all
of the factual information that
want... WHEN I NEED IT."
Westinghouse H-196 and H-217
R.
me?"
Your answer probably would be-
"Medical science grows more com-
COMPLETE,
Vertical Hold Improvement: If insufficient range of the vertical hold
control makes it difficult or impossible to lock -in the picture, the value
of the fixed resistor in the grid circuit of the 12AU7 vertical oscillator
(Rs7 in H-196, and R.1, in H-217)
should be checked. In the original
production, the resistor was a 1.5
megonm unit, and it was used in series
with a 1-megohm vertical hold control
(R10 in H-196 and
in H-217).
Later, the fixed resistor was changed
to 1 rnegohm, and the hold control
was changed to 2 megohms to provide
greater hold control range. However,
some sets used a 1-megohm fixed resistor and a 1-megohm hold control.
In these sets the range of the hold
control is limited, and better results
may be obtained by changing the
fixed resistor to 1.5 megohms.
And now, ask yourself-"What
Do RIDER MANUALS mean to
And, should you ask any Doctor
-"What does your medical reference library mean to you?"
TURER'S DATA. They give me oll
of the factual information that
want ...WHEN I NEED IT."
I
I
RIDER MANUALS
ARE EQUALLY IMPORTANT TO
RIDER RIDER
TV
ture.
Under this condition C. (4
operating at reversed polarity
mfd is
and may become damaged.
VOUME
XX
Available Soon at Your Jobber's. Reliable, au-
thentic, factory -authorized servicing information covering the latest AM -FM Radio, Auto
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every respect, but with the added advantage of
text and double spreads assembled in position.
MANUAL
*
*
*
V O L.
3
More than 1700 pages. More than 70 manufacturers. Price $18.00. Publication February 1950.
PLACE YOUR ORDER TODAY! NOW!
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RIDER MANUALS
Television Manual Volume 3
"How It Works" Bock and
Television Manual Volume 2
"How It Works" Book and
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"How It Works" Bock and
Volume XIX
Volume XVIII
Volume XVII
Volume XVI
Complete, Accurate, Authentic Data
Direct From The
,Manufacturers Themselves!
74 manufacturers. 441 models. 243 chassis.
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RIDER TV MANUAL Vol. 3 from your Jobber(
Vols.
PA
Mallory TV Service Encyclopedia, 1st
schematics - Rider TV Manuals.
The Mallory Radio Service Encycloped'
receiver schematics - Rider Manuals.
,
NOTE:
The C-0 Capacitor Manual for Radio S
Rade' Manua'C.
W ei r%We, srbermatirc
Ito
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$
Equipment Manua'), Vol.
I
"Successful
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Serviceman. Write for it
it's FREE!
...
to every
Inc., 480 Canal Street, New York 13, N. Y.
13
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RIDER, MANUALS
NOTE:
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Index)
NOTE: Are you receiv.ng your copy of
Export Agents: Rocke International Corp.,
NOTE, The
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Cumulative Index Volumes 1, 2 and 3,
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JOHN F. RIDER PUBLISHER,
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(Plus
Index)
(Plus
Volume XV
Volume XIV to VII (each volume)
Volume VI
Abridged Manuals I to V (one volume)
$21.00
Damping Tube: The receiver must
not be operated with a defective
damping tube as indicated by a white
streak down the left side of the pic-
YOU IN YOUR WORK!
TV
Edition, makes
th
,s
Y
C.
Coble ARLAB.
mea4e SUCCESSFUL
SERVICING
--
rerenco to
-
only one source of
TV
receiver
Edition, makes reference to only one source of radio
e
48 Edition No. 4. makes reference to only one source
SE`RVICE{
19geteriBtigaNItZ
290E
Signal Strength TV
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SERVICE, DECEMBER,
1949
www.americanradiohistory.com
UU
00
n
Oo
rag
Test Set
I See
Front Cover]
To PREDICT TV receiver operation at a
given location, as well as to provide a
visual tes: of operation from the standpoint of interference, a 7" TV receiver
(Nationa' Videometer) featuring a
field-intensity meter system was developed recently. The basic circuit of
this system, shown on the cover this
month, includes a selector switch in
the meter circuit which makes it possible to read' either line voltage (0 -150 volt scale) or field intensity (0-10
scale). In the latter position, the field
intensity meter reading may be converted drectly into microvolts by
means of a chart provided with the
receiver.
When the meter selection switch on
this instrunient is connected to the ac
line position, the line voltage at the
receiver input terminal may be read
directly. Rotating the switch to the
signal strength position provides a
means of reading signal intensity on
the meter. This reading is independent of the contrast or brightness control settings, being a function only of
the signal strength at the antenna
terminals of the receiver.
The instrument can be used for adjustment of antenna feeders, check on
antenna orientation to provide maximum signal strength and elimination
of ghosts or interference, etc.
The first rf amplifier uses a 6AU6.
while a 6AG5 is employed as a mixer
and a 6C4 Serves as a local oscillator.
Three 6AUps are used in the first, second and third if stages. A 6AL5 has
been included as a video detector agc
diode. In the video amplifier is another
6AU6. A pair of 6SN7GTs are used
in the horizontal sweep oscillator and
horizontal sweep output, while another pair of 6SN7GTs are used in
two vertical sweep oscillator circuits.
The 6AU6s serve also as a sync clipper, and dc restorer, and as a ratio detector driver. The output of this
driver feeds into a 6T8 ratio detector,
its outpnt being fed into one-half of a
6T8 audio amplifier and finally to a
6V6GT audio output. In the rf high voltage po*er supply there is a 12AU7
high -voltage oscillator and a 1B3GT8016 high -voltage rectifier. The general power supply includes a 5V4G
rectifier and a 6X5GT B- rectifier.
The picture tube is a 7JP4 type.
Left: Circuit of the National videometer
s gnal-strength check receiver.
The little lamp that
learned to love "high C"
ASOPRANO'S "high C" can be
just too much for many dial
lamps. Severe vibrations caused by
such high notes are often sufficient
to tear an old-style lamp filament
apart. General Electric engineers
found a simple way to minimize
this cause of early lamp failure. By
making the filament supports longer
and moving the bead closer to the
coil, they greatly reduced the effects
1.
of vibration.
That's why G -E dial lamps have
actually learned to like "high C"...
and to give long life in spite of the
continuous vibration.
For information on prices and
types of G -E miniature lamps, call
your nearby G -E Lamp office. Or
write to General Electric Company,
Div. 166-S 12, Nela Park, Cleveland
12, Ohio.
Dependable, trouble -free performance.
2. High level of maintained light output.
3. Low current consumption..
4. Long life.
5. Profitable to handle.
6. Greater dealer acceptance.
..Radio
dial Ligfs
You can put your confidence
GENERAL
in-
ELECTRIC
SERVICE, DECEMBER,
www.americanradiohistory.com
1949
31
(.5-mmfd capacitors) and L. and
serve as an if filter to prevent any
of the if or harmonic frequencies from
being amplified by the video amplifier.
In addition to amplification, the first
section of the 12AÚ7 video amplifier
operates as a noise limiter. The B -F
voltage applied to this tube is relatively low and the video signal applied
to the grid is negative -going. Any
large excursions of voltage above sync
level, such as introduced by transient
noise, will drive the grid voltage sufficiently negative to cause plate current
cut-off. Thus, the interference will be
limited close to the level of the super sync signal. This improves the signal to -transient noise interference ratio
without affecting the video signal.
Since capacity coupling of the video
amplifier stage is used, the dc component of the video signal must be
restored to maintain the proper background illumination. This is accomplished by one-half of a 6AL5 diode.
The negative -going output signal of
the 12AU7, which is coupled to the
picture tube, is also applied to the
cathode of the 6AL5 through a resistor (10,000 ohms) -capacitor (.05
mfd) coupling. The rectification of
this signal causes the .05-mfd capacitor
to charge to the peak value of the
sync pulse. Since this charge will
vary with the amplitude to the pulse
above the ac axis, the resulting dc
voltage will provide the required restoration of the dc component. This
dc is supplied to the ac video component through a 390,000-ohm resistor,
so that the grid of the picture tube will
have a composite video signal with a
dc component.'
On early T version models, the
6AL5 diode also performed the function of the first clipper, developing
the sync pulse voltage across a resistor
(Rana) to be passed on to an additional
clipper and the sync circuits which followed. On later U and W receivers
this tube was not used as a clipper, its
only function being to restore the dc
component at the picture tube grid.
By connecting the cathode of the
picture tube to a variable positive voltage source, the picture tube may be
biased so as to change the brilliance.
A potentiometer.control ¡which changes
this bias' voltage: is brdtight out tb- the' l'
front pakiel -as thé brightness et:muttit' '
In additi.bn; to the bias supplièdT the
cathe der; a1 volta d -waveshapé ltAvéti
from the vertieafsweep output;'is"sup-'
plied through -á=iA2,mfd capaèitcir.
Casa
Lana
You Get
OVERALL
Test
Performance
With...
Electronamic*
SERIES 10-12
TESTER Onire
TUBE PERFORMANCE 'lteg.
U.S. Patent
12 ELEMENT free -point Master Lever Selector System
*To test modern tubes for only one characteristic will not necessarily reveal
Mutual
overall performance capabilities. Tube circuits look for more than just
Conductance or other single factor.
*In the Precision Electronamic Circuit, the
with
tube PERFORMS under appropriately phased
and selected individual
element potentials,
wide range of plate family
complete Path
This
curves.
characteristic
of Operation is integrated by the indicating
meter in the positive PERFORMANCE terms
encompassing
a
of Replace -Weak -Good.
* Facilities to element prongs.
* Filament voltages from to volts.
pin acorns;
pins;
Noval
* Tests
amplifiers; low power
double -capped
12
117
3/4
5 and 7
9
H.F.
transmitting tubes; etc.
REGARDLESS OF
FILAMENT OR ANY OTHER ELEMENT PIN
POSITIONS.
*
sensitivity for special
short
*
tube selection.
Tests under dynamic load
* Battery
conditions.
ISOLATES EACH TUBE ELEMENT REGARDLESS OF MULTIPLE
PIN POSITIONS.
check
DUAL
purpose
* Full Vision Meter.
-Window, brass -geared roller
* Built-in
chart.
Replacement Roll Charts
*
tube test data service.
41/2"
Dual
and
FREE
(illustrated): in sloping,
portable hardwood case with tool com-
sup-
MODEL 10-12-P
partment and hinged removable cover.
Size 133/4" x 171/4" x 63/a"
MODEL 10.12-C (Counter Type)
MODEL 10 -12 -PM (Panel Mount)
;96.10
;99.40
5
$99.40
the "Precision"Master Electronamic Tube
Testers at leading radio equipment distributors.
Write for catalog describing Precision Test Equipment for all phases of modern A.M., F.M., and TV.
PRECISION APPARATUS CO-, INC
92-27 Horace Harding Boulevard, Elmhurst
Export O,', ion: 458 Broadway, New York. U.5
Ser -Cuits
(Continued from page 12)
a fixed negative voltage source, while
on the U and W version receivers this
bias was obtained from the video de=
tector and clipper tube circuits which
furnished a variable sourceof bias for
s',113111TTstc»
agc purposes.
-n
Video
D
i
o
li(gr
i
ppl e
The vi
plied to one section of a 6AL5 dual
321E
A.
6
-
New York
Coble%-Morhone.'
diode, which is connected as a series
diode so as to develop a negative going signal across a 5,100 -ohm dioç
signal is th Fï
load resistance. T
iode-amplifie
ampli
A 7 dual triode.
stages using a
series compensating
Lana and
Low,
cho
g
yzeo, and Lanz, shunt
) üand
11 W)
are used to ob compensating cT
the required high -frequency re-
Lei.,
e
Idipbrad
*
,
s
p
at
afpfass-
s
1
The combination of
C.
SE$taPllC1536643E126frRPt9'4t82
www.americanradiohistory.com
and
t
jati
voltiagéL:dotr spFindei
The positive
to retrace time so that by application
to the cathode circuit, it causes the
pictueq;t ;llkrr n?ioiYLY.
during itg-duccatibnla
`
i4s2z1I,d`ftiSu.tf 3'.S'
4TriPm9'-f
gilts in
the reinc' al of most of the retrace
lines.
[To Be Continued]
Admiral TV/FM/AM
U
0
CO NTIN LUNG
analysis of the Admiral -V and FM/AM tuner model
(21A1 TV and 4K1 FM/AM), we
find that a 6AU6 pentode pulsed -type
amplifier provides an automatic bias
voltage ti the control grids of the rf
amplifier and the first two video if amplifiers, lased on the transmitted sync
pulse le cl. The grid of this tube is supplied with signal voltage from the output circuit of the video amplifier. A
secondary winding on a width control,
serves as a source of pulsed plate
voltage (15.75 kc). This voltage is
supplied to the plate of the tube
through et .001-mfd capacitor, C,,, and
no dc i9ows through the secondary of
?he application of the 15.75 kc
pulsed -plate voltage to the plate of the
6AU6 causes the tube to conduct only
during positive half cycles; agc voltage
is therefore developed during this
period only. Rectified voltage is developed across á pair of 47,000 -ohm
resistors (CR:u. and R,,,), and 27,000 ohm and 100,000 -ohm resistors (R,,,:,
and R:_,, í, varying in accordance with
the level of the sync pulses applied to
the grad of the 6AU6. R,,,, R,;x, and
C,,, (.005-mfd) act as a filter to the
pulse tipple. A dc bias voltage is developed across R:,,, (and R:u,.) which
is dependent upon the transmitted sync
pulse level and this voltage is applied
to the controlled stages through appropriate decoupling networks.
Sync
pulses are used to control the grid of
the agc tube, since they remain at a
constant level with respect to the carrier. If the video signal were used,
the ayc voltage would fluctuate with
variations of black and white.
QUESTION-What's the one antenna that
installation troubles and service call1. cuts
backs to the bone in all locations?
ANSWER-Telrex Conical Antennas, the
conical "V beams that cover all TV channels and FM, and
afford best reception in every signal area. There's an engineer -designed, service -tested model for every TV location.
S.
QUESTION-Why have Telrex Conical "V" beams replaced
every possible combination of antennas for TV reception?
ANSWER-Because Telrex "V" beams are the only antennas offering true conical performance-top TV reception
without bulky metal cones. For experience -designed models
to meet every problem, workmanship that gives longer
service ... continue to look to Telrex!
3.
QUESTION-Who has built 95% of all conical antennas
installed today?
ANSWER-Telrex! Leadership in engineering and quality
keeps Telrex out in front. The Telrex staff is ever seeking
better methods, improved materials and design advancements. Supply a Telrex antenna on your next TV installation-you'll see the difference!
TELREX MODEL
Bì
2X -BD
-Directional Stacked
Conical
"V"
Beam
Low Vertical Angle
Video Amplifier
The video amplifier is a pentode
voltais` amplifier with a constant K
filter for a plate load; a 250 -micro henry cod wound on a 33,000 -ohm resistor, another 250-microhenry coil
\vounc on a 33,000 -ohm resistor and a
4,300 -ohm resistor (1,10--R3,,,,
R:,.,,, K:,,,).
The gain of this stage is
controlled by a 25,000 -ohm potentiometer, R,., B, which serves as a contrast
control by varying the voltage applied
to the screen of the 6AC7. The plate
load circuit is direct -coupled through
a 1-megohm resistor, R:,,:,, to the cathode of the picture tube, eliminating the
need for dc reinsertion. Sync voltage
(Continued on page 34)
Extremely High Signal to
Noise Ratio
Constant Center Impedance
Uses 72, 150 or 300 Ohm
Transmission Lines
Universal Mounting Clamp
TELREX _
still your one
Engineered
best bet.
for better
pictures
built to give
longer service,
oughly field
thortested for
your pro
tertian. Select
DeLuxe
economy
Models or
Special
Series
priced
equalwconfidence.
the reputation
You'll find
Telrex trademarkbacked, genuine
on both!
PATENTS PENDING
COPYRIGHT 1949
'Telephone-ASBURY PARK 2-7252
J'f
AMERICA'S
OUTSTANDING
TELEVISION
BEAM
ASBURY PARK
SERVICE, DECEMBER,
4..
N. J.
1949
33
ACES UP!
(Continued from page 33)
taken from the resistive branch of
the plate load.
is
Sync Limiter
The second half of the 6ÁL5 dual
diode functions as a limiter on the grid
6SN7) limitof the sync inverter
ing the level of the sync signal, thereby
eliminating transient or impulse noise
peaks.
(/
Sync Separator
/
of a 12AU7,
The sync separator,
separates the syric pulses from the
composite video signal. The second
half of this tube amplifies the sync
pulse and also clips peaks off impulse
noises.
TUBE TESTER
SET TESTER
BATTERY
TESTER
CONDENSER TESTER
AUDIO
R. F. -F. M.
SIGNAL GENERATOR
Every square inch solid -packed with value! Look
what you get in this phenomenally low-priced
tester: (1) A complete tube tester with over 800
listings in its famous Rollindex roll chart, (2)
A battery tester indicating actual voltage under
rated load, (3) A capacitor tester, (4) A fixed
point calibrated AM -FM signal generator, (5) An
audio oscillator; and a dozen additional features.
Readable scale divisions on the ohm meter start
at 0.05 ohm to 25 megohms.
DC Volts: 0, 2.5, 10, 50, 250, 1000. 5000
AC Volts: 0, 10, 50, 250, 1000, 5000
DC Milliamps: 0, .5, 2.5, 10, 50, 250. 1000
DC Amps: 0, 10
Megºhms: 0, 2.5, 25
Ohms: 0, 250, 2500, 25000
Decibels:
to +15, 15 to 29, 29 to 49. 32 to 55
Sync Inverter
Horizontal Sync Discriminator
Balanced horizontal sync voltage
from the sync inverter is supplied
through an RC coupling circuit to the
sync discriminator. A reference ,volt:
age from the horizontal output circuit
is fed from a secondary winding on
(width control) through an RC
network made up of a 18,000 -ohm resistor (R..) and a .01-mfd capacitor
(C.1.) to the junction of pins 1 and 2
of the 6SN7GT.
The discriminator develops a dc
voltage across a 4,700-ohm resistor
(R.2a) that is proportional to the phase
difference between the transmitted
sync pulse voltage and the horizontal
sweep voltage. When the frequency
and phase relationship between these
two voltages is correct, the sync discriminator supplies normal operating
bias to the first triode section of the
6SN7 horizontal oscillator. When a
change in the phase/frequency relationship between the transmitted sync
pulse voltage and the horizontal sweep
voltage occurs, the dc output voltage
across Ram changes accordingly. This
dc voltage is fed to the horizontal oscillator through an RC filter (470,000 ohms, .01-mfd and .05-mfd capacitors;
R., C. and C.re) which removes any
noise or sync voltage.
T.
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FM -AM
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OUTSTANDING BUYS AT YOUR
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WRITE FOR CATALOG DS
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152 West 2Sti, Street,
34
tJ
New York 1, N.
SERVICE, DECEMBER,
Y.
FOR PHOENIX PAM -11
.. Fastest, Strongest Antenna
Mast Stand -Off Insulator
Attaches to
any size mast in
IO seconds)
- Genuine
One-half of a 6SN7 dual triode
serves as a phase inverter for providing a balanced voltage to the horizontal sync discriminator. Vertical sync
pulses are taken from the cathode circuit of this stage and fed to the vertical integrating circuit.
-8
Output Voltmeter: 0, 10, 50, 250, 1000, 5000
Complete with tubes, batteries and test leads, output
leads, etc., housed in natural finish oak case; hammer tone gray panel.
NOW! NEW LOW PRICE
Horizontal Oscillator
A 6SN7 dual triode combines the
1949
www.americanradiohistory.com
Polyethylene parts.
AT LEADING
JOBBERS
Write for
folder M of
complete dine
of television
accessories.
two fuac ons of horizontal oscillator
and conta I tube within one envelope.
The circa t is that of a modified Franklin oscilla or. Frequency of oscillation
is largel controlled by an iron -slug
coil, .003-mfd capacitor, 8,200-ohm
resistor, 100,000 -ohm resistor and
Rte,, R.
50,000 -ohm pot;
and R.eEs A slug adjustment, L.,
serves as the horizontal lock control
while 3,o, is a vernier frequency adjustment which acts as the horizontal
hold control. The circuit differs from
the conventional Franklin oscillator in
that the grid of the first triode section
is isolated for control purposes and
plate circuit feedback is through the
common cathode 1,500-ohm resistor,
COO
L.-C.,
11432.
The dc output voltage of the horizontal sync discriminator supplies a
bias vc1 e which is added to the normal oiler ting bias of the first triode
section o the 6SN7 provided by the
drop a_r s cathode resistor R.ffi. The
frequency' of oscillation is determined
not only by L1, C.16, R., R. and
Rena, but is also affected by the plate
resistancd of the first triode section.
The prate resistance in turn is determined by the bias applied to the control grid: A shift in phase or fretween the transmitted sync
quency
pulse an the horizontal sweep voltage
produces a chahge in the output voltage of th sync discriminator which is
fed to pi r No. 1. This voltage results
in the required horizontal oscillator
phase or frequency correction.
Horizontal Output
A 6BG6 beam tetrode in the horizontal output circuit has the dual function of providing driving power for the
horizontal deflecting coils and a high
potential pulse for the 1B3GT second
anode rectifier.
The c>itput of the horizontal amplifier is transformer -coupled to T.e.., the
horizontal deflecting coils.
is
shunted cross a portion of T., the
horizontal output transformer and, by
means of a slug adjustment, functions
as a wid h control.
has a secondary wt ding which supplies pulsed
plate vol ge to the agc tube and an ac
referee
voltage to the horizontal
sync dis iminator.
T.
T.
econd Anode Supply
A 6B 6G horizontal output amplifier is th source of pulsed voltage for
the 1B3 T/8016 second anode voltage reef fiers. This voltage is in-
WHERE THE TWAIN MEETS
Whatever the operating conditions the
Turner Model 33D Dynamic will stand the
gaff . . . and perform. Its ruggedness is only
surpassed by its sensitivity.
Regardless of the application; voice or music,
studio or public address, the Turner Model
33D delivers crisply and clearly. Volume and
tone gradations are faithfully retained. It's the
microphone that combines high output over
a wide range of frequencies.
Yes, whatever your requirements, you can
depend on the Turner Model 33D to perform
and conform to high standards. It is also available as 33X Crystal. Write for complete details.
THE TURNER
930 17TH
STREET N. E.
COMPANY
CEDAR RAPIDS, IOWA
IN CANADA: Canadian Marconi Co., Ltd.
Montreal, P. Q., and branches
EXPORT: Ad Auriema, Inc.
89 Broad St., New York 4, N. Y.
Crystals licensed under patents of
the Brad, Development Company
creased
auto -transformer action in
T. and ectified by a cascade rectifier
ontinued on page 36)
(
SERVICE, DECEMBER,
1949
35
(Continued from. page 35)
1FD
is a TV pioneer. We
know what's needed
and we know how to
make it. Equally important, we sell it to
you at o price on
which you can make
a good profit.
arrangement having an output
of
12,000 volts.
Pulse Duration
Control
The positive half -cycle of the
primary voltage is a snort duration pulse of very high amplitude.
The negative half -cycle has relatively
low amplitude and is of longer duration. During the first positive half cycle, V,,,7 conducts, charging a 500nlmfd capacitor, CE.,, to the peak value
of the full T, e primary voltage pulse.
The 1B3 tube does not conduct during
this period. During the negative half cycle, neither rectifier conducts and
the sum of T,,,,, primary voltage plus
the charge on the C,., (acquired during
the first positive half -cycle) charges a
100 -ohm resistor, C,41, through a pair
of 1-megohm resistors, R. and R454.
The next positive half -cycle causes
both 1B3s to conduct; V,na conducts by
virtue of the charge on C. adding to
the positive pulse of the primary of
Ti,,,.
Conduction through V. recharges C. to the peak value of the
positive pulse. Conduction through
V. charges a 2,200 -ohm resistor, C,.,n,
through the T. primary circuit to approximately half the potential of C,.,1.
The potential of C. plus that of C.
produces a total of 12,000 volts.
T.,,e,
JFD
TA 161
Double "D-Xer"
Antenna
'29"
LIST
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Antenna that really pulls
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areas. A bang-up job at economy price!
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INSULATORS
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Studio Microphones
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Ideal for
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PUBLIC ADDRESS
"The ultimate in microphone quality," says
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New Yorker.
Shout right into the
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Not affected by
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Guaranteed to with
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Models
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"Kontak" Mikes
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Special
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Introductory
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illustrated
and 4-page
AMPERITE Gmpany
561 BROADWAY
Offer'
Inc.
NEW YORK 12. N. Y.
Canada: Atlas Radio Corp., Ltd., 560 King
St.
W., Toronto
Servicing Helps
Snap -on in a
stay putpermanently.
Two models: No. SPT-
Damper
100 for 1" Masts, No.
(Contiun,'d from page 23)
SPT125 for 11/4"
Masts.
Al)
A 6W4 damper is connected in a
manner which provides an effective
increase in plate voltage to the horizontal output amplifier. The plate current of this tube flows through the
6W4 for the major portion of the horizontal trace.
R3
RANGER TV
Capacitive Networks
ANTENNA
Ali -Channel
Due -
Orienting Hi - lo
array. As simple
to assemble as
opening an umbrellal AnotherJFD" Economy" Value.
Write for FREE JFD Catalog of TV
Accessories No. TV100
More than a catalog, it contains installation and servicing data of invaluable
interest to every Serviceman.
Also FREE tor the asking... JFD Cat
slog of Radio Accessories. 'No. 438.
MANUFACTURING CO., Inc.
6109 16th Avenue
Brooklyn 4, N, Y.
2IRST IN
36
TELEVISION ANTENNAS AND ACCESSORIES
SERVICE, DECEMBER,
A pair of capacitors, .05 and .1 mfd,
and C,a1, are fully charged during this period and supply current
to the 6BG6 during the time that
the 6W4 is not conducting. An average voltage due to the 6W4 current
is developed at the network consisting of a pair of .05-mfd capacitors
and an iron -core coil, C120A, I.-,,,2 and
C,2e0, which adds about 50-60 volts to
the supply voltage. The network provides linearity control by adjusting the
cathode wave form (bias) of the
damper tube. R. and C4200 provide
some RC clamping in the output circuit
in addition to the clamping provided by
the 6W4.
C.
1949
tive if the external antenna is disconnected. When the external antenna is
connected the loop still acts as a means
for picking up a certain amount of
signal and, of course, noise if noise is
present in the immediate vicinity.
If local noise is present, a separate
antenna transformer may be used in
place of the loop antenna.
The most suitable arrangement
when using an external antenna is
believed to be a method whereby the
loop antenna is removed entirely from
the circuit and in its place a conventional antenna transformer, consisting
of a primary and secondary is used.
The secondary winding should have
the proper inductance to track with the
gang capacitor across the hand. A
transformer having a variable inductance such as those employing a magnetite core is advantageous to provide
proper tracking. When using a separate antenna coil instead of a loop the
connecting leads for the circuit should
be kept short to avoid pick up on these
leads.
Tube News
STANCOR
(Continued from page 19)
the horizontal sweep circuit, as well as
for power rectifiers.
The 6U4GT is also a high-perveance
diode, designed as a damper in circuits
employing direct coupling between the
horizontal -deflection amplifier and the
yoke. A high heater -cathode pulse
rating makes it possible to eliminate
the usuali low -capacitance heater transforme-, with an attendant reduction in
the distributed capacitance of the circuit.
circuit for the 6BQ6GT/
A
25BQ6GT employing a direct -coupled
system is shown in Fig. 1; page 19.
The grid of the 6BQ6GT is driven
by a -legative peaked sawtooth. This
causes a linear current to be drawn
through 'the yoke. At the end of the
grid pulse, the 6BQ6GT is driven into
cut-off. At this point the energy
stores in the yoke collapses and a high
spike of voltage is generated. The
period of this transient corresponds to
the period of the LC circuit comprising the yoke, the charging transformer,
and the stray capacitances.
This
period will be of the order of the retrace time; 1/7500 second, approximately.
At thé end of the first half-cycle of
trans ent oscillation, the 6U4GT
damper tube starts to conduct heavily
and quenches any further oscillation.
The degree of damping is controlled
by adjusting the diode bias. Linearity
of scan is controlled over a range by
this means. The horizontal size is
controlled by means of a variable series
inductance in the yoke circuit. This
series inductance acts as a current control ton the yoke and therefore, as a
size control for the picture.
When the energy collapses in the
yoke circuit, the pulse generated by the
energy collapse is induced in the
charging winding.
By auto -transformer and resonant principles, the
high voltage is stepped up to a high s
value, sufficient upon rectification to
supply the second anode of the picture
tube.
There are several novel economies
affec-ed, in a circuit of this type. The
first is the use of the picture tube
coati-ig as a filter capacitor. As a
rule, this coating offers a capacitance
ranging from 500 to 2,500 ninifd, adequate to filter the rectified high voltage. The use of the 6U4GT as a
damrcr tube is also unique. An examination of the damper circuit shows
that the cathode has the high potential applied to it. The use of a 6W4GT
or 5V4GT as a damper requires a low-
EXACT DUPLICATE
TRANSFORMERS
Every call-back you make means lost timi. and
profits. Why take a chance with transformers
that "almost fit?" You're sure of a good job
and a satisfied customer when you use Stan cor Exact Duplicate transformers for TV
servicing. These units meet the exact
specifications, electrically and physically, of the original components. Rep' resentative types are listed below.
Vertical Blocking - Oscillator
Transformer. Stancor Part Number A-8121. Exact duplicate of
RCA type 208T2. For generation
of 60 cps required to drive grids of
vertical discharge tubes.
Plate and Filament Transformer.
Stancor Part IN amber P-8156.
Exact duplicate of RCA type
201T6 used in model 630TS
receiver.
Deflection Yoke. Stancor Part
Number DY -l. Exact duplicate
of RCA type 201D1. For use with
direct viewing kinescopes such as
7DP4 and 10ßP4.
Part Number
FC-10.. Exact Duplicate of RCA
type 202D1. For use with magnetiFocus Coil. Stancor
cally focused kinescopes such as
RCA type 10BP4.
Horizontal Deflection Output and
JUST PUBLISHED-Ask your Stancor distributor
HV Transformer. Stancor
or write for your free copy of the New STANCOR TV
COMPONENTS REPLACEMENT GUIDE, Bulletin 338C.
Lists Stancor replacement components for two -hundred
and fifteen models and chassis made by forty-three
leading receiver manufacturers.
Number :1-8117. Exact duplicate
of RCA type 211T1. For use with
direct viewing kinescopes, such as
types 7DP4 and 10BP4.
l'art
For complete specifications and
prices of these and other Stancor
TV replacement components, see
your Stancor distributor or write
for Television Catalog 337.
STANDARD TRANSFORMER CORPORATION
3588 ELSTON AVENUE
capacitance filament transformer to
isolate the heater and cathode from
ground. The 6U4GT, however, has
been designed to withstand a heater cathode potential up to 3,850 volts peak
pulse with a duty cycle not exceeding
15%.
Incorporation of the 6U4GT
eliminates, therefore, the need for a
filament isolating transformer.
In Fig. 2 (p. 19) appears a conventional sweep system using a standard
8.3-mh yoke and coupling transformer.
This circuit works similarly to horizontal systems in general use today,
except that the damper diode -load resistor and the linearity control have
been removed from the circuit. Elimi-
CHICAGO 18, ILLINOIS
nation of the damper load resistor is
possible because the transformers used
were designed to present the proper
load across the damper tube. The
elimination of this linearity control has
little effect on the linearity. It has been
found that better linearity correction
can be obtained by changing the drive
to the sweep amplifier tube.
In both the direct -coupled and the
transformer -coupled circuits, the high
voltage rectifier used is the miniature
type 1X2 tube. In the direct -coupled
system, the lower 1X2 plate -to -filament
capacitance has been found to provide
about 500 volts more anode voltage
than is obtainable from a 1B3GT.
SERVICE, DECEMBER,
1949
37
Performance Diagnosis
RM S
(Continued from page 20)
VERSACONE
and with the operating point of this
line already located. If we assume a
plate voltage change from the operating point of 160 volts,
160
E
.,I=
RL
=-=57
ma
2800
Iv= 57ma+50ma= 107 ma
This value added to Io will provide the
current point on the zero plate -current
axis.
Now we can draw a load line YY'.
From this gain can be found. Let, us
assume a conservative grid swing of
15 volts peak -to-peak.
198 -120
78
Gain
=
15
-
15
-
5.2
It is interesting to note that the
voltage separation between X' and Y'
along the plate voltage axis is 60 volts
or actually the sum of the dc voltage
drops across Rd and Rk.
SAVES YOU DOLLARS
ON TV INSTALLATIONS
Easily pierces brick, mortar between brick,
most concrete. Acts as a mast coupler
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HOT NAILS, INC.
40,WEST 4th STREET, NEW YORK 12, N.Y.
MARCH OF DIMES
Cathode -Follower Calculation
A similar procedure can be used to
determine the operating characteristics
of a cathode follower. The unusual
feature of the cathode -follower procedure is that the plate load is the actual
cathode resistor across which the output is developed. As an example, let
us probe the characteristics of the circuit shown in Fig. 3.
First, we have to plot a load line
XY with a slope of 4,000 ohms and
the supply voltage as one point of line.
We can then plot the cathode line
by finding current points IA, IB, and L,
for bias points of 7.5, 15, and 30.
The operating point is located where
two lines intersect: Ie of 38.5 ma, -E,
of 19.25 volts, and E, of 245 volts.
The true dynamic load line must
now be drawn with a slope of 500
ohms, with the operating point as one
point on the slope. To do so, let us
assume a plate voltage change of 15
volts from the operating point:
6 FRONT
2 BACK
(straight
reflector)
Model V-1
(8 rods)-list
W-2 stac leeast
10.60
21.95
By simply shifting the 8 rods in the
versatile, preassembled insulator and
reflector plates, either arrangement
can be installed in seconds!
Insulator is -piece molded Bakelitesturdy, all-weather resistant.
1
Back plate of plated steel, rib reinforced.
Sturdy construction withstands rugged
service conditions.
Rk
500
We find that this represents a change
of 30 ma in the 500 -ohm slope. Therefore, it is necessary to locate a second
point of the slope which is at D (38.5
ma - 30 nia = 8.5 ma and 245 volts +
15 volts = 260 volts) .
A load line is now drawn between
the operating point and D. This line
can now be used to calculate gain, grid
drive, etc.
In a cathode follower the applied
signal voltage is always greater than
the output voltage or
your local Jobber
RADIO MERCHANDISE SALES, INC.
550-S Westchester Ave.. New York 55
:
escg=ec+e.
The parameter which is presented
SERVICE, DECEMBER,
PARALYSIS
JANUARY 16-31
o Ep
Dipole ends are so sealed as to prevent
wind noise-yet allow water drainage.
38
INFANTILE
15
3,IP=-=-=30ma
Provides high signal gain for both
moderate and fringe areas.
See
FIGHT
1949
You'll be
interested in
ÉLE_,Ir
._
..;;.
is. enq ineerin
,
First
issue-
January
on the characteristic curve is eg and
not e.,g. It is therefore necessary to
calculate e.,g. This is done by assuming an eg change of 13 volts peak -to peak. The plate -voltage change or e.
from the load line is 254 - 230 or 24
volts. Then we can find the signal
TELEVISION SELLS
Alliance Tenna-Rotor
lcz' Tire ifieste!
voltage with the formula:
e.,g=eg+e0
es,.=15+24=39
e.
24
es,g
39
Gain=-=-=.615
'Son,'lrlere's Uie answer I
\
clearer pictures .. .
... more elation&
ALLIANCE TENNA-ROTO
Control -Checker
(Continued from page 16)
curren- cannot flow through any of
the components.
On the left side of
control panel was placed a toggle
switch for connecting the female receptacle on the rear of the instrument
to the male plug also on the rear so
that the voltage at the output receptacle
(female) could be fed directly from the
wall receptacle. This occurs when the
switch is thrown down.
Wit: -s the switch in the upward position the variac voltages can -be applied
to the output (female) receptacle.
Voltmeter Readings
The voltmeter, connected to the output receptacle, provides a reading at
all times.
Should the line voltage .during a
check be found to be low, it is only
necessary to throw the toggle switch
to the variac position and adjust the
selectcr switch until the voltmeter
reads :he desired voltage.
4,500,000 Viewers
Around 40 TV Stations
See
TENNA-ROTOR
in Action
-
ALLIANCE MANUFACTURING COMPANY
BURLINGAME ASSOCIATES EXPANDS
Burlingame Associates and its affiliate,
Brujac Electronic Corporation, have
moved to 103 Lafayette Street, New
York 13 ; phone number, Dlgby 9-1240.
The new facilities, occupying an entire
floor cf 4,000 square feet, include a technical sales and customers service department, a conference and show room which
is sound -treated, and a fully equipped
repair and service department.
Bruce O. Burlingame and Jack Grand
are partners in the company.
Companies represented by Burlingame
Associates include: Hewlett-Packard Co.,
The Brush Development Co., Audio Development Co., Sorenson & Co., Tel- Instrument Co., etc. Brujac Electronic
Corporation is the sole distributor for
Tektronic Inc., Brown Electro -Measurements Corp., Beta Electronic Corp.
and Electronic Measurements Co.
week!
Each
Every TV set owner wants more distance-less interference-clearer
pictures! Alliance Tenna-Rotor means faster antenna installationsfewer call-backs happier customers! Guaranteed for one year!
Alliance, Ohio
Export Department: 401 Broadway, New York, N. Y., U.
AERCVOX ACQUIRES ELECTRICAL
REACTANCE CO.
The entire outstanding stock of Electrical Reactance Co., has been purchased
by Aerovox Corp., New Bedford, Mass.
EIectrical Reactance, with plants at
Franklinville, N. Y., Jessup, Pa., and
Myrtle Beach, S. C., will be operated as
a wholly -owned subsidiary under the continuing management of Charles E.
Krampf as president. Krampf, largely
responssble for the development and
growth of Electrical Reactance, manufacturer of ceramic capacitors, becomes a
director of Aerovox.
S.
A.
SYLVANIA ELECTRIC RADIO-TV
SERVICE MEN'S CAMPAIGN
Facilities of radio and television Serv-
ice Men will be promoted by the radio
division of Sylvania Electric Products
Inc., in a series of national ads in the
Saturday Evening Post, Life, Look, Collier's, and Radio & Television Best,
scheduled to start in January.
Sylvania will supplement the ads with
a cooperative campaign kit for Service
Men and dealers which includes fourcolor window posters based on the
monthly ad, two-color streamers, threecolor postal cards, free mats for local
newspaper advertising, and radio spot
announcements.
SERVICE, DECEMBER,
1949
39
American
Beaut
New TV Parts
a
.
Accessories
C -D
AND
NEW
DIFFERENT
CONICAL TV ANTENNA
A conical
antenna, the
Jfitthty-X
r'D
Cornell-
Dubilier Electric Corporation, South
Plainfield, N. J.
Available in two models LZX-2, a
2 -hay package, complete with an 8 -foot
mast, and model LZX, a single -hay
package without a mast. Separate wave jumpers available for stacking.
....
miowyfp mmea
'
IC)
1fÿ
tl'
:
are sturdily built for the
hard usage of industrial
service. Have plug
type tips and are constructed on the unit
system with each
vital part, such as
heating element,
easily removable
and replace-
able. In
TENNA-CLAMP
COMPLETELY
S7,,yhftaok, has been announced by
ELECTRIC SOLDERING
IRONS
.
CLAMPS ON PIPE
UP TO 13/8 O.D.
i>
______f(-..
.,
,,,,,,,,,,,,,,,,,,,,,,,,,,,,
,and
'`.
IT CLAMPS
ONTO GUY-WIRE
TV LEAD-INS ON MASTS,
PIPES, CROSS -ARMS, GUTTERS
SUPPORTS
AND GUY-WIRES
5
ONE STANDARD SIZE solves all sorts of lead -In
problems.
BRINGS LEAD-IN TO EDGE OF ROOF-right
where you want it-holds lead-in away from gutters.
DULL POINTED SCREW-solid grip on mast.
ON MASTS TOO BIG for elamp-use the guY-wlre:
AVAILABLE FOR COAX and double lead -Ins.
sizes, from 50
watts to 550
watts.
LOW PRICES!
9c
*
*
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net-only
SEND
LENNOX TV/FM LIGHTNING
$7.80 per 100
AND CATALOG 810
%
yF//FREE
ARRESTER
A ligtning arrester, Rex type, for FM
TEMPERATURE
REGULATING
STAND
and T \', which it is said can be used
on flat 300 ohm, round 300 -ohm, and the
shielded twin -line has been announced by
Lennox Industries, Inc., 6007 Euclid
Ave., Cleveland 3, Ohio.
One side oi the bottom plate, which
holds leadin in place, has a shallow
groove for flat twin leads. The other
side of the plate has a half round groove
which fits both the round and shielded
This is a thermo-
statically con-
trolled device for
the regulation of
the temperature
of an electric soldering
iron. When placed on
lines.
For descriptive IBerature write
"
All insulating parts
and connected to this
stand, iron may be maintained at working temperature or through adjustment on bottom of
stand at low or warm
temperatures.
Electrical
are of polystyrene.
circuit consists of a balanced bleeder network and a small gap
for each wire in the leadin. Listed by
the Underwriters Laboratories.
110.1
*
AMERICAN ELECTRICAL
HEATER
COMPANY
DETROIT 2, MICH., U. S. A.
40
SERVICE, DECEMBER, 1949
PHILCO TV AND SOUND ACCESSORIES
Three types of biconical TV- antennas
six alignment jigs, a three -speed record
changer, 45 -rpm record adapter discs and
non -slip driver have been announced by
the accessory division of Philco.
1565
E.
31st ST., CLEVELAND 14,
OHIO
HYTRc)N RECTANGULAR ALL -GLASS
TV PICTURE TUBES
1f -i Hi
picture tube, type 16RP4
with a re angular screen is now being
nianufa'7tu ed by Hytron Radio & Electronics Co p., Salem, Massachusetts.
Tube is -aid to take approximately the
same cibi et space as a round 12 -inch
picture tut
The pic ture, with standard 3 by 4
aspect rai i ?, has a usable screen area of
138.7 sc+uai e inches. A neutral gray face
increases ontrast ratio.
Weight of the 16RP4 is said to be
approxima ely two-thirds that of the 16 inch, all- lass round tube. Magnetic
focus anc deflection are employed.
VOICE COILS
i
ASSURE FINER PERFORMANCE
QUALITY FEATURES
`I
WEATHER-PROOF
Speakers play under water.
STRONG CONSTRUCTION
3" speaker supports 300 lbs.
vINDIVIDUALLY PACKED
In strong corrugated canons.
,
*
SNYDER WALKER-DUALCOTED STEEL
TV MASTS
\\ alkrr
ualcoted steel masts, which
it is clai, ed, offer greater protection
against i:or osion, are being used with the
Redi-Moun
and Head -Line antennas
made by
'nder Mfg. Co., at 22nd and
Ontario S reets, Philadelphia 40, Pa.
Both irnel and outer tube walls are
said to be protected by a double safety
coating that will not crack or chip if
bent durini installation.
S/lA
3ü112] -11J DISSIPATES HEAT
QUICKLY AND ALLOWS HIGHER POWER
ALUMINUM VOICE COILS have proved tops in performance! They handle greater power than ordinary coils without distortion or heat. Aluminum withstands any climatic condition
there's no warping, buckling or corrosion. Test
them all
you'll choose Cletron Aluminum Voice Coil Speakers.
...
...
LOUDSPEAKERS
CROWN CONTROLS MAST GUY RINGS
A roller aring guy ring, designed so
that mast; of antenna can be rotated
without loo ening the guy wires, has been
announced y Crown Controls Company,
Inc., 24 S.
Ohio.
Housi ig
CLEVELAND ELECTRONICS, INC.
6 6
1
1
EUCLID AVENUE
CLEVELAND, OHIO
MORÜAN EXPORTING CORP
458 BROADWAY, NEW YORK. N.Y.
ashington St., New Bremen,
f
COMPLETE LINE
An Alnico V or EM speaker
for every sound need.
the guy ring is of a one
altmi uni casting, molded of a material whit is said to have high corpiece
rosion resi tance qualities. Has a patented 11" e- filer Guard feature which
direct; wat r and ice formations out of
the path o3 the bearing race.
Unit is p ckaged with three guy thimbles, one , nd-off insulator, and all the
necessar,- 1pcking bolts and nuts. ready
for inst .lil_ion.
CLEAR BEAM V -CONE TV ANTENNA
A \r -cone line of TV antennas featuring phenolic heads, have been announced
by Clear Beam Antennas, 618 North La
Brea Avenue, Los Angeles 36, Calif.
Head is said to be guaranteed for five
years.
Antennas, with the new head are available in three models, for normal, fringe,
and low signal areas.
INSULINE TV MULTIPLIER PROBE
A multiplier -a robe, the !'. iloz'olter,
which, in effect, is said to add 15,000
volts to the scale readings of conventional
high -resistance voltmeters, has been announced by the Insuline Corp. of
America, 3602 35th Ave., L. I. City, 1,
N. Y. Three models are available, for
50,
100 and 200 -microampere meter
movements.
SERVICE, DECEMBER,
1949
41
TRIO YAGI ANTENNA
A yagi (double -folded dipole) TV antenna has been announced by the Trio
Manufacturing Co., Griggsville, Illinois.
Antenna is available for each of the
12 TV channels.
Antenna is said to have a gain of
10 db on the optimum channel, front-to
back ratio of over 25 db.
Available for channels 2 to 6 with mast
and mounting hardware, and for the high
bands, less mast.
NewTECH-MASTER
BLUE RIBBON
TELEVISION KIT
featuring AGC
(automatic gain control)
Vice/9
Çemad
for 10" or 12" KINESCOPES
-4
Mc band width.
Four-stage video IF
Completely assembled . . . ready to wire.
Factory tested parts of finest make. Trouble free wiring diagrams permit wiring in a
week-end Write for complete information
Blue Ribbon" and other Tech on the
Master TV products.
Complete with all tubes,
Via9
TECH -MASTER PRODUCTS CO.
443-445
MERIT
*
7de
*
*
/et
*
*
for
OUTDOOR -INDOOR USE
Hot Nails which are said to pierce
brick, mortar between bricks, wood or
even most concrete have been announced
by Hot Nails, Inc., 40 West 4th Street,
N. Y. C. Furnished with a polyethylene
insulator. Fits all types of transmission
line including light and heavy 300 ohm
50 and 72 ohm coaxial cable. On the
antenna itself, a Hot Nail acts as a mast
coupler.
Made of high carbon steel, 3%" long.
MERIT
Lightning Arrester
Protects Television Sets Against
The ONLY Twin
LIST
Lead Lightning
Arrester Approved by UL for Outdoor -Indoor Installation.
SIMPLE TO
INSTALL... attaches to any grounded ob-
ject-pipe, radiator, roof, wall-at
any position between
antenna and the set, indoor or outdoor.
WIRE
STRIPPING
or CUTTING
One Dozen To Pack-
age with FREE
No. AT102.12
COIL & TRANSFORMER CORP.
SPREADING of
or
ohm impedance
Self
Selling Display Card.
I
...
does
not
Advertised in Con
sumer Publications
To Help Your Sal3s
(l950,
JFD
MFG. CO.. Inc.
MANUFACTURING CO., Inc.
6109 16th Avenue
Brooklyn 4, N. Y.
ILL.
FIRST
1949
$225
Lightning and Static Charges
lines necessary. 300
unbalance line.
SERVICE, DECEMBER,
I
Twin Lead
NO
4435 NORTH CLARK ST., CHICAGO 40,
I F/GUARD
SAFE I
-
42
N.Y.
*
TV INSTALLATION HOT NAILS
OF
13,
.
Two antenna models, Versacone and
Jacknife, have been announced by Radio
Merchandise Sales, Inc., 550 Westchester
Ave., N. Y. 55.
Versacone is a conical which is said to
be adaptable in various arrays by shift of
rods in the reflector and insulator plates.
The Jacknife is a pre -assembled, all channel model that requires no manipulation of the rods, in conical, folded and
straight dipole models.
1950
PRODUCTS
Broadway, New York
leading engineers and technicians
have built Tech -Master for their own use
than any other Television Kit.
More
RMS TV ANTENNAS
Vea
$119.95
less Kinescope
eace
ACCESSORIES
IN TELEVISION ANTENNAS AND
New Parts, Accessories
ASTRON METALLIZED PAPER
:
a
a
a
ALL-WEATHER
ROLLER BEARING
GUY RING
.
(patents peiding)
CAPACITORS
A midget self -healing metallized paper
capacitor, in both hermetically sealed and
carboard tubular design, has been announced by Astron Corp., 900 Passaic
Avenue, East Newark, N. J.
Known as type MO, they are available
now in voltage ratings up to 600 volts
and are supplied with glass -to -metal hermetic terminal seals.
Officers of Astron include Joseph
Frank, president; John H. Fisher, chief
engineer and Irving Black, production
director and vice president, all former
Solar Mfg. Corp. employees.
rlICA1
TELEVISION
COMPONENTS
engineering
parin
Figsfin quality.
°
zyp
2081
O
-gw`k`n9
t
p'ot
Eotmet
* * *
HEATH IMPEDANCE BRIDGE KIT
An impedance bridge kit featuring use
a General Radio main calibrated
control and 1,000 -cycle hummer, Mallory
ceramic switches with 60° indexing, 200
microamp zero center galvanometer and
of 1% ceramic non -inductive decade
resistors has been announced by the
Heath Co., Benton Harbor, Mich.
Measures' inductance from 10 micro henries to 100 henries ; capacitance from
.00001 mfd to 1,000 mfd ; resistance
from .01 ohms to 10 megohms ; dissipation
factor from .001 to 1 and Q from 1 to
of
Permits TV and FM Antenna
Musts to be Rotated
Without Touching Guy Wires
Furnished complete with standoff
insulator, nuts, and guy wire thimbles. Laughs at rain, snow, and ice.
Corrosion free. For use with or with-
out antenna rotators.
1,000.
Circuit utilizes Wheatstone, Hay and
Maxwell circuits.
q\I5andcHnSta°*`o
1ÓtPot
..
-4
Write for name of nearest jobber.
ie
CROWN CONTROLS CO., INC.,
New Bremen, Ohio
r
.
.
7.O,JpH,t`O.
tyQ. o-o
Better because they're RCA engineered
widely accepted because they're backed by the leader
in television ... RCA standard television components mean greater
sales and service volume for you
throughout the year.
RCA television components are
the quality standards of the field for
all TV replacement requirements.
...
\GINALITY
WHAT BETTER BUY
In Quick -Change Tools?
o
Here's a real saving over buying separate
tools! Faster work, tool The XCELITE
No. 99 Kit has 9 chrome plated detachable
nut drivers, 3/16"-1/2"; 2 screwdriver
sizes in chrome plated detachable blade;
detachable reamer; big, comfortable
XCELITE combination handle that fits them
all. In compact, good-looking
Lim
--wst.sENNO.s
---
_......_
..____.....
Always keep in touch
RCA Distributor
with your
$9
metal case-all for
95'
ASK YOUR TOOL SUPPLIER NOW!
TURN TO NEXT PAGE
Or write:
PREFEl2EJ
EXPERTS
BY
Dept. V
7
ELECTRONIC COMPONENTS
PARK METALWARE CO., INC.
RADIO CORPORATION of AMERICA
HARRISON. N.J.
Orchard Park, N. Y.
SERVICE, DECEMBER,
1949
43
ELECTRO -VOICE OMNI DIRECTIONAL
CRYSTAL MICROPHONE
Three decades of radio -television "know-how"
insist
on...... 0.. insuline
Challenger
ANTENNAS
...for superb television
1... for fidelity FM reception
a.. for high quality
...for
2/"
low prices
KITS and ACCESSORIES'
The "Challenger Line" features precision engineering
11W
An omni directional crystal microphone, the Spherex, has been announced
by Electro -Voice, Inc., Buchanan, Michigan.
Features 360° omnidirectional polar
pattern, frequency response that is said
to be substantially flat from 60-7000 cps,
output level -50 db, standard %" -27
thread for desk or floor stand mounting.
Size,
diameter. Net weight, 8
ounces. High impedance ; can be used
with any standard amplifier or recorder
employing high impedance input.
. manufacturing skill .. .
maximum performance , . .
competitive prices. There is
an
Insuline "Challenger"
for every requirement , . .
outdoor, indoor, window.
Illustrated
Hi -Band Lo -Band
Folded Dipoles and Reflectors
is the
6444
Model No.
Challenger
Antennas
are first
choice with
TV installation
For outstanding reception over the entire high band
and low band television range. Ideal for "fringe" areas.
Antenna sections rotate separately. Easy to install.
Write for latest catalog illustrating and
describing the complete "Challenger"
line of Antennas and Accessories.
men
insuline
CORPORATION OF AMERICA
AEROVOX BANTAM ELECTROLYTICS
LONG ISLAND CITY, N. Y.
36-02 35th AVENUE
INSULINE BUILDING
West Coast Branch and Warehouse: 1335 South Flower Street, Los Angeles, Calif.
Exclusive Canadian Sales Agents: CANADIAN MARCONI COMPANY, Montreal
Miniaturized bantam -type eLectrolytics,
type SRE, have been announced by
Aerovox Corp., New Bedford, Mass.
Hermetically -sealed in tubular aluminum cases. Wax -impregnated cardboard insulating jackets. No. 18 gauge
tinned -copper leads said to assure positive mechanical and electrical contacts
even with the smallest units.
e,atd4it
TELEVISION
GENERATOR
KIT
X3950
ieeitder
SIGNAL
TRACER KIT
$19e
TIeatgei
CONDENSER
`,.CHECKER KIT
$195?
Heathkita are beautiful factory engineered quality service instruments
supplied unassembled. The builder
not only saves the assembly labor
coat but learns a greet deal about
the construction and features of the
instrument. This knowledge aids
materially in the use and maintenance of the equipment. Heathkite
are ideal for and need by leading
unersities and schools throughout
theUnited States. Each kit is complete with cabinet, 110V 60 cycle
transformer (except Handi-Tenter),
all tubes, coils assembled and calibrated, panel already printed ,chassis
all punched, formed and plated,
every part supplied. Each kit is provided with detailed instruction manual for assembly and sue. Heathkita
provide the perfect solution to the
problem of affording complete eervice equipment on a limited budget.
Write for eomblete catalog.
'eat4Or`"+r;<.
fM BATTERY
4
$225
ELECTRON
SWITCH KIT
$34"
NEW
ifearddie
ifeattkie
deatk&it'.
VACUUM TUBE
SIGNAL
IMPEDANCE
R.F.
BRIDGE SET
GEN. KIT
$6950
$1950
ELIMINATOR
KIT
VOLTMETER
KIT_".
$245?
HEATH COMPANY
BENTON HARBOR,
rfeatláet
NEW
MICHIGAN
HANDITESTER
K T
$13.50.
I
44
.
.
EXPORT DEPARTMENT
13 EAST 40th STREET
NEW YORK 16, N.Y.
CABLE- AeiAe-N.C.
.
SERVICE, DECEMBER,
tt
1949
* * *
IRC MULTISECTION CONTROLS
Complete control sections, Multisections, that can be added to any of the
recently announced IRC miniature Q,
PQ, or RQ volume controls, just as
switches are attached, have been announced by the International Resistance
Co., 401 Ñ. Broad St., Philadelphia 8,
Pa. Each Multisection adds 19/32" depth
to the basic control.
Multisections are made in 17 different
standard resistance values ranging from
1,000 ohms to 10 megohms. Bulletin
DC1A contains complete data.
RIDER MANUAL VOL. 20 OUT IN
JANUARY
Rider's. Manual, volume 20, with servicing data on AM, FM, auto receivers,
and record changers, will be published
in January by John F. Rider Publishers,
Inc., 48C Canal St., New York 13.
A How it Works hook with cumulative index for volumes 16 through 20
will he included.
ee,ee
PRECISION APPARATUS MANAGEMENT
CHANGES
S. M. Weingast who was the cofounder, with the late Murray Mentzer,
of the Precision Apparatus Company,
Inc., Elmhurst, L. I., N. Y.,17 years ago,
has been elected president and general
manager of the company.
The company's chief engineer, G. N.
Goldberger, has been named vice president, in charge of engineering, and treasurer.
J. M. Kirschbaum has been named
vice president in charge of sales. A. S.
Weingast, formerly personnel and production manager, lias been advanced to
the office of secretary and director of
purchasing.
*
*
TELEVISIO N
COMPONENT S
A complete line
for replacement
purposes
*
WORKSHOP ASSOCIATES CATALOG
A four -page brochure describing beacon antennas (144-152, 152-162, 162-174,
450-460, 460-470 mc) has been published
by The Workshop Associates, Inc., 66
Needham St., Newton Highlands 61,
ori
QUAM
ago:s you 45'
ñOEva/ue
A rrong all the radio speakers made
today there's only one that's different.
Orly Quam has the adjustable voice
coil, permitting accurate centering after
assembly, and virtually eliminating
rubbi ig voice coil trouble!
Only Quam has the U -Shaped Coil
Pot, providing an unbroken path for
the magnetic flux, thus producing a
stronger magnetic field, greater
effi-
ciency and better performance.
Only Quam has these plus values,
only Quam is different.
Specify Quam for all replacements!
Mass.
Described are principle of operation,
installation hints, electrical and mechanical specifications. A page is devoted to
a description of adaptors and connectors
used with the antennas.
yoke
H!CKOK OSCILLOGRAPH BOOKLET
A 50 -page booklet, Thc Oscillo!lraplr,
prepared by Walter Weiss, has been
published by The Hickok Electrical Instrument Company, 10521 Dupont Avenue, Cleveland 8, Ohio.
Covered are application data on the
power supply, oscillator section, first
detector, if amplifier, first and second
audio stages, final audio, and TV and
FM alignment. Book, with actual diagrams of wave shapes drawn from a
'scope screen, available at $1 per copy.
*
TV BOOSTER FAN
MAIL
Ms il this coupon for free catalog.
QUA.M-NICHOLS CO.
RCA has all the major components
required for television receiver repair or construction. Designed at
"Television Headquarters," RCA
vertical and horizontal output transformers, yokes, focusing coils, etc.,
are the originals around which modern television receivers are designed.
And you can get them all from one
dependable source of supply . . .
your local RCA Distributor.
Always keep in touch
with your RCA Distributor
52o E. 33rd Place
Chicago 16, Illinois
Please send me Quam catalog.
TURN TO NEXT PAGE
Name
Address
City.
State
William J. Doyle, left, general sales manager of
The Astatic Corporation, Conneaut, Ohio, reviewing fan mail from users of Astatic's Channel
Chief booster, with F. H. Woodworth, company
president.
ELECTRONIC COMPONENTS
RADIO CORPORATION o1 AMER/CA
HARRISON N. J.
SERVICE, DECEMBER,
1949
45
1950 RCA VESTPOCKET TUBE
REFERENCE BOOK
it
*
*
The 1950 edition of the RCA Tube
Department's, Tube Reference and Calendar Notebook, is now available from
RCA Tube Department distributors.
Edition includes television service data
and the latest information on tubes and
batteries. The book contains 47 pages of
receiving tube characteristics and socket connection diagrams, and 12 pages of
technical data on 300 RCA power,
cathode-ray, photo-, and special tubes.
Included are a Quick Selection Buying
Guide, and a Replacement Directory
listing RCA tubes that are directly interchangeable with or similar to corresponding types.
A four -page section on batteries features chart giving descriptions, voltages,
and sizes of 80 RCA batteries plus an
interchangeability chart.
Factory -fitted to most Clarostat
carbon and wire -wound controls.
Control -to -ground breakdown
rating better than 10,000 v.
New design eliminates
troublesome backlash.
Permits more critical settings.
IMPROVED HIGH -VOLTAGE CONTROLS
Straight -through plastic shaft simplifies and improves operation. No
back -lash to throw off critical adjustments. Cheaper. Better. Simpler.
Improved design high -voltage controls for TV sets, oscillographs and
other high -voltage electronic assemblies. Safe operation up to 10,000 v.
*
*
A twelve -page booklet, High-fidelity
Music Guide, has been issued by Lafayette Radio, 100 Sixth Avenue, New York
City.
Brochure was created by David Randolph, music consultant for Lafayette.
Guide presents parts assemblies, together with suggestions for cabinets and
their location, a glossary of technical
terms, a chart of the range of musical
sounds, and a technical explanation of
the requirements for high fidelity sound
reproduction.
Ask your Clarostat jobber for these
controls and other aids to TV and
radio servicing.
*
CLAROSTAT MEG. CO
,
INC.
DOVER, NEW HAMPSHIRE
In
Canada:
P.
0,
and
*
*
CARL J. HOLLATZ NOW RCA TUBE
DEPARTMENT CONSULTANT
CANADIAN MARCONI CO., LID.
Montreal,
*
LAFAYETTE RADIO HI-FI MUSIC
GUIDE
branches
gMMIfflffle
Carl J. Hollatz has been retained as
a consultant to the sales division of the
SHOOTS
FASTER!
II
I
tube department of RCA. Hollatz, formerly vice president of the Belmont Radio
Corporation, will make his headquarters
in Chicago.
TROUBLr
mar
takes more
r
you on Ìo
at service bench:
PRICE
$
I
I
*
at distributor
or postpaid.
Sorry.
direeL
A 24 -page illustrated catalog with a
listing of replacement cone assemblies,
both postwar and prewar, including some
1948 and 1949 models, has been published by Waldom Electronics, Inc., 911
North Larrabie Street, Chicago, Illinois.
Information offered includes part number, set model number, outside diameter
of cone and pertinent dimensions consisting of outside diameter of speaker, inside diameter of voice coil, depth of
cone, type of spider, etc.
s rnaleite
3% State Sala
I
MULTI -FREQUENCY GENERATOR
Locate
In radio service work, time means money. of work
trouble faster, handle a much greater volume
tool.
with the SIGNALETTE. As a trouble shooting
SIGNALETTE has no equal. Merely plug In any
I110V. AC -Dc line, start at speaker end ofin eirsult
set's
and trace back. stage by stage, listening
Generates RF,IF and AUDIO Frequenspeaker.
Also used fer
2500 cycles to 20 Megacycles.
tcues,
Gain, Peaking, Shielding,
checks on Sensitivity.
Tube Testing. Wt. 13 oz. Fib pocket or tool kit.
* * *
NEWARK ELECTRIC CATALOG
lSee at your distributor or order direct.
I
eh,.pale
INSTRUMENT
LABORATORY
5, 1125 BANK STREET
CINCINNATI 14, OHIO
QUALIFIED JOBBERS WRITE,
WIRE FOR DETAILS.
DEPT
46
SERVICE, DECEMBER, 1949
*
WALDOM CATALOG
COD's.
add
Ohioans
I Tax.
*
I
A catalog covering television receivers,
kits and wired chassis, cabinets, tubes,
parts, etc., test instruments, FM -AM
tuners, amplifiers, speakers, record
changers, wire, tape, and disc recorders,
phono, record discs and accessories, has
been released by Newark Electric Co
Inc., 242 West 55th St., New York 19.
RACON SOUND BOOKLET
A 4 -page booklet with practical intructions and wiring diagram for the
home-building of an economical, professional type 1,000 -cycle crossover network, has been released by Racon Electric Co., Inc., 52 East 19th Street, New
York 3.
A full range of specific inductance,
capacitance and resistance values are
given, plus complete coil winding information, to adapt the crossover network
for use with cone speaker impedances of
from 4 to 16 ohms. Steps for the installation of crossover networks, wide range
tweeters, and standard cone speakers are
also described in detail.
Tv
Mp
r
Here's
f
<
PREof
of
i
*
*
Acceptance
SOUTH BEND, IND.-"We have found Anchor TV Pre Amplifier o be superior in performance to anything else
on the mai ke+. It has been a profitable item on which we
have built ,p dealer good will.'
COMMERC IA- SOUND 8 RADIO CO.-A. E. Keifer, Pres.
PHILADELPt'ftA, PA. -"Anchor Booster's consistency, its high
gain and Fs performance in outer fringe areas have built
for it a res ut ]rion which cannot be beat in our area. The
excellency of this product has opened up many television
areas and many additional sales in Television Receivers,
their comp,nerst parts and accessories:'
RADIO ELECTRIC SERVICE COMPANY OF PENNSYLVANIA
Albert N. Kass, Sales Manager
has established
general acceptance and good will
for all good boosters through its own
top-notch performance!
*
The standards
for TV set
construction
*
TUNG-SOL TUBE DATA
A bulletin, describing the 5687 twin
triode, has been released by Tung -Sol
Lamp Works, Inc., Newark 4, N. J.
Offered are rating and characteristic
data.
*
*
*
APPROVED FM -AM TUNER BULLETIN
Unanimous proven verdict of users. Anchor's engineering is not approached-nor will it ever be.
The ANCI4OIR'BOOSTER is built to help you make
the best TV installations possible for your customers.
Why then be satisfied with the ordinary? Anchor
builds derrand for reliable boosters-making more
sales-adding good will. Tie Anchor Booster into
every tele 'is an sale.
Here is dependability with instant sales appeal
21/2 times average gain (Voltage Ratio), guaranteed coverage of low and high band
precision
with beauty-pride in having the best!
Get in touch with your jobber-or writs ANCHOR
-
Germanium diodes, types 1N34A and
1N58Á, recently announced by the electronics division of Sylvania Electric
Products Inc., will be marketed to Sylvania distributors in a 25 -unit carton and
counter merchandiser featuring an oval
window in the top permitting visual inspection.
*
i
*
SYLVANIA GERMANIUM DIODE
MERCHANDISER
Distribu tor
TELEVISION
COMPONENTS
-
ANCHOR ENGINEERING ALWAYS A YEAR AHEAD
A four-page catalog covering a highfidelity FM -AM tuner, model A710,
has been published by Approved Electronic Instrument Corp., 142 Liberty St.
New York 6.
*
*
*
KAMEN COAX PAPER IN JANUARY
THE CONCLUDING installment of the
Ira Kamen article on coax cable instal-
lation originally scheduled for December will appear in the January issue of
SERVICE.
*
*
*
NEWCOMB HIGH FIDELITY AMPLIFIER
PUSH TO LOCK
y
GET THIS
QUICK -WEDGE SCREW -HOLDING
SCREWDRIVER
Ho s, Starts, and Drives
Sc ews with same tool!
E iminates Fumbling!
6 in
90c
8 inch 95c
Made In Three Types
Light Duty 2" to 8"
tedium Duty 4" to 8"
Heavy Duty 4" to 14"
ASK 1O ]R JOBBER OR ORDER DIRECT
Machinery Sales & Equipment
626 Broadway, Cincinnati 2, Ohio
A 25 -watt amplifier with a frequency
response from 20-20,000 cycles, that
offers 6 input channels, five for microphone and one for phono with built in
preamp to permit use of magnetic pickups, has been announced by the Newcomb Audio Products Company. All 6
channels may be remote controlled from
the audience by a control unit. A locked
cover over controls prevents tampering
with adjustments.
Bandwidth control is said to provide
adjustment of frequency bandwidth of
the amplifier in keeping with the program
quality, leaving tone controls free to provide correct balance between highs and
lows. Plug-in input transformers permit
Jong mike lines where desired. Visual
indicators reveal power output in watts
and indicate distortion.
Distortion at rating is said to be less
than 3% with 90% of full output at less
than 1%.
You don't have to shop around
for television parts. RCA has a complete line of genuine components
and units for replacement heeds . - .
or shop construction of a top-quality
television receiver.
The parts and units you need are
all described in a new bulletin now
available from your local RCA Dis tri butor. Or write RCA, Commercial
Engineering, Section 56LV, Harrison, New Jersey.
Always keep in touch
RCA Distributor
with your
ELECTRONIC COMPONENTS
RADIO CORPORATION of AMERICA
HARRISON. M J.
SERVICE, DECEMBER,
1949
47
h1-iietilty
JOTS AND FLASHES
y®uC
TV's boom in popularity appears to have
made quite an impression on many large
apartment realtors, who have begun to
make wide -scale plans for antenna outlets for their tenants. In New York,
builders of three huge projects, including
the Schwab House, with seven hundred
apartments, agreed to install antenna systems which will enable over a thousand
families to plug into wall assemblies for
WIDE vT SELECTION
BEST
connection.... R. W. Fordyce has
antenna
VALUE HIGHEST QUALITY
succeeded E. C. Bonia as sales manager
of the Bendix television and receiver divi. John
sion of Bendix Aviation Corp.
Winter is now executive vice president of
MODELS 4408, 4409.-600
the House of Television, Inc., 40 west
CYCLE TWEETERS: Recommended for highest quality
Bruno New
4th Street, N. Y. C.
reproduction systems requirYork, Inc., 460 W. 34th Street, N. Y. C.,
ing a low crossover fre
have been appointed distributor for the
auency. Cobra shooed horn
results in perfect wide angle
.
John F.
J errold Mul-TV system.
distribution. Frequency re.
Rider, Publisher, Inc., 480 Canal Street,
sponse 600 to 15,000 cycles
N. Y. 13, N. Y., has been elected to an
Model 4408 handles 6 watts
4croand 4409 25 watts.
associate membership in RMA
Tennn, an indoor TV antenna, recently
announced by Aero Needle Co., 619 N.
MODEL 4407 ADAPTER
MOUNTS 4401 TWEETER
Michigan Avenue, Chicago, will be dis12"
UNIT:
IN ANY
CONE
.
Al Elmer has
tributed nationally.
Converts any 12" cone
been named manager of the new Atlantic
speaker into o wide -range coaxial reproducer in a few
City, N. J., store of Almo 'Radio Co., at
minutes. Installation is ex.
George W.
4401 Ventnor Avenue.
3
tremety simple and results in
Davis, 1406 S. Grand Avenue, Los Ana dual speaker occupying little more space than the orig
geles, Calif., has opened his own office
inol cone speaker. Complete
William O.
as a manufacturers' rep.
with 4401 tweeter.
Schoning of Lukko Sales and Aaron
Lippman have been named chairman and
MODEL 4401-2000 CYCLE
vice chairman, respectively, of a disTWEETER: An economical 6
watt unit for converting any
tributors advisory committee, recently set
good 10.15" cone speaker for
up by the Radio Parts and Electronic
extended response to 15,000
Equipment Shows, Inc. Other members
cycles. Wide Angle horn.
low
design
and
compact
of the committee are Sam Poncher, Newprice bring excellent high
ark Electric; Lewis J. Bonn, Lew Bonn
fidelity well within the popu
Co. ; Merle Applebee, Burstein-Applebee ;
for price ronge.
H. L. Dalis William A. Wilson, Hughes Peters, Inc. R. V. Weatherford, R. V.
Weatherford Co.; Milton Deutschmann,
Radio Shack Corp., and John Stern,
MODEL 4402, MODEL
Radio Electric Service Co.... Ben Wil4404: Model 4402 repro.
duces to 15,000 cycles. Cross.
lig and Ed Deutsch have formed the Marover at 2000 cps. Horizontal
athon Sales Co., 466 W. 42nd Street,
dispersion 100°, Vertical 50°.
Benray DisNew York 18, N. Y.
Handles 12 watts. Compact
design mounts in any rodio,
tributors, 506 Coney Island Avenue,
phono, or speaker cabinet.
Brooklyn 18, N. Y., have been appointed
Model 4404 incorporates
exclusive distributors for American Tele4402 tweeter in handsome
walnut cabinet complete with
vision and Radio Co. auto radio replacehigh.pass filter and high frement vibrators in the Flatbush area of
auency volume control. Any
Brooklyn.... Edward J. Bacher is now
one con install.
the National Union Tube sales manager
to initial equipment accounts in the Chicago area and adjacent states. Bacher
The 40th
was formerly with RCA.
MODEL 4405 HIGH PASS
FILTER: An effective and
anniversary banquet of the Radio Club of
economical unit for preventAmerica was held recently in New York.
ing lows reaching the tweeter
Guest of honor was Major General Harry
unit. Contains high frequency
C. Ingeles, formerly chief signal officer
control to balance highs and
lows. Cutoff frequency 2000
and at present president of RCA Comcycles.
munications, Inc.... An eight -page flyer
describing a variety of test and TV kits
MODEL 4410, 4420 LC
has been released by the Heath Co., BenCROSSOVER NETWORK,
Ben Joseph, 551
ton Harbor, Mich.
Genuine LC frequency dividers for segregating highs and
Fifth Avenue, N. Y. C., has become a
lows. Not to be confused with
Tricraft Products Co. rep in metropolitan
ordinary high-pass filters.
New York. A. P. Williams, RR 1 Box
Crossover frequencies: Model
62, St. Joseph, Mich., and Jack West,
4410 600 cycles, Model 4420
2000 cycles. Attenuator con,
6747 N. Octavia Avenue, Chicago, will
trols included and wired.
represent Tricraft in Michigan and Illinois
Write today for illustrated literature
Wiland Wisconsin, respectively.
-address inquiries to Department C
liam H. Sahloff, formerly merchandise
manager and vice president of Montgomery Ward, is now manager of the
G. E. receiver division.... Paul Nichols
and Robert Sargent have become regular
members of the New York chapter of
INC
The Reps. Jerry Greenberg is now an
N.Y.
80 SO. KENSICO AV., WHITE PLAINS,
associate member.
TWEETERS
.
.
.
.
.
ADVERTISERS IN THIS ISSUE
SERVICE INDEX-DECEMBER,
ALLIANCE MFG.
1949
CO
39
AMERICAN ELECTRICAL HEATER CO
Agency: Dudgeon, Taylor & Bruske, Inc.
AMPERITE CO.
40
Agency: Foster & Davies, Inc.
36
Agency: H. J. Gold co.
ANCHOR RADIO CORP
Agency: Symonds, MacKenzie & Co.
CHANNEL MASTER
47
CORP
6
7
Agency: Serge Loukfn
CLAROSTAT MFG. CO.. INC
46
Agency: Austin C. Lescarhnura & Staff
CLEVELAND ELECTRONICS, INC
41
Agency: Bonsib Adv. Agency
,
CLIPPARD INSTRUMENT LABORATORY
46
Agency: The S. C. Baer Co.
CORNELL-DUBILIER ELECTRIC CORP.,
Agency: Reiss Advertising
Inside Front Cover
CROWN CONTROLS CO.. INC
Agency: Don Kemper Co., Inc.
43
ALLEN B. DUMONT LABORATORIES, INC
Agency: Austin C. Lescarboura & Staff
GENERAL
Agency:
GENERAL
Agency:
ELECTRIC
Maxon, Inc.
4
CO
ELECTRIC LAMP DEPT
Batten. Barton. Durstine & Osborn. Inc.
21
31
.
.
.
THE HEATH COMPANY
Agency: D. Dean Arend, .\dcertising
HOT NAILS, INC
Agency: A. D. Adams. Advertising
HYTRON RADIO & ELECTRONICS CORP
Agency: Bennett, Walther & Menadier, Inc.
44
INSULINE CORPORATION OF AMERICA
44
38
9
Agency: Bass & Co.. Inc.
J.
36. 42
F. D. MFG. CO., INC
Agency: Shappe-Wilkes Inr.
:
KEN -RAD DIV.-GENERAL ELECTRIC
Agency: Maxon. Inc.
;
;
.
.
.
.
LOUDSPEAKERS
48
SERVICE, DECEMBER,
1949
.
Inside Back Cover
MALLORY & CO., INC
Agency: The Altkin-Kynett Co.
P. R.
MACHINERY BALES &
EQUIPMENT
47
CO
Agency: /tie -et -Guenther. Inc.
MERIT COIL & TRANSFORMER CORP
Agency: Symonds. MacKenzie & Co.
42
MUELLER
40
ELECTRIC
CO
PARK METALWARE CO., INC
Agency: Melvin F. Ball Agency. Inc
PHOENIX ELECTRONICS, INC
Agency: Milton Richards
PRECISION APPARATUS CO., INC
Agency: Shappe-\\-ilkes inc.
43
QUAM-NICHOLS COMPANY
Agency: Triangle Adv. Agency
45
THE.RADIART CORP
25
Agency: Stern and warren
RADIO CITY PRODUCTS COMPANY
Agency: Jaman Advertising. Inc.
RADIO CORPORATION OF AMERICA,
43,
45, 47.
34
32
34
Back Cover
Agency: .1. Waller Thompson Co.
RADIO MERCHANDISE SALES, INC
Agency: Nottingham & Yhaneuf
JOHN F. RIDER PUBLISH ER, INC
Agency: Shappe-Wilkes Inc.
38
28, 29
HOWARD W. SAMS & COMPANY, INC
Agency: George Brodsky, Advertising
SNYDER MFG.
3
17
CO
Agency: Bionics and London
STANDARD TRANSFORMER CORP
Agency: Burnet -Kuhn Adv. Co.
SYLVANIA ELECTRIC PRODUCTS, INC
37
TECH -MASTER PRODUCTS, INC
Agency: Bass & Co., Inc.
TELREX, INC.
Agency: George Homer Martin Associates
42
10
Agency: Newell -Emmett ce
TRIPLETT ELECTRICAL INSTRUMENT
Agency: Western Adv. Agency, Inc.
TURNER CO.
Agency: W. D. Lyon
8
35
Co.
LOUDSPEAKERS. INC
Agency: George Homer Martin Associates
UNIVERSITY
33
CO
48
High Temperature
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on Long Life...
Mallory Capacitors
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Ii takes
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And MALLORY CAPACITORS DO IT!-tests have
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You can count on Mallory Capacitors for
longer shelf life-longer life in an inactive
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Mallory Capacitors cost no more than ordinary capacitors-they're easy to install,
and when they're installed they're dependable
and that-means the kind of service that
satisfies customers. Order from your Mallory
...
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Don't Miss the Mallory Television Service Encyclopedia.
Get Your Copy From. Your Mallory Distributor
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www.americanradiohistory.com
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For quick and accurate TV trouble shooting
...
Cunningham brings you the indispensable Pirct-O-Guide
I of the RCA Television Pict-O -Guide has
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Now-in addition-there is a second Volume, with
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