GE Modular - American Radio History

GE Modular - American Radio History
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August, 1976 O
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A HOWARD W.
SAMS PUBLICATION
Satellite Update
GE
Modular
Accurate CB Tests
1977 Color Features
reliability and the
From the beginning,
our goal has been to
provide the best tuner
standards of excellence we apply to every
service never the
cheapest. You get what
you pay for in business
and tuner service is no exception.
The extra dollar you might pay at PTS
is peanuts when you consider the added
SAME DAY SERVICE
job. Thousands of PTS
customers must agree or
we wouldn't be the world's
largest tuner service company.
When you are comparing tuner service
companies, price alone doesn't tell the story.
ORIGINAL PARTS
WE REPAIR THEM ALL
.
.
.
COLOR, BLACK & WHITE, TUBE,
TRANSISTOR OR VARACTOR
VHF or UHF.
.
.
ONE YEAR GUARANTEE
.
.$10.95
.
.
ANY MAKE OR MODEL.
UV -Comb.
(MAJOR PARTS AND SHIPPING EXTRA
.
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.$17.95
DEALER NET)
PTS ELECTRONICS,
PRECISION TUNER SERVICE
General Headquarters: P.O. Box 272, Bloomington, IN 47401
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INC.
August, 1976
Cl
Volume 26, No.
8
Electronic Servicing.
It elk ¡We I..
Modular Color TV, Part 1-General features
and layout ofthe GE 19YC2 chassis begin the coverage-Gill
Grieshaber, CET.
16 Servicing GE
Update-Events leading to reception at home of
signals from TV satellites are proceeding as predicted two
years ago-David A. Ferre'.
22 Satellite TV
Trends-Many of the
new receivers have fewer,
but larger, modules. Does this mean an eventual return to
non -replaceable circuit boards?-Carl Babcoke.
24 1977 Color TV
30 CB Test Readings...Right Or Wrong?, Part 1-Incorrect readings when you're troubleshooting CB radios can cause serious
problems. Here are suggestions for stopping those mistakes before they happen-Marvin J. Beasley, CET.
40 Servicing Electronic Organs, Part 3-Is that one dead note
caused by a defective key switch or a bad divider stage? Tested
methods are explained-Norman H. Crowhurst.
50 Reports From The Test Lab-Model 239 tiny color -bar generator, Model 270 function generator, and Model 380 fre-
quency counter from Hickok are
tested-Carl Babcoke, CET.
MORE
DEALERS
THAN EVER
BEFORE
HAVE US
WHERE THEY
WANT USI
THE NEWEST PTS
SERVICE CENTERS
SYRACUSE, NY 13204
4-8 Solar St.
315-475-2330
elvin Burns, General Manager
SALT LAKE CITY 84106
1233 Wilmington Ave.
P.O. Box 6218
801-484-1451
Bruce Nelsen, General Manager
DAVENPORT, IOWA 52805
2024 E. River Dr.
P.O. Box 187
319-323-3975
Keith Pratt, General Manager
ABOUT THE COVER
Richard Shipley, a technician around Kansas City for many years,
is shown measuring voltages and looking at waveforms of the GE
19YC2 chassis in the ELECTRONIC SERVICING laboratory.
DEPARTMENTS
Electronic Scanner
Symcure
Troubleshooting Tips
Reader's Exchange
Product Report
Test Equipment
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Published monthly at
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Ouivira Road. Shawnee
,
Ncw More Than
40 Locations
Offer Complete
Tuner Service
4
8
9
10
54
55
Antenna Systems
Catalogs and Literature
56
57
Book Review
58
59
60
Photofact
Advertiser's Index
paid at Shawnee Mission, Kansas and additional mailing offices.
9221 Ouivira Road, Shawnee Mission, Kansas 66215 by InteriSC
Wyandotte St., Kansas City, Mo. 64105. Send Form 3579 to 9221
VHF or UHF. ..$10.95
UV Comb. . .$17.95
PTS ELECTRONICS, INC.
Mission, Ks. 66215.
& Co., Inc. All rights reserved. Material may not be
reproduced or photocopied in any form without written permission of publisher.
PRECISION TUNER SERVICE
e Copyright, 1976, Howard W. Sams
August, 1976
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EDITORIAL
RONALD N. MERRELL, Director
CARL H. BABCOKE, Managing Editor
SHARON ELWOOD, Editorial Assistant
DUDLEY ROSE, Graphic Designer
MEET
OUR FAMILY OF
ELECTRONIC TEST
ACCESSORIES
ELECTRONIC SERVICING
1014 Wyandotte Street
Kansas City, Missouri 64105
Tele: 913/888-4664
TECHNICAL CONSULTANT
JOE A. GROVES
EDITORIAL ADVISORY BOARD
LES NELSON, Chairman
Howard W. Sams & Co., Indianapolis
CIRCULATION
EVELYN ROGERS, Manager
ADVERTISING SALES
Kansas City, Missouri 64105
Tele: 913/888-4664
MIKE KREITER. Director
GLORIA PARMENTER, Production
REGIONAL ADVERTISING SALES OFFICES
ELECTRONIC
Indianapolis, Indiana 46280
TEST ACCESSORIES
Tele: 317/846-7026
ROY HENRY
2469 E. 98th St.
Greenlawn, New York 11740
CHARLES C. HORNER
P.O. Box 175
Tele: (516) 757-8868
Mountain View, California 94043
DENNIS TRIOLA
2680 Bayshore Frontage Road, Room 102
Tele: 415/961-0378
London W.C. 2, England
JOHN ASHCRAFT & CO.
12 Bear Street
Leicester Square
Tele: 930-0525
Badhoevedorp, Holland
John Ashcraft & Co.,
John J. Lucassen, Mgr.
Sloterweg 303
Tele: 2968-6226.
11
POMONA ELECTRONICS
ITT
1,
Tokyo, Japan
INTERNATIONAL MEDIA
REPRESENTATIVES LTD.
Shiba-Kotohiracho, Minatoku
Tele: 502-0656
(
This new General Catalog is our latest family portrait.
In the past twenty-five years (1976 is our Silver Anniversary year) it has grown from a handful of items to
almost 500 products for the electronics industry.
Our catalog has grown to 76 pages for 1976, and we
are introducing E5 new items this year. It describes and
illustrates every member of our family. You're bound
to find the solution to your testing problem with one or
more of these quality products.
For your free copy, circle the reader service number
listed below, or write:
E
ABP
C
ELECTRONIC SERVICING (with which is
PF Reporter) is published
monthly by Intertec Publishing Corp.,
1014 Wyandotte Street, Kansas City,
Missouri 64105.
combined
Subscription Prices:
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year
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Adjustment necessitated by subscription
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MAILOR
MAORY
42!
PTC1i
mfürcier
PTT," MN
PTT181
PTC1i3 PNP
[email protected]
TJ.
Nf
POI
»ET
PNP
MALLORY
IF
ne
43PIWVPC
4y1fVlC
158 pi
EyFIAT10
IOU
BOWpC
.1
IIfAÚORY
MALWRY
EWF
A1)1
){1u1
TCtlO NUA4OATTE
PTCyU1r10LE.8A
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IOEfPVOC
pO
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Get your Mallory
riifit-ppcka!
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It's an introductory offer with an unbeatable
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A huge assortment. With the Mallory
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the electronics in almost every type of CB
radio made. Because, unlike limited -coverage
programs, you get more than 370 of the most
commonly used semiconductor and
other replacement parts.
And a hefty discount off column
pricing. Which can add up to a whopping
up to 25 times the cost of the
profit in CB repair
parts to you.
Plus, free Malobin® cabinets, the great space seven rugged plastic 15 -drawer
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units with each Mallory CB package you buy. And a
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What a deal for a very modest investment. Under $200, in fact. It's a profit
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Act now. Fill in and mail the coupon today.
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r
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TO: Dept. 103, Mallory Distributor Products Co.
Box 1204, Indianapolis, IN 46206
want to take advantage of your introductory offer now.
Send one complete CB replacement package through
my Mallory distributor. It is my understanding that will
be billed by my Mallory distributor.
I
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Send more information on the Mallory CB profit package.
Name
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MALWRY
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State
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Telephone
J
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MALLORY DISTRIBUTOR PRODUCTS COMPANY
a division of P. R. MALLORY $c CO. INC.
Box I284. Indianapolis, Indiana 4620d: Telephone: 317-856-3731
Batteries Capacitors Controls. Security Products DURATAPE® Resistors- Semiconductors SONALERT' Switches Fastening Devices
DURATAPE^' and SONALERT are registered trademarks of
For Mcre Details Circle
(12) on Reply Card
P. R.
Mallory & Co. Inc.
1[IM
ilt2-10111101'
news of the nous ry
Recently, the Federal Communications Commission (FCC) called in samples of CB
radios along with the applications for Type Acceptance. After FCC tests, all 25
radios were rejected as failing to meet the requirements. Previously, Type
Acceptance was granted or refused from specification sheets alone. According to
Ray Spence, FCC chief engineer, some manufacturers will be given 60 days to
correct the problems found; but other applications were dismissed, and these must
be resubmitted.
The RCA Service Company has installed the sound system called "Sensurround"
in 289 theaters for the film "Midway". It is the same sound system which thrilled
audiences with ultra -realistic sensations in "Earthquake". In "Midway", movie
spectators will experience special effects that duplicate the vibrations of huge naval
artillery, airplane bombings, and explosions.
Sansui Electronics presented an AM -radio quadriphonie stereo sound system at
the Audio Engineering Society's Show in Los Angeles. Two of Sansui's AM stereo
systems are capable of delivering frequency response to 15 kHz with full dynamic
range comparable to the best FM -stereo transmission and reception. Both Sansui
systems are compatible with QS 4 -channel encoding. Currently being studied by
the National AM-Stereo Radio Committee, the two systems will go on the air for
field tests this fall.
Sony Corporation of America has broken ground for a multi -million -dollar
distribution center and product -testing facility at the Air World Center in Kansas
City. Completion is scheduled for 1977. This is the fourth such Sony facility.
It has been predicted that the use of microprocessors in conjunction with video
technology will expand video games into home computers, which could provide
educational programs, as well as games of higher sophistication. Two products
illustrating this point are Fairchild's video system and Rockwell's Videospond.
Greg Reyes of Fairchild is quoted in Home Furnishings Daily as saying that,
although the original Fairchild video entry is a game, it is expected to evolve into a
home computer. Not only should the computer control the home temperature,
lights, home security, fire and smoke detection, and other useful functions, but
would include a video monitor displaying catalog pages from which merchandise
could be ordered and billed to a credit card. He also predicted that by 1980, a
majority of homes will have a computer, and by 1985 all homes will have one or
more. Videospond has a keyboard (similar to a typewriter) and a video screen for
the answer to be displayed.
"The greatest source of the 'new energy" which the world needs for continued
growth will have to come from improved productivity", Harold S. Geneen,
chairman and chief executive of International Telephone and Telegraph
Corporation said recently.
The Communications Equipment Distributors Association (CEDA) has charged the
New York Times News Service with misrepresenting CB to the public in an article
that ran in the July 11th editions of the Chicago Tribune. The article stated that
many CB's now in stock may be made unsaleable and partly obsolete by channel
expansion and that the addition of channels is also an FCC attempt to slow the
sale of CB radios as prospective customers wait for the new equipment, thus
(Continued on page
4
6)
ELECTRONIC SERVICING
TUNER SERVICE CORPORATIO
sees
-
^'
1
STILL ONLY
ONE YEAR
GUARANTEE
JUST
U.SLY.A.
ON
'
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AND SHIPPING
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WITH CABLES
ff"
PROVIDES YOU WITH A COMPLETE SERVICE
FOR ALL YOUR TELEVISION TUNER REQUIREMENTS.
C FEATURES
A UHF Tuner with 70 channels which are
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AC Powered
90 Day Warranty
VHF OR UHF ANY TYPE
UHF/VHF COMBINATION
to
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Fast, efficient service at our conveniently located
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AII tuners are ultrasonically cleaned, repaired,
realigned, and air tested.
UNIVERSAL REPLACEMENT TUNER $12.95 (U.S.A. only)
This price buys you a complete new tuner built specifically by Sarkes Tarzian Inc. for this purpose.
shafts have a maximum length of 101/2" which
can be cut to 11/2".
Specify heater type parallel and series 450 mA.
or 600 mA.
NEWS FLASH!
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NOW AVAILABLE-TUNER SERVICE
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Tel.
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54
MEMPHIS, TENNESSEE 38111
DALLAS, TEXAS 75218
NORFOLK, VIRGINIA 23513
ST. LAURENT, QUEBEC H4N-2L7
CALGARY, ALBERTA T2H-1Y3
32-3493
d."1.358-1186
-788-8206
-429-0633
Tel,. 02-384-4235
T= 609-393-0999
1. 201-792-3730
f el. 716-647-9180
el. 919-273-6276
I. 513-821-5080
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le Av.
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ark
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Box 10141
1732 N.W Jth Ave.,
15 Gr
Avenue
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Avenue
3
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t arland Road
3295 Santos Street
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P 0 Box 5823, Stn. "A"
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01-458-2355
14-327-8413
Tel. 804-855-2518
Tel. 514-748-8803
Tel. 403-243-0971
Te
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IF YOU WANT TO BRANCH OUT INTO THE TV TUNER REPAIR BUSINESS,
WRITE TO THE BLOOMINGTON HEADQUARTERS ABOUT A FRANCHISE.
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278-4217
452-1191
el.
Tel. ,..-221-3027
.
.,
GON 97210
PA. 15209
3
Tel
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5505 Reist:rstow
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1507-09 E. 14
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Tel. 602-79 -9243
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Tel. 415- 7-57i13
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Tela409 213
24
Tel,
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CLEVER
OREGON
PENNSYLVANIA
TENNESSEE
TEXAS
VIRGINIA
CANADA
405 E:
OIS
204
IS,
'y NAP
MOIN S, IOWA ''r 319
..ÿ
`
....104 S
..646
/ PAIGN, ILL
Tel. 812-334-0411
537 South Walnut Street
1528 S. 6th Ave.
10654 Magnolia Boulevard
1324 Marsten Roa
....1505 ypress
FLORIDA
IE,
INDI'.'
NEW YORK
Customized tuners are available at a cost of only
(U.S.A. only)
$15.95. With trade-in $13.95.
Send in your original tuner for comparison purposes
to any of the Centers listed below.
BLOOMINGTON, INDIANA 47401
TUCSON, ARIZONA 85713.
OOD, CAEIF. 91601
_NORTH ,,O
RLIN L E.
' 0
.
9.95
$15.00
$
MAJOR PARTS AND SHIPPING
CHARGED AT COST
You may place your order through
any of the Centers listed below.
HEADQUARTERS
ARIZONA
CALIFORNIA
(U.S.A. ONLY)
(U S.A. ONLY)
z
news of the indus ry
iciioer
(Continued from page 4)
reducing the interference caused by the 4 -watt CB's. In a rebuttal statement issued
by CEDA President E. Craig Martin, he pointed out that "When and if channel
expansion does come, the present 23 channels will become the bottom 23 channels
on the expanded band, and that's where 99 percent of the CB conversations will
take place." He also stated that "Most interference is not the result of CB radios,
but rather the lack of proper shielding in televisions, stereos and other electronic
devices."
General Electric's 25 -inch color console TV sales to dealers reached an all-time
high for the comb:ned months of May and June. Fred R. Wellner, of GE's TV
Business Department. reported a 26% increase over the same period last year. He
attributed much of the increase to GE's new VIR "broadcast -controlled- color
feature.
The new warranty labor -claim form developed by NARDA now will be honored by
MGA, RCA, Sylvania, and Zenith, according to an article in Home Furnishings
Daily. In addition to sufficient space for all information needed by the
manufacturers, the six -part form has room for the store name and logotype at the
bottom. All copies are numbered. To order Forms, or request samples, write to:
NARDA. 318 West Randolph Street, Chicago, Illinois 60606.
Magnavox has expanded Es all -electronic Touch -Tune system in the 1977 color -TV
line, and has introduced a field -installed remote control system to the new 25 -inch
Videomatic Touch -Tune models. The field remote feature means that the TV set
can be purchased as a non -remote unit, and then converted to a remote unit either
at the time of purchase, or at a later date. According to Home Furnishings Daily,
the unit will retail for $40 to $75.
RCA has announced production of the 70 millionth RCA television picture tube at
its Scranton, Pennsylvania plant.
6
ELECTRONIC SERVICING
Suddenly, you're the most versatile
shop in town.
With this little 25 -pound test jig, you
can adapt to over 10,000 color sets, 59
different brands. Delta 70° and 90° tube,
hybrid, transistor, SCR sweep.
Anode voltages
The Sylvania CK3000
to 30kV and more. Regular 4.5kV and
7.1 kV focus voltages.
And our new optional In -Line Test Kit
lets you handle
more than 100
precision in -line chassis, including RCA,
Magnavox, Admiral and Sears. (We're
the first test -jig manufacturer to offer a
kit like this.)
CK3000 comes to you fully assembled, pretested
and ready to use.
Just plug it in,
and you're in business. See it now, at
your Sylvania distributor.
GTE Sylvania, Electronic Components
Group, 100 First Avenue, Waltham, Massachusetts 02154.
Simply the most versatile test jig
you can buy.
cro SYLVANIA
Symptoms and cures
compiled from field reports
of recurring troubles
rcorei
r --I
Chassis-Zenith 25EC58
T
PHOTOFACT-1370-2
I
-------Chassis-Zenith 25EC58
PHOTOFACT-1370-2
I
+240 V
i
I
+23.5VIA1
jQ061
+22.6 V IA)
TO U8 OF
CHROMA
I
(
390KS2
MODULE
I
L
C240í
TO RED,
AND GREEN
100
NF
OF
I
CRT
75KS2
.01
5%
OPEN
I
INCREASED
I
I
Symptom-No color at left, and vertical "jail bars"
Cure-Check C240, and replace it if open
Symptom-Vertical-retrace lines after a few minutes
Cure-Check R260, and replace it if increased or
------. ------ --varying
I
-11M-
'NOW
I
«NM»
Chassis-Zenith 25EC58
Chassis-Zenith 25EC58
PHOTOFACT-1 370-2
PHOTOFACT-1370-2
I
.110
I
7
_
HORIZ
T5
OUTPUT
HORIZ
I
MODULE
(R355)
I
-
j
U10
1250
(R22)
WQ
+240 V
TO VIDEO
(C27(D
J
OUTPUTS
10uF`-
1
INCREASED
+125 V
I
Symptom-No video, excessive brightness with
I
retrace lines
Cure-Check R355, and replace
it
if open
or in-
I
I
Symptom-Intermittent horizontal displacement (tearing)
IF"
II
I
am
........
IMOM
IMIM
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el
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Chassis-Zenith 25DC56
PHOTOFACT-1312-3
PHOTOFACT-1312-3
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HORIZ
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TO
:
u 1
II
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I
....., MOW
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Chassis-Zenith 25DC56 (also 25DC57)
MODULE
I
'..
------
Cure-Replace horiz driver transformer, T206
creased
1800
TO CRT
HEATERS
TRANSI STOR
11
R351
HORIZ
OUTPUT
0R352
3 W
J
800
SQUARE WAVE
S2
FUSE WIRE
7W
10
-
SINE WAVE
125 V
LEAKY
Symptom-HV and raster slow in appearing
Cure-Check C258, and replace it if leaky
Symptom-Picture tube appears to be weak
Cure-Check CRT heater transformer, T208, and
re-
place it if defective
I
WOO»
8
1111. /WEI dMII
IMMMOELECTRONIC SERVICING
IiiiIesÌootìnO
Sendin
your
helpful
tips-we pay'
No color on right
RCA CTC72 (Photofact 1439-2)
Color was okay on the left half of
the screen, but there was none on
the right. Problems that show different symptoms on the right and
left sides of the screen usually
originate with horizontal pulses
somewhere. But where? After some
testing with a scope that did not
pinpoint the source, I tried substituting all the diodes involved
with horizontal pulses.
was higher than at the beginning,
but there was still no color.
No color -killer adjustment is provided on these sets. Q21 is made to
stop conduction during b -w pro-
at the collector. Also, the DC collector voltage was high, about +30
volts. The transistor was open, and
a new one brought in strong color.
0
grams, and this opens the emitter
circuit of Q10, the second chroma
bandpass amplifier. I shorted Q21
from collector to emitter as a shortcut test of the killer action. There
still was no color, but that proved
the killer circuit was not responsi-
IST CHROMA
AMP
4 10V
ble.
BURST AMP
uI
r
3p1
3
What about the noisy sound? It
was just a bad audio -output tran-
40
4
sistor.
Ery Schrader
Albuquerque, New Mexico
390 pf
01
FREE ALARM CATALOG
10ez
4700
S7
Huge selection of burglar & fire systems, supplies. Motion detectors, infrared beams; controls, door switches,
bells, sirens. 500 items, 99 pp. packed
with technical details, notes.
(Outside U.S., send $1.00.)
Al' KO
Back to the scope, I found
chroma (using color bars as a
CLAMP
signal) at the base of Q2, but none
mountain west alarm
4215 n. 16th st., phoenix, az. 85016
j
For More Details Circle
11. 13 V
CR306 was the cause, but it
checked okay on an ohmmeter, so I
don't know the exact defect.
C. W. Hume, CET
Greenville, South Carolina
No color, and noisy sound
RCA CTC44A chassis
(Photofact 1191-1)
There seemed to be no connection between the frying noise in the
sound and the lack of color, so I
decided to check the color problem
first.
Collector voltage of QS ACC killer amplifier was near zero, leading me to believe the burst was
weak at the phase detector. My
dual -trace scope did measure weak
burst at CR3 and CR4, and I installed a GE -21 (as listed under
replacements) for the burst amplifier (01). Now there was no burst at
all!
After more checking, I discovered
a GE -21 is a PNP; however, a NPN
was needed. Back to the cross -over
charts, and found a GE -18 to be a
good substitute. This time the burst
August, 1976
Put safety first ...
Use RCA
flameproof
film resistors .
(14) on Reply Card
Design engineers prefer
them because they won't
flame or short tinder the
most severe conditions.
Service technicians prefer
them because they're safe
replacement parts.
RCA flameproof film
resistors have a 2% tolerance
and are available in 1/4 watt,
1/2 watt, 1 watt, and 2 watt
ratings. Resistance values
range from 10 Ohms to 1.5
Megohms, depending on
wattage rating. Altogether,
there are 475 film resistors to
choose from.
See your RCA Distributor for
all the details, or write to
RCA Distributor and Special
Products Division, Sales
Promotion Services, Cherry
Hill, NJ 08101.
RC,'
Flameproof
Film Resistors
9
November 30
will be here
sooner than
you think!
November 30th is the deadline to tear
off and send in those gray bottom flaps with
the GE monogram from GE entertainment
receiving tube cartons. Entries postmarked
after November 30, 1976 cannot be
accepted.
He who hesitates loses an opportunity
to choose from 63 exciting gifts or "Go for
the Green" in the fabulous world of S&H
Green Stamps.
Tips for fastest delivery.
Collect gray bottom flaps with the GE
monogram from GE tube cartons.
Include only these flaps.
Package them in a good corrugated
cardboard container to guard against
damage in transit.
Use registered mail or UPS so you
have a traceable receipt for your
order and valuable flaps.
When ordering merchandise, include
quantity, award description, award
number and the correct number of
flaps required.
Be sure your name and address are
legible. Be sure to include your
name-use of firm name alone makes
awards difficult to trace.
1
2
3
4
5
&iOexchaooe
For Sale: Heath kit color-bar generator. Model IG-28,
$60: RCA market -adder. $40: and Knight RF sweep
generator, $30.
Charles B. Cerates
10420 Wise Road
Auburn. California 95603
Needed: Schematic and/or service manual for
Packard Bell Electronics Model 5 Mc 2P oscilloscope.
Please send card.
S. C. Dean
Box 55293
Indianapolis. Indiana 46205
For Sale: Sylvania Polymeter Model 301 with manual
and leads. Excellent condition, $27, postpaid.
David Bloom
21 Dodge Road
Hyde Park, Massachusetts 02136
Needed: H.O.T..for Motorola, part #24D68804A02 or
#24D67601A10. Also need schematic/service manual
.for Ward TG900 video set generator.
T. E. Gregg
Montgomery Center, Vermont 05471
For Sale: Heath 5MHz triggered -sweep scope, $175:
Heath 21/2 -digit digital multimeter. $80: and Heath
color-bar/dot generator, $100. All calibrated and in
excellent condition.
Tom Henry
5825 Bird Cage St.
Citrus Heights, California 95610
For See: Used test equipment, and some old service
manuals and magazines. Write ,for list and make
offèr.
Lloyd's Radio & TV
807 13th Street
Box 504
Auburn, Nebraska 68305
Mail orders and flaps to:
GENERAL ELECTRIC AWARD HQ
3003 E. Kemper Road
Cincinnati, Ohio 45266
TUBES
and
TRANSISTORS
10
TUBE PRODUCTS DEPARTMENT
GENERAL ELECTRIC COMPANY
OWENSBORO, KY 42301
Needed: Horizontal-scan output choke for Sylvania
Model 1-125-1, chassis 1-186. Sylvania part #2410002, or Merit part #2980. Will pay reasonable price
,for new or good used part.
Charles L. Pierce
Highway 180
Suches, Georgia 30572
Needed: Schematics for RCA amplifiers, Models
MI-9257-C, MI-9333-A and MI -9358-A. Will buy or
copy and return.
Robert E. Byars
P. O. Box 1297
Corinth, Mississippi 38834
ELECTRONIC SERVICING
How to stock 300 instead of 112,000. All it
takes is RCA's "Top of the Line" SK Series
1976 Replacement Guide. Our most
comprehensive list to date of transistors,
rectifiers, thyristors and integrated cir300 RCA types to replace 112,000
cuits
in entertainment or industrial equipment.
Excellent Product. Excellent Catalog. As
a product, RCA SK replacement semiconductors measure up to strict AQL standards. As a catalog, our 1976 Replacement
Guide is a thorough, accurate informational source, representing thousands of
engineering man-hours.
Get the "top of the line" now. With RCA's
SK Series and RCA's SK Replacement
Guide. Contact your RCA Distributor. Or
send $1.00 (check or money order) to
RCA Distributor and Special Products
Division, P.O. Box 85, Runnemede,
-
N.J. 08078.
Rca
Needed: Supreme radio manuals #2, #7, and #17.
Schmidt's TV & Radio
Highway 281 NW
Jamestown, North Dakota 58401
For Sale: Heathkit I0-103 oscilloscope with low -cap
and demodulator probes, and manual; 2 years old:
$150, or best offer.
David A. Day
P. O. Box 476
Apalachicola. Florida 32320
For Sale: RCA Model WR -69A sweep generator:
good condition: reasonable.
George H. Bleeker
200 Ira Avenue
San Antonio, Texas 78209
For Sale: Hickok CA -5 universal adapter and roll
charts for Model 6000 tube tester: 30KV Pomona HV
probe #2900A, ,first offer.
K. R. Berquist
7328 Independence
Merrillville, Indiana 46410
Needed: Schematic or operators manual for a
Realistic CB Transmi-Test. Will pay cost of copying,
or send manual for copy and return.
Herbert Naugle
1792 Finch Ct.
Hayward, California 94545
SK Replacement
Semiconductors
Needed: Schematic for a Telecon walkie-talkie CB
radio, 13 transistors. 2 channels [it's not Sams CBIO
early model]. Customer purchased in Japan several
years ago. Will buy, or copy and return.
G. M. Eckert, Apt. 18
2460 S. Federal Hwy.
Boynton Beach, Florida 33435
For Sale: RCA 19" 10J103 test jig with adaptors ,for
most RCA and Zenith sets. Also IG57 Heath
alignment generator and IG37 FM stereo generator.
Assorted GE tubes for color servicing.
Joel Malmberg
1715 Crosby Road
Wayzata. Minnesota 55391
Needed: Schematic for a Contact 23 CB radio made
by United Scientific Labs. Will buy, or copy and
return.
Jack Bùrgess
Box 124
West Blocton, Alabama 35184
gxchange: Will exchange a 27 -volume set
of Rider's
TV manuals, for some or all of Rider's radio
manuals. plus a cash payment to adjust. Would
consider buying outright.
Lawrence Beitman
1760 Balsam Rd.
Highland Park, Illinois 60035
(Continued on page
August, 1976
12)
11
(Continued from page
11)
Needed: Address of Delmonico-Nivico, or a horizontal
driver (A42131) for a Model 9T-4UHF. Also, need a
new tube index for a Model 107B Seco tube tester.
Marin CB
968 Second Street
Novato, California 94947
Needed: Deflection yoke (part #UTRAD 9A -2654001D) for a Bradford color TV, Model 1205C40. Will
pay any reasonable amount.
Joseph J. Mehalko
324 4th Street
Blakely
Olyphant, Penn. 18447
Wanted: 1923 and 1924 Radio News Magazines.
J. E. Smith Radio Shop
130 Cherry St.
Montezuma. Georgia 31063
For Sale: Heathkit Model IG -57A post-marker/generator. Factory aligned. Unit has never been used.
$160.00.
Dale A. Rotz
Hurley Drive, RD -5
Shippensburg, Penn. 17257
Needed: Schematic and service manual for Lambda
power supply Model LT 2095M.
Frank Quackenbush
53 Otsego St.
Canajoharie, New York 13317
For Sale: Telequipment D-67 oscilloscope, with
probes, $900.
William D. Shevtchuk
One Lois Avenue
Clifton, New Jersey 07014
Needed: Service literature for a Lantz Model TV4R2
4 -inch b -w TV.
Tri/Tronics
1313 Geo. Wash. Way
Richland, Washington 99352
Needed: Schematic and service data for a Candle
MT510 5 -inch b -w TV. Will buy, or copy and return.
Al's Radio and TV
9 Leonard Road
Hyannis, Massachusetts 02601
1
output cable for a Triplett Model 3433
FM -AM signal generator.
John D. Villano
2207 Palermo
San Diego, California 92106
Needed:
For Sale: Sencore SM -152 sweep/marker generator,
$260. Also Sencore CRT tester CR -161, $90.
Mario Rosignuo
368 South Hill Blvd.
Daly City, California 94014
Needed: Service information on a Model OP -51G
general service scope manufactured by the Kikusui
Denpa Co.
Neil R. Matheson
107-28 134 St.
Richmond Hill, New York 11419
Needed: Stringing diagram for dial of a radio;
Radiola (made by RCA) Model 61-3; chassis
#RC1011 Will pay, or copy and return.
B. Kutilek
17215 70th Ave.
Tinley Park, Ill. 60477
Needed: Schematic for Precision Series E-400 sweep
generator; schematic for Triplett 3423 tube tester;
schematic for Heathkit audio generator, Model G-2;
and schematic for Eico Model 950 resistance
capacitance -comparator bridge. Will buy, or copy and
return.
Enrique Diaz
966 Halsey Street
Brooklyn, New York 11233
Needed: Time base (sweep) amplifier for Type 561A
Tektronix scope. Have Type 3A75 amplifier for trade
if desired.
Chaparral Electronics
Hwy. 28
Messilla, New Mexico 88046
For Sale or Trade: Rider's radio manuals; also
antique radio tubes OIA, OOA, 99, 40, 6F7, 7B8, 7F7,
6S7, FM 1000, 14AF7, 25B8, 70A7, 70L7, 117L7, and
others. I need Rider's radio manuals 1-2 and 23.
Goodwin Radio Shop
Rankin, Illinois 60960
Needed: Dial cording stringing instructions for
Realistic Model #12-1469. Dial cord is not shown in
Sam's #MHF, #43. Will pay copying cost.
Hughes Electronics Service
Route 2, Box 271
Kings Mountain, North Carolina 28086
Needed: Schematic and/or service information for GE
radio, Model M-125. Will copy and return.
Michael Helgerson
Box 103
Electric City, Washington 99123
(Continued on page
12
14)
ELECTRONIC SERVICING
PHENOMENAL BREAKTHROUGH
IN UHF RECEPTION!
Don't say you can't get good UHF reception
until you've tried this new combination by Winegard
New Super Lo -Noise
Preamp With New
Antenna Makes Poor
Pictures Good and Fair
Pictures Excellent
Good reception of UHF stations is more important than ever. Programming has greatly improved in recent years on the U's
and many offer exclusive sports coverage
viewers so eagerly want. If you sell sets
or install antennas in UHF areas, you know
what we're talking about.
Winegard AC -4990 Preamplifier Combined With
CH -9095 Antenna Delivers Amazing UHF Reception.
The Problem
You also know what we're talking about
when we say that reception of UHF sta-
tions in most areas is rarely as good as
you get on the VHF stations. This is a
major, universal problem.
Why the problem? For one thing, many
UHF stations are not on full authorized
power. And, transmission line losses at
UHF frequencies present difficulties. But
the biggest culprit of all is the high noise
figure of the TV set tuners at UHF frequencies.
Generally speaking, you have to deliver
3 times as much clean UHF signal to the
set as you do VHF signal-in order to
get comparable reception.
The quantity and quality of UHF signal
you feed the set is greatly determined by
the antenna and preamplifier you use.
SPECIFICATIONS
AC -4990
GAIN
UHF
BANDPASS (MHZ)
VHF -FM
UHF
17.5db
54 to 216
470 to 890
.882
MAX. TOTAL INPUT
(Volts)
UHF
.126
NOISE FIGURE
UHF
August, 1976
A few months ago Winegard Company in-
troduced a new line of Chromstar UHF
antennas featuring a new Tri -linear director system. This configuration offers the
highest gain we've ever seen on a UHF
antenna and the field reports we've been
getting from professional installers have
been most enthusiastic.
Now Winegard Company is introducing
another...and even bigger breakthrough.
This is a super to -noise UHF preamplifier,
Model AC -4990* It has a 6db signal-tonoise improvement over the best UHF pre amps previously available.
Combine the AC -4990 with a Winegard
CH -9095 Chromstar UHF antenna and you
get a 9db improvement or 3 times cleaner
signal.
This means you can give good UHF pictures to customers who can barely get
UHF now. It means you can deliver "excellent" reception to those who now receive just "fair" pictures.
*Pat. Pending.
MAX. TOTAL OUTPUT
(Volts)
UHF
The Solution
2.2db
00
For More Details Circle
In actual practice, good reception of all
UHF stations is now extended up to 30
additional miles ...in many cases nearly
doubling the effective reception range.
New Sales Potential
Potential sales of CH -9095's and AC 4990's are greatly increased. This combo
can be sold in areas where UHF reception hasn't been good enough to bother
with and, as a replacement for customers
who are only getting "fair" reception now.
Incidentally, the AC -4990 preamp has a
VHF bypass so it can also be used with
any Winegard V -U Chromstar antenna with
excellent results.
Antenna dealers in UHF areas are advised to try this new Winegard antennapreamp combination as soon as possible.
Seeing is believing ...and the new profit
opportunities are tremendous.
NOTE: Due to demand, the AC -4990
preamp will be in short supply for a few
months. An order should be placed now
with your Winegard distributor.
WINEGARD
COMPANY
3000 Kirkwood
(16) on Reply Card
Burlington, Iowa 52601
13
NSt
Shale
Electronic
Components
hade IvtarniseRegstered
*
*** aF;*
*
Everything we make
has you in mind.
When you're looking for profitable electronic lines, look
to RCA Distributor and Special Products Division:
CB CO- PILOT
TRANSCEIVERS
EXACT REPLACEMENT
PARTS
ANTENNA HARDWARE
ANTENNA ROTATORS
CAR RADIOS & TAPE
PLAYERS
(Continued from page 12)
Needed: Audio output transformer
(#1080-15) for a Lafayette amplifier,
Model LR800.
Bernard William
929 East 77th Street
Brooklyn, New York 11236
SEMICONDUCTORS
FLAMEPROOF
RESISTORS
STEREO SPEAKER
SYSTEMS
SCANNERS
Needed: Schematic with parts valves
and component numbers for a Precise oscilloscope, Model 300. Will
buy, or copy and return.
Daniel Evans
P.O. Box 4227
Huachuca City, Ariz. 85616
COLOR & BLACK -AND WHITE PICTURE TUBES
SERVICING AIDS
ELECTRO -OPTIC
DEVICES
Needed: UHF, VHF plug-in circuit
boards for Peterson Model HL -44
police scanner radio.
SK REPLACEMENT
RECEIVING TUBES
INDOOR & OUTDOOR
ANTENNAS
See your RCA distributor. Or, for more information,
contact RCA D&SP Division, Bldg. 206-2, Cherry Hill,
N. J. 08101.
R Cn
Distributor and
Special Products Division
Phil Hanson
C/O Hanson Appliance Co.
207 Long Avenue
North Aurora, Illinois 60542
Needed: Schematic and/or operating manual for Cadre 510-B CB
radio. Will buy, or copy and return.
Aero -Marine Electronics
950 La Mesa Drive
Menlo Park, Calif 94025
ELECTRONIC SERVICING
14
www.americanradiohistory.com
Just Tear and Get your Share.
RCA's Super Prize Program is Back by
Popular Demand! As before, just save your
RCA entertainment receiving tube carton
ends and color picture tube warranty
serial number stickers*
to earn
valuable awards:
-
Pick up your copy of the RCA "Tear and Share
'76" Prize Book, saver envelope and gift order
form at your participating RCA distributor.
You have until November 30, 1976 to tear 'n
share in RCA's bonanza of great gifts. RCA
Distributor and Special Products Division,
Cherry Hill, N.J. 08101.
Lots of great merchandise premiums. Choose
from a wide selection for yourself, your
family, or your home.
Money -saving
discount certificates, good toward purchases
of more RCA receiving and color
picture tubes.
*Save the receiving tube carton end that is not
marked with the tube type number, and the warranty
serial number sticker that appears above the
warranty envelope on the upper right hand corner
of the color picture tube carton. One warranty
serial number sticker is equal in value to
20 receiving tube carton ends.
ncn
Needed: Will pay top price for set of speaker lid
hinges for Sony TC-530 tape recorder. Send price.
Scott's TV, Inc.
P. O. Box 33013
Fort Lewis, Washington 98433
Wanted: Field strength meter _for VHF TV.
Joseph E. Strenk
R. D. 2. Box X
Rhinebeck, New York 12572
For Sale: 1 Eico scope demodulator probe, with
manual; 1 Eico VTVM, Model 232, with manual; 1
visual -aural Heath signal tracer, Model IT -12. Good
condition; reasonable offer plus shipping.
R. C. Migliorino
231 Birch Lane
Forked River, New Jersey 08731
Needed: Operating/service manual for Triplett Model
3434-A TV/FM sweep generator and marker. Will
buy, or copy and return.
The Village Electronics
P. O. Box 73
Gambier, Ohio 43022
Needed: Schematic and alignment data for an RCA
MX -7 stereo FM -AM receiver. All -tube unit from
about 1962-1965; resembles a Fisher. Will buy, or
copy and return.
Gordon Trump
2113 Main Street
Rothsville, Pennsylvania 17573
August, 1976
For Sale: Sony EV-310 1" black -and -white video tape
recorder, good condition, might need new heads, $400
plus shipping.
Mark M. Byrum
P. O. Box 2044
Wintersville, Ohio 43952
Needed: Schematic and/or service manual ,for
Magnavox Model S973 color TV test.fxture. Will pay
$5 ,tbr schematic, or $10 ,for both.
H -G TV & Electronics
233 S. Victory Blvd.
Burbank, California 91502
For Sale: Ampex 1" video-tape recorder with
Motorola 19" monitor, service manual, cords and
extra tape included. Both in working order. Also have
Berlantz audio tape deck, uses 101/2" reels, has five
tape heads. With schematic, two single -channel
recording amps. patch cords and extra tape; all in
good working order.
Dailis Melbarde
644 Washington St.
Hackettstown. New Jersey 07840
Needed: Heath Model IG-57A sweep/marker generator; any condition. Also need Eico flyback tester
Model 944K; any condition. State price, age, and
completeness.
Robert Boudreau
290 Prospect St.
D
Bridgeport, Connecticut 06604
15
Servicing
GE Modular
Color TV
Part 1/By Gill Grieshaber, CET
Most of the Part 1 coverage of the GE 19YC2 color
chassis is a picture story to familiarize you with the
locations of the major components, and to illustrate
the ,features and overall performance of this model.
General Electric Model WYC7518WD 19" table
model color receiver has been selected for our next
detailed analysis. This modular TV is new in the 1977
GE line. It uses the 19YC2 chassis, which is similar
to the YC chassis of last year, except for better
convergence and pincushion circuitry, and "Cable
Ready" provisions for direct cable connection. Some
YC2-chassis receivers have digital readout of both
VHF and UHF channels, and also an extra module
for VIR Broadcast -Controlled Color. A preliminary
report on the VIR feature was in the July issue of
ELECTRONIC SERVICING.
Of course, the circuitry is all -solid-state, except for
the picture tube, which has the three guns in -line
horizontally and vertical stripes of phosphor on the
screen.
Six modules plus the convergence board hold most
of the circuitry of this hot -chassis color receiver.
Features Shown By Pictures
The following pictures should make you feel "at
home" with the YC2 GE receiver, and help locate the
modules and major components.
Picture
1
When the power is off, the GE
WYC7518WD color -TV receiver seems conventional
(this model does not have the VIR circuit). Below the
UHF detented dial is the "Automatic" pushbutton,
which selects preset color, tint, and brightness. To the
right is the "Custom Picture" control (adjusts color,
contrast, and brightness), with the "On/Vol" control
at the extreme right. Along the bottom, under the
speaker grill, are the color, brightness, and tint
manual controls.
ELECTRONIC SERVICING
16
www.americanradiohistory.com
tlCC
TELEVISION
Picture 2 Turn on the power, and the '/cinch channel
numbers light up in orange. All 12 VHF and 69 UHF
channels are displayed on the two -character 7 segment glow-discharge type of readout. The position
between 2 and 13 of the VHF knob at the top causes
the same display to show the UHF channel which is
selected. The lower knob is detented for every UHF
channel, and it can't turn beyond 14 and 83. When I
first tried it, the mechanism worked excellently, and I
liked it after I became familiar with the action. But
the operation felt strange and different because the
numbers do not move sideways (as older models did
where the numbers were on a drum), and there was
no vibration, except for the detenting.
Picture 3 The back cornes off easily, leaving most of
the works exposed, such as the two tuners. For the
VHF digital display, the switch is at the rear of the
tuner; while the UHF switch is in front of the UHF
tuner, with the detenting mechanism. The tuner
assembly comes out as a unit.
Picture 4 Just behind the speaker is the audio output transistor, with the output transformer on the
other side of the heat sink. Two modules are visible
at the rear: the vertical module is at the top, with the
IF/audio module below.
August, 1976
17
www.americanradiohistory.com
CAE LE
PRE-SETS
CONVERGENCE
TUNER
CRT DRIVE
HV RECTIFIER
FLYBACK
CHIPOMA/VIDEO
Picture
Picture 6 Here's a closer look at the
vertical module above (the output
transistors are inside the large heat
sinks), and the IF/audio module
below. The vertical module has 9
transistors and five diodes; while the
IF/audio module has
3
IC's, 4
transistors, and three diodes. Each
module is secured by one screw, plus
the connectors and a plastic track.
18
POWER!
HORIZ DRIVE
FUSES
5
HORIZ
OUTPUT
Arrows point to the nodules and several major components.
Picture 7 On the center side of the
partition shield are two more modules: the horizontal -oscillator module
(above); and (below) the large chroma/video module.
Picture 8 With the horizoscillator and chroma/video
modules removed, the plastic
guide track is visible.
E'_ECTRONIC SERVICING
NASSIs
1
TEp
EIkE.ItSE
SE
ISç71
Tß
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A?13p dNAMS=BR#IEi
UPPEN
FUSE
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ilti,
Picture 12 Looking a bit higher, along the top at the
left are the factory "preset" tint, brightness, and
color controls for the "Automatic" feature.
Picture 9 Power comes in through a polarized plug
having one large and one small prong. It's mounted
on a plastic bracket that has the focus control, labels,
and some holes not used in this model. On the back
side are two fuses, as shown in the next picture.
Picture 13 Just to the right is the antenna bracket,
which stays attached to the chassis framework. Two
antenna dipoles are on top, along with the AFT
switch. Along the back are the connector for cable
TV, and the usual connectors for UHF and VHF
antenna leads.
Picture 10 On the back of the plastic power bracket
are two fuses. The 1.8 -ampere B+ fuse is above, and
the 4 -ampere AC fuse is below.
Picture 11 With the power bracket removed, the filter
choke and the picture -tube heater transformer (front)
can be seen.
August, 1976
Picture 14 The CRT socket is combined with the
color -drive circuitry. Just in front of it are the purity
magnet and the assembly with the center -and
dynamic -convergence components. The last item on
the neck of the picture tube is the yoke, which has a
toroid configuration of both the vertical and
horizontal windings. This CRT -drive module has the
video -driver, red -output, green-output, and blue output transistors on it.
19
Picture 15 The dynamic -convergence board is located
in the upper -right corner of the chassis frame. Only
one coil and three controls are adjustable.
Picture 16 Horizontal -sweep and high -voltage components are found in the lower -right corner. The
three screen controls and the regulator heat sink
identify the power-supply/horizontal-driver module. A
bracket fastened to the flyback shield holds the
horizontal -output transistor, the damper, and the
boost -rectifier diode.
Picture 17 Around the right end are the flyback and
something that appears to be a rectifier tube.
Actually, it is the HV diode rectifier with socket and
cap, so replacement and testing should be easy.
Picture 18 In front of the HV rectifier is a black box,
resembling some HV tripiers. This box has the HV
bleeder resistors which furnish the focus voltage by
voltage -divider action.
ELECTRONIC SERVICING
20
www.americanradiohistory.com
Comments
easy to remove. Only one screw
(and the connectors and guides)
hold them in position. I advise you
to use moderate care when you re-
If you are to diagnose with
greatest accuracy, you need to know
how good (or bad) the picture
quality should be, for the model in
question. Therefore, I will give my
impressions .of this 19YC2 General
Electric chassis, after a preliminary
examination of the receiver operating from both the usual local
stations and two color -bar generators.
Picture sharpness and brightness
were very good; there was more
color available than anyone would
want, and the tint control had a
wide range, with correct hues
obtained near the center of the
control.
When I examined the screen of
the picture tube up close, I could
see the pattern made by the trios of
vertical lines of the phosphors (see
Figure 1). However, the pattern
disappeared as I stepped back to
the normal viewing distance.
No regulation of the DC supply
voltage for the horizontal -output
stage is provided, so I tested for the
effects of different line voltages. As
shown in Figure 2, the picture size
did decrease slightly when the line
voltage was reduced 10 volts (from
120 down to 110 volts). However,
the other picture characteristics
(such as focus, and locking of both
vertical and horizontal) were not
affected at all. DC voltage for the
vertical -output transistors is ob -
11111111191.110111111111111111111111111.111111Z
11111131M11111111111111111111111111111111111111111
111111111111131/
11111/111111it1!\1111111
13111111111111111111111111ilffti
11111111111111/311
1111111111111111.111111111
11111111i1tifs111111
111111
M/1111211111111111131
1».11tl1111111111t11111111
1111111/111/
i1111111111111111111111111111111f11111111111111111111
install a module. Line up the
connectors, and hold one hand
Fig. 1 This drawing shows the approximate shape and positioning of
the color stripes of phosphor on the
screen of the GE picture tube using
in -line guns.
tained by rectification of horizontal
pulses, so any change of width also
produces a like amount of width
change.
There is no vertical linearity
control, because the waveform of
the vertical yoke current is used for
negative feedback, giving automatic
good linearity (Figure 3 shows the
linearity when the height was
reduced to minimum).
The modules were moderately
Next Month
Several readers have asked for
explanations of transistor -regulated
power supplies, so we will include
some extra information about them
next month as part of the power supply coverage of the GE 19YC2
chassis.
try
r
i.f1131
i/111
ái1
I1I
11
1311
11111111
1i3111
11111111!
1UUUR1111
li1111i11
i1111111131
1/a1111131
i11\3131
Fig. 2 Good linearity, both vertically and horizontally, and equally good pincushion correction are shown by these crosshatch patterns. The picture size
shrank slightly when the line voltage was changed from 120 volts (left picture)
to 110 volts (picture at the right).
August, 1976
behind the main chassis and connectors to reduce the strain against
them.
Only about 0.5 KV reduction of
the high voltage could be measured
between a black raster and normal
brightness. The gray -scale procedure limits the maximum brightness to a reasonable amount, and
the automatic brightness -limiter circuit prevents most moderate overloads of the picture tube. Whatever
the reasons, the HV regulation was
very good.
Looking back on the various
tests, I think the one characteristic
that impressed me the most was the
excellent stability. There was no
noticeable drifting of any kind. For
example, neither variations of line
voltage nor the changing to a
color -bar pattern ever required
relocking the vertical or the horizontal.
i311fA3113111=111111111111111111111111111131
111rr
1111111111 11111 1111 111 M111111111
11111r111111.1111111111111111A
11111.111111311r31131111111111311n11311111
Ira11111111w11111111
1IN311Ir111111'1111111r
1131111311rf#r
1111
1111.11111111111111111ti11111111fi
111111111111MIrMrIRIONIN
r11
1111w11131111111A1h
111111111111113111111A0111111111111111111
1r111 11r11
11i11111111111r1111111111111111.111111111111
3 When the vertical height was
reduced to the limit of the control, the
vertical linearity remained perfect.
Fig.
21
Satellite
TV Update
Western Union's Westar 1, shown blasting off into orbit, can rebroadcast 12 TV programs simultaneously. Other satellites that
are being designed will broadcast as many as 65 TV channels.
(Courtesy of Western Union)
By David A. Ferre'
Engineer, RF Communications, Inc.
In the July, 1974 issue of Electronic Servicing, we predicted that
reception of TV programs direct to
homes from satellites would be a
reality by 1980. So far, the developments leading to this goal are right
on schedule.
Our prediction of CATV (cable)
via satellite became a reality in
November of 1975, when a broadcast relayed by satellite was received
by a CATV system in Fort Pierce,
Florida. At this time, three "channels" are available from the satellite
to CATV operators, and certainly
more will follow.
22
The Wall Street Journal newspaper operates this
direct -reception terminal, so type set in Massachusetts can be printed in Florida. (Courtesy of
American Satellite Corporation)
New Developments
Newsworthy Events
On the engineering drawing
Here are some of the satellite
boards are new high -power, high - developments during the past two
frequency satellites for the Ku band years:
(12,000 MHz), that could provide
the direct link between TV studios
and individual homes. Of course,
Satellites launched since July of
earth terminals are available now, 1974 could broadcast more than
but the price of $65,000 is a bit 150 TV channels simultaneously, if
high for an individual viewer.
required. Presently, they are used
TV receivers operating from digi- for voice and data communications,
tal video signals (rather than the plus three TV video channels for
present analog type) have been CATV systems;
developed. They are said to provide
sharper pictures, have bandwidth Toshiba of Japan has announced
reduction circuits, allow receiving the development of a $500 earth
noisier signals without snow, and terminal to receive signals from
are compatible with the proposed Japan's direct -broadcast satellite,
picture -on -the -wall flat TV screens. which is scheduled for launch in
In fact, it's likely that in just a few 1977;
years, all communications will be
by digital synthesis.
Direct reception of MUZAK pro ELECTRONIC SERVICING
typical CATV receiving antenna is this $65,000 30 -foot
dish. Reorientation to another synchronous satellite reA
This is the small "heart" of a mixer to down -convert Ku band signals (12,000 MHz) to TV Channel 4 (70 MHz).
(Courtesy of Westinghouse)
quires only about 15 minutes. (Courtesy of the Harris
Corporation)
10' conical -horn antenna, mounted on a boat trailer,
was used to receive MUSAK programs. Five other demonstrations also were successful, some operating from a 4'
A
dish antenna. (Courtesy of Antennas For Communications, Inc.)
grams has been demonstrated using
both a 4 -foot parabolic antenna
dish, and a 10 -foot conical horn
antenna;
One commercial satellite -demodulator covers frequencies
between 3,800 MHz and 12,000 MHz. Only an antenna and
a TV monitor are required for operation. (Courtesy of
Terracom)
direct -broadcast satellite for the
European community. Size of the
receiving dish antenna is expected
to be about 3 -feet; and
COMSAT, ATENA, and IBM
formed a company called Satellite
Business Systems (SBS) to launch
an all -digital satellite in 1979. The
Scientific-Atlanta (an earth -term- satellite probably will broadcast 65
inal manufacturer) predicted that TV channels at one time, using the
250 CATV companies will own Ku band.
satellite terminals by the end of
Roadblocks?
1976;
Not all individuals and groups
Andrews, Harris Corporation, are in favor of direct reception of
Scientific-Atlanta, and others offer TV programs from satellite relay.
direct -reception terminals for ap- Immense amounts of money are involved (consider the effects of
proximately $65,000 each;
closing all present TV stations in
the country). And there are emoAgency
anSpace
European
nounced the scheduled launch of a tional roadblocks, as well.
In India, $1,000 earth terminals
receive TV programs everyday from
the ATS -F satellite;
As reported in Communications
News last September, the National
Association Of Broadcasters (NAB)
warned the FCC that satellite -to home broadcasting could contain
the "seeds of destruction" of the
world's best system of localized
service. Further, NAB is quoted,
"There
is
something foreboding
about the thought of the government or any other party being in a
position to reach virtually every
home in the country without any
intermediate cut-off points."
So, the technology of satellite
broadcasting is proceeding smoothly, with the future expansion to be
determined partially by the opposition.
Electronic Servicing will keep you
informed of all new developments.
23
August. 1976
www.americanradiohistory.com
Fig.
Seven modules are used in the "Era II" and "Era II Limited" (lines from Admiral. More
components are mounted on these modules and fewer are on the mainframe.
1
1977 Color TV Trends
By Carl
Babcoke
One definite trend in the new 1977 color receivers is towards larger and
,fewer modules per chassis. Tubes and conventional boards have lost out
completely; I know of no new models that have them. Most vertical
circuits seem to have complementary -symmetry outputs, and pre -CRT
matrixing of video and chroma signals is common. Single -button selection
of factory pre-set color controls is being replaced by more sophisticated
circuits (RCA ColorTrak and GE WR systems, for example). Although
many models seem to have similar features, the individual circuits are
completely different. More IC's are used each year.
them just as hard as it has us as
individuals. I know of no industry
that has had such mild retail price
increases (inflation has been cancelled by cost reductions).
Competition has been fierce, and
it will continue to increase. RCA is
making giant efforts to regain the
number one position lost a few
years ago to Zenith. General Electric is determined to be a strong
Each manufacturer knows he number three in total sales. Others
must make a profit soon or be are trying equally hard.
forced out of business. ConsequentQuality of these new modular
ly, every company has made strong products is excellent, probably beefforts to reduce expenses. Auto- cause of the strong competition.
mation is one method of mini- Solid-state has decreased the avermizing the price rises that have hit age number of repairs, and these
Outlook For TV Makers
These next few months will be
critical ones for television receiver
manufacturers. The "survival of the
fittest" has left few TV manufacturers remaining in business. And
many of those have changed hands.
Offhand, I can think of only three
major companies (RCA, Zenith,
and GE) which remain under the
same management.
24
Fig. 2 Admiral "Era Il Limited" Model
19C7089RA is a 19" deluxe model with
matching stand, photo -electric eye,
electronic tuning, and digital channel
readout.
ELECTRONIC SERVICING
www.americanradiohistory.com
When you install a B -T Booster outside,
you get a lot of new boosters inside.
The service technician's job is a
tough one. Customers are always
grumbling about the high cost of TV
service calls. And they complain
about poor reception-even when it's
aimost impossible to get a good
signal.
But now and then a TV service
technician wins one. And one of the
products that can make him a winner,
and create customer goodwill, is a
Blonder -Tongue outdoor booster.
B -T Boosters can produce a dramatic improvement in picture quality,
particularly on color and especially
in difficult reception areas. After 25
years of making outdoor boosters,
B -T is number one in sales, and enjoys the finest reputation for making
products of highest performance and
reliability. B -T Boosters do cost a bit
more than competition, but they perform and last longer. And that's what
makes satisfied customers.
The VAULTER, for example, is the
number one outdoor booster today in
the B -T line...and in the entire industry. This ultra -high performance,
all -channel amplifier offers the ideal
combination of lowest possible noise
figure (4.6dB. VHF; 7.0dB, UHF) and
high gain (15dB). While it can't make
unusable, snowy pictures perfect, it
can reduce fading, loss of color,
overcome cable loss and reduce
lead-in cable noise. It can even feed
more than one TV set from the same
antenna in fringe reception areas. It
For More Details
Cirae (4) on Feply Card
has separate U/V inputs and a coax
output. Finally, it's specially designed for lightning prone areas.
The B -T line consists of 5 all -channel models (including the popular
VOYAGER); 5 VHF models and 4 UHF
boosters (the ABLE-U2b is a favori',e).
See your B -T distributor for details.
And see why you can count on
boosters inside, when you install B -T
Boosters outsi de. Blonde Tongue
Laboratories, Inc., One Jake Brown
Road, Old Bridge, N.J. 08857.
BLONDER TONGA
Fig. 3 Several Admiral "Era Il Limited" models have provisions for adding a
remote amplifier at any time. The plug-in unit, plus the portable remote hand
unit, provide full remote operation.
new modular designs might well
reduce service even more.
Some service shops already are
reporting a general reduction of
gross income that's not attributable
to general business conditions. Has
the impact of fewer repairs per
chassis begun in earnest?
Certainly, we cannot ask for a
return to the old days of "six calls
per year". What is the answer for
our repair industry?
an automatic limiter to stabilize the
color saturation; a color processor
that eliminates green halo; and a
DC restorer for better black level,
especially during low -contrast or
night scenes.
Portables
Two 13 -inch
and
one 17-inch
portables join the four 19 -inch
portables already in the Admiral
line. A new -type chassis is used in
the portables just introduced.
Admiral
New color -TV models of the 1977
Black -and -white
Admiral television line are offered
in two categories: the "Era II"; and
the "Era II Limited", which is the
top -of-the -line.
Eleven black -and -white models,
from 9 -inch to 22 -inch, first were
shown in May. The 19 -inch and
22 -inch versions have a new chassis
that is said to have improved sensi-
Era II
tivity, better locking, increased
brightness, and pre-set VHF fine
Eight 25 -inch and two 23 -inch
consoles comprise the "Era II" line.
Nine of these have a negative black matrix picture tube, and four are
equipped with a digital channel
read-out display.
The chassis has seven modules
for rapid repairs of most service
troubles. Each module snaps in or
out of an interconnect frame (see
Figure 1), which takes the place of
the conventional chassis pan. More
components are included on the
modules, and fewer components are
handwired on the mainframe.
Some electronic features include:
tuning.
Era II
Limited
Fig. 4 The Admiral remote-control
transmitter requires only a 9 -volt
battery to become operational.
Channel selection is by electronic
tuning with digital readout. The
viewer can select any UHF or VHF
channel by pressing buttons on the
receiver's control panel. For example to select Channel 41, you
push four, push one, and then press
the "Select" button. Before you can
withdraw your finger from the
button, the channel is tuned and
the number 41 showing on the
digital display.
Several of the "Era II Limited"
models have provision for an electronic control that can be installed
(even by the customer) at any time
(Figure 3). The cover plate is
removed and the remote amplifier
plugs in. A 9 -volt battery installs in
the remote -control transmitter,
which has controls similar to those
on the receiver (Figure 4). The
receiver can be controlled then
from either the receiver's control
panel or by the remote control.
Admiral's top -of-the -line series,
called "Era II Limited", has three
25 -inch consoles and three 19 -inch
models with optional stands. Model
19C7089RA is shown in Figure 2.
All "Era II" features are included.
Automatic brightness level is
provided by a built-in photo -electric
cell that measures the amount of
room light falling on it, and the cell
resistance determines the bright-
Volume control has a variable
adjustment, providing any volume
desired. The remote has a test for
the condition of the battery.
ness.
guns. Convergence was simplified
26
General Electric
Way back in 1965, General
Electric introduced the HB -chassis
"Portacolor". One of the unique
features was the horizontal in -line
arrangement of the picture -tube
ELECTRONIC SERVICING
www.americanradiohistory.com
APERTURE MASK
PHOiiPHOR DOT
SCREEN
INANE ELECTRON GUNS
6 General Electric offers
several deluxe table models with
stands, such as this WYC7660WD, having gas -discharge
digital readouts for both VHF
and UHF channels, plus six
modules. Many 1977 GE's have
Fig.
BLACK MATk
Fig. 5 The horizontal -in-line -guns color picture tubes from General Electric come
either with phosphor dots or with small trios of stripes. All of the 1977 GE's have
in -line picture tubes, including the new 25 -inch size.
the new VIR module, which
adjusts both color and tint according to the VIR signal sent
out with the network color
programs.
by this configuration. For one
reason, the gun in the center
needed no dynamic correction. And
the other two demanded less,
because they at least were in the
center of the yoke in the vertical
direction.
Let me digress to say that many
of the "facts" given in books, about
the need for dynamic convergence,
are completely wrong. For example.
the non -spherical contour of the
faceplate with the phosphors has
been blamed for the errors of
dynamic misconvergence at the
edges of the picture. Actually, the
near -flat faceplate degrades the
focus near the edges (the distance
from gun to phosphor is greater
there), but other possible discrepancies are solved in the original
placement of the phosphor dots or
stripes.
No, the principal error is caused
by the guns not firing down the
exact center of the deflection yoke.
That's why an in -line tube requires
fewer dynamic adjustments. (A true
single -gun tube would require even
less.) GE says total convergence can
take as little as 4 minutes.
In the 1977 line, General Electric
has in -line -gun picture tubes in all
color receivers. Figure 5 shows the
beam paths inside a tube having
conventional color dots. Many of
the new GE's have the colors
applied in trios of small stripes, as
explained in the article about GE
modular color elsewhere in this
magazine.
Some models of 19 -inch and
25 -inch receivers have 0.4 -inch -high
gas -discharge digital readouts,
which are activated by switches on
the tuners (see Figure 6).
Quasar
Quasar Electronics, a subsidiary
of Matsushita Electric Corporation
of America, recently completed a
multi -million -dollar modernization
of the color -TV production lines in
Franklin Park, Illinois. Much of the
assembly work is done by automated and computer -controlled
equipment.
VIR color
A slow -moving line takes each
Probably the most important Quasar color receiver for a 45 feature of any brand or model color minute ride during operation at full
TV this year is the circuit in certain power (see Figure 7). This time test
General Electric models which gives an opportunity for the compoautomatically adjusts both color nents to stabilize before the final
saturation and tint according to the checkpoint is reached.
Vertical -Interval Reference (VIR)
The new color line of 35 models
signal that's broadcast during most is the first complete Quasar line
network color programs.
engineered and produced since the
The circuitry required to make acquisition from Motorola, so any
automatic color and tint corrections trends are significant.
from the condition of the VIR
Models from 12 -inch through 17 signal is sophisticated and complex, inch, plus some 19 -inch versions
requiring identification of two hori- incorporate the "Service Miser"
zontal lines out of each 525, testing modular chassis, which was first
for the presence of the VIR signal, used last year, and in -line matrixand then the precise selection and stripe picture tubes.
Perhaps the most unique new
comparison of certain parts of the
signal to provide a DC signal for feature is the "Super Module"
(shown in Figure 8). This one huge
control of color and tint.
A preliminary report on the module has 5 IC's, all the customercircuit appeared last month starting used secondary controls, plus most
on page 30 of the July issue of of the components and wiring.
ELECTRONIC SERVICING. Later, Eliminated are many plugs and
we intend to provide an in-depth wiring that formerly connected to
the secondary controls. This "Super
analysis for you.
August, 1976
27
www.americanradiohistory.com
Fig. 7 New Quasar color receivers take
their time test before final testing.
Module" can be replaced from the
front of those 20 models that
continue the "Works in a Drawer"
tradition.
Perhaps you remember that the
first Motorola modularized receivers
had 11 modules.
Five top -of-the -line models
feature the "Satellite III" remote -
control tuning system, "Super
Module", "Super Insta-Matic" tuning, "Glare Guard" picture -tube
filter, and delta matrix picture
tube.
RCA
RCA Consumer Electronics division continues to phase -out the
previous XL-100 models in favor of
the "ColorTrak" versions (Figure
9). "ColorTrak" receivers have 6
modules versus 12 for the older
models.
Two basic chassis are used in the
"ColorTrak" line: CTC74; and
CTC81.
a
slow ride during
Fig. 8 Quasar "Super Module" color receivers have just
one huge module. All of the secondary controls are
mounted on the "Super Module", thus reducing wiring
and eliminating many connectors.
CTC74 chassis receivers
Features of the CTC74 RCA
color receivers include:
CTC74K Direct-Address Remote
(DAR), varactor VHF and UHF
tuners.
modular construction with six
modules;
30 KV of HV anode voltage;
"AccuFilter" (individual filters
for color dots or stripes), Precision In -Line (PIL), negative -matrix
picture tubes with slotted shadow
mask and phosphors;
automatic color control and AFT;
automatic room -light compensator circuit; and
a constant -voltage power transformer (the kind with a 3.5 -micro farad capacitor across the secondary).
The four versions of the CTC74
chassis are:
CTC74F, detented-switch tuners;
CTC74J, varactor VHF and UHF
tuners;
CTC74H remote, varactor VHF
and UHF tuners; and
28
Fig. 9 RCA "ColorTrak" color TV's,
which have six modules, are replacing
the top models of the older 12 -module
XL -100 receivers in the RCA line.
Some features include a constant voltage power transformer, room -light
compensator, automatic skin tint, and
"AccuFilter" (individual filters for
some color phosphors). Shown is the
RCA Model GA830.
ELECTRON?C SERVICING
www.americanradiohistory.com
CTC81 chassis receivers
Features of the RCA CTC81
chassis color receivers include:
modular construction, using the
same modules as the CTC74, except
for the vertical/horizontal-oscillator
module;
31 KV of high voltage;
"AccuFilter", 25 -inch delta -gun
picture tube with dot trios;
AFT and automatic color control,
including semi-automatic tint;
constant -voltage power transformer; and
automatic room -light compensator circuit.
Automatic tint correction
One feature attracted my attention immediately; the one called
"automatic tint correction". Quickly, I read the RCA description
about how the circuit worked. A
sample of the chroma -IF signal
goes through a limiter to level the
amplitude changes. Output of the
limiter and some 3.58 -MHz carrier
from the tint circuit are combined
in a phase detector. Output of the
phase detector plus more limited
chroma go to an adder, whose other
input signal is the main 3.58 -MHz
carrier.
Phase of the output signal from
the adder is a vector sum of the
phase of the 3.58 -MHz carrier and
the phase of the sample of chroma
sidebands (chroma IF). This output
signal is the 3.58 -MHz carrier going
to the "I" demodulator (and
through the usual phase -shifting
network to the "Q" demodulator).
In other words, the phase of the
3.58 -MHz carrier that is applied to
the demodulators is changed to
pull -in all tints (which are near skin
color) so they become skin color.
At that point, I opened the
Photofact for the CTC81 (Folder
1572-2) to check the complete
schematic of this interesting circuit.
Unfortunately, I could not trace it.
The entire function that I listed is
done inside one of the chroma IC's!
As one RCA service manager said,
"You have to take it on faith."
oneg Generator
e
$299.95
PAT. PEND.
ATC-
I
O
GENERAL TELEVISION
SERVICER
of t he most
useful, UNIQUE patterns of the ATC-10
is the GRAY QUAD
pattern below. Use
it for checking and
adjusting gray scale
tracking
for
or
checking effects of
video level upon horizontal sync. Use it
to check for reversed yoke connections vertical, horizontal or both. Use
it to check low frequency video response. It can aove
you time, trouble
and money! Write
One
-
Extra wide range RF/IF attenuator for
testing receiver sensitivity.
HATCHDOTS - versatile composite pattern for dynamic & static convergeance
plus other checks.
COLOR BARS pattern with 6th bar
marked to make your job easier.
3.58 MONITOR pattern for oscillator
frequency checks with no need to short
the AFPC test point.
RED RASTER pattern for checking and
adjusting purity at the flip of a switch.
High level, 75 ohm output provided.
2 year factory warranty.
30 day money back guarantee.
2 volume owner's manual available separately - $1.00.
A
us.
American Technology Corporation
225 Main Street, Dept. 8A, Canon City, Colorado 81212
Credit card & COD phone orders accepted. Same day shipment. (3113) 275.8991. ext. I.
For More Details Circle
(5) on Reply Card
Cut your Installation time and Cost.
Use a SITCO SPEED MAST !
Drill 4 holes, slap in 4 screws, and the
job's finished about as fast as you can
climb up and down the roof. That's the
way to make a profit!
Sitco speed masts fill the needs for
homes, MATV, Communications, Ham,
CB and TV Translators.
-
ORDER 5 FOOT SPEED
MASTS FOR MOTELS
HOMES! Mast is 11/4" seamless
aluminum tubing with two rigid V2" leg
supports attached to adjustable collar
allowing installation on flat or slope roofs.
SPECIAL PRICE ON QUANTITY ORDERS
Other mast models available
Direct -address remote
In addition to tuning the selected
channel instantly by the varactor
tuners, the channel number is fed
through the video circuit so it
appears on the screen with the
picture. Or the time can be displayed in the same way.
August, 1976
CIRCLE READER SERVICE CARD
FOR LATEST LITERATURE
SITCO
ANTENNAS
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www.americanradiohistory.com
10330 N.E. Marx St.
P.O. Box 20456
Portland, Oregon
97220
Tel. 503-253-2000
(6) on Reply Card
29
Here is one correct way of measuring power output and frequency of a CB radio transmitter. Shown
at the left is a Johnson 120 feeding a Pace Model P-5430 (tests power, SWR and modulation) which
has a built-in 25 -watt dummy 50 -ohm load, and at the right is a B&K Model 1801 frequency
counter.
CB Test Readings...
Right Or Wrong?
Part 1-By Marvin J. Beasley, CET
Land Mobile Regional Manager, E. F. Johnson Company
It's bad enough to feel uneasy about the
accuracy of readings when you're testing
CB transceivers, but it's much worse to
depend on them, not knowing they are
wildly inaccurate. It requires more than
good test equipment to produce correct
readings; you must know how to connect
and use every one.
30
Incorrect results from tests can
be more detrimental to CB repairs
than if you made no tests at all.
This sobering fact has not been
given proper emphasis in most
service literature.
What tests and test equipment
should be used? How can you be
certain the results are accurate?
We'll try to answer those questions.
Not all of the test equipment will
be expensive, nor will all of the
tests be complicated. Everything
has limitations; it's essential that
you know what has been proved or
disproved within those limitations.
First, we'll describe some problems that appear to be internal
ELECTRONIC SERVICING
Autoranging
Frequency
Counting
to 60 MHz
with
1Hz
Resolution
B&K-PRECISION
MODEL 1801
$240
For laboratory, production line
or maintenance applications
Automatic ranging, 20 Hz to
40 MHz is guaranteed...readout
to 60 MHz is typical
TTL circuitry updates the six digit display five times per
second
Resolution to 1 Hz obtained by
suppressing digits above 1 MHz
when switching to 1 SEC mode
MHz display of
3.579548 MHz input (AUTO mode)
KHz display of overflow of
3.579548 MHz input (1SEC mode)
Available for immediate delivery,
from local B&K-PRECISION
distributors
10 -day free trial offer
Supply -Voltage Problems
Well -designed CB radios have
internal voltage regulators that
prevent any noticeable change of
performance within the normal
range of voltages in an auto.
Defects in the auto can force the
battery/alternator voltage outside of
the usual range, causing various
problems.
Also, the unprecedented demand
for CB radios has allowed some
poorly -designed "cheapie" models
to be installed.
Not all customer complaints
about poor performance will be
caused by defects inside the radio.
Therefore, the first part of your
diagnosis should be to determine
which of these three possibilities is
true:
The radio is normal, but the
supply voltage is wrong;
The radio is not defective, but
the design is not adequate to prevent certain symptoms that are
triggered by normal supply voltage changes; or
The radio has an internal defect
and needs repairs.
Excessive voltage
At the other extreme, excessive
supply voltage can cause failures of
transistors, IC's, and fuses, without
any other defect.
Low supply voltage
In an auto, the
supply voltage
from the battery should not measure less than 11 volts at the radio.
A lower voltage might cause:
a drifting frequency;
erratic shifting of the frequency,
causing a variable volume change
during reception;
a loss of oscillation (the radio
would become dead); or
weak transmitting power, which
reduces the maximum range.
Testing the voltage
A complete voltage -supply
`+KPREC/S/ON
PRODUCTS OF DYNASCAN
6460 West Cortland Avenue
Chicago, Illinois 60635 312/889-9087
LIn Canada: Atlas Electronics,
Toronto
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defects of a CB radio, but which
actually are caused by things external.
test
should include the readings on
receive and transmit with the
engine not running, and also on
receive and transmit with the
engine running fast enough to give
maximum charge.
Failure of the alternator voltage
regulator can raise the voltage when
(7) on Reply Card
NEW
3'/2 Digit
Multimeter
from
B&K-PRECISION
E
MK -PRECISION
283-$1 70
MODEL
...you'll want it for its
features
...but its the price that
will sell you!
High intensity LED display is
easily read from at least 6 feet in the
brightest room
Measures AC and DC voltage, AC
and DC current and resistance.
0.5% DC accuracy
100% overrange (1000 scale reads
to 1999).
Automatic polarity
Automatic decimal point
Flashing overrange indication on
display
Four voltage ranges to 1000V
Four current ranges to 1000mA.
Six resistance ranges to 10 meg.
In -circuit resistance measurements
at voltage levels below conduction
threshold of semiconductors.
Overload protection on all ranges
Complete new circuitry makes the
Model 283 the most dependable and
versatile 31/2 digit multimeter you can
buy. The extra -bright display allows
you to use it where other units would
cause reading problems. The selectable "low ohms" function permits
accurate measurement of semiconductor shunted resistors.
An optional, internal battery pack
(BP -83, $50.00) provides 8 hours of
continuous use on one overnight
charging and charges when the
Model 283 is in use on 115/230 VAC.
Your B&K-PRECISION distributor has
the Model 283 in stock and will be
glad to demonstrate its features to
you. Call him, or write for additional
information.
:4KPRECISION
PRODUCTS OF DYNASCAN
6460 W. Cortland Avenue
Chicago, IL 60635 312/889-8870
In Canada: Atlas
Electronics, Toronto
For More Details Circle
August, 1976
(1)
on Reply Card
31
www.americanradiohistory.com
the engine is running up to 15 or
even 18 volts. Standard idling
voltage, according to the Electronic
Industries Association (EIA), is 13.8
volts. This is the correct voltage for
measurement of transmitter output
power.
With the engine shut off, a
voltage reading of less than 10 volts
probably means a defective cell in
the car battery.
Another kind of voltage problem
is indicated when switching to
transmit dims the dial lamp and
the transmit power is very weak.
One possible cause is the small
"crimp -on" connector that's supplied with many radios. Recrimp or
solder the connector to increase its
current -carrying ability.
Other causes of poor supply
regulation have been traced to
stranded wire that has been carelessly stuffed into the fuse block
with only a strand or so touching
the hot lead.
Transceivers with polarity switches sometimes blow fuses when the
switch is set for the wrong polarity.
If a customer says the radio
lights up and operates only when
the antenna is connected, the radio
is not grounded properly. Chances
are the transceiver bracket is
mounted to a plastic dash. Unless
the receiver has a good ground, the
supply voltage will vary excessively,
and probably too much ignition
noise will be picked up.
SWR Measurements
Over the years, many myths
about coax, antennas, and RF
measurements have crept into the
service world. Often the terms
"SWR" and "VSWR" are used
incorrectly or without any explana-
A maximum legal RF output of
4 watts is being measured from a normal CB
radio when the connections to the test equipment are correct.
tion.
An antenna acts as a terminating
load for the signal coming through
a transmission line (coax cable). If
the load is purely resistive (properly
tuned so it's neither inductive or
capacitive), and the resistive value
is the same as the characteristic
impedance of the line, the line and
antenna are matched. In that case,
no energy is reflected from the
antenna back to the transmitter.
But if the matching is poor, part of
the signal is reflected back to the
source. This signal is out of phase
with the original signal, so "standing waves" (points of maximum
voltage or current where the two
signals add, and points of minimum voltage or current where the
two signals subtract) are formed. Of
course, any standing waves that
return to the transmitter are subtracted from the power radiated by
the antenna. Excessive standing
waves can cause damage to the
Power output during this test is only 0.6 watt. Is the transmitter defective? No,
a mistake has been made in connecting the test equipment. The error will be
explained next month in Part 2.
32
output stage of the transmitter.
"VSWR" (often pronounced viz wahr to save time) means Voltage
Standing -Wave Ratio, and it is the
most common method of measuring
SWR. VSWR is the ratio of the
maximum voltage found in the coax
relative to the minimum voltage
there. With perfect matching, the
minimum and maximum voltages
are the same, so the VSWR is 1:1,
ELECTRONIC SERVICING
or a one-to-one ratio. If the
maximum voltage is 8 times the
minimum, the VSWR is 8:1.
Most inline CB power/VSWR
meters have a bridge circuit to read
separately the voltage to the an-
tenna and the voltage reflected
back to the transmitter.
Remember, SWR is a relative
measurement. For example, service
techs for commercial two-way radios use an RF wattmeter and
measure the power in both directions. They don't calculate or worry
about the actual SWR just so long
as the reflected power is less than
5% of the forward power.
VSWR versus the percentage of
reflected power is:
VSWR
1.5:1
2:1
3:1
4:1
6:1
8:1
% Power Reflected
5%
10%
25%
30%
45%
50%
If you measure a VSWR of 3:1,
then one-fourth (25%) of the power
from the transmitter is wasted. This
loss added to other losses in the
system could mean that half of the
power is wasted.
Only a matched 50 -ohm impedance coax and antenna system
will allow the readings of SWR
meters and RF wattmeters to be
accurate. These fine items of test
equipment can be notorious liars,
when the conditions are not right.
For example, an antenna manufacturer specifies that a certain
antenna has a 50 -ohm impedance.
This is not necessarily true, for
most such antennas have the rod
slightly too long so it can be
trimmed (shortened) to match the
radio.
Of course, we should attempt to
obtain a VSWR as near 1:1 as
possible, for low VSWR readings
indicate high efficiency along with
minimum chances of damaging the
RF output transistor in the trans-
mitter. But remember this: it's
possible to obtain a low VSWR at
the transmitter although the antenna or coax cable might either be
open or shorted! How can you
know when to rely on these
readings? First, check the power
into a 50 -ohm dummy load, then
become suspicious if the power or
VSWR readings change too much
when the antenna is connected. An
example of "normal" amount of
mismatch is a quarter -wave whip,
which at 27 MHz probably will
have an impedance of 36 ohms with
a VSWR of 1.5:1 or 2:1. Worse
readings should be investigated.
Next, check the coax and antenna for opens and shorts. A fulllength non -loaded (without loading
coil) whip should check open when
measured by an ohmmeter. Antennas with a loading coil check as
though shorted. To check the coax
or connector, remove the base load
from the antenna mount and check
the line separately.
Don't confuse impedance and
DC resistance. Some technicians
believe a 50 -ohm antenna should
read 50 ohms on an ohmmeter!
Impedance is AC resistance, which
cannot be read by an ohmmeter.
Coax cable should measure low
resistances from the shield of one
end to the shield at the other end,
and from the center pin of one end
to the center pin at the other end of
the cable. Between the center wire
and the shield, when the cable is
checked alone, there should be an
infinite reading.
Antenna And Coax Damage
Automatic carwashes indirectly
provide you with lots of extra
business. Before getting a wash job,
a CB user often will unscrew the
load, instead of removing only the
whip. A few such removals will
break the center conductor in the
mount, bringing intermittent opera-
C
3c
tion. Also, removal of the base load
leaves a cavity which collects soapy
water, and a buildup of soap and
corrosion can weaken the signal.
Many trunk -lid antenna installations damage the coax, crushing it
flat between the gasket and the
trunk lid. Such crushing displaces
the center conductor, and this
changes the characteristic impedance, causing a higher VSWR
reading.
Sharp edges of the trunk lid can
sever the cable or break the inner
conductor. To prevent these problems, flatten or bend the sharp
edges. And position the cable,
perhaps with cable clamps, so it
enters the trunk at the same place
each time the lid is opened and
closed.
Also, look for cable trouble
under the seats where weight of the
driver or passengers exert pressure,
under the metal trim along the
door openings, and around any
loops of coax that might be
snagged when the trunk is loaded
or unloaded.
More Wrong Readings
Another way of getting erroneous
VSWR and power readings is to
leave the car doors open and the
trunk lid up. An open trunk lid
affects the performance of antennas
regardless of the location, although
a roof-top mount is affected the
least. You can appreciate the
importance of the lid position after
you watch an experienced two-way
"r.
CONNEC TOR
COAX
CE
E TRANSCEIVER
WATTMETER
C
E
MODULATION
METER
DU'.1h1Y
34-L_Ff=c
LOAD
RLO
'ALTER
AUDIO
GENERATOR
WIDE -BAND
USE
COAX FOR
ALL
RF
SCOPE
WIRING
Fig. 1 These instruments are required for a complete test of a CB transmitter.
Often the wattmeter, modulation meter, and dummy load are combined in one
instrument. Care must be used in the length of the coax lines, and in coupling
to a frequency counter.
37
August. 1976
www.americanradiohistory.com
using carbon or composition resistors whose total wattage is several times the expected maximum
amount. (Carbon and composition
resistors tend to change with heat,
Measuring Frequencies
It should be a snap to measure and when overloaded and recycled
the frequencies in a CB transceiver. many times, this change can beJust use a frequency counter that come permanent. The solution is to
has five times the accuracy required make certain the heat always is
kept far below normal ratings.)
by the FCC for CB transmitters.
The relative -power load assembly
Unfortunately, you can obtain erratic or erroneous readings, if you of Figure 2 can be constructed
use the wrong wiring to bring in the easily. Use a VOM or multimeter
as an indicator, and calibrate it
signal to the counter.
Counters have one blind spot: against a standard of known acthey can't discriminate between curacy.
Warning: a #47 dial -lamp bulb is
cycles from the desired signal and
not
a satisfactory load, although
noise
or
a
spurious
from
those
signal. For example, noise pulses many books and articles recomriding on the signal add to the mend it. These bulbs are rated at
6.3 volts and 150 milliamperes,
count, producing serious errors.
which calculates to 42 ohms. Right Fig. 3 Bird Electronics offers several
there is a mismatch. But there's types of power wattmeters. Although
Good wiring minimizes errors
Figure 1 shows an efficient setup more. The rated wattage is about this kind does not measure SWR
of test equipment, with the wiring .95 watts, and many transceivers directly, it measures both forward and
arranged to minimize lost time and have 4 watts of output power. Now, reverse power flow. If the reverse
to reduce the chances of wrong 4 watts into 50 ohms figures about power is less than 5% of the forward,
SWR is satisfactory.
14 volts RMS, so it's obvious that a the
readings.
The wattmeter and modulation full -powered CB rig might burn out
meter can be in a single instrument the bulb. The only thing preventing as I recall, the resistance changed
along with the dummy load. It's the failure is the same character- from perhaps 15 ohms when the
vitally important that the dummy istic of the bulb that makes it bulb was barely lit to over 80 ohms
load be exactly 50 ohms and non - unsuitable as a load: the resistance with more than 6 volts across it.
inductive. Also, the resistance varies with temperature of the Our advice is to use one of the bulb
should not change from the heat of filament. I made a chart of those test gadgets (coax connector with
normal operation. One way is to resistance changes at one time. The #47 bulb) for a quickie test that
make up your own load (Figure 2), chart is filed away somewhere, but tells you only, "Yes, there is some
radio technician crawl inside the
trunk and pull down the lid during
a final tuneup.
5 pF
22KS2
30 pF
PHONE
JACK
INPUT
S0239
COAX
J
1N60
_
CONNECTOR
EXT METER
JACK
1000
pF
§330
S2
8 LOAD RESI STORS ARE EACH 100
2
§
180KQ
S2
- WATT CARBON
LOAD BOX
Fig. 2 You can build this dummy load in a metal box. A reading of relative power output can be obtained if you use a
VOM connected to the "external -meter jack".
ELECTRONIC SERVICING
38
www.americanradiohistory.com
output."
signal without loading.
One of the most popular dummy
loads over the years is the Heath
Cantenna. It has a gallon bucket
with a 50 -ohm non -inductive load
resistor immersed in mineral or
transformer oil. Power handling can
reach 1,000 watts for short periods.
It should not even run warm with
CB's. Bird offers a wide range of
wattmeters and loads for every need
(Figure 3). Motorola has a low power load, and supplies a chart to
show the power when used with a
50 -microampere meter.
If actual contact is needed, add
the capacitor and resistor at the
end of the cable, as shown. Remember to keep all the leads short.
Next Month
The first subject will be an
explanation about why and how a
length of coax cable can function as
a trap, giving an open or a short,
according to the conditions.
Also, correct methods will be
described about making accurate
and meaningful measurements of
the receiving functions.
ADD
"T
CONNECTOR
5 pF
CAPACITOR
RF FROM
TO COUNTER
TRANSMITTER
OR SCOPE
Connecting Counters
Modern frequency counters are
extremely sensitive, requiring very
little input voltage to produce
reliable readings. In fact, excessive
input is responsible for far more
wrong readings than is too little.
CABLE IS
Measuring output frequency
It is good practice to check
the
frequency and approximate power
output on all channels, as the final
checkout of a transceiver. Figure 4
shows one way to connect the
output RF to a counter that has a
50 -ohm input. A direct connection
is not recommended because it
would allow too much amplitude to
reach the counter; and the 50 -ohm
input impedance would parallel the
dummy load, making the total load
only 25 ohms (a mismatch).
The 5 pF capacitor has about
1,000 ohms of reactance at 27
MHz, so the loss is about 20 -to -1.
If the counter has a high -impedance input, then add a 50 -ohm
carbon resistor on the counter side
of the coupling capacitor.
This kind of coupling works fine
with a scope, also. But most scopes
can accept the full output signal
without any problem from overload.
RG -58
WATTMETER
LOAD
Fig. 4 Use "T" connectors to wire in different items of test equipment. To prevent overload of a frequency counter that has a 50 -ohm input, add a 5-picofarad
capacitor inside the shield of the coax, as near the connector as possible. A
high -impedance counter should have a 50 -ohm carbon resistor added between
the counter side of the capacitor and the shield (as shown in Figure 5). Do NOT
wire these components at the counter end of the coax.
Measuring individual frequencies
Troubleshooting synthesizers often requires you to know the frequencies of the high and low
oscillators. The problem here is
making the reading without loading
down (detuning) the synthesizer circuit.
One way is to prepare a shielded
cable (Figure 5) with a short length
of the "hot" wire extended to act as
a probe. Ground the shield, and
position the "hot" center wire near
the circuit. Capacitive action of the
nearness usually gives sufficient
Fig. 5 Most counters that have a high -impedance input will pick up enough
signal in the transmitter stages when the coax is prepared as shown, exposing
a short length of the center conductor. The center wire is positioned near to the
circuit under test. In the event a direct connection is required, add the capacitor
and resistor, using short leads.
39
August, 1976
www.americanradiohistory.com
Check the main power amplifier
as a whole unit by a simple
SERVICING
ELECTRONIC
ORGANS
Part 3/By Norman H. Crowhurst
Both general and specific methods of troubleshooting electronic organs are
presented. Included are ways 0/ telling by symptoms and logic whether a
key switch or an oscillator/divider stage is causing a dead note.
Last month, we briefly described
the unique circuits of those brands
of organs you are most likely to be
asked to service. Next, you need to
know the general troubleshooting
methods for organs, and some
specific ones for different models.
Of course, some servicing techniques will be nearly identical to
those used successfully for radios
and TV's. One basic is checking for
AC and DC power.
Dead Organ!
Suppose the organist reports that
the instrument produces no sound;
it is completely dead. Try the organ
for yourself, making sure at least
one stop is turned on, and that the
headphone (used for silent practicing) has not been left plugged in
accidentally.
The Wurlitzer Model 805 is
not intended for beginning
organists or inexperienced
technicians. It has
pedals,
manuals
full
plus a
two
61
25
-note
small
synthesizer keyboard, and
a full range of stops and
percussions. This one is
used as a store demonstrator, and has extra
speaker switches (at lower
left of the great keyboard).
One switch connects the
Leslie (rotating speaker)
tone cabinet, which is
shown on the right.
40
After you're certain there are no
errors of operation causing the lack
of volume, follow these steps:
Make certain the wall duplex
outlet has full voltage;
Check the AC plug for a tight fit
with the wall outlet, and look for
an open circuit near the plug;
Check the indicator lamp (if the
organ has one). A lighted indicator
proves there's AC power, at least;
Examine the tubes (if any) for
heater glow, especially the power output tubes; lack of glow in all
tubes suggests an AC power failure;
If these preliminary tests indicate
normal power, listen near a speaker
for hum (a normal organ will have
a small amount), and move the
expression control, noticing any
noise or change of hum level that
suggests the main power amplifier
is alive; and
"buzz"
test. Find the input, perhaps at a
plug or connector, and touch it
with a small screwdriver blade. To
obtain more buzz, keep a finger
against the blade and don't ground
yourself to anything. Power hum
picked up capacitively through the
air will give enough distorted sine
waveform to produce a strong buzz
when the amplifier has full gain.
After a little practice you can learn
how much volume to expect. Of
course, if there is no buzz, the
amplifier is dead and must be
repaired.
If the main amplifier (usually on
a separate chassis) is okay, you
must check upstream through the
pre -amplifier stages. But for now,
we'll assume that the problem is in
the amplifier or power supply.
In the following explanations, we
are assuming that you have had
little experience at troubleshooting
audio circuits of this kind. If they
seem simple to you, just use the
procedures as a review.
Testing Tube -Type Amplifiers
Although it's true that visual
tests give complete and correct
answers only with certain defects,
they are very worthwhile because
they save much time in those
specific cases.
Several visual conditions of the
tubes should be examined first.
With tube rectifiers (such as the
5Ú4G), a common defect is an open
filament, often from poor soldering
of a pin. If the tube filament does
not light (and you don't have the
correct type with you), check the
pins with a reading glass, and
resolder the bad pin. A new tube
can be brought out later.
Output tubes, also, should have a
definite heater glow. The glow in
smaller tubes is more difficult to
see, but it should be there. Of
course, all operating tubes should
be warm or hot to the touch.
Look for cracks in the glass,
especially around the base. Even a
tiny crack lets in air; which, in
addition to ruining the tube, also
turns the "getter" white. The getter
is a black area on the inside of the
glass where some material was
flashed during manufacture to use
up the last of the oxygen. White
getter indicates an air leak.
Another warning sign is a blue or
ELECTRONIC SERVICING
purple glow from either gas or
fluorescence. Such a blue glow
inside the metal elements indicates
gas, and the tube should be
replaced. But, when the glow is on
the inside of the glass, that is
merely fluorescence; the tube is not
defective.
When the plate current of an
output tube is excessive, red areas
might appear on the metal of the
plate. This can be caused either by
a circuit defect (insufficient bias
from a leaky coupling capacitor to
the grid), or by a gassy condition in
the tube itself.
Other visual tests should include
a search for burned resistors and
defective filter capacitors. Many
filters are housed in aluminum
cans, and they should be checked
for bulges or running too hot. A open of one diode changes either
white powder around the terminals circuit into a half-wave type, thus
reducing the DC voltage and inis proof of some leakage of the
electrolyte. and often means the creasing the hum level.
A shorted filter capacitor, diode,
capacitor is open.
Check all fuses. When a high - or rectifier tube loads down the
amperage type blows from a severe power transformer, usually tripping
overload, a prominent black area the breaker or blowing the fuse.
Open filters seldom eliminate all
usually shows on the glass. Small current fuses might not show a sound; instead they produce other
definite visual defect; it's best to symptoms. The filter nearest the
check those with an ohmmeter. Of rectifiers affects the amount of DC
course, a blown fuse points to a voltage, as well as the hum level.
more serious problem, such as a For example, when it's open, the
DC voltage might be 20% to 30%
short circuit of some kind.
low. Other open filters increase the
hum level or reduce the bass
Power -supply defects
Figure shows two variations of response. Sometimes, an open filter
popular power -supply circuits. Both will remove the decoupling, perare full -wave types, having a ripple mitting an audio oscillation.
A peculiar type of defect can
frequency of 120 Hz. However, an
1
SMOOTHING CHOKE
OR RESI STOR
POVVER
TRAN SFORMER
j000i
13-)-
TUBE
RECTIFIER
ELECTROLYTIC
FUSE
la
b
Mr>
120 V
AC
_
CAPACITORS
{-
1«.>
B
r
(GROUND?)
SMOOTHING
HEATER
RESI STOR
SUPPLY
OR
CHOKE
B+
DIODE
BRIDGE
120 V
B
AC
(GROUND?)
HEATER
SUPPLY
Fig. 1 Many variations of these two basic power supplies are to be found in organs. For example, a resistor added
between B -minus and ground develops a negative voltage across it, for use as tube bias. The way the heater supply is
grounded affects the hum pickup inside the tubes; retain the original wiring if you replace the power transformer.
August, 1976
41
endeco
soldering &
desoldering
equipment
Ow'
SOLDERING
IRONS
-
Pencil style. Safety light. Two heats
20w and
40w. 6 tips. Unbreakable handle. 2 and 3 wire
neoprene cords.
DESOLDERING
IRONS
False hum
Pencil style. Safety light. Some operate at 40w, idle
at 20w. 8 tip sizes. 2 and 3 wire neoprene cords.
SOLDERING &
DESOLDERING
KITS
Everything needed
to solder or de solder or both. All
in a handy lifetime metal
box with hasp.
See your distributor or write...
Enterprise Development Corp.
5127
E.
65th St
Indianapolis IN 46220
PHONE (3171 251-1231
For More Details Circle
(8) on Reply Card
need belts?
c)
0
o
occur in power supplies using a
filter resistor, rather than a filter
choke (Figure 1B). If the first (or
input) filter opens, the second one
tries to function as the peak reading capacitance. However, the
capacitor -charging current flows
through the filter resistor, overloading it and often causing it to burn
up. Since the charging current is
AC, the usual DC measurements
and Ohm's Law do not indicate any
overload, thus it seems to be a
defect without a cause. After the
resistor burns open, the amplifier is
completely dead.
o
By the way, organs are susceptible to "false" hums. Sometimes the springs or adjustments of
the pedal mechanism can change
enough that a pedal note sounds all
the time. Those Baldwins that have
a straight volume control to key
each pedal note make the condition
even more mysterious because the
note can sound softly.
Pedal notes sound very similar to
hum, and it's easy to confuse the
two sounds. Also, B -natural pedal
is just a few cycles away from 60
Hz, making that note seem to be
pure hum when it is a "cipher"
(sounding when no key is pressed).
There are two ways of checking
for pedal ciphers. One method is to
try each pedal note in turn. When
you reach the bad note, no change
ADD RESISTOR
TEMPORARILY
of pitch will take place. Of course,
if the noise is a loud hum, each
pedal produces a beat note.
Replacing filter capacitors
Filter capacitors for tube -type
amplifiers often are required to
operate near the maximum DC
voltages that are possible with the
electrolytic type. Be sure you do not
use any replacements having lesser
voltage ratings.
If you can't find replacement
filter capacitors of the exact ratings,
select the next higher values. Most
circuits operate just as well (or
better) with filters increased to as
much as twice the original capacitance.
Forming new filters
Electrolytic capacitors gradually
deteriorate when stored too long,
causing excessive current and heating when full voltage is applied. In
rare cases, filter cans have been
known to explode.
Therefore, it's an excellent idea
to be on the safe side and prevent
callbacks by re-forming any replacement filter capacitors.
Figure 2 shows how to form a set
of filters. Add a resistor (perhaps a
100K, 2 -watt value) temporarily
between the rectifiers and the first
filter capacitor; also, disconnect all
of the load wires at the output of
the filter circuit. Operate the power
supply for a time (perhaps 15
SMOOTHING CHOKE
OR RESISTOR
REMOVE WIRE
GOING TO LOAD
B+ WIRE
FROM
RECTIFIER
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-
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BELT CORP.
Fig. 2 Some electrolytic filter capacitors de -form (lose capacitance and develop
leakage) from a long shelf storage. Temporarily change the wiring as shown to
form the new capacitor after it is installed. A 100K 2 -watt resistor should be
about right to limit the current during forming.
319 Whitewater St., Whitewater,
WI 53190
(414) 473-2151
ELECTRONIC SERVICING
-
For More Details Circle
(9) on Reply Card
www.americanradiohistory.com
CARTOON CORNER
"There, there, dear. Of course he's
not using the oscilloscope properly; after all,
it's only an old war movie."
SOUTNSIDE
"Hey! This new zoom feature is pretty nice!"
TV SER\ICE
HONEST
REPNRS
"Personally, think he's carrying this
honesty gimmick a bit too far!"
I
August, 1976
"I think this old scope has
finally had it."
43
minutes) this way, noticing if the
capacitor operates too hot. After
the capacitor temperature returns
to normal, restore the original
wiring.
Signal -Tracing Tube Amplifiers
After you have determined that
the AC and DC power -supply
voltages are normal-but the main
amplifier remains silent-then sev-
eral simple signal -tracing techniques should be tried, to locate the
dead stage.
As mentioned before, your fingers touching the blade of a small
screwdriver or soldering -aid make a
convenient source of buzz. Insulating yourself from earth ground
and from any part of the organ
makes the buzz louder, and enables
you to touch pre -amp or driver
plate circuits (which have a moderate amount-say up to 200 voltsof DC voltage), without receiving a
shock. Be careful to stay away from
the plates of the output tubes.
A much better idea is to use a
regular audio oscillator, or a small
home -built tone source, which has a
special output circuit that's safe to
C3
.1
use with transistors (Figure 3).
Warning: Don't connect an audio
source directly-or through a capacitor only-to any transistorized
stage. If the audio source has a low
impedance, such as a transformer
secondary, there's danger of increasing or decreasing the bias
enough to destroy or cut-off the
transistor. And, if the audio is
coupled through a capacitor, the
charging current (when it's connected to a circuit having voltage)
can zap a transistor. Use the
protective circuit shown in Figure 3.
Starting with the grids of the
output tubes, use the buzz test or
the audio source at each plate and
grid in turn, working back towards
the input, until you find a stage
that does not pass the signal.
Figure 4 shows some of the points
to be tested. Normally, the volume
of the test signal increases as the
point of injection becomes farther
from the output tubes. The precise
amount of volume depends also on
the impedance of the circuit where
the test signal is injected; therefore,
it is impossible to state an iron -clad
rule.
(-^
R3
10K4
After you've found the dead
stage, try a new tube. If the tube
replacement doesn't help, measure
the DC voltages at the tube socket,
and analyze the defect from the
voltages. Figure 5 lists some examples. A high -impedance DC meter-such as a VTVM, FET meter,
or digital multimeter-is recommended for these voltage tests, to
minimize the errors from meter
loading.
If the problem is in the pre -amp
stages, rather than the power
amplifier, use the same techniques
to locate the defect there.
Testing Organ Circuits
These audio tests are exactly the
same as those used in the audio
section of a tube -equipped TV, or
in a public-address amplifier.
After the pre -amp and main -amp
circuits are known to be okay, but
the organ remains dead, it's time to
start checking the non -audio circuits.
What can kill all notes?
In order to silence all notes, the
TO
HIGH
IMPEDANCE
T1
2N408
PNP
TO
8
LOW
IMP
.47
47
27KQ
6V
o-ait
Fig. 3 Here is an audio tone -source you can build easily. It's very handy for testing any kind of audio amplifier, including
both tube and transistor versions in organs. Nothing in the schematic is critical; most values can be changed without
problems. The circuit is a Hartley -type oscillator built around a push-pull miniature transistor-radio output transformer,
which has a speaker secondary useful for feeding low -impedance transistor circuits. The resistors in the output circuits
are to limit the charging currents of the coupling capacitors, and R4 can be switched out when necessary to increase the
output amplitude.
To prevent ruining any transistors by poor connections of the test unit, we recommend this procedure: before attaching
the tone source, turn off the power to the unit being tested; connect the tone source, preferably using the insulated -hook
type of "hot" lead, then turn on the power for the listening test; turn off the amplifier power before disconnecting the
audio test source; if necessary to use the switch SW1 for shorting out the resistor-to obtain more transistor drive-have
the tone source connected and the power on before switching out the resistor.
The waveform of the sample built by Editor Babcoke is a distorted sine wave, which is a good substitute for music,
since it has harmonics that make the volume sound louder and more clear than a pure sine wave. Your version probably
will have a slightly -different waveform.
44
ELECTRONIC SERVICING
must be universal. If the
operates on DC rather than
perhaps a defect has elimiall keying voltage. Or, a
failure of the regulator circuit
became zero. An open stop -tab
switch would eliminate only that
one function, and a defective keying
switch could silence only one note
of one pitch.
supplying all the oscillators could
prevent all tones.
Many features from pipe organs
defect
keying
audio,
nated
Another possibility, especially
Because many of the general
functions of electronic organs came
connectors. Modern organs fre- from pipe organ design, it might be
with older organs, is corroded plug
interesting and helpful to digress
for a brief look at some pipe organ
features.
Figure 8 shows the operation of
the old "tracker" pipe organs, in
which all functions were accomplished mechanically and directly,
without any power assists. The
"stop valve" actually stopped (or
prevented) the air from entering the
quently incorporate gold-plated
contacts to minimize connector
problems.
Stop Tabs
Organs with the stops wired as
shown in Figure 6 are not likely to
lose all notes because of either bad
keyboard contacts or stop switches.
A short circuit to ground from the
common input to the stop filters
would kill all those tones; however,
similar circuits are provided for
other pitches, and these would not
be affected. If only one stop does
not work, the defect is certain to be
inside the stop circuit itself.
Stop switches that furnish DC
voltages for indirect control of the
notes (Figure 7) could prevent all
sound. if the DC supply voltage
VIA
{
OUTPUT
A
I(
INPUT
Fig. 4 These points of a tube -type amplifier are best for the "buzz" or
audio -source tests. With signal -injection checks, you usually start at the input
of the output tubes or transistors and work back toward the low-level stages.
A
B
INPUT
4----1(
C
OLTPUT
i(
i
D
DC
METER
Typical of solid-state amplifiers in
small organs is this one in a Lowrey.
For tests, the audio input can be
found at one of the input plugs at the
top, or at the terminals of the
expression control.
August, 1976
Fig. 5 In this type of audio circuit, the grid should measure zero. A negative
voltage indicates either an increase of the grid resistor value, excessive signal
input, or insufficient cathode voltage. If the grid is positive, the input -coupling
capacitor is leaking, or the tube is gassy. Excessive tube current increases the
cathode -to -ground voltage and decreases the plate -to -ground voltage. Insufficient plate voltage might be caused by insufficient bias (wrong grid or cathode
voltage) or an increase in the resistive value of the plate -load resistor. An open
cathode -bypass capacitor reduces the gain, but does not distort the tone.
45
chest which supplied one rank of
pipes.
Some early electrically -operated
pipe organs adapted the wind stop
so it could be closed or opened by a
kind of solenoid relay (Figure 9). It
was only natural, then, for some of
the first stops of electronic organs
to be operated by relays that locked
in the last position selected (Figure
INPUT OF
AMPLIFIER
TO
KEY
CONTACTS
tttt
ETC
10).
KEYBOARD
STOP
TAB
Tone -Wheel Hammonds
STOPS
ETC
All of the older Hammond or-
gans had electromechanical (tone
wheel) generators of sine waves, and
the generator shafts were driven by
a synchronous motor.
Actually, there were two motors.
One was a starting motor. It was a
conventional type with gearing selected so it would turn the generator shafts just slightly too fast.
During turn -on of the organ, the
first switch position (Figure 11)
energized only this starting motor
(the amplifier and synchronous
motor were not powered yet). After
a wait of several seconds for the
starting motor to reach maximum
speed, the organist was supposed to
flip the switch, turning off power to
the starting motor, and on to the
synchronous running motor and the
amplifiers.
In a quiet room, you could hear
the various motor speeds. First, for
six or eight seconds, the speed
SWITCHES
Fig. 6 Organs that key the audio directly, as shown, are not likely to lose all
notes at once, except because of a loss of supply voltage to all the oscillators.
Notice which notes of what stops are wrong; usually it's not difficult to figure
out where the defect begins.
increased and steadied, and then
the speed decreased as the synchronous motor locked to the line
frequency.
If the switches (some organs had
two) were not operated in the right
sequence, or the starting motor not
allowed to run long enough, the
synchronous motor would not start.
In such cases, the amplifiers were
okay, but the organ would not play
a single note.
The motor and generator bearings were supposed to be oiled
constantly by a filling of the oil
reservoirs every six months. A few
organists who did not listen to the
explanation and wouldn't read the
instruction book ended with frozen
bearings, after failing to have the
organ oiled. In fairness to Hammond, we must say the organs often
ran for three or four years without
oiling before any problem occurred.
Few of these synchronous motors
ever burned up from improper
starting. The reason is that the
resistance of the windings was very
high, thus preventing excessive current in a stalled motor. In fact, the
Model M3 had an input for a
phonograph, and the instructions
STOP TAB
SWITCHES
8' KEY CONTACTS
4' KEY CONTACTS
SUPPLY
DC
VOLTAGE
ETC
1
1
CONTROL CIRCUITS
8' AUDIO
8' OUTPUT
4' AUDIO
INPUTS
AUDIO
INPUTS
1
-
4' OUTPUT
AUDIO
Fig. 7 A loss of the supply voltage probably would eliminate all notes of any organ using this kind of circuit. Defects in
the key contacts or the control circuits can silence any one note.
46
ELECTRONIC SERVICING
www.americanradiohistory.com
stated the organ was to be turned
on without using the starting
switch. The amplifier was on to
amplify the phono, but the motor
and generator shafts were not
turning.
Swell -Pedal Problems
One potential source of a dead
organ, surprisingly enough, is the
swell -pedal circuitry. Some older
organs (and perhaps new economy
models) simply used an audio -taper
potentiometer (Figure 12) that was
rotated by gears from the expression pedal, or by metal linkages.
Many organists operate the swell
pedal continuously, and even a
heavy-duty pot eventually will become noisy. In some cases, the
element has broken or worn
through, and this stops all sound.
Other basic types of swell controls were designed by manufacturers trying to improve the
reliability. One solution that appeared in several versions was to
use an air -dielectric variable capacitor (Figure 13), which was similar
to those found for years in AM
radios. These circuits worked quite
well, with occasional problems from
moisture or dust inside the plates.
Figure 14 shows another low noise swell circuit. Early models
used a variable -mu tube, and had a
variable negative voltage from the
potentiometer as grid bias. Noise
from the control and hum could be
filtered out by the capacitor connected across the control voltage.
Other models used a similar idea to
change the bias of a transistor, or
FET.
Lower distortion can be obtained
from the expression circuit of
Figure 15. The DC control voltage
(filtered to remove hum and noise)
varies the brightness of a small
bulb in a light -tight assembly. More
light causes the CdS "light-depen-
PIPES
uuu
WIND CHEST
RANK CHEST
KEY -OPERATED
VALVES
STOP VALVE
Fig. 8 Ancient "tracker" pipe organs had an air "stop" valve for each rank of
pipes, and the notes of the keyboard mechanically controlled the air going to
the individual pipes from the wind chest. It took a strong man to play such an
organ, when several stops were "pulled"!
ARMATURE
TILTS
U
Most stop switches have a "snap"
action, to prevent intermittent contacts. When this stop is moved about
half way or more, the spring action
pulls the switch spring tightly against
the bus wire.
Fig. 9 The first electrically -operated pipe organs changed to solenoid operation
of the wind "stops".
47
August, 1976
www.americanradiohistory.com
dent" cell to reduce its resistance,
thus varying the amount of signal
applied to the main amplifier. A
burned -out bulb eliminates the
volume.
Dead Notes
failure of just a few notes
(perhaps only one, or one pitch of
one note) is a common complaint
with electronic organs.
First, you should try all notes, all
stops, and all pitches (8', 4', etc.)
and make a list of any failures.
Next, you must know whether each
A
note has a separate oscillator
circuit, or whether the notes are
generated by 12 oscillators followed
by dividers to provide the lower
octaves.
For example, let's say the organ
is a Conn, with a separate oscillator
for each basic note. However, the
same oscillator is used for an 8'
pitch of one note, for the 16' pitch
of the note an octave higher, and
for the 4' pitch of a note an octave
lower. It's important to know these
facts, because they simplify the
analysis.
STOP
CONTACTS
ARMATURE
''ON
COI
Fig. 10 Pipe -organ
practices guided
the manufacturers
of the first
electronic organs,
and they used
solenoid -relay
activation of the
stop switches.
Suppose middle "A" of the 8'
stop is dead. There are two main
possibilities. The oscillator circuit
might be dead; or the key switch
might not be making connection.
Which is it?
Try the "A" one octave above
middle "A" with the 16' stop down.
If it plays, the oscillator (also used
for 8' middle "A") is okay, and the
trouble probably is the key switch
under middle "A". But if it doesn't
sound, the 8' middle "A" oscillator
is dead. Of course, the test can
include the 4' stop of "A" an
octave below middle "A", in the
same way.
With oscillator/divider organs,
the first part of the analysis is the
SPRING
RETURN
LOCKING TYPE
L
STOP RELAY
"OFF
COIL
Fig. 11 Hammond organs, which had the tone wheels, had
either two switches for starting the synchronous motor, or
a single switch (as shown) with three positions. The "start"
position was of the spring -return type, so it could not be
left in the wrong position after the starting time was over.
TO
POWER
SHIELDED
AM
P
CABLE-
EXPRESSION
PEDAL
FROM STOPS
OR
PRE AMP
AUDIO
POTENTIOMETER
Fig. 12 Some expression pedals rotate a heavy-duty audio potentiometer by a
system of gears. The carbon elements can wear out, causing noise or
intermittent operation.
48
Fig. 13 A few organ models merely
used a couple of metal linkages to
turn the potentiometer expression
control over part of a revolution.
ELECTRONIC SERVICING
same. However, there is one important difference. A dead divider
also eliminates all of the same notes
below it. Let's say the 8' "B" -flat in
the middle octave is dead. If the
problem is in the divider, rather
than the key switch for that note,
then all the "B" -flats of all octaves
below it will be dead, also.
FROM ORGAN
PRE
-AMP
DOUBLE
VARIABLE
CAPACITOR
Swapping tubes
TO POWER
AMPLIFIER
Cross -switching tubes to see if
the defect moves with the tubes is a
time -saving technique. For example, with an old Baldwin which
has three 6SN7 tubes in each of the
12
generators (oscillator/divider
type), move all the tubes from the
bad generator to another that is
normal. If the problem stays with
the original bad note, the defect is
in the generator circuit; but when
the problem changes to the other
note, the cause was a bad tube.
Tube sockets occasionally become
intermittent or open, particularly
the 9 -pin types. A temporary cure
often can be obtained by spraying
tuner cleaner in the socket holes,
and wiping the prongs of the tube
with a cloth moistened by tuner
cleaner. Check for intermittents by
playing the bad note as you rock
the suspected tube in its socket.
Fig. 14 Variable capacitors of the aluminum -plate, air -dielectric type used in
radios were included in some organ designs. These generally were dependable
and not subject to failures, but dust or moisture in the plates caused noise or
intermittents.
Fig. 15 One
low -noise
variation of the
AUDIO
TO POWER
FROM
PRE
AMPLIFIER
-AMP
the pot to
develop a
variable DC
voltage, which
was filtered to
remove hum
and noise
before it was
used to
control the
gain of a tube,
transistor, or
FET amplifier.
DC
Key contacts
Key contacts (switches under the
keyboard) often cause trouble.
Many are made of small -diameter
spring wire, and can become bent
or misshaped.
Many manufacturers specify that
the switch should close when the
keyboard note is depressed to about
half of the maximum movement.
Some caution and experience are
needed to adjust these key contacts,
and it can be a tedious job when
many need adjustment.
If you must bend a contact wire,
it's best to bend it near the mounting point, and not near the tip.
Some organs have bus -bar adjusters, which can be used to move
the larger, common part of the
contacts to either side, thus exposing an unused area where the
spring can make better continuity.
This is much preferred to any
attempt to clean the springs or
bus -bars individually.
Next Month
More typical organ repairs and
troubleshooting methods will be
presented next month.
August, 1976
+ OR
DC
-
SUPPLY
potentiometer
expression
control used
CONTROL
VOLTAGE
AUDIO
INPUT
AUDIO
OUTPUT
ttt
DC
CONTROL
LIGHTTIGHT
BOX
VOLTAGE
Fig. 16 Light -Dependent -Resistors (LDR's) function very well in expression
circuits; the distortion is very low, and the bulb -control voltage can be filtered
to remove hum and noise. The LDR's seldom fail, but a burned -out bulb can
eliminate almost all volume of the organ.
49
Fig.
1
In a
space small-
er than 3-1/4 X 5-3/4 X
xlCKCW
MODEL_
ass
MOS 1.S5 c01.oR p,PY
PA1\ERN GENEP.PCP
uviror.
î
1
1-7/8
inches
(when
including
two batteries), the
Hickok Model 239 color bar generator produces
nine useful test patterns of perfect stabiliclosed,
and
ty.
b test
lab
Each report about an item of electronic test equipment is based on
examination and operation of the device in the ELECTRONIC
SERVICING laboratory. Personal observations about the performance,
and details of new and useful features are spotlighted, along with tips
about using the equipment for best results.
By Carl Babcoke
Three products (tiny color -bar
generator, function generator, and
a frequency counter) from Hickok
are reviewed this month.
Hickok Pattern Generator
Nine different patterns of excellent quality and stability-this
phrase sums up the features of the
Hickok Model 239 Color -Bar
Pattern Generator (Figure 1).
Two 9 -volt batteries take up
almost half of the room in the case,
and that illustrates the extreme
miniaturization made possible by
Large -Scale Integration (LSI) of the
50
modern count -down digital circuits.
Another space -saving technique is
found in the selector switches. Two
slide -type switches, each having
three positions, determine which
pattern modulates the RF carrier.
A single rotary switch would have
required much more space.
Drawings of the various patterns,
as they appear on the screen of a
color TV, mark the 8 positions
giving dots and bars. The color bars position says "GATED RAINBOW". A sliding control adjusts
the intensity of the color bars to
150%.
A toggle switch turns the generator power on and off. A metal
bracket in the lid flips the switch to
"off" whenever the lid is closed,
thus preventing discharge of the
batteries because of someone's
memory lapse.
On the left, a small jack connects
an external battery charger that's
used when the 100-182 kit (including NiCad batteries) is added.
Late -production versions bring
out the RF through a phono jack
on the right side of the case. A
screwdriver adjustment (accessible
through a hole in the panel)
ELECTRONIC SERVICING
1111111ZIMwIIw
wwww//
ti111ww/i///
wwww//i//
wwwwii//
riwwwii/
wwww////
wwwi///
wi
11wwwi////
ZIwwi/i///
wi/////
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>wwww/////
Fig. 2 The Model 239 Hickok generator
showed these patterns on the screen
of a GE color receiver. Top photo, the
bottom switch was at the left position,
and the switch at the right was at the
top. Moving the right switch to the
center position gave one vertical line
at the middle (center photo), and
moving the right switch to the bottom
produced one single dot at the middle
of the screen (bottom photo).
Fig.
3 Moving the bottom switch to
the middle position, and moving the
right switch from top, to middle, and
to bottom positions gave these
pictures.
Fig. 4 With the bottom switch in the
extreme right-hand position, these
pictures were obtained on the screen
of the color receiver.
permits you to change the carrier
anywhere between Channel 2 and
Channel 4, according to which one
is not used in your area.
Figure 2 shows actual photos of
the three patterns obtained with the
left position of the selector that
moves horizontally. Patterns from
the center position of the selector
are shown in Figure 3; and the last
three patterns are in Figure 4. The
gated -rainbow color bars are on top
of pedestals so the spaces between
bars are black.
Because crystals are used for
control of the color -bar 3.56 -MHz
carrier, and for the top frequency
that is divided by digital logic down
to the other displays, the patterns
all had perfect stability.
Lines and dots were very narrow
and sharp. There are more lines
than the number available with
many larger generators, and I like
the squares that are produced when
perfect linearity is obtained with
the crosshatch pattern.
the definition of "function generator". Basically, a function generator is an audio generator with
Model 270
Function Generator
Perhaps we should explain first
August, 1976
several waveforms, plus several
extra features.
Usually, sine, triangular, and
square waveforms are supplied, and
that is the case with the Hickok
Model 270 (Figure 5). The basic
waveform is triangular, and it is
shaped by several stages of diode
clippers into a low -distortion sine
wave. Square waves are created by
filtering. Special IC's make these
waveforms possible in fairly -simple,
low-cost circuits. Any attenuation
51
www.americanradiohistory.com
high and low. The low sweep range
of the B&K Model 1470 scope
made possible such a photo.
Other waveforms
Fig. 5 The Hickok Model 270 Function Generator not only produces sine,
triangular, and square waves between 1 Hz and 1 MHz, but by use of some
connections in the rear, also can generate sawteeth and pulses.
On the back of the Model 270 is
an edge connector. When you
connect together two of the terminals of the female connector which
is furnished, and provide a resistance between two more terminals, then sawteeth or pulses are
produced. Figure 8 shows the
progression from the nearly-symmetrical triangular waveform with
100K resistance to the sawteeth (at
bottom) when the resistance was
zero ohms. Also, you will notice
that the number of cycles increases
follows the waveform shaping ranges provide coverage from 1 Hz
to 1 MHz. For example, the first
stages.
The oscillators are equally un- range is from 1 Hz to 10 Hz; then
usual. Tuning of the desired fre- 10 Hz to 100 Hz, etc. Sinewave
quency is accomplished by rotation amplitude exceeded 9 volts RMS.
Frequency response was very
of a potentiometer that provides a
variable DC voltage to the Voltage- good between the low and high
Controlled Oscillator (VCO). The ends of each range, and between
the various ranges, except for the
pot is calibrated in frequency.
One feature, rarely used for highest range. The dial calibration
repair work, is that the output is not necessarily accurate above
waveform can ride on an adjustable 200 KHz; also the amplitude falls
DC voltage, perhaps from +10 to above that frequency. Only expensive lab -type generators exceed
-10 volts.
Most function generators (as a those specs.
Pushbuttons select sine, triangubonus from the VCO oscillators)
have provision for a change of lar, or square waves (Figure 6).
frequency either in steps or a Waveshapes of the square waves at
gradual change, from application of the frequency extremes were very
a suitable DC voltage or waveform good, as shown in Figure 7.
from an external source. More Between the usual Hi-Fi limits of
about that later. Also, several cali- 20 Hz to 20 KHz, the square waves
brated and one variable uncali- were perfect.
Incidentally, this is the first time
brated attenuators are supplied.
The Hickok Model 270 Function I have photographed a 1 -Hz square
Generator has all of these features, wave. All I could see at any time
was just a dot of light that moved
and more.
Six push -button -selected decade slowly across the screen, alternately
Fig. 6 These are the three basic
waveforms generated by the Model
270: sine waves (top); triangular
(center); and square waves (bottom).
52
as the retrace time of the sawteeth
becomes shorter. That means the
dial calibration no longer is accurate, and you must use another
means of determining the repetitive
frequency.
The method of obtaining negative -going pulses is similar. The
connector in the rear is prepared,
but the "function" pushbutton for
square waves is pressed. Figure 9
shows how the width (and repetition
rate) of the pulses varies as the
external
resistance
is
varied.
Narrowest pulses are obtained with
zero resistance. Again, the repetition rate changes as the pulse width
is varied.
These extra waveforms are a real
bonus, and the small disadvantage
of the loss of dial calibration is
more than offset by the nearly zero
added cost.
Swept audio
Two more interesting things can
be done with this function generator, by using the connectors on the
Fig. 7 These waveforms were taken at the extreme frequencies of the Model
270. At the left is a perfect 1 Hz square wave (the first one I ever have seen).
200 KHz square waves show rounding of corners and slowing of the rise and fall
lines (right photo), but probably some is due to the scope.
ELECTRONIC SERVICING
ibttt
Fig. 8 By wiring the rear connectors of
the Model 270, triangular waves can
be tilted into sawteeth. The effect of a
100K resistor is at top; about 10K
produced the sawteeth of the center
trace; and zero ohms gave the
sawteeth shown at the bottom. Lower
resistances also increased the repetition frequencies.
rear. The frequency can be changed
by application of DC voltage to the
right pin. If the voltage is changed
in specific steps, the frequency will
change in the same way. It's
possible to obtain an effect sounding like an electronic organ.
An input of a sawtooth, when the
controls are set correctly, will
produce a swept audio (that is, the
frequency gradually changes from
low frequency to high, and then
repeats).
I
tried sawteeth from
another brand of function generator, and had fair results. Hickok
says (and I believe them) that
another Model 270 wired to produce sawteeth would sweep a wider
frequency band. Such a swept audio test can furnish very -rapid
response curves of moderate accuracy when viewed on a scope.
Hickok Model 380
Frequency Counter
Hickok certainly must have had
CB technicians in mind when they
developed the 380 series. Four
pulses
models are offered. One counts up
to 80 MHz and has an overall
accuracy of 10 parts -per -million
(Model 380). Model 380X is similar,
except for the temperature -compensated crystal oscillator which gives
an overall accuracy of 1 part -per million (PPM).
Model 385 is a dual -range
counter. The low range counts from
1 Hz to 80 MHz. It has two input
connectors, and the one for the low
(bottom). The vertical lines have been
drawn in; otherwise the lines would
appear to be unconnected.
(with an impedance of 50 ohms)
Fig. 9 Starting with square waves and
the recommended wiring of the rear
connector gave these pulses. At the
top a 50K resistor gave these broad
pulses. Decreasing the resistor to
about 10K ohms narrowed the pulses
and increased the repetition rate
(center trace). A zero -ohms resistance
produced
these
narrow
range has an impedance of 1
megohm. The second connector
permits counting from 10 MHz to
512 MHz. Model 385X is similar,
except it has a temperature compensated oscillator, providing
an overall accuracy of 1 PPM.
Both the 380X and the 385X
have connectors on the back giving
MHz output signal
a buffered
from the low -drift timing oscillator.
Models 380 and 385 each have a
connector on the back to accept an
external -MHz timing signal.
Therefore, a single 380X can
drive up to four 380's, providing
high -accuracy readings for all five
counters. Similarly, a single 385X
can drive four Model 385's, giving
an accuracy of 1 PPM.
All models have automatic selection of either 0.1 second or 1.0
second, according to , which gives
the best accuracy of readout. Or, if
you want the fastest update, a
pushbutton switch (AUTO/SPEEDREAD MODE) locks in the 0.1 second mode. The decimal point
moves automatically as well.
No input -level control is used,
and the inputs are protected against
excessive voltage (the exact voltage
depends on frequency).
In appearance, all four models
are similar (see Figure 10 for 380
and 385 pictures), except for the
extra input connector and input
switch on the 385 models.
We examined a Model 380
Hickok Auto -Ranging Frequency
Counter in the lab, and were very
favorably impressed by the convenience and accuracy of the readings.
All models have seven 0.3 -inch
LED digit readouts.
El
1
1
Fig. 10 Here are two of the four Model 380 series of Autoranging Frequency Counters from Hickok. At the left is Model
380, which counts to 80 MHz, and Model 385 (a dual -range version) is shown at the right.
August, 1976
53
COM show in New Orleans.
EN
E
MEASURE IT ANYWHERE
To 60 MHz with the FM -7.
NLS proudly announces
a
NEW Frequency Meter.
rodocti T
T
-
These features supplied by the
manufacturers are listed at no -charge
to them as a service to our readers.
ll you want factory bulletins, circle the
corresponding number on the Reply
Card and mail it to us.
Multi -Purpose Tool
multi -purpose hand tool that
performs a wide variety of assembly
A
and maintenance chores is now available from Hollingsworth Solderless
Terminal Company.
The Multiplier cuts and strips wire,
cuts six common sizes of bolts and
With Rechargeable
Batteries
&
Charger Unit
$195
Features Include:
Portable, battery operated for measurement
10 Hz to 60 MHz input with LED 7 anywhere!
High sensitivity; 30 mV -50Hz
digit resolution.
Input
to 30 MHz (100 mV - 10 Hz to 60 MHz).
Small, only 1.9"H x 2.7"W
overload protection.
For
x4"D.
High stability internal time base.
field application, servicing or production testing.
See your local distributor!
Distributor Inquiries invited.
The low -voltage, battery -operated,
ground-free unit is the first that can
be recharged from "dead" to "full" in
one hour. With the "60", the user can
enjoy virtually uninterrupted service
from a single unit.
The "Iso-Tip 60" has the capacity
for up to 125 or more electronic joints
on a single charge. It can be kept at a
constant "full" charge by resting it in
the recharge stand between joints.
The iron will accept a very fast
charge when the battery is down,
then switch to a trickle rate for
maintenance purposes. An LED indicator shows when the charge is full.
screws, and crimps insulated and
non -insulated terminals to wire sizes
22-10 AWG. Equipped with plastic coated handles, the Multiplier also
features a tapered nose with serrated
surfaces which serves as needle -nose
pliers. Each wire, bolt, and terminal
size that the tool handles is engraved
on it. Complete instructions are
furnished with each tool.
For More Details Circle
(30) on Reply Card
Non -Linear Systems, Inc.
Originator or the digital voltmeter.
Box N, Del Mar, California 92014
Telephone (714) 755-1134 TWX 910-322-1132
For More
Details Circle (17) on Reply Card
What would
you like
to read
in ES?
Send in
your ideas.
Tuner Guide and Parts Catalog
A new 134 -page tuner -replacement
guide and parts catalog is now available from PTS Electronics.
The new catalog, Number 6, features extensive listings of all major
makes and models of tuners and
replacement parts and includes photo
enlargements of tuners, enabling
quick detection of a tuner problem
and easy location of the correct
replacement part.
The catalog also includes considerable detail about PTS products;
For More Details Circle
(31) on Reply Card
Cordless Soldering Iron
Wahl Clipper Corporation introduced its new "Iso-Tip 60" cordless
soldering iron at the recent NEW -
w
:
ea
J
Pat. Pend.
$299.95
If you service TV receivers or other video equipment, you owe it to yourself to find
out more about the ATC-10 GENERAL TELEVISION SERVICER. Far more than
just a color bar pattern generator, its special features make color servicing faster and
more precise. Write direct for free owner's manual and complete technical specs.
Available on credit cards, special 30 day trial period.
American Technology Corporation
225 Main Street, Dept. 81A, Canon City, Colorado 81212 (303) 275-8991
For More Details Circle
For More Details Circle
(32) on Reply Card
(18) on Reply Card
www.americanradiohistory.com
CB Home -Study Course
ATIA (Associated Technical Institute of America) has announced a new
audio-visual, self -teaching, CB radiooperator course for CBers, retailers
and store sales personnel.
The home -study course is designed
to help everyone, whether beginner
or 18 -year veteran, understand CB
radio electronics and applications,
instead of learning just facts and
figures. It includes easy -to-understand
Autoinstruction-method lessons of
programmed, step-by-step training in
[exult 2.6
Generator
54
tip, and an instruction booklet.
it sells for $2.
the
Money
The "Iso-Tip 60" kit, #7800, includes
a recharging stand, a fine tip, a chisel
all phases of CB radio operation,
installation, and troubleshooting. Also
included is a pre-recorded cassette
with samples of conversations covering a variety of communication situations, plus tips on microphone tech-
nique, etc.
Price of the ATIA CB radio
operator course is $19, plus $1.95 for
shipping and handling.
For More Details Circle
(33) on Reply Card
ELECTRONIC SERVICING
test euìpment
MMPil
versal yoke; and an up-to-date cross
reference.
Suggested price of the PJS-298 is
$229.95.
These features supplied by the
manufacturers are listed at no -charge
to them as a service to our readers.
It you want factory bulletins, circle the
corresponding number on the Reply
Card and mail it to us.
Test Jig Adapter
The RCA 10J107 test jig adapter
increases the capability of present
test jigs, permitting the servicing of
color TV receivers produced by some
45
3000); 90° CRT extension; yoke extension; safety anode extension; uni-
manufacturers, including tube,
hybrid, and solid state models.
Horizontal and vertical yoke impedances can be matched to a wide
range of TV receivers by means of
front-panel switches, thereby eliminating the need for transformer adapters
and plug-in switch units common to
most other jigs. The 10J107 also can
be used to update earlier RCA test
jigs 10J102; 103; 104; and 105.
For More Details Circle
SEND FOR
FREE CATALOG
(37) on Reply Card
Frequency Counters
WITH ALMOST
A full 8 -digit LED display, a high -
3000
stability TCXO internal reference,
and overdrive protection now are
available as standard equipment on
the Series 7500C frequency counters
from Dana Laboratories. All three
features were previously options costing $250.
The standard 8 -digit display provides 10 times greater resolution than
was previously available on the standard 7500 series counters. The overdrive protection is a fuse between the
50 -ohm input and the attenuator circuitry, protecting from input signals
exceeding 5 volts. Sinewave sensitivity is 15 mV rms through the entire
frequency range to 1 GHz. The Model
7580C measures signals up to 1 GHz
with automatic gain control from 15
mV to IV rms; the 7570C to 600 MHz.
For More Details Circle
INCLUDING
B&K, EICO, RCA,
FLUKE, SENCORE,
SIMPSON, HICKOK
and LEADER
plus a complete line
of tubes, tools and
electronic supplies
at prices you won't
believe.
FORDHAM
(38) on Reply Card
RADIO SUPPLY CO., INC.
Conklin St., Farmingdale, N.Y. 11735
855R
Frequency Counter
A frequency counter has been
added to the Non -Linear Systems' line
of miniature, battery -powered test
instruments. The portable FM -7 frequency meter will monitor frequencies
from 10 Hz to 60 MHz and display the
User price of the 10J107 is $89, and
includes a low -impedance yoke, yoke extension cable, ground lead, test jig
yoke cable, and complete instructions.
For More Details Circle
frequency to seven digits, using 0.25"
high LED's. Input sensitivity is 30
millivolts RMS from 50 Hz to 30 MHz,
and 100 millivolts RMS from 10 Hz to
60 MHz, with a 1-megohm input
impedance. It has an input -signal
overload capability of up to 250 volts
RMS at 500 KHz. The gate time is 1
Tel: (516) 752-0050
For More Details Circle
I.C.C.TUBES-BO%& 1O%0FF LIST
I.C.C. 608
100 for $59.00
VALUE
SALE
SYLVANIA -70%& 10%OFF LIST
(ALL TUBES NEW & FACTORY -BOXED)
Write In All Tube Numbers Wanted
...
TRANSISTORS EQUIVALENT
UP TO 95% OFF LIST -MINIMUM 10
ECG
SK
O
0
3018-108
3024-128
3041-152
3103-157
3079-162
.... ea.
.... ea.
.... ea.
.... ea.
221-45,
46,
YOKE
SK
ea.
ea.
ea.
ea.
ea.
ea.
$ .20
$1.20
$
$
.20
.20
$1.20
$
.69
$3.95
I42
133,
ea. $1.47
ea. $1.95
BSR SC7M2
EV
26-$1.49
GE
650,
5015
ea.
ea.
ea.
ea.
ea.
660
TETRAD -AI Numbers
TN4B,
VARCO-
0
CN75
ZEN.- 0 142-167, 0 142-168
N44, 075, 0N91, V1
0 N3 -89c
TETRAD Dia. Univ.
10
$1.95
$2.50
$1.95
$1.50
$1.95
$1.95
for $5.90
CB HARDWARE
PL259
10 for $3.90
10 for $4.90
PL258
3 ft. RG58U Cable 2PL259
20 ft. RG58U Cable 2PL259
O 20 ft. RG58U Cable PL259 Spade lugs
will accept thousands of chassis listed
cross-reference
chart.
August, 1976
.
48
-Y-130
Astatic-
Color Test Rig
The Universal PJS-298 test rig for
tube and solid state color-TV chassis
Accessories include: convergence
yoke assembly; blue lateral assembly;
convergence load; transverter (TA -
ECG
3114-159 ...
3115-165 ...
3124-123A ..
3132-161
$.20
5.20
$.39
$.39
AUDIO -CARTRIDGES -NEEDLES EQUIV.
(36) on Reply Card
The PJS-298 incorporates a special
33KV 19" leaded -glass CRT to protect
technicians from any radiation produced by the increased high voltages
of the newer color receivers.
Included as standard equipment:
40KV meter with 50 microampere
sensitivity for accurate, low drain
monitoring of the anode voltage; and
a built-in speaker which hooks -up
with alligator clip extensions.
(19) on Reply Card
T&T
I
on the Telematic
ITEMS
0
100 ft. RG58U Caole 2PL259
Quantity Prices Available-We Will
Custom -Make Any Size.
CB Stereo Lock Mount
GENERAL
second, giving a resolution of 1 Hz
below 10 MHz and 10 Hz from 10
MHz to 60 MHz. Accuracy is ±1
digit; there is only a ±10 PPM
change over a temperature range of
0°C to 40°C.
Priced at $195, the FM -7 comes
with rechargeable NiCad batteries
and a charger unit. Options include a
panel -mount flange, a tilt stand, and a
leather case.
For More Details Circle (39) on Reply Card
Matching Transformer
300 ohm Signal Splitters
72 ohm to 300 ohm
ea.
ea.
ea.
ea.
$1.00
$2.50
$2.00
$5.50
ea. $2.95
..10 for $4.95
10 for $5.95
200 ft. Bell Wire
500 ft. Speaker Wire, Heavy Gauge
$1.00
$5.00
LETTERS OF CREDIT AND ALL CHECKS PLACED ON DEPOSIT
WITH MANUFACTURERS HANOVER TRUST BANK, N.Y.C.
$100.-C.O.D.'s 50% DEP.
MASTER CHARGE
MINIMUM ORDER $60. FOB BROOKLYN, N.Y.
REFUNDABLE UPON YOUR ORDER
CATALOGS
SEND CHECK OR MONEY ORDERS TO:
-MIN.
-$2.,
CT
& T
SALES CO.)
4802 AVENUE
K
BROOKLYN, N. Y. 11234
Phone: (212) 241-5940
For More Details Circle
(20) on Reply Card
55
less than 4 dB; an Omni -directional
capacitive end -loop folded -dipole element; a shielded coaxial cable; and a
75-300 ohm matching transformer for
matching the antenna to an FM tuner.
aotenna systems
ÎjI1JUt
These features supplied by the
manufacturers are listed at no -charge
to them as a service to our readers.
ll you want factory bulletins, circle the
corresponding number on the Reply
Card and mail it to us.
coax with a PL-259 connector at one
end and lugs on the other. This kit
has been designed for mobile installations, and can be used as a replacement coax for CB antennas, such as
Hy -Gain's Gypsy.
Kit #526 is a base station accessory
for antenna installation complete with
50 -foot RG58/U coax and solderless
PL -259 connectors that slide easily
through mounting holes.
For More Details Circle
Rotor Bearing
Unarco-Rohn has a new thrust
bearing (TB -3) for mounting antennas.
Made of heat -treated cast aluminum
for extra strength, the bearing incorporates 30 stainless -steel bearings
in a race that is protected from the
elements. Three lock nuts fasten the
antenna mast in position, thus relieving the weight of the antenna on the
rotor and allowing a free turning
movement.
The FM500 mounting kit includes
antenna, power supply, 10-ft. coaxial
cable and mounting hardware. List
price is $51.95.
More Details Circle (41) on Reply Card
For
Coaxial Cable Kits
Three new pre-cut coaxial cable kits
are available from Hy -Gain ElecAmplified FM Antenna
tronics.
JFD Electronics Corporation has
Kit #523 includes a 3 -foot RG58/U
produced a miniature electronic FM coax with PL -259 type connectors for
antenna.
use between transceiver and station
The FM500 provides the following accessories, such as preamps, power
features: a built-in solid-state transis- meters, or antenna matchers.
tor amplifier that has a noise figure of
Kit #524 includes an 18 -foot RG58/U
(40) on Reply Card
For More Details Circle
(42) on Reply Card
MATV Amplifier
Model A510UV from Ava Electronics is a UHF -VHF -FM amplifier
for MATV systems.
Both 300 -ohm and 75 -ohm inputs
are furnished, bandwidth is 50-900
MHz, and the output can reach +30
dB without overload. The circuit provides surge lightning protection, and
the power supply has a transformer
for isolation.
Model A510UV lists for $37.95.
For More Details Circle
(43) on Reply Card
Coax Switch
The two -position coax antenna
switch from Breaker Corporation permits quick change -over from single to
duals, or other CB antenna arrange-
ments.
COST EFFECTIVE COMPONENTS
Bi -Centennial Special
ASSORTMENT 25 COMMONLY USED
IC
Assortment
IC FOR TV
$17.76
C.E.C.'s First Line Transistors
C.E.C. Specials
Equivalents
ICs
CEC
CEC
CEC
CEC
CEC
CEC
CEC
TRO1
TRO2
TRO3
TRO4
TRO5
TRO6
TRO7
ECG
162
123
159
152
241
197
154
RCA
SK3079
SK3122
SK3114
-
SK3041
SK3085
SK3044
-
GE
61
67
14
--
$3.45
.34
.34
.75
1.30
1.90
.82
160 MFD 250 VDC
Filters 1"
160 MFD 250 VDC
Filters 1-3/8"
Miniature electrolytic
kit 25 popular types
C01
CO2
CO3
ECG
RCA
714 SK3075
731
C11
713
790
712
709
710
725
718
720
723
C12
C13
C14
C15
C16
780
788
793
912
C04
C05
C06
C07
C08
C09
C10
SK3173
SK3077
-
SK3072
SK3135
SK3102
SK3162
SK3159
SK3160
- ---
SK3141
SK3147
--
----
for $9.00
10
for 11.00
8.25
Matching Transformer
GE
IC04 5 for $4.50
5 for 4.50
IC05 5 for 4.50
5 for 4.50
ICO2 5 for 4.50
IC11 5 for 4.50
5 for 4.50
5 for 4.50
IC08 5 for 4.50
IC07 5 for 4.50
5 for 4.50
5 for 4.50
5 for 4.50
5 for 4.50
5 for 4.50
5 for 4.50
10
72 ohm to 300 ohm
Equivalents
ICs
CEC
CEC
CEC
CEC
CEC
CEC
CEC
CEC
CEC
CEC
CEC
CEC
CEC
CEC
CEC
CEC
AND STEREO
Ics
221-31
5
221-32
221-34
221-42
221-45
221-46
221-48
5
221-51
5
5
5
5
5
5
Zenith
numbers
for $4.50
for 4.50
for 4.50
for 4.50
for 4.50
for 4.50
for 4.50
for 4.50
10 for 6.50
Zenith
numbers
Ics
221-52
5 for 4.50
221-62
5 for 4.50
221-65
5 for 4.50
221-79
5 for 4.50
Delco numbers
DM -11
5 for $4.50
0M-31.
5 for 4.50
DM -54
5 for 4.50
also stock new and used
ultrasonic cleaners.
Minimum order $25.00. We pay shipping.
We
C.E.C.
Cost Effective Components
P.O. Box 1965, Burlingame, CA. 94010 415/344-6383
Model 13-200 has a single SO -239
transceiver input connector that can
be switched to either of the two SO 239 antenna cable connectors. It is for
mobile or base station usage, and lists
for $7.95.
For More Details Circle
Dual CB Antenna
The bumper -mounted co -phased
whip combo from Shakespeare features 2 half -wave center -loaded antennas with Shakespeare's Diplexer
harness.
Vertically polarized and matched at
50 -ohms impedance, the SWR reads
1.9 to 1 or less over the entire bandwidth. Gain is 3 dB over a single
loaded quarter -wave antenna.
The 76" fiberglass antenna has
spring loading to protect against
damage from low hanging obstacles.
For More Details Circle
For More Details Circle
(44) on Reply Card
(45) on Reply Card
(21) on Reply Card
56
ELECTRONIC SERVICING
www.americanradiohistory.com
cata IDos
OJIiii
Circle appropriate number on
Reader Service Card.
100. Heath
Company-has
a free
catalog that includes complete de-
scriptions of over 400 electronic
kits-from build -it -yourself color
TV and hi-fi equipment to amateur
radio gear. Two new products introduced are an electronic digital
miles -per -gallon monitor/speedometer, and a low-cost fire and smoke
detector kit.
101. Dana
four-color
Laboratories-a 16 -page,
brochure describes
Dana's full line of 3-1/2 and 4-1/2
digit multimeters. A complete product line recap provides a summary
of Dana's other DVM's as well as
frequency counters. Included is a
detailed accessory listing, as well as
a color -coded specification chart
covering the 3-1/2 and 4-1/2 digit
multimeters, Highlighted is Dana's
new 4600 digital multimeter.
of electronic test accessories. The
76 -page
publication includes a
new -products section,
special
hundreds of photographs, and separate sections on molded banana
plugs, banana plug accessories,
molded patch cords, cable assemblies, test socket adaptors, spaced
engineers. The 86 -page catalog
provides cross references,
specifi-
cations and configurations. Included are twist prong, electrolytic
(aluminum) film dielectric, AC,
mica dielectric, ceramic dielectric
and DC Kraft. Information on
CDE's relays, TV/FM antenna
molded accessories, molded test rotor systems and CB noise filters
leads, connecting leads, and IC test
clips. Special charts cover a cross
index of UG numbers, and an
alphabetical and numerical index is
included.
Enterprise Development
Corporation-features the full line
106.
of Endeco soldering and desoldering equipment in their "Catalog
76". Included are soldering irons,
desoldering irons, kits and the de -
soldering head that converts a
soldering iron into a desoldering
iron. Also shown are tips, desoldering bulbs, solder paks and soldering tool stands.
107. Cornell-Dubilier-has released
their 1976 General Line Catalog
and Electrolytic Guide for professional electronic technicians and
are also provided.
108. Fordham Radio-offers a complete line of electronic equipment
and accessories in their 1976 catalog. They specialize in selling test
equipment, featuring such names as
B&K, Hickok, RCA, Leader, Sen core, Simpson and many others.
Considerable savings are offered on
receiving tubes, parts, and CB
equipment. Also included are parts
kits, tools, and
ment.
soldering equip-
Products-the 52 -page
catalog features coaxial and twin lead cables for CB, amateur radio,
and television use, plus antenna mounting hardware, tools, hook-up
wire, intercoms, audio connectors,
and decorator telephones.
109. Saxton
102. Breaker Corporation-offers a
12 -page, full -color catalog with a
Bicentennial theme. The "Freedom" line of 27 -MHz mobile,
trucker, and base -station CB antennas and accessories is described
with many application pictures. A
technical reference section provides
useful tips on antennas and CB rig
operation.
103. Tab
Books-free 44 -page
1976
catalog describes over 400 current
and forthcoming books, plus 14 of
the firm's electronic book/kits.
Some of the subject matter listed
includes: Amateur Radio License
Study Guides; Appliance Repair;
Basic Electronics Technology; Cornmunications-2-Way, Shortwave
and CB Radio; Do -It -Yourself;
FCC License Study Guides; Radio
Receiver Servicing; Television
Servicing; and many other subjects.
104. Mouser Electronics-offers a
free 56 -page electronics purchasing
manual. Electronic components,
test equipment, tools and production aids are some of the items
featured.
105.
Pomona Electronics-an-
nounces its 25th anniversary catalog
The "New Generation"
Flat -Rate Pricing...
is proving itself in thousands of shops from
coast to coast-it prices your work profitably
while creating customer good -will.
Fast tab indexing to 19 major repair
categories prices all bench, home and overthe-counter repairs with authority.
tv&rodio
tech guide
f
to pricing
Plus, Computerized
Pocket-Size Parts
Catalog.
Customized to
your desired
parts profit.
Lists over 3500
most -used parts,
continually up -dated.
Can easily recover
initial investment in
less than 30 days...
$75.00 plus $10.00
per catalog.
Professional
6 x 9 hard cover,
steel ring -bound
edition....
$19.95 ea. post pd.
Satellite Edition...
the same system described
above, only reduced to
shirt -pocket size for
outside service...
$16.95 ea. post pd.
Quantity prices available.
P.O. Box 5234
Lincoln, NE 68505
Sferry tech
_,
it
!!!!Ili
inc.
copies, Satellite
copies, Hardbound
More information
copies, Parts Catalog.
Amount enclosed, check or money order.
(NE res. add sales tax)
1
NAME
CO.
ADDRESS
CITY
STATE
ZIP
!!!!!!!!m!!!!!!!!!!!!!!!l
For More Details Circle
August, 1976
(22) on Reply Card
57
www.americanradiohistory.com
booki°ie t
new phosphor picture tube
with twice the brightness
CB Radio Accessories
Author: Leo G. Sands
Publisher: Howard W. Sams & Co., Inc., 4300
West 62nd Street, Indianapolis, Indiana 46268
Size: 128 pages, book number 21124
Price: $4.25 paperback
Many accessories for CB transceiver radios are
_.
available factory-made, others can be constructed
by the owner or a technician. Generally,
accessories are used for making the operation
more convenient, increasing the range, reducing
interference, and preventing interference to other
electronic equipment. One limitation in the
addition of accessories is because of the few
"interfaces" on the CB radio. Most such radios
have an SO -239 coaxial connector for the
antenna, a phone jack for an external speaker or
public-address speaker, and a jack for the microphone. Many of the accessories described make
use of these radio outlets, but some require
modification internally of the radio. The book
describes antenna system accessories, audio input
and output devices, control systems, performance
indicators, noise suppression, preamplifiers, and
frequency converters.
Contents: Antenna System Accessories; Performance Indicators; Audio System Accessories;
Power Supplies And Sources; Interference Prevention; Vehicular Noise Suppression; and Receiving Accessories.
TO -60 automatic
dual -trace
triggered -sweep oscilloscope
double the brightness for bright
displays even in high speed dual -trace modes. Bandwidth: DC to 15 mhz. Unique features for the industry's
Automatic Triggering Automatic
greatest value are:
Astigmation Automatic Horizontal Sweep Automatic
Horiz/Vert. TV Triggering provides positive display on
composite video signals. Vertical sensitivity: .01
volts/cm to 20 volts/cm in 1-2-5 step sequence.
Horizontal Sweep Speeds: .2 sec/cm to .5u sec/cm in
1-2-5 step sequence. Has 5X magnifier at all sweep
speeds. External Horiz. Amp. Bandwidth: DC to .5 mhz;
Sensitivity: .5 volts/cm. Calibrated Test Signal: 1 volt
P -P square wave. Power: 105-125 volts, 60 cycles, 65
watts
$489.50
Model TO -60 Less Probes. Net
P-31 phosphor CRT has
TO-55 automatic single -trace triggered sweep oscilloscope. Features same as TO -60 except Vert. Bandwidth
is DC to 10 mhz.
Model TO -55 Less Probes. Net
$379.50
For the "bright one,"
see
your distributor, or write:
eLECTROTECH, INC.
5810 N. Western Avenue, Chicago, Illinois 60659
Troubleshooting With The Dual -Trace Scope
Author: Robert L. Goodman
Publisher: Tab Books, Blue Ridge Summit
Pennsylvania 17214
Size: 224 pages, book number 772
Price: $8.95 hardbound, $5.95 paperback
Veteran servicer Goodman's new book tells all
about the dual -trace scope and its features; how
to use triggered -sweep and automatic -sweep
modes, dual -alternate and dual -chopped sweep
modes, and all the other features. The first
chapter describes several of the various models of
dual -trace scopes available; it lists features, and
defines the specialized operation of these scopes
and their application to color TV and Hi-Fi
stereo -system troubleshooting. The reader will
learn the most important specs to look for before
buying a dual -trace scope. Uses for the dual -trace
scope are described in detail, such as stereo
channel -comparison testing, stage -gain measurements, comparison of pulse widths, checking
countdown and frequency -divider circuits, time
measurements in delay lines, timing checks, and
many more applications. The author provides tips
for locating the specific problem, tells how to use
a dual -trace scope to trouble -track and fault isolate in a quarter of the time required for
single -sweepers. The book is complete with some
252 illustrations.
Area (3121 769-6262
58
For More Details Circle
(23)
ELECTRONIC SERVICING
on Reply Card
www.americanradiohistory.com
Two ways of
vhotoIacti
taking a closer look
BRADFORD
1171A25 (WTG-80150)
1
CORONADO
TV6-1614A, TV6-1624A
597-3
15 MHz @
Alt -chop
1593-3
select at all
speeds
HITACHI
CT -C90, CT-916, CT -926
2mV
Automatic DC balancing
and drift control
1598-1
JC PENNEY
X -Y operation
2112(855-0105)
1574-1
Complete triggering
facilities incl. TV
MAGNAVOX
Chassis T998-01-ZA
1597-1
Lightweight
Approx. 4 kg.
PHILCO
Chassis A22-2
(9 lbs.)
1596-1
Compared to similarly priced instruments, these two new Philips
oscilloscopes give you better viewing value than ever before.
RCA
Chassis CTC74K
Chassis CRK22A l DAP -1A
1588-1
Available at your Magnavox Parts Centers. Or, call our toll free
Hot Line number for complete price, delivery and technical
information. Dial 800 645-3043. New York State residents, call
(516) 921-8880 collect.
Philips Test & Measuring Instruments, Inc.
Woodbury, N.Y. 11797
1588-1A
SEARS
562.42100500
1598-2
SHARP
C-1350, C-1350 \N, C-1351
1596-2
SYLVANIA
Chassis E20-3
1584-2
PHILIPS
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CB testing just became a snap.
r-
Now one unit does it all.
Hook our versatile Model 388 in line with your
transmitter and instant digital readouts of a transmitter's four most important operating parameters
are a turn of a switch away.
A front -panel AM Monitor Output makes scope
display of modulation easy. A pushbutton selects
front panel or in -line frequency input. And changing
to 12V operation is easy, too.
Get your hands on the new Hickok Model 388 CB
In -Line Tester. We're betting you can't let go.
HICK OK
nnooF. -+fie
CB
IN LIN
'F,TER
The Hickok Model 388 CB In -Line Tester
element of the
modular Hickok CommLine. To
put together the CommLine
system that's right for you,
talkto your H ickok distributor.
is one
F-equency
SWR
Comm/
MODEL 388
$349
Power
MODEL 388X
$475
HICKOK
%
Modulation
Hickok Model 388X features a precision temperature
compensated crystal oscillator with 1 ppm accuracy.
.
ine
HICKOK
the value innovator
INSTRUMENTATION & CONTROLS DIVISION
THE HICKOK ELECTRICAL INSTRUMENT CO
10514 Dupont Avenue Cleveland. Ohio 44108
(216) 541-8060
TWX 810-421-8286
August, 1976
For More Details Circle
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59
www.americanradiohistory.com
The MARKETPLACE
This classified section is available to
electronic technicians and owners or
managers of service shops who have for
sale surplus supplies and equipment or
who are seeking employment or recruiting
employees.
FOR SALE (CONT.)
TRANSISTOR TESTER. Convert transistor radio
into in -circuit transistor tester. Tone indicates
good transistor. Plans $2.00. SZA Electronic Systems Inc., 39 Bayberry La., Levittown, NY 11756.
7-76-3t
GET LATE MODEL Color TV's (rebuildable) for
$10-$20-$30. All you can use. Practical plan
makes to $100 day plus for skilled TV Techs. Detailed instructions, method, $10 ppd. Economy TV
7-76-2t
Rentals, Box 2890, Denver, CO 80201.
Advertising rates in the Classified Section are 35 cents per
word, each insertion, and must
be accompanied by cash to
insure publication.
Each
counts
SOLID STATE &
HOBBY CIRCUITS MANUAL
$1.95 postpaid to your door. The new
manual offers over 400 pages of circuits for the hobbyist, engineer, experimenter and do-it-yourself kit builder. HURRY-Supply limited. Free catalog. Frazer & Associates, Dept. ES,
1888 Century Park East Suite 10, Century City, Calif. 90067.
initial or abbreviation
a
full word.
Minimum classified charge $3.00.
For ads on which replies are
sent to us for forwarding (blind
ads), there is an additional
charge of $3.00 per insertion to
cover department number, processing of replies, and mailing
costs.
WANTED
Classified columns are
to advertising of any
regularly produced by
turers unless used
longer owned by the
turer or a distributor
not open
products
manufacand no
manufac-
WANTED: TV SERVICE BUSINESS in Pennsylvania, New Jersey or New York. Dept. 510, Electronic Servicing, 1014 Wyandotte St., Kansas
City, Mo. 64105.
8-76-1t
EDUCATION -INSTRUCTION
symptoms with a copy
schematic and self-addressed stamped envelope and $2.00, to Troubleshooter, Box 4553,
Downey, Ca. 90241 Results Guaranteed. 9-75-tí
TV PROBLEMS??? Send
of
FOR SALE
NEW Canadian Magazine "Electronics Workshop". $5 00 yearly. Sample $1.00. Ethko, Box
10-75-12t
741. Montreal "A" Canada.
CONVERT any transistorized T.V. tuner to a tuner
substituier. Plans $2.00. New accelerated Radio
& T.V. course. RADIO TELEVISION TRAINING,
8-75-tf
Box 279, ES -66, Syracuse, N.Y. 13206.
SAMS PHOTOFACTS-1 to 1451. Owner retiring.
Equipment, parts, all for sale. Write for list and
prices. Sol Coker, Willow Springs, Mo. 65793.
417-469-2515.
8-76-1t
OLDER & OBSOLETE-Radio & TV tubes. All
new and boxed. Old Sam's Photofacts too. If it is
an oldie we have it. Send $1.00 (Refundable) for
tube catalog. Garrentt's, P.O. Box 2055, San
8-26-2t
Diego, Calif. 92112.
TV & RADIO TUBES 36c EA!! Free color catalog.
Cornell, 4221 University, San Diego, California
92105.
8-76-tf
REPAIR TV TUNERS-High Earnings; Complete
Course Details, 12 Repair Tricks, Many Plans,
Two Lessons, all for $2. Refundable. Frank
Bocek, Box 3236 Enterprise, Redding, Calif.
8-76-tf
96001.
CONVERT YOUR B&K 465 OR 466 REJUVENATOR
to a powerful c.r.t. restorer system. Step by step
plans with pictures. $8.00. James Chancellor,
1708 Edgerly, Albany, Ga. 31707.
8-76-2t
HINTS-Repair your TV. Send make, model,
$2.00 and stamp. Charles TV, 2033 McGraw Ave.,
NY 10462.
8-76-1t
TV
FREE-Giant bargain electronic catalog, listing
thousands of components, tubes, transistors,
IC's, kits, test equipment. EDLIE'S, 2700 -EA,
Hempstead Tpke., Levittown, N.Y. 11756. 8-76-31
SHOPS-Increase your income. Repair and
update MATV systems with patented method.
$200.00 day possible. Training available. P.O.
7-76-61
Box 809, Boynton Beach, Fla. 33435.
TV
SAMS -1 through 1563, $3000. Herrick Electronix,
RR 1, Box 492, Coos Bay, Oregon 97420. Phone
(503) 267-2773.
8-76-1t
STOP...don't junk that television set. ASE manufactures the world's most complete line of television picture tubes. No other company offers:
Over 2200 types of television picture tubes. Most
types immediate delivery. Transportation paid in
some areas. Tubes for old or new models.
Complete line of black & white and color. Full 2
year factory warranty. Lowest prices anywhere.
Finest quality. We accept BankAmericard and
Master Charge. Write today for more information.
Allied Sales & Engineering, Inc., Dept. 40,
Pimento, IN. 47866. Telephone - 812-495-6555.
8-76-2t
UNUSUAL SURPLUS AND PARTS Catalog. $1.
ETCO Electronics, Dept. E.S., Box 741, Montreal
7-76-10t
"A" H3C 2V2.
BUSINESS OPPORTUNITY
location 15 years.
over $25,000. Retiring. Including truck,
equipment & inventory $25,000. A. Bolin, 6361
Balsam Lake, San Diego, Ca. 92119.
6-76-tf
TV SALES & SERVICE in same
Nets
TELEVISION SALES & SERVICE business for
sale. Same location for 18 years. Test equipment,
Parts, Sams, RCA & Sylvania Franchise. Building
for sale or lease with business. 3200 sq. ft., 2
floors, 2 furnaces, 2 air conditioners. 73 Ford
Van (optional). Net's $20,000 +. Piedmont, N.C.
Selling for health reasons. Write to Box 511,
Electronic Servicing, 1014 Wyandotte St., Kansas
8-76-1t
City, Missouri 64105.
BUSINESS OPPORTUNITY
BUSINESS- with 3 bedroom ranch
acre in rural town of 12,500. Retiring. Gross
TV SERVICE
on
1
$20,000 annually. Authorized factory service
Magnavox, RCA, Zenith. $7,500 in merchandise.
$5,600 in equip. Everything for $42,000 or mdse.
and equip. for $5,000. Delux Electronics, 156
Robert St., Westport, Mass. 02790.
8-76-1t
BEAUTIFUL SCENIC MONTANA-Take over 20
year TV Sales and Service business. Gross
$45,000. For more details write: Box 370, Red
Lodge, Montana, 59068 or call (406) 446-1102.
8-76-3t
HELP WANTED
VIRGIN ISLANDS-Family-run shop needs solidstate audio & TV bench techs. CB exp. helpful.
Send resume to: Glentronics Inc., Box 6-L,
Sunny Isle, St. Croix, U.S.V.I. 00820..8-76-1t
advertisers' LI N
_
American Technology
29, 54
Corporation
B & K Div., Dynascan
29,31
Corp.
Blonder-Tongue Laboratories,
Inc.
25
Bussman Mfg. Div.,
McGraw -Edison
Cover 3
Cover 4
Castle Electronics, Inc.
Cost Effective Components ....56
Enterprise Development
42
Corporation
Fordham Radio Supply
55
Co., Inc.
10
General Electric Company
Hickok Electrical
Instrument Co.
59
Lectrotech, Inc
58
Mallory Distributor &
Special Products
3
Mountain West Alarm
Supply Co
9
Non -Linear Systems, Inc.
54
Philips Test & Measuring
Instruments, Inc.
59
Pomona Electronics Div. of ITT
2
Precision Tuner
Service
1, Cover 2
Projector Recorder Belt Corp. ..42
RCA Distributor & Special
Products
9, 11, 14, 15
29
Sitco Antennas
Sperry Tech, Inc.
57
GTE Sylvania ECG Consumer
Renewal
7
T & T Sales Company
55
Tuner Service Corporation
5
Winegard Company
13
ELECTRONIC SERVICING
60
www.americanradiohistory.com
Buss® Fuses
Specïalìze
Too!
in the protection o
four new BUSS fuse assortments
Now
exclusively designed with replacement fuses to
offering a
service most Citizen Band Radios
whole new area of opportunities for increased
profits.
5 in metal boxes
Two assortments contain 48
(240 fuses). BUSS No. 240CB-3 fuse assortment
comes in a handy metal display stand. BUSS No.
240CB-4 fuse assortment is packed in a compact
plastic display box.
In addition, there are two fuse assortments con5 in metal boxes (80 fuses). BUSS
taining 16
No. 80CB-1 fuse assortment packed in a metal
display stand and BUSS No. 80CB-2 fuse assortment in a plastic display box.
Both BUSS fuse assortments contain a careful
selection of the most popular fuses used in CB
radios.
CB dealers can now have the fuses they need in
a neat complete package to service all their
customers fuse needs.
For full fuse assortment details, write for BUSS
Bulletin CBA.
.
.
.
-
-
-
Nc. 240CB-3
Metal Display Stand
No. 240CB-4
Plastic Display Box
No. 80CB-1
Metal Display Stand
No. 80CB-2
Plastic Display Box
BUSSMANN MANUFACTURING
McGraw-Edison Company Division
St. Louis, Missouri 63107
a
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www.americanradiohistory.com
s
FUS
THE QUALITY UNE
CASTI E Timesavers
... for the
Professional
SOlDER®
Ti' signal circuit analysts
Analyze the ENTIRE signal circuit system of any Color or Black
& White Television receiver
by signal substitution.
...
Outputs at video i.f., sound i.f., video and audio.
Inbuilt monopole antenna
Inbuilt loudspeaker
carrier level meter
Battery indicator meter
Use on the bench or in the home ... anywhere.
Video
Complete with 120vac wall plug-in transformer and matched
test cables.
MASTER SUBBERG Analyst Mk V net $169.95
UH! -VN!
IV tuner and i -f
IV tuner and i -f
signa/ analyst
signal analyst
120 VAC
120 VAC + Battery
*
Battery
Mark /V -C
Mark /V -CUL'
net $64.95
net $54.95
NEZZER. Tv field
Use for measurements of TV signals
Strength Meters
in:-
Antenna installation
Antenna evaluation
CATV
MATV
Output calibration of TV signal generators.
TV Service VHF
field Strength Meter
Simple to operate
Measures 300uV to 30,000uV.
Uses ordinary 9v transistor batteries
Mode/ TVS
net $69.95
VHF field Strength Meter
Range:
20
100
UHT field Strength Meter
microvolts to
millivolts.
Attenuator: x 1, x 10, x
Inputs: 75 & 300 ohms.
120vac &
Range:
microvolts to
millivolts.
Attenuator: x and x 10.
Inputs: 75 & 300 ohms.
100.
1
batteries
120vac &
Model FSM -V
net $119.95
Castle products
20
10
batteries
Mode/ TSM- U
net $99.95
- advanced technology - modern styling -
Ask your electronic distributor for them
CASTLE ELECTRONICS, INC.
and they work!
... or write for more details.
5701 N. Western Ave., Chicago, III. 60645
In
Canada: Len Finkler Ltd., Ontario
For More Details Circle
(3) on Reply Card
Ph. (312) 728-1800
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