S D COLOR TV - americanradiohistory.com · ing the screen is fully synced - automatically. And for...

DS

WHY WAIT?YOU CAN MAKMONEY NOW!

4

COLOR TV

...IF YOU'RE EQUIPPED - AND

A WIDE BAND SCOPE IS A MUST

OVER 750,000 SETS IN 1963

65% OF NBC PROGRAMMING*IN COLOR

LOWER PRICED 70° SETS TO BEINTRODUCED IN 1963

1,500,000 ALREADY IN USE

This Hickok -quality, full 5", wide -bandscope - factory assembled, wiredand calibrated can put you in colorTV service ... for less than $200.00.

Rise time -less than 0.08,4sec. AC response -5 cycles to 4.5 MC within 3 db Vertical sensitivity- 40 MV RMS/inch 5 times horizontal sweep expansioi Sharp, bright (1600 volts anode po7.ential)

Trace with full astigmatic correct.onand, of course, it's...

moan r15 L 656XC MODEL

THE COM'LETE COLOR LINE

MODEL fill

HE

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ELECTRICAL INSTRUMENT10566 DUPONT AVENUE

- - - for more details circle 22 on post card

Another BUSS First

New BUSS

VISUALPAKWith the clear plastic box,

there's no need to open

to see how many fuses are in it.

Th.?, new BUSS fuse Tisual-Pak' origi-nated by BUSS holds five fuses and is anoutstanding development in fuse packaging.

Thy box doesn't have to be opened to seethe n -amber of fuses in it. This is a real helpwhen taking inventory-and it also guardsagainst running short on fuses.

Slide cover top securely grips bottom ofbox t3 prevent accidental spilling of fuses.

For quick identification, size and type offuses are printed in large clear type on aflat apron on the lid of box.

The new BUSS Tisual-Pak' fits ±splaystands and channels-it has the samedimensions as the BUSS metal box.

Many sizes of BUSS fuses are now beingshipped in the Tisual-Pak', and shortly allsizes will be shipped in this modern package.

BUSS continues to be your profit line infuses because-it's the complete line-it'sthe quality line-and it's the line with out-standing merchandising aids, such as thenew 'Visual -Pak'.

BUSSMANN MFG. DIVISION

MAKERS OF THE COMPLETE LINE OFFUSES OF UNQUESTIONED HIGH QUALITY

McGraw-Edisoi Co. St. Louis 7, Mo. VAUGUST 1963

- - - for more details circle 14 on post card19

From RCA Victor anotherbig advance in

Space -Age Sealed Circuitry

RCA Victor Color TV Chroma Circuitry

You can see at a glance how new streamlined "road -mapping"makes servicing faster, easier, surer than ever before

Pictured above is the "new look" in RCA SpaceAge Sealed Circuitry . . . the new precision -crafted boards that you'll see in all 1964 NewVista Color and in most RCA Victor black -and -white television sets for 1964.

This new schematic diagram "road -mapping"consists of straight white lines that run directlyfrom point-to-point. No confusion, no difficultpaths. And the extra space gained has been used

to make the label markings larger. You can seeand trace the circuits at a glance.

Here again RCA Victor has made a vitallyimportant contribution to easier, faster andmore accurate servicing. It is part of our con-tinuing research program to offer the utmost inreliability with Space Age Sealed Circuitry.

See Walt Disney's "Wonderful World of Color,"Sundays, NBC-TV Network HIS MASTER'S VOICE

The Most Trusted Name in Electronics

Trilk(s)'

20 ELECTRONIC TECHNICIAN

WORLD'S LARGEST

ELECTRONIC TRADE

CIRCULATION

RON KIPP

VICTOR L. BELL

JACK HOBBS

WARREN CREWS

ALEX ORR

JERROLD PATTERSON

EARL HINTZ

MAGGIE KANE

JIM GHERNA

JERRY WHITTLEiEY

Publisher

Editor

Managing Editor

Technical Editor

Assistant Editor

Assistant Editor

Production Manager

Advertising Production

Art Director

Circulation Mgr.

ETHEL NASH Circulation Fulfillment

AN OJIBWAYPUBLICATION

OJIBWAY PRESS, Inc.Ojibway BuildingDuluth 2, Minn.

AREA CODE 218 727-8511

Sales Offices:

NEW YORK: Ron Kipp, 480 LexingtonAve., New York 17, N. Y. TN 7-0011CHICAGO: William Klusack, 221 N.LaSalle St., Chicago 1, Ill. CE 6-1600CLEVELAND: Arnold T. Suhart, 6207Norman Lana, Cleveland, OhioYE 2-6666LOS ANGELES: Boyd B. Garrigan, 1145W. Sixth St. Los Angeles 17, Calif.HU 2-2838

Copyright 1963 by Oilbway Press, Inc.,Duluth 2, Minn. Reproduction and reprintingprohibited except by written authorizationof the publication.If you have a change of address or a ques-tion about your subscription, write: ELEC-TRONIC TECHNICIAN, Circulation Depart-ment, Oilbway 3uilding, Duluth 2, Minne-sota. BE SURE TO SEND ALONG THE AD-DRESS LABEL FFOM YOUR MOST RECENTISSUE.

ELECTRONICTECHNICIANAUGUST 1963 Vol. 78 No. 2

COVER: The cover photograph this month was made by RCA. The subject is their newestchassis, the CTC 15 which features a cooler Novar horizontal output tube, dark heater de-sign in all tubes and a Nuvistor tuner. New designs it color TVs from most manufacturers makethis a year to watch for the start of the color boom. To help technicians prepare for setsthey will be selling and servicing ET is focusing on cclor information in this issue.

CONTENTS

Letters to the Editor 22Technical Digest 27Editor's Viewpoint 31Manufacturers Color TV Review 32Understand Color TV Signals 33

by Andrew Murnick Jr

Evolution of a Color CRT at Sylvania 36Test Equipment for Color TV 38

by Ken R. BasilThe Versatile Neon Tester 41

by Joe E. SportRadar Alarm System 42Update Your Mailing List 42

by Ernest W. FairSubstituting Deflection Yokes 44

by Jay ShaneThe Best Test Equipment is Free! 46

by Art MargolisAntenna Installations for Color TV 48New Circuits for Color Sets 50Servicing Hand -Held Citizens Band Transceivers 51'Tough Dog' Corner 56

5860

Transmission Lead-ins for Color TV 70by Roland Miracle & Robert Spode

Transistors Require Proper Meters 72by Max Alth

Servicing Transistor Amplifiers in Hybrid Auto Radios 74by Jack Brayton

Auto Radio ReverberationNew BooksNews of the IndustryFree LiteratureAdvertisers Index

Shop HintsNew Products

7880808182

TEKFAX 16 PAGES OF LATEST SCHEMATICS

AIRLINE: Reverberation Unit, Model GVC-9019A

DELCO: Reverberation Unit, Oldsmobile andPontiac Models 7284742 and 7284893

DUMONT: TV Chassis, 120622-A, 23-B, 44-Aand 88-A

RCA Record Player, Series 4VC6 and 4VC8

TELE:TRO: Tape Recorder, Model MM -214

UTICA: CB Transceiver, Model T 8 C II

WESTERN AUTO: Tape Recorder, 4DC7465

ZENITH: Remote Control, Chassis 5-60804,44, 1204 and Hand Control S-54344

AUGUST 19d3 21

makeexin dollardolla

with for sto eAn oscilloscope gives a visual picture of what ishappening in a circuit, something no other testinstrument can do. This very feature makes agood scope a money maker for your shop. Itsaves you time, analyzes those intermittentfaults, and makes routine servicing easier thanever. Once you start using a scope regularlyyou'll never be without one.You've pulled a set with a buzz in the sound. Isit 60 -cycle hum or 60 -cycle buzz? A quick lookwith the scope and you'll know. You'll eithersee a 60 -cycle sinewave caused by heater -cathodeleakage or there'll be a vertical deflection saw -tooth probably resulting from a defective bypasscapacitor.I.f. alignment required? A scope is a must. Setit up along with your EICO post injection sweepgenerator, and you have only to adjust trans-former and sound trap slugs to finish the job.Same thing for setting up the 4.5 -me soundtakeoff network..Losing the signal somewhere in the video cir-cuits? Hook up the scope and see where it'sgoing astray. There's a good rhance you'll spotthe bad component at the same time.But when you go to buy a scope, what do youlook for? Large screen, high sensitivity, fre-quency response, attenuators, synchronization,calibrator? All of these are important and areincluded in the design of any professional scopeintended for the service technician.Large screen: You can get by with 3 inches,but take the 5 -inch screen of the EICO 460. Geta close look at what's happening. It's got anedge lit calibrated bezel too. High sensitivity:The 460's vertical amplifier delivers 25 my percm. All you'll ever need and more. Frequencyresponse: EICO makes it flat from de to 4.5 me

in the 460. Ideal for color and black and white aswell as industrial production and research.audio testing and experimenting. Attenuators:The vertical attenuator in the EICO 460 is4 -step frequency compensated network. Can'tbeat this kind of design. Sync: Any signal reach-ing the screen is fully synced - automatically.And for special purposes you can inject yourown external sync signal. Calibration: Accuratepeak -to -peak voltage calibrator is built rightinto the 460.All this adds up to the top scope for TV service.You can get it as a kit for $89.95 or completelywired for $129.50.If you don't need so elaborate an instrument,take a careful look at the 427 de to 1 me scopeor the new 3" General Purpose scope, the EICO430 (Lit, 865.95: wired, $99.95). The new 430does everything bigger and more expensivescopes do. Vert amp/flat from 2 c to 500 kc,-6 di, at Ime. Sensitivity 25 my/cm. Horiz amp.flat from 2 c to 300 kc. Sensitivity .25 V/cm.Flat face 3" tube: mu -metal shield eliminateseffects of external fields.There are plenty of accessories for EICO scopestoo. An Electronic Switch to put two differentsignals on the scope screen at the same time( EICO 488: kit, $23.95; wired, $39.95). VoltageCalibrator for the less expensive 427 and 430( EICO 495: kit, $12.95; wired, $17.95). Threeaccessory probes -demodulator, direct and lowcapacitance types.Whether it's scopes, tube testers or VTVM's youget the best for less with EICO. Save money bybuilding your instruments from kits, or buythem factory -wired at a substantial savings.See your distributor. Write for complete 28 pagecatalog. Dept. ET -8 Add 5% in west

EICO ELECTRONIC INSTRUMENT CO. NC., 3300 Northern Blvd, L. I. C. 1, N. Y.

LETTERSTO THE EDITOR

Wants Styli -Record ArticleI enjoy your magazine a great

deal. Your articles are both in-formative and helpful.

However, there is one article Iwould like to see which has not ap-peared. This is an article on phono-graph records. A few of the ques-tions I have are as follows: Whatcauses the surface noise found oneven the most expensive records?Can it be avoided through care ofthe records or must it be filtered outalong with parts of the music? Isthere some preparation on the mar-ket with which a record may betreated to lessen the static? Doesthe type of needle or needle wearhave any effect on this problem?

Thank you very much for yourattention. Keep up the good work.

JOHN R. FINKRoanoke, Va. We have an article on styli andphonograph record wear scheduledfor the September Stereo Annualissue of ELECTRONIC TECHNI-CIAN. - Ed.

March ArticleIn your March issue, an article

by Mr. Faler was illustrated withtwo antenna pictures. These twoproducts are not made by the Gen-eral Electric Co., nor does the Gen-eral Electric Co., either directly orindirectly, recommend the use ofthese products. When this articlewas submitted by Mr. Faler, therewas no mention of the use of suchillustrations, and it is of serious con-cern to our company that the useof such illustrations in conjunctionwith the article may be wrongfullyconstrued as a possible companyendorsement of the products.

J. S. KELLY,General Electric Co.

Syracuse, N. Y. The article in question was il-lustrated by the editors. These pic-tures were intended simply to showexamples of FM only antennas. -Ed.

May ViewpointI just finished reading "Editor's

Viewpoint" in the May, 1963 issue- - - for more details circle 17 on post card


the HIDDEN 600*PRESENT `-'4:1iTN_

WORLD FllillOUS PEINERERS,V *The "Hidden 600" are Sprague's behind -the -scenes staff of 600 experienced researchers; who man the largest research organization in the electronic component industry and who/ back up the efforts of some 8.500 Sprague employees in 26 plants.

DIP-I:LDS® EXA,ACX ExiElitt771Y"MOLDED TUBULAR CAPACITORSThe world's most humidity -resistant molded capacitors. Dual dielectric-polyester film and special capacitor tissue-combines best features of both. Exclusive HCX" solid impregnant produces rock -hard section-nothing to leak, ordrip. Tough case of non-flammable phenolic-cannot be damaged in handling.

DIFILMORANGE DROP® DIP.WATCUITBOUR1-."Especially made for exact, original replacement of radial -lead tubulars. Ideally suited forprinted wiring boards. Dual dielectric combines the best features of both polyester film andspecial capacitor tissue. Exclusive HCX) solid impregnant-no oil to leak, no wax to drip.Double dipped in bright orange epoxy resin to beat heat and humidity.

II

SPRAGUEvintic,)

fl7'6 ELECTROLYTIC CAPACITORS

0 The most dependable capacitors of their type. Builtto "take it" under torrid 185°F (85°C) temperatures-in crowded TV chassis, sizzling auto radios, port-able and ac -dc table radios, radio-phono combinations,etc. Hermetically sealed in aluminum cases for excep-tionally long life. Withstand high surge voltages. Idealfor high ripple selenium rectifier circuits.

A SPRAGUE

ELECTROLYTIC CAPACITORSThe smallest dependable electrolytics designed for 85°C operation in voltages to 450 WVDC. Small enough to fitanywhere, work anywhere. Low leakage and long shelf life. Will withstand high temperatures, high ripple currents,high surge voltages. Metal case construction with Kraftboard insulating sleeve.

CERA-MITE®CERAMIG CAPACITORS -1',Tiny, tough, dependable in practically every application. Low self-inductance of silvered flat -plate designgives improved by-pass action in TV r -f circuits. Higher self -resonant frequency than tubular ceramicsor micas. Tough moisture -proof coating. Designed for 85°C operation.

LNOW APPEARING DAILY AT YOUR FAVORITE SPRAGUE DISTRIBUTOR!For a permanent reference to this world-renowned galaxy of star performers, ask your Distributor for a copy of Sprague'shandy Hanging Wall Catalog C-457, or write Sprague Products Company, 65 Marshall Street, North Adams, Massachusetts.

65.370

AUGUST 1963- - - for more details circle 33 on post card

23

NEW

SECO TUBE TESTER

Model 98GUARANTEED

TO GIVE ALL MODERECTIFIERS ARN TV TUBES,

RADIO TUBES AND FILAMENT

COMPREHENSIVEANALYSIS checks heater current

on series string tubes

N*oNO

40

10.. TO5VVIrC.

111111rFAD.O.

0,

N

c ',THOME SitaatIVM.01 v $

NEW SECO MODEL 98ONLY 50

'7 NETThis new test instrument is acomplete tube tester that locates alltube faults quickly and accurately. It hasa two -stage DC amplifier which isolates the rugged1 ma meter from the tube under test, protecting themeter and permitting a wide range of load currents andtest conditions. The new Model 98 tests more than 2500 differenttubes. The entire unit is contained in a compact case with removable cover.The cover holds speed -indexed tube data cards, pin straighteners and condensed operatinginstructions. For complete information see your electronic supply dealer or write to Seco.

A SECO PLUS! Replaceablesocket chassis plugs into meter-ing chassis. Can be econom-ically replaced as it wears outor becomes obsolete. Availablewith special sockets upon re-quest. Guaranteed up-to-datefor all modern receiving tubesincluding novars, nuvistors,10 -pin types, compactrons

t and MAGNOVALS.

GRID CIRCUIT TEST de-tects faults such as gridemission, leakage and shorts-a rapid, reliable multiple -checkdeveloped and patentedby Seco.

TUBE MERIT TEST indi-cates functioning ability of atube by the quality of cathodeemission.

HEATER CURRENT TESTreads on meter. Relies onheater resistance to show coldoperation or improper voltagedistribution in a series stringof heaters.

SECO SELECTRO SYSTEMisolates or transposes tube cir-cuits and controls test current-achieves laboratory pre-cision and flexibility with dial -switch ease and speed.

SECO ELECTRONICS, INC.1211 S. Clover Drive, Minneapolis 20, Minn.

A DIVISION OF DI-ACRO CORPORATION- - - for more details circle 28 on post card

LETTERSTO THE EDITOR

Of ELECTRONIC TECHNICIAN.May I extend my personal appre-

ciation, that you would print thisarticle to vindicate to some extentthe many, many intelligent, hardworking, honest technicians whomust never cease study, must putup with non -understanding custo-mers; who must not only be genius'sat servicing, but also diplomats,businessmen, philosophers, lawyersand, yes, even politicians.

After spending 18 years as anelectronic wholesale salesman andstore manager, I feel more qualifiedto pass judgement on the techni-cians than Canby.

It has been my pleasure to havecalled upon and know practicallyevery technician in Iowa at one timeor another in the past 18 years.

No doubt that we do have somerum-dums and chowder heads thatshould rightfully be in some otheroccupation. There is a constantturn over and it has been my ex-perience that time or nature has away of taking care of all of this.

I wonder if Edward Tatnal Can-by has even had the grevious ex-perience of being "had" by someone supposedly a mechanic, aplumber, a carpenter, a painter oreven our highly educated profes-sional men such as doctor or law-yer? I imagine he has.

It would appear to me that manyof our good citizens ask to be "had"-primarily by looking for thecheapest not the best in service andalso merchandise.

It was indeed a pleasure to readyour article.

DAVID G. KINGDes Moines, Iowa

Directory OmissionIn your May Annual Directory

and Parts issue, we note that the1963 MANUFACTURERS' DI-RECTORY LISTING (omits) . . .

Philco Parts & Service Operations,C and Westmoreland Sts., Philadel-phia 34, Pa.

R. G. SUTTONBala Cynwyd, Pa. 0 u r apologies. Techniciansshould insert this important addressin their May issues. - Ed.


don't

sell

half a

television set!

When your customers come in for a truly portable TV, don'tsell them half a television set. Just consider this : Only withthe remarkable SONY Micro -TV, the Television of theFuture, can they get total reception with the new transistor-ized UHF adaptor that tunes channels 14-83 for a whole newworld of television enjoyment. Micro -TV, with 25 transistorsincluding the advanced epitaxial type in the power supply,is only 8 lbs. to let them carry it anywhere ; it operates on 3types of power-its own rechargeable battery pack, 12vauto/boat power and AC. A full range of accessories for view-ing fun everywhere, in-cluding the back of thecar*. Micro -TV $189.95. ON'IrsUHF adaptor $49.95. RESEARCH MAKES THE DIFFERENCE

1litIIII/IIIIIIIII ttttttttttttttttttttt altIl.

t,,

Before installing or using a TV set in an automobile, cheek with your Motor Vehicle Bureau to verify permissibility.

Please send me more information on the SONY MICRO -TV. ET -8

SONY CORPORATION OF AMERICA Name

580 Fifth Avenue, New York 36, N.Y.. Store

Regional Offices AddressWestern: 500 West Florence Avenue, Inglewood, Calif.

Central: 4959 W. Belmont Ave., Chicago 41, III. City Zone State

Sony Corporation of America 580 Fifth Ave. New York 36, N.Y.


25

3 SPEAKERS CAN NOW REPLACE 16

A. Tn.") 1.7asr sad DelcoThese three new Delco Radio 8 -10 -ohm replacementspeakers permit you to cut 16 numbers from yourinventory. They can replace all units in current Gen-eral Motors cars and many competitive makes. They

install easily and quickly, take a "tip jack," "blade," orsolder connection. Excellent for home hi-fi and TVsets, too! Speak up for the latest in replacementspeakers. Cal! your United Delco supplier today.

THREE NEW SPEAKERS, ALL WITH SLOTTED MOUNTING HOLES SPECIALNumber Size Magnet Wt. Mounting UNIVERSAL 8 -10 -OHM

6 x 9" REAR SPEAKER PACKAGEContains all materials necessary for6126 6 x 171` 1.6 oz. front/rear

6127 4 a 10° 1.6 oz. front/rear rear -seat speaker installation: Speaker,

6128 6" round 2.5 oz. rear -seat Grill, Wiring, Switch. Part No. 6122.

Delco Radio Automotive Radio Service Parts and Electro-Mechanical Devices are distributed nationally through "United DelcoDELCO RADIO. Division of General Motors, Kokomo, Indiana

United %.0Delco

26


ELECTRONIC TECHNICIAN

V28211909

9099.9100

-.I R901 279

- 1-/

\\9V PP

CS0.1 0:11

GENERAL ELECTRIC

vtvSCANS019MAW 09C

NV PP

IttS r1111266itY re4111. me...Ir. 6 I-0, Olt. 61.6066 11111

....VIM 111116616;6.1661.1

--3i411" ittc-OW HDRI I AIM

Radio - P870 Dial Slippage

Some model P870's may be returned to you wherethe complaint is dial pointer sticking at either end.

This condition is usually caused by excessive ten-sion in the dial spring used in the bead chain thatdrives the dial pointer. Correct this by either substi-tuting a replacement spring or by reducing the tensionon the dial bead chain by stretching the spring slightly.

MOTOROLA

Color Sync, Gate and Amplifier - Operation

The gate and color sync amplifier circuitry pass-es and amplifies the color sync signal and rejects allother information. A composite color signal from the

32V -PP I etCOLOR SYNC VITACOLOR130V-FL_

COLOR 4 IN ORMATION

68L8 SYNC

385

FROM COeR I F AmP100

VI7BCOLOR SYNC GATE

200

390

R3

AI - 2700 100K

COLOR SYNC GATE AND AMP

I5OV

3859/

TO AFC010DES

Color sync and gate amplifier circuitry in Motorola's new set.

plate of the first color IF amplifier is fed to the gate -color sync amplifier circuitry. The gate tube is aswitch to turn the color sync amplifier on when thecolor sync is present at its grid and allows the stageto be turned off at all other times. The basic cir-cuitry is shown in the accompanying drawing.

The color sync amplifier plate is fed from a + 385v source and the cathode from a 200 v source. R2and R3 form a voltage divider from the 200 vsource to ground. This causes the V -17A grid to be+150 v. Since the cathode is + 200 v, the tube has-50 v bias and is cut off.

The gate tube plate is connected directly to thecolor sync amplifier cathode. A positive pulse fromthe horizontal transformer is fed to the gate tube grid.When the pulse is present, V -17B draws heavy plate

4501

VII1 ?Wel

Put VtitleI3

LAN NI

current causing V-17A's cathode to become less pos-itive and thus, turn the sync amplifier on. This samepulse causes V -19A to draw current which chargesCl providing bias for this tube.

The color sync signal and the pulse from thehorizontal transformer both occur during horizontalretrace so that the color sync amplifier tube is turnedon during the time the burst of color sync is present,and off during the remaining portion of each scan line.

If the sync amplifier and gate circuitry shouldbecome completely inoperative for some reason, therewould be a complete loss of color sync if a color pro-gram was being viewed; color would be present onthe screen but would be out of sync (scattered throughthe picture). A partially inoperative color amplifier -gate circuit may cause the color sync to be unstableor the hue range to be incorrect.

These circuits can best be checked for normaloperation by removing the chassis and observing thewaveforms with a wide band oscilloscope. The setshould be connected to the color pattern generatoror tuned to a color program. The color signal ampli-tude in the sync amplifier control grid will depend toa degree on the signal strength but the sync signalamplitude on the plate of the stage should be approx-imately 13 times greater than that on the grid. Thearea between the plate circuit color sync bursts shouldbe clean. Any evidence of color information in thisarea would indicate that the amplifier stage is biasedincorrectly. A dc voltage check on the tube elementsshould disclose this.

The gating pulse amplitude should be checkedat V-17A's cathode to insure that the sync amplifieris turned on completely when sync is present. Thesync signal should be centered in the gating pulsemeasured at V-17A's cathode when the horizontalhold control is adjusted at its most stable point. Thisinsures correct timing for the gating pulse to turn thesync amplifier on at the instant the color sync ispresent on the control grid. If these two signals donot coincide, an undesired sync signal phase shift re-sults, causing a hue change on the screen. Incorrecttiming could be caused by incorrect R and C valuesin V-17A's grid circuit.

The gate tube, V -17B, is biased by grid currentcaused by a pulse from the horizontal transformer.In servicing this chassis, the set should not be oper-ated with the horizontal sweep system inoperative foran appreciable period of time without removing V-17or connecting sufficient negative voltage to its grid toprevent tube damage.

AUGUST 1963 27

TECHNICAL DIGEST

When servicing the color sync system, the de-fective stage must be located before the precedingchecks can be applied. If color sync is poor or non-existent, the AFC circuit should be checked first. De-termine if color sync is received at the detector tubeby measuring the dc voltage at pin # 1 of the 6AL5(color oscillator tube removed). This should be near+ 18 v. Determine if the AFC diode is receiving alocal oscillator reference signal by measuring the dcvoltage at pin #1 of the 6AL5 (color sync ampli-fier tube removed). This should be approximately+7.5 vdc.

If the AFC will pass these two tests, the defectis probably in the reactance or oscillator stages. Ifsync is not present at the AFC diode, the defect islikely in the sync gate -sync amplifier or color IF cir-cuitry.

Chassis 136Z - Automatic Brightness Control Circuit

The ABC circuit operates as follows: After op-timum brightness has been set, any change in roomlighting acts on the light dependent resistor. An in-crease in overall room light causes the LDR to de-crease in value. This places the low side of the bright-ness control nearer to ground potential, decreasingB + on the kinescope cathode. Lower potential at

VIDEOOUTPUT

CONTRASTCONTROL

BRIGHTNESSCONTROL

JKINESCOPE

LDR

Automatic brightness control using light dependent resistor in RCAreceivers.

the cathode decreases grid -cathode bias and causesthe kinescope to conduct more heavily thus increasingraster brightness. A decrease in room brightness hasthe opposite effect.

RCA

Record Player Chassis RS -202A - Critical Lead Dress

1. Dress signal cable around transformer T2 on thatside between transformer and "Sing -Along" jack tokeep it from coming into contact with V3.2. To keep hum to a minimum, the portion of thepower cable under the circuit board should be freeof slack so that it dresses toward the interlock.3. The red and blue leads of T2 should be dressedaway from V3 to prevent damage to the wire in-sulation.

ZENITH

Color TV Chassis 25LC20 - CRT Drive Connections

The red cathode is connected to receive maximumfixed output from the Y amplifier. The blue and greencathodes go to two gain adjustments providing Y sig-nal variable coupling. Connections are made througha slip connector and terminal lugs arrangement fromthe three separate gun cathodes. This particular ar-rangement may not be the same on every receiver, how-ever. This is determined at the factory and the arrange-ment depends on which CRT phosphor is least efficient.The least efficient phosphor gun cathode (usually red)is connected to receive Y amplifier maximum fixed out-put. If a new CRT is installed, the least efficient phos-phor gun cathode should be connected to receive max-imum Y signal. Generally, if a new CRT tube is in-stalled, the red cathode gun lead should be first con-nected to the terminal marked R. All cathode leads goto a terminal strip near the chassis rear -center. Theseterminals are indicated R (maximum Y signal), B andG. If a black and white picture cannot be obtainedduring the tracking procedure, it will be necessary tointerchange the connection, placing the least efficientphosphor gun lead on the terminal indicated R. Theother two cathode leads should be connected to theremaining terminals.

SUBSCRIPTION SERVICECHANGE OF ADDRESS

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ATTACH LABEL HEREIf you're moving, please let us know five weeksbefore changing your address. Place your magazineaddress label here, print your new address below.If you have a question about your subscription, placeyour magazine address label here and clip this formto your letter.

name

your job title or position

address

city zone storeI.


Vt..401Z W.

co Oa !YRS00,.

CG126

C )LOR OUTPUT

C)1=1 STANDARD COLOR BAR GENERATOR

ASTANDARDCOLOR BARGENERATOR

THE COST OFOTHERS

$9950Dnly

0.62.-natA)-- 1\1 C O 1=tCG126 STANDARD COLOR BAR GENERATOR

A stardard color bar, white dot, crosshatchger arator especially made for field service oncolcr TV ... and at a great savings to you.

Cleck these outstanding features and youwill see why this generator belongs on the topof y )ur list for color TV servicing.

Al pitterns crystal controlled offering "rocklike" stability. You'll think the patterns arepal ted on the TV screen.

Sirnrlified operation speeds up every servic-ing job. Just dial the standard keyed bars,white dots, crosshatch, vertical bars or hori-zontal bars and watch them "pop" on thescr en. That's all there is to it.

Ezclusive adjustable dot size. The white dotscan be adjusted to the size that satisfies yourneeds by a screwdriver adjustment on the rear.No need to argue about dot size anymore. Justselect the size that you like to work with best.

Pretuned RF output to Channel 4. Other lowcha-inels can be selected if Channel 4 is beingused in your area by simple slug adjustment.Patterns are injected directly into antennaterminals, simplifying operation and savingservicing time.

Reserved output on color bars for forcingsigral through defective color circuits. The coloroutput control is calibrated at 100 percent atthe center of rotation, representing normal out-put. A reserve up to 200 percent is availableon the remainder of rotation.

Smaller and more portable. With colorreceivers weighing much more than black andwhite TV, portable equipment becomes essen-tial for home servicing. The CG126 weighs lessthan 10 pounds and measures only 11"x 8" x 6".

Ten standardkeyed colorbars (RCA type)that automati-cally pro rideall colors atspecified NTSC

phases without need ofinterpretation when servicing.

Stabilizeda crosshatch

pattern for sim-plifying con-vergence ad -"M":"1 justments.

Stable whitedots with newexclusive dotsize adjust-ment in rear.

10 thin whitevertical linesfor horizontaldynamic con-vergence ad-lustmentsoften missing

on other generators.

Ell14 thin horizontal linesfor vertical dynamicconvergence. Alsomissing on many highpriced generators.

March into your local parts distributor and demandthe CG126 Sencore color generator that sells at 1/2the price of others. Don't let him switch you.

e C C 1=1426 SO. WESTGATE DRIVE ADDISON, ILL.

AUGUST 1963

- - - for more details circle 29 on post card29

Compactrons take the heat off service dealers

More and more of today's newest TVsets are featuring compactrons . . .

G.E.'s multifunction electronicdevices. This means, eventually,you'll be seeing more compactroncircuits in your shop. Therefore, toanticipate some of your questionsabout compactrons, let's take a lookat how compactrons can help takethe heat off you and your business:1. Long waits for repair will be athing of the past. Simple compactroncircuits mean you can locate troublefaster, repair it easier, get sets back toyour customers quicker. Fast, effi-

cient service builds repeat businessand gets you free word-of-mouth ad-vertising.Repairs are consistently better be-cause compactrons combine functionshaving similar life spans. Thus if onesection fails, the entire compactronmust be replaced-automatically re-storing top performance through re-placement of the other weakenedsections. You save time by not havingto check extra tubes and you elimi-nate the possibility of "weakened or-dinary -tubes" not showing up on thetester.2. No more call backs! When you fixa compactron set, it stays fixed. Callbacks are virtually eliminated by ser-vice -designed compactrons whichhave a 40% lower operating temper-ature than ordinary tubes. Cooleroperation means greater reliabilityand gets rid of a difficult trouble spot- peeling and cracking of printedcircuits.

3. You make more profit on compac-trons because the unit price is higher.Replacing a compactron is like replac-ing 2 or 3 ordinary tubes. Simplercompactron circuits, plug-in replace-ment, and fewer tubes to check, letyou service more sets in any giventime. Employees become more effi-cient, and need less training.Multifunction design means thateventually you can substantially re-duce your tube inventory. This givesyou more "free" operating capital,more shelf space, plus less capital in-vestment . . . hence a greater profitper dollar invested.Remember, you'll be seeing morecompactrons in the future ... They'llmean easier servicing and happiercustomers for you.

Arm /s Our Most important Prodoct

GENERAL ELECTRICDISTRIBUTOR SALES

30- - - for mare detail's circle 19 on post card

ELECTRONIC TECHNICIAN

EDITOR'S VIEWPOINT

Now or NeverFor some technicians this will be a year of reck-

oning. Color TV has arrived. I must say, however,that many of you put up a good fight - you retardedcolor TV for several years.

Most of you have customers that ask you aboutthe merits of color TV daily. And in the past (somestill do) you've said "It's not perfected yet . . . toomany bugs. Wait another year."

You've stymied the growth of an area whichcould reap greater profits than any other in the homeentertainment equipment field. Why? Because youhaven't seen a good color picture yet? Becauseyou don't understand how it works? Because you haveenough B/W service work?

Well, if you are still preaching non -perfectionand have enough ambition to try to reverse that trend,you still have a chance to stay in the service business.Don't worry about saving your face - you're theauthority; you have the prerogative to change yourmind.

You see, while you were busy in your own littleworld, the manufacturers have been telling the publicanother story. And it's starting to get through in spite

of your insistence that color is still a toy. I've had acolor set for five years. It's been moved all over themidwest and gets played hours and hours every day.It still has the original picture tube and produces pic-tures with quality nearly equal to sets now being man-ufactured. I'm glad I didn't listen to the local TVtechnician. I might have believed him.

Its high time you wake up and see which sideof the bread is buttered. Color TV sales involve alarger money transaction and consequently, a greaterprofit is realized. Service is somewhat more frequentsince a larger number of parts are involved in eachset. Service charges can justifiably be higher sincespecial equipment, additional training and more timeis required to service color TV.

Every industry needs an occasional "shot -in -the -arm." The electronic service business has had its sharein the form of TV (let's say radio was the beginning);the phonograph boom, Hi Fi, and stereo. But the ad-ditional shot that up until now hasn't been receivedis color TV. It's not a sleeper any longer, however.You're either going to get into it or get out of thebusiness.

Lesson from the PastThe other day I was looking through some old

magazines and came across an editorial that had agreat deal of significance 10 years ago. It is unfortu-nate, however, that many of you took the writer'sadvice: Charge 15 or 20 cents each to test tubes.Don't -give your services away. The article said thatyour time would cost you several dollars a week totest tubes for "nothing."

He failed to point out that a lot of tubes wouldbe sold through this service - and he failed to pointout the consequences to the service shops all over thecountry: People look for what is apparently the cheap-est way out; they will not be victims of crude treat-ment. Now drug stores, hardware stores, grocery storesand filling stations sell tubes.

And look who's screaming. You've lost a lot oftube sales over the past few years and there's noone to blame but yourself.

You're faced today with many similar problems;your response to each situation should be based ona prediction of your customers' reactions formed fromyour experience. Of course, thinking about your costsand rewards are foremost. But don't let this be the onlycriteria you use.

(14- PaiLs1...st-_.AUGUST 1963 31

MANUFACTURER'S

COLOR TV

REVIEW

The TV -consuming public has become more color -conscious during the past year. A number of factorshave contributed to this change, including: increasedand improved color telecasting, better sets, lower -cost service and brighter color CRTs.

Manufacturers who wouldn't touch color witha "ten -foot -pole" only a few years ago have scentedprofit -tracks on the frontier and are now in hot pursuiton a cold trail. Difficulties encountered in mostcases - especially in color CRT production - arebeing hurdled in stride.

Predictions for 1963 production range from450,000 to one million sets. More realistic crystal -bailers visualize between 500,000 and 700,000 sets.One thing is certain - there's more color activitythis year than last. And many technicians are makingmoney right now by selling and installing color TVsets and appropriate antenna equipment.What Manufacturers Are Doing

Admiral Corp. - has hit the market with itsSheldon (T1000) table model color set at $399.95list. The complete color line has 16 models - thelargest ever shown by the company. All the sets areavailable with the full -function Sonar wireless remotecontrol for an additional $30 list. All contain provis-ions for UHF reception - with a continuous tuneror with UHF strips. Admiral says it is tooled -upto make 100,000 or more sets.

Radio Corp. of America - has increased itscolor TV line also. Included in the 21 -model colorline, which ranges in price from $495 to $1700,is a 66 -in. credenza -styled AM/FM stereo phono,21 -in. color set, at top price. RCA executives pre-dicted that 750,000 to one million color sets couldbe sold this year - depending on the industry'sability to produce color CRTs. It is estimated thatthe company made between 260,000 and 290,000sets last year. RCA has stuck to its colors from thebeginning - splashing an estimated $130,000,000 onthe palette. Its president, Elmer W. Engstrom, an-nounced some time ago that "color TV receivers and

color picture tubes were the greatest profit contributorof any RCA product in 1962."

General Electric - has a number of new colormodels. It has also recently announced a $5 millioncontract with National General Corp., a 220 -movie -theater chain, for Talaria - a large screen projector.The movie chain expects to project Broadway shows,symphonies, boxing matches, etc. on regular -size mov-ie screens.

Emerson Radio and Phonograph-DuMont com-bine, Olympic Radio & TV, Magnavox Corp., Pack-ard -Bell and some others are showing increasedactivity. It was reported that Magnavox is buildinga $5 million plant in Greenville, Tenn.

Sylvania, a subsidiary of General Telephone &Electronics, is working to increase its share of the colorTV market and has its own color -tube plant in opera-tion.

Motorola - has contracted with National Videoto produce its 21 -in., 90 degree rectangular CRT,which the company believes will give color TV a sig-nificant shot -in -the -arm, by making `thin -line' typecolor sets feasible. In the meantime, Motorola is usinground tubes in present beefed -up -production models.

Zenith, a hard-hitting color -TV set manufacturer,predicts sales of about 600,000 sets for the industry in1963. It estimates that one-third of the sets will bemanufactured by Zenith. Production facilities havebeen expanded throughout - including the Corpora-tion's Rauland color TV tube plant. Zenith is nowproducing 18 basic models ranging from a compactconsolette to complete "home theatre" units. The com-pany has its own patented two -tube color demodulationsystem and has recently added a focus voltage adjust-ment circuit and "clover -leaf" convergence assembly.An automatic "Fringe -Lock" circuit is incorporated inall 1964 color TV receivers.

Consensus indicates a bright future for color. Noone predicts a sudden boom. The process will prob-ably be a steady increase in sales, dependent on over-all economic conditions, and more money in the pock-ets of alert and aggressive service -dealers.


UNDERSTANDCOLOR TV

SIGNALS

Since color and black -and -whiteTV signals are compatible, color issupplementary information includedwith normal black -and -white sig-nals. These color signals are fittedinto the TV transmitter's 6 Mcbandwidth. Because previously es-tablished TV bandwidths were nar-row, it was necessary to design acolor system to give low color in-formation detail. Thus, only thelarger areas of the scene are repro-duced in color. The remainder isreproduced in black and white. Thisdoes not prevent production of apleasing picture because the humaneye cannot detect fine detail in col-or, though the eye can perceive fineblack -and -white detail.

It should always be kept in mindthat two signal -types are required toproduce a complete picture - col-or signals for the low detail colorportion and black -and -white signalsfor the higher detail portions.

Producing Basic Color Voltages

All signal information in colortransmission originates in a color-camera which is essentially threecameras in one - since a separatetube is used for each primary color- red, blue and green. Selectivefilter's are placed in front of thecamera tubes to allow correspon-

Knowledge of

fundamental concepts

essential in adjustment,

troubleshooting and repair

ding -color light to enter its respec-tive camera tube and charge themosaic surface.

As the mosaics of the three tubesare simultaneously scanned withindividual electron beams, instant-aneous voltages are produced ineach tube. These three voltagesare designated R, B and G and formthe basis for all picture signals incolor TV.

It is important to remember thatthe color signals will eventually beplaced in the three guns of a tri-color picture tube. These guns mustreproduce the color portions of thepicture - as a speaker reproducesa microphone's action in audio. Toexplain further: red, blue and greenlight enters the camera and is re-solved into R, B, and G voltage.In the tri-color picture tube only thecorresponding R, B and G voltagesremain to control current flow intheir respective guns and the vol-tages are resolved into red, blue andgreen light. See Figure 1.

Monochrome Signals

The human eye notices an appar-ent difference in brightness in thethree primary colors. By combininga certain portion of the three cameraoutputs - actually 30 percent ofthe red, 11 percent of the blue and

ey 7igeizew Wicetoec4.

59 percent of the green - it wasfound that an instantaneous bright-ness signal voltage could be pro-duced. This signal is designated as"Y" and is used to reproducehigher detail black -and -white por-tions of a TV color picture and re-produce black -and -white pictures onsets tuned to the color program.

R -Y and B -Y Signals

A block diagram (Fig. 2) showshow low detail color portions of thepicture are created. The procedureis as follows: First, the Y bright-ness signal is passed through a 180degree phase inverter to produce a-Y signal. The output voltage of thered camera (R) is then electron-ically added to the -Y to produceone color signal, R -Y. The bluecamera tube output (B) is addedelectronically to the -Y signal toproduce the second color signal,B -Y.

The R -Y and B -Y signals (oftencalled color difference signals) carryall the color information throughthe system from program to the TVreceiver. These signals are furtherprocessed by passing through a fil-tering system to limit their fre-quency components effectively to0.5 Mc. Hence, the R -Y and B -Ysignals are able to reproduce only

AUGUST 1963 33

Color TV SignalsContinued

RRED TUBEGREED

BLUE TUBE BBLUE

GREEN TUBE G RED E

TRI-COLOR TUBE

Fig. 1 - Reversing camera action in tri-color CRT.

low detail color information - upto a maximum of 500,000 changesin color per -second -of -time.

It is noted here, by FCC stan-dards, that R -Y is converted to an"I" signal (frequency componentsas high as 1.5 Mc); and B -Y isconverted to a "0" signal (fre-quency components of 0.5 Mc).However, since most present-dayreceivers do not use the extra detailcarried in the "I" signals and de-modulate directly for R -Y and B -Y,the "I" and "Q" signals can beignored in arriving at an understan-ding of color signals.

A graphical analysis of how R -Yand B -Y are able to reproduce allthe color hues in their various sat-uration levels (amount of whitemixed with the basic hue) can bemade by comparing a land area, aChicago city map, for example, anda color wheel. (Fig. 3.)

It will be noted that locations ofonly the primary and secondarycolors are indicated on the colorwheel although all colors that canbe reproduced in color TV appearon it. The colors on the outer areaof the circle are fully saturated (nowhite mixed with them) toward thecenter of the circle. The circle'scenter represents white.

A study of Fig. 3 shows that anylocation in the city of Chicago canbe represented by a direction (N -S-E or W) and a distance along twoperpendicular coordinates - Mad -

REDCAMERA

R

BLUE

GREENCAMERA

ADDER

)

3 R PLUS

IIB PLUS.59G

PHASEINVERTER

R -YADDER

B -YADDER

> R -Y

3, 11-Y

Fig. 2 - Producing color and brightness signals.

ison and State Streets. Likewise, inthe color wheel, any hue of color inany saturation level is representedby a direction (here positive or neg-ative), and an amplitude of the per-pendicular coordinates, R -Y andB -Y. For example in the illustra-tion, point "A", the intersection ofIrving Pard Rd. and Kedzie Ave.,can be described as 3200 West and4000 North as, indeed, many Chi-cagoans describe it. Similarly, apale red color which contains abouthalf white, point "B" on the colorwheel, is represented by a certainamount of positive R -Y (up fromthe intersection of the coordinates)and negative B -Y (to the left of theintersection of the coordinates).In either case, the exact location;on the city map or on the colorwheel, is at the intersection of twolines extended the proper distanceand direction from the intersectionof the coordinates as illustrated by"a" and "b" in Fig. 3.

Coordinates on the map are ac-tually streets. In the color wheeltoo, R -Y and B -Y coordinates areactually colors. Colors of R -Y andB -Y differ when they have positiveinstead of negative values. WhenB -Y is positive, for example, it isnear blue but when negative, it isnear yellow.

"Packaging" Color Signals

The Y brightness signals, in avideo range from about 30 cps to

4.2 Mc are passed through thesystem without further packagingin order to preserve compatibility.These are high -detail signals be-cause they are able to reproduce upto a maximum of approximately8,400,000 changes in brightnessper -second -of -time (each cycle rep-

negative). The R -Y and B -Y colorsignals, however, must be packagedso that they will not, during trans-mission, combine with one anotheror with the Y signals in a manner tomake separation impossible in thereceiver. This is accomplishedthrough a scheme of amplitude mod-ulating a 3.58 Mc sub -carrier withthe R -Y signals to produce an upperand low sideband. The 3.58 Mcsub -carrier phase is then shifted90° before it is modulated by theB -Y color signal. Thus, a secondset of upper and lower sidebands isproduced. In each case, the 3.58Mc carrier is eliminated through asuppressed carrier modulation sys-tem. This is necessary because ofpower requirements and to preventinterference beats. Since the R -Yand B -Y sidebands will now alwaysremain 90° apart, they will maintainindividual identities.

The color sub -carrier's frequencyis 3.579545 Mc and has been cho-sen to provide frequency interleav-ing of the color sub -carrier infor-mation in between the video infor-mation energy groups which form


CHICAGO

MADISON WST

STATE GT.01

0000

4000LARIE

1,008 locoman

mon, -a-,

1000

4000

1000

QUADRANT III

0

P

- R -v

WHITE INCENTER

a

QUADRANT I

+a,

QUADRANT Z

Fig. 3 - Comparing two streets with R -Y and B -Y as coordinates in terms of which any pointin an area is identified.

as a result of the scanning methodused in TV. The video signal com-ponents group about the harmonicsleaving a void or space betweenthese energy groupings. It is in thisunoccupied region that the colorsub -carrier is placed.

One other signal is required inthe system. In the receiver, themodulated sidebands will have tobe de -packaged or demodulated;but this cannot be accomplished un-less the original sub -carrier is pre-sent at the same frequency andphase as it was in the modulator.Since the 3.58 Mc sub -carrier waseliminated when producing the R -Yand B -Y sidebands, it must be re-created with an oscillator in the re-ceiver. A sample of the 3.58 Mcsub -carrier as used in the modulatoris therefore transmitted. It is usedin the control of the 3.58 Mc os-cillator in the receiver. This sampleis called the "color burst" and issent during horizontal retrace timewhen R -Y and B -Y signals are notpresent.

It should be noted that the R -Yand B -Y sidebands will occupy thefrequency area from 3.08 to 4.08Mc when assuming that the maxi-mum 0.5 frequency componentsare present in the color signals.This happens because the uppersideband in amplitude modulation iscreated by adding the modulatingfrequency components (here up to0.5 Mc) to the 3.58 Mc sub -carrier

and the lower sideband is createdby subtracting the modulation fre-quency components from the sub -carrier.

Receiving Color Signals

After amplification of the R -Yand B -Y sidebands, Y signals andcolor burst in the RF and IF sec-tions of the receiver, detection isperformed. Further amplificationoccurs in the first video amplifier.

At this point, the color burst isseparated by merely allowing anamplifier tube - called the burstamplifier - to conduct on videosignals but only during horizontalretrace time. The burst is then usedin the oscillator control circuitryto insure proper phase and fre-quency insertion of the 3.58 Mcsub -carrier to the demodulators.

The R -Y and B -Y sidebands arealso applied to the demodulatorsafter being removed from the videoamplifier through stages having abandpass essentially from 3.08 to4.08 Mc in most receivers. Afterthe R -Y and B -Y sidebands are de-modulated and the 3.58 Mc com-ponent has been removed, the colordifference signals are again in avideo range. A G -Y signal is nowproduced by combining the properproportion of -(R-Y) and -(B-Y).

After the Y signals are furtheramplified through a video amplifier,we are ready to apply them to thepicture tube.

0

0

Fig. 4 (Al - Signals applied to tri-color CRTto produce color portion of picture. The Y

components cancel out leaving only R, B andG on grids. (B) - Signals applied to pre -produce b w portions of the color TV pictureprogrorn.

Applying Signals to CRT

As shown in Fig. 4A, the R -Ysignal is placed on the grid of thered gun, B -Y on the grid of the bluegun and G -Y on the grid of thegreen gun. The Y signals are ap-plied to the cathodes of all threeCRT guns in a negative or -Y po-larity.

For reproducing the low detailcolor portions of the picture, whenR -Y, B -Y and G -Y are present;the factor "-Y" appears both as apart of the color signals (placed onthe grids of the guns) and as thebrightness signal (placed on thecathodes of all three guns). Sinceany tube can change ac conductiononly if there is a signal differencebetween grid and cathode, the -Ycomponents, appearing on both thegrid and the cathode, cannot changegun conduction and thus effectivelycancel one another out; leaving on-ly the R, B, and G voltages in therespective guns.

Thus we have accomplished whatwe set out to do - the tri-colorpicture tube has reversed the actionof the cameras to reproduce thecolor portions of the picture in fullcolor by virtue of the fact that onlyR, B, and G voltages (which werethe camera outputs) remain to con-trol beam current in the respectiveguns.

For higher detail (about 0.5 Mc)Continued on page 82

AUGUST 1963 35

Aperture masks are removed from conveyor after annealing in lehrshown in background....

Aperture masks are lowered in a steam tank for blackening. Pro-cess increases thermal radiation properties....

EVOLUTION OF A

COLOR CRT

AT SYLVANIA

Applications engineer adjusts test equipment to evaluate color CRTs. Color patterns are produced on the color CRT by an external alternat-ing magnetic field. Pure colors of red, green and blue are borderedby combinations of these primary colors....


Masks are then shaped properly ('domed') on this press....

After mask is insert-ed in CRT facepanela n d photosensitivescreen is deposited,facepanel s exposedon exposure table....

Beading machine is used to produce electron guns - th-ee foreach CRT....

Control panel monitors tests lo determine if mask contours are prop-erly formed....

When dots are on faceplate panel, screen is inspected for dotsize, structure and density. nspection is made with aid of a power-ful microscope.

AUGUST 1963 37

The 88K model 853 analyst concealsall cables in a rear compartment. Thisunit features a special deconvergence un-it built-in.

New test instruments

are an absolute necessity

to service color

4 R -ea Vaal

- PACO

Test Equipment

PACO'S color gener-ator features onlythree operating con-trols. Available inkit form.

The Simpson colorbar generator util-izes only three maincontrols with fourseparate output jacksfor video, RF, andhorizontal and burstfrequencies.

The advent of color TV haschanged test equipment require-ments nearly as much as the adventof TV itself. Absolute test equip-ment requirements since the earlydays of B/W TV have been a scope,meter, and some sort of a generator.

True, other test devices served alegitimate purpose by aiding thetechnician in preventing call-backsand speeding his work. But the ab-solute requirements did not change'until color TV became a serviceproblem. Now, in order to do aproper job at least one new multi-function unit is needed: The ColorBar Dot/Crosshatch generator. Sev-eral units are available from an in-creasing number of test equipmentmanufacturers. Prices range fromless than $100 to more than $500.

To stay in business the TV tech-nician will have to include colorservice in his service repertory. Andto service color, he must obtain theproper equipment.

Why Special Equipment?

Special equipment for color ser-vicing in necessary for several rea-sons. Special circuits, never beforeused in B/W receivers, heads thelist. Color demodulators which op-erate at precise frequencies in themegacycle range leave no room forerror in chroma circuit alignments.

Aside from the color alignmentthere are other uses for the Bar/Dotand Crosshatch generator. Theprime use, of course, convergence.


for COLOR TV

Although there are several "gim-micks" available which claim to bejust the thing for convergence align-ment, the full-fledged crystal con-trolled test sets are the only onesrecommended.

Another group of items found inthe TV caddy or the shop are alsonecessary for servicing: The CRTextension cable along with necessarycables for the yoke and high vol-tage leads. Working on the colorchassis can be a real challenge with-out these aids. Most of the timeit's not necessary to bring the pic-ture tube along when it becomesnecessary to pull the chassis - infact, most of the time it is more de-sirable to leave the CRT in place.The tri-gun CRT costs too much tocart it around for no good reason.

The CRT tester and rejuvenatorused with B/W TVs can no longerbe used with color CRTs - sometechnicians have hay -wired their oldtesters to the color tubes but withless than desirable results. Colortube testers are specially designedto handle the heavy current de-mands placed on them; more thantwice that of most testers. When theold testers are wired to the colortube, test voltages and rejuvenationvoltages are decreased causing err-oneous readings and poor rejuvena-tion.

The scope you have used up tocolor will also be less than desirablein the color channels of the colorset. The burst frequency, for ex -

The Heath color bar and dot generatorhas standard outputs plus one for shadingbars. The unit is available in kit form.

Sencore's newest color generator is a compact version of theirmore expensive CA -122.

ample, is 3.58 Mc; in order to seethe burst - as is often necessary-a scope with high frequency cap-abilities is a must. Most servicescopes which were built severalyears ago cannot handle these fre-quencies.

What to Look for in New Equipment

As with buying any equipment,you must set up standards withwhich to measure your purchase.Since the bar generator, the dot gen-erator and the crosshatch generatorall have the same output frequency,it is wise to select a unit which com-bines all these functions. Buyinga one -function unit with the idea ofbuying another unit later is not wisefor several reasons: Different synclevels are invariably required foreach piece of equipment; connectingone instrument to a set and thenanother can be very time consumingand not least, the multi -unit ap-proach is far more expensive thanequivalent single -function generat-ors.

Whether you buy a generatorwith an RF output, video strip out-put, CRT output or combinations ofall will depend on your budget. Themore outputs these instruments

have, the better opportunity you willhave to pinpoint a particular areawhen troubleshooting a set. Don'tjump at the first deal offered youunless you've carefully consideredthe drawbacks and advantages.Also, some sets now being builthave sync taken ahead of thechroma sections which negates thepossibility of troubleshooting in thechroma section without externallyavailable sync. Whether or not thiswill be a feature you will requireis a decision you must make.

Even something as apparentlysimple as test extension cables canbe full of surprises if care is notused in their selection Some ofyou who have made home-brewmodels will probably be aware ofthe smear that develops with whatwere perfect dots without the cablesor perhaps the variations in therelative position of each of the colorpatterns. Obviously this is not thetype of equipment necessary to dothe professional job expected of acolor expert.

When intermixing different equip-ment makes, it is often found thatconsiderable outlay of cash wasspent for function duplications too.Again, this can be avoided by a

AUGUST 1963 39

Test Equipment Continued

careful analysis of the equipmentwhich best suits your needs beforemaking a selection. Even if youplan on buying only one piece ofequipment now and the rest later,you should decide what type ofequipment you will need from everystandpoint now to spend your moneymost wisely and to get the most outof your new instruments.

If you feel a new scope is in or-der you may want to consider keep-ing the old one for the radio benchor as a spare. The controls on awide band scope used for colorwork are identical to those foundon its older counterpart. The spec-ifications are widely divergent, how-ever. The vertical amplifier re-sponse is the prime consideration

Hickok's newest col-or generator doesnot have an NTSCoutput. The olderHickok generatorswhich are still avail-able have NTSC out-put.

Kine-Color circuit an-alyzer is an exten-sion for CRT cablesand allowsient tests for all el-ements in the colorCRT. Any or all gunscan also be killedwith switches.

in what you will see of a 3.58 Mcburst. It is best to purchase a scopewhich is flat within 3 db up to about4.5 Mc.

The horizontal or sweep frequen-cy should not be overlooked either.The maximum horizontal scan fre-quency will determine the numberof bursts you will see on the screen.The higher the sweep frequency,the better. For even though thevertical amplifier is capable of fol-lowing the changes, the signal mustbe broad enough so you can view iton the screen.

NTSC and Other Considerations

NTSC colors are standard colorswhich have been set up by the Na-tional Television System Committee.

The question in many technicians'minds is "do we really need NTSCcolors?" This question is not aseasy to answer as it may seem. Al-though there are certain advantagesto NTSC color, a good alignmentcan be performed without actuallyusing NTSC signals.

Most rainbow patterns are gener-ated by delaying the chroma signal(operating at the same frequencyas the burst oscillator) so that aconstant and varying difference ex-ists between the burst and the inputsignal. This generates a changingcolor pattern which is called therainbow pattern. As long as the in-put is kept at the same frequencyas the burst, but one frame out ofphase, this condition will generatean identical color pattern on eachsucceeding line.

Another major difference is thatNTSC color bar generators availableproduce a saturated color pattern.This is not always true in otheravailable instruments.

Portability should also be consid-ered when buying any piece ofequipment. In color equipment thisis particularly important since it isusually required that the final ad-justments for the TV be made inthe home if optimum performanceis to be obtained.

Additionally, you should considerthe equipment's set up ease. Doesthe unit require difficult to readcharts? Is any guess work involvedin setting up? Are the results diff-icult to determine? If you get ayes in answer to any of these ques-tions you should consider verystrongly looking at another unit.

Special features are also includedin many late models which aid insetting up color receivers thoughthey aren't necessary. Examples ofthis are shading bars which are usedto adjust tracking and deconver-gence methods to aid in CRT con-vergence. Most all units availablehave a 4.5 Mc sound output whichcan be switched off and on to maketuning the set possible. If the finetuning is not set properly, the entirechoma alignment will prove fruit-less.

Be alert to these features andget in the color business now bygetting the color equipment youneed.


TheVersatile

NeonTester

4 Pe Signe

One of the most useful test in-struments is the neon lamp tester.This device is no more than a neonlamp, similar to the NE -51, moun-ted in a plastic base with two testleads having phone tips on theirends.

Many technicians have alreadydiscovered that this little instrumenthas varied uses when servicing TVreceivers and other electrical equip-ment. In servicing TVs, quickchecks with the neon tester can helptechnicians analyze faulty receivers.

Dead ReceiverIn the "dead" receiver with no

filaments - the neon tester can beused first to check the AC outletfor voltage by inserting the twophone tips into the outlet. If AC ispresent, the neon lamp will glow;if it is not present, the lamp will notlight. Second, the "cheater" cordcan be tested similarly by insertingthe phone tips into the female endof the cord. Again, if the lampglows, AC is present, and if it doesnot glow, (assuming voltage is pre-sent at the AC outlet), the cheatercord is bad.

If both outlet and cheater cordcheck good, the fuse in the set's ACline can be checked by shunting

Rapid short-cut checking techniques

reduce troubleshooting time

Quick -check neon tester can help

the fuse with the tester. If the fuseis open, the neon lamp will glow,and if the fuse is good, it will notglow.

An alternate method of checkingthe fuse with the tester is to putone tip at either end of the fuse andthe other to ground. If the fuse isgood, the lamp will glow when con-nected to either end of the fuse, andif the fuse is bad, the lamp willonly glow on the voltage -source sideand will not glow on the side awayfrom the voltage source.

Fusible resistors and filamentdropping resistors in series filamentreceivers may be checked by thesame methods for checking fuses.The off/on switch may also bechecked from either side of theswitch to the other side of the ACline. If the switch is good, thelamp will glow when connected toeither side of the switch, and if theswitch is open, the lamp will glowonly on the side toward the voltagesource and will not glow on theother side.

Sound Bu- No Raster

When no raster is present, thetester can be used for a quick high -voltage test. The tester is attachedto one end of a plastic slug -adjust -

technicians isolate many circuit faults.

ing tool with a rubber band and thelamp is held inside the HV cage.If the horizontal output and associ-ated flyback circuits are working,the neon lamp will glow. In fact,the lamp should light as soon as itbegins to enter the cage if the cir-cuit is working properly. Note,also, that no physical contact ismade between the lamp and anypoint in the cage. The lamp is ion-ized by the RF generated by andradiated from the HV circuit.

If RF is present in the cage, asindicated by the neon tester glowing,a defective HV rectifier would besuspected. If no RF is present, adefective horizontal output tube orassociated parts might be checkedalong with damper tube and flybacktransformer. However, if RF ispresent and a check proves the HVrectifier tube is good - but no highvoltage is present at the CRT anode- then a check for a bad HV rec-tifier tube socket, filament resistor,or limiting resistor might be made.If high voltage is present at the pic-ture tube anode, then, of course,the CRT with associated grid andcathode circuits might be checked.

It may be pointed out that theneon tester is not a final analyzer

Continued on page 82

AUGUST 1963 41

Protection over a 30 -ft diameter area is provided for offices by the'Radar -Eye' alarm system.

A low-cost, fully portable radardetection device for stores, homesand offices has been placed on the

RadarALARMSystem

market by the Pinkerton Electro-Security Corp., a division of Pinker -ton's National Detective Agency.

Called the "Radar -Eye Minute-man," the device is priced withinthe range of a good television or Hi

Update Your The number one advertising me-dium for many TV -radio shops isfrequently the mailing list. Surveyshave shown that a properly organ-ized mailing list produces good re-sults at optimum expense.

But no mailing list, large or small,can be effective unless it is kept up-to-date. Converting a run-down listinto a business -building tool is wellworth the little time, expense andeffort spent.

Below is a check list for modern-izing your shop's mailing list. City directories not more than

one year old. Classified and regular telephone

directories. Crisscross telephone directories

listed by address and by name


Fi set and the manufacturer feels itwill open up a popular new bus-iness line for electronics dealers andothers in related fields.

The system consists of a detectorand alarm unit, both about the sizeof a table radio, and a match -box -size control unit.

The detector unit plugs into anordinary 110 v wall socket. Aftera simple adjustment to provide therange of coverage desired, the unitis "on guard."

The system is activated by turn-ing a key in the control unit, whichcan be placed anywhere outside theradar field, including a remote lo-cation.

An antenna on the detector unitfloods the area with high frequencyradar waves. If the waves strike areflecting surface that is stationary,they are bounced back to the an-tenna at the same frequency onwhich they were transmitted, andnothing happens. However, if thereflecting surface is in motion, thewaves are returned on a differentfrequency. This trips a relay andsets off an alarm.

The field has a maximum rangeof 15 ft in all directions and athickness of 10 ft. Visualized, thepattern has the shape of a doughnutwith a 30 ft diameter. When it isnecessary to confine the coverageto smaller areas, the installer cancontrol the range by a simple ad-justment.

The unit will sound an alarm theinstant any motion is detected.When the intruder leaves the scene,the alarm continues to ring for oneminute, then automatically re -setsitself for the next intrusion. Thedevice can also be set to sound acontinuous alarm until shut off by

System can be usedto provide home pro-tection. Key s turnedat bedside to acti-vate the detector unitbefore retiring forthe night.

the key -switch. The alarm will alsosound if power fails, a wire is cut,detector tube fails or covers aretampered with.

While the Minuteman has manyapplications for large establish-ments, company officials feel it an-swers a particular need for low-cost,highly simplified and virtually fool-proof security by those with a rel-atively small area to protect.

A number of dealerships for thesystem have already been estab-lished and others are being added asquickly as those qualified to installand service the equipment can befound.

as well as telephone number. Utility companies such as elec-

tricity, water and gas. Commercial and industrial direc-

tories offered by mailing -listfirms in one's own communityor a nearby large city.

An exchange of mailing lists withother firms. CAUTION: Poten-tial business can be lost if thelist received is not up-to-date and"alive."

Legal and business newspapers. Business correspondence. Customer purchase records. Bus-

inessmen have been surprised tofind mailing lists didn't includea number of active customers.

Old office records frequently re-veal good prospects.

Voting list. The advantage is ge-ographic arrangement for speci-fic business -building in definiteareas.

Annual homeowner list fromcounty tax rolls.

Building permit lists publishedin local newspapers.

Social registers of prominentcommunity people.

Annual church membership lists. Newcomer lists issued in some

cities by the Chamber of Com-merce.

Club membership rosters perhapsobtained from a member friend.

Contributor lists from charitableorganizations. If your firm is acontributor, it should have nodifficulty borrowing the list.

Graduate and alumni director-ies from educational institutionsfor a nominal fee.

Newspaper "Vital Statistics" list-ings appearing almost daily re-veal deceased persons who maybe removed from the mailinglist and new names in marriagelicense and birth notices.

Local automotive owner listswhether or not the shop offersauto radio service.

Contests modestly promoted forno other purpose.Weed out the "deadwood" on a

regular basis. When new directoriescome out, check your mailing listagainst them.

An up-to-date mailing list is avaluable asset.

AUGUST 1963 43

Fig. 1 - Windings of deflectionyoke with insulation and housingremoved to show approximateplacement of vertical and horizon-tal coils.

4 pay Seuce

Substituting Deflection Yokes

Next to flybacks, yoke replace-ment is a confusing aspect of TVservicing. Yoke substitution is notnew. It's done every time a stan-dard "replacement" is used. Thisis proven when you get a yoke, sayfor DuMont, and find the cartonmarked, "Exact replacement forRCA," or "Muntz," or "Sylvania."Too many shops hold up repair jobswhen an "exact" replacement isnot readily available. It takes onlya little ingenuity to resolve the prob-lem to everyone's satisfaction - es-pecially the customer. And youwon't get inventory -loaded withyokes.

Yoke Categories

Basically, there are four yoke cat-egories, regardless of sweep angle,and they can be broken down im-pedance -wise as: high -high, high -low, low -low and low -high. To un-derstand this, compare the wire sizein the windings. If both windingshave, say #24 wire, then the yokecan be called, for all practical pur-poses, a high -high (Fig. 1). But ifthe horizontal winding is #24 andthe vertical #20 or #22, it is ahigh -low. Almost any yoke with

comparative windings will substitutefor the defective one.

Another factor is millihenry in-ductance. Here, there is reasonableleeway in many cases. Suppose, forexample, a set calls for a yoke ratedat 17.8 mh horizontal and 13.5 mhvertical. Good results can frequent-ly be achieved by using one ratedat 16 mh to 19 mh, and 12 mh to15 mh. Make sure its sweep angleis the same.

It may be argued that this ap-proach can only produce negativeresults. The practical answer to thisis, if no visible effect is noted on thescreen or in the set's operation, thenthe sweep system's latitude has notbeen violated.

Case Histories

Here's an example of how far onecan go. Take, for instance, a Mo-torola PTS 546 chassis. Triad showsa Y-60-2 as replacement. But Triadis not distributed in this area. Byusing the above procedure, it wasdetermined that a G -E RLD-080yoke (Fig. 2) was a fair substitute.It's ratings were horiz. 18n, vert,4211. Motorola called for horiz.3511, vert. 3011. Nothing available

on the mh ratings, and the G -Eyoke's horizontal windings were inparallel. These were changed toseries and the damping network in-stalled. Everything was fine - ex-cept not enough width. A violationof sweep latitude was evident. Butthe flyback was "tuned" with a56 pf/7.5 kv capacitor across thedamper plate and cathode whichgave an inch -and -a -half wrap-around on both sides of the screen.Good linear picture without loss ofbrightness resulted.

No replacement was locally avail-able for a Packard Bell 98D8 chas-sis, with "keystone." An RCA"tapped" yoke was available (Fig.3A). The problem was resolvedby altering the yoke as shown inFig. 3B. After several months, theset is still doing fine.

In some areas the Philco port-able, 10H25 chassis, is a popularsmall set. Its yoke is #76-10508-9,horiz. 4012, vert. 30f1, with no stan-dard replacement available. Theregular yoke will substitute in theSeventeener series, from I throughIII, as well as the 9L35 chassis,along with several Silvertone mod-els. If you run into a crowded sit -


Case histories indicate replacement -yoke inventory can

be reduced by knowledgeable approach to problems

uation, remove the side magnet usedfor horizontal centering.

If a replacement yoke doesn'thave centering tabs, or the old cov-er does not fit, trim the edges offthe old cover and cement it to thenew one.

01M01, 490-V005M01, 490 -V00 -H04.

RCA 4105632, Stancor DY26Aand Merit MDF113 will substitutefor RCA 105053, 104408, 104078.

Philco #76-10508-9 will substi-tute for Philco #76-102823, 76-10-

- 3

10

Substitutions

Zenith yoke #95-1768 will sub-stitute in any Zenith using the 21C-XP4 picture tube, from 1957 into1963. If the white or orange leadsare not needed, cut and tape them.Zenith's 95-1666 yoke, for smallnecked 114° tubes, will substitutefor Admiral's 15B1 series throughZenith's 1963 portables.

Below is a list of yokes and themakes and numbers for which theywill give excellent results:

RCA #235D1, Stancor DY16A,Merit MDF92 and Triad Y-41-1will replace Hoffman #99810 and790002; Magnavox #360617-1,#360660-1, 361222-1; Olympic

CL3600, CL3600-1, R-2060;Westinghouse V-15995-1, 490-V0-

508-3, 6, 8, 13, 14, 16 and 76-12279-4, 6. Also for Silvertone#80-7-4, 80-10-4, 80-13-4, D80-11-4 and D80 -12-4A.

Admiral can be pretty well cov-ered with Stancor's DY13A, DY-16A and DY26A.

Fig. 2 - G -E yoke schematic modified forMotorola PTS 546 chassis.

-tool.

'CO 1201100

2KV T2KV

9 6n12002KV

06-

RED

WHITE

onno-

BLUE

0 1,20T2KV

WHITE.

9.6 n

1202KV

BLUE

RED

075'00o6

Fig. 3 (Al-Schematic of RCA 'tapped' yoke. (B)-RCA yoke wasaltered as shown for Packard Bell 98D8 chassis.

AUGUST 1963 45

PART I

The best test equipment is notonly free but turns a neat profit.Our accountant verified this fact instatistical figures.

Comparison was made with oursituation two years ago. At thattime I made a careful study in theinterest of increasing the gross andat the same time cutting costs. Onemajor way I accomplished this wasby establishing a new test equip-ment budget.

With the budget, I retire oldequipment with newer models, in-crease the number of our gardenvariety pieces, purchase new unitsthat employ new techniques to speedup solving old problems and buynew equipment to handle new typereceivers, we are always being calledupon to fix.

As a result of these purchases,our over the counter sales of partsmore than doubled, we are turningout, with the same man hours, 40percent more completed bench jobsand have eliminated all avoidableguesswork.

Tube Tester City

Before out test equipment rev-olution, I noticed with concern, thatour over the counter tube salesdropped off considerably. Since thisincome has been a sweet rent de-frayer I decided to do somethingabout it.

We had two self service tube test-ers in the store front yet the custo-mers seemed to prefer drugstores,gas stations and bargain shops.

I got into my station wagon andstarted driving from one tube testingcompetitor to another. Here are thethings I noticed.

The most successful testers werelarge and gaily colored with festiveflashing lights and moving signs.All contained a shelf to hold thebatch of tubes while the customertested them one by one. The tubelist and test instructions were moun-ted on one easy to read poster.Lastly and very important, thenumber of pulls, twirls, or pushes,on levers, dials, or buttons num-bered only three.

Then I examined our own do-it-yourself tube testers as objectivelyas I could. I was shocked at ourdeficiency. Our tube testers werecompact, colorless and without anysign of any kind. There was noshelf to hold the tubes and I remem-bered a few loud pops and unhappycustomers' faces when they droppedone of their tubes. Instead ofeasy reading posters we had out ofdate roll charts; the number of pulls,twirls and pushes came to a stag-gering eight!

I went shopping. I bought threeof the prettiest flashiest tube testingmerchandisers you've ever seen. Ilined them up like a group of pin-ball machines and put a large fluo-rescent type sign in the window say-ing TUBES TESTED BY EX-PERTS.

The testers give an excellent emis-sion gas and short test. They checkvibrators and batteries. In addition

New equipment

pays for itself

when purchased

to speed servicing

The Best

4 744ze 7/627906v

to placing the tube in the right soc-ket there is only one move. Pushone button.

The men call the tube testingarea "Tube Tester City" and itdoes the trick. If the customer isa rugged individualist, and feels hewants to test all his tubes at leasthe comes to us and we ring the reg-ister. Also, we give him advice andbest of all, when more often thannot, he fails in his repair attempt,we are right there to take over.

Pre -Bench Checkup

Admittedly, a good roadman isnot necessarily a good benchmanand vice versa. Each has his ownspecialty. A roadman leans heavieron his personality than his theory.A benchman lives in the circuits andhis personality is not important. Asa result, and it cannot be feasiblyhelped, roadmen pull chassis that abenchman might have repaired onthe spot.

I have found that I must acceptthese facts of life and as a resulthave set up what I call the Pre -Bench Checkup. This procedureweeds out the easy jobs from therough ones.

An easy job is one that is easy todiagnose and a tough one is whenyou are having real problems fig-uring out which part is bad. Anytechnician can replace a bad part,that's only a mechanical job. The re-pair skill consists mainly of locatingwhich component has "gone west."

So in our shop a good diagnos-


Test Equipment is Free!

tician tests every TV as it arrives offthe street. The TV can be on thefloor, on a shelf or on the incomingracks. About 25 percent of jobs areby-passed around the bench by lo-cating and replacing bad parts dur-ing the pre -bench checkup. By-passing the bench saves about sevendollars labor.

An extra bonus to the procedureis, if the trouble is diagnosed asflyback, yoke or some other partwe might not have in stock. Thatpart can be ordered then, ratherthan a day or two later when theTV gets its regular rotation on thebench.

The most valuable piece of testequipment during pre -bench is theVOM. Its portability coupled withan assortment of pin socket testadapters permits voltage and resist-ance checks of most circuits.

Not only is it important to havea VOM during this time but it isimportant to have a VOM with cer-tain salient features. In fact, it cancost money to use an older VOMinstead of one of the latest.

For instance I was training a newbenchman to do the pre -bench work.John is a competent workman whoprefers using his own tools and me-ters. I go along with this as long asthere is no complication. He wastesting a 19L2A Admiral with hisown well worn VOM. There was nohigh voltage.

The chassis was still in the con-sole cabinet and he was lying onhis back under the chassis inside

FREE!

FREE!

FREE!the cabinet. He was making somevoltage checks.

His first approach after tubechecks was horizontal output con-trol grid drive. He said, "No biasattall." With that he extricated him-self from the awkward position, andbegan filling out the repair card forthe bench.

One of the things we do is lookup the schematic file number andmark it on the card. If the TV isgoing to be worked on presently,we pull the schematic too. He pull-ed the schematic and laid it on topof the cabinet. Then I intervened.

"How come you only made theone bias reading?" I asked.

"Well," he thought as he rubbedhis chin, "to tell you the truth,"and he did come out with the truth:"The bias is a negative reading. IfI would have checked the oscillatorplates, I'd have to come out of the

No. B was notedon the esc Ilatorplate. An open coilprevented B fromreaching the *late.A new coil solvedthe problem.

cabinet, shut off, then reverse theprobes, then turn the TV back onto make a plus reading. I figuredit's easier to do that on the benchwith a VTVM - besides, I'm notgoing to hook this alligator clip onB + without turning the set off."

I handed him my new VOM. Ipointed to the polarity switch onthe brand new model. "This is whatyou mean," I smiled.

He nodded back and crawled un-der the chassis again. Quickly henoted no B + on the oscillatorplate. An oscillator coil led ontothe plate. There was B + on theother side of the coil.

A fast look at the schematic sheetrevealed no other components near-by to cause complications. Diag-nosis - open oscillator coil. A newcoil was ordered and I lost the useof my VOM as John adopted it.

Continued on page 78

AUGUST 1963 47

AntennaInstallations

for Color TVSatisfy your color customers with

a good antenna installation

When a dealer sells a B/W set,he very frequently leaves the instal-lations entirely up to the customer.In most areas, the biggest problemis finding an outlet for the set'spower. Color TV, however, posessome problems unlike any encoun-tered in B/W work.

First, the antenna itself must bemore precisely designed. It musthave a relatively flat frequencyrange as wide as the channels beingreceived in color. Ghosts are alsomore annoying on color broadcasts,so care must be taken to select anantenna with good directivity inareas where ghosts are prevalent.

Many antennas now being usedfor B/W reception will definitelyprove inadequate for color recep-tion. Considering that the set ownerhas paid from $400 up for his set,you should have no trouble convin-cing him that he should also havea new antenna installation. Even

4 PO61 j0 ellf

customers who have been used to"getting along" with a degradedB/W picture will be among thecomplainers with color program-ming. And where degraded B/Wpictures were normal with the oldset, a new antenna will definitelybe in order for color.

Antenna Types

The same antennas which havebeen used for B/W reception can beemployed with color with few ex-ceptions. The old conical, for ex-ample, is an excellent antenna forcolor because of its wide responseand its relatively flat response onany one channel. In areas whereghosting may occur with the B/Winstallation, the conical can't beused; it's simply not directionalenough.

The basic type best suited for col-or reception is the in -line antenna.Although a simple in -line antenna

will not be sufficient for many in-stallations, several of the "broad -banded yagis" available will fill thebill. These antennas should not beconfused with the cut channel yagiwhich many manufacturers suggestshould not be used with color sets.Modified yagi antennas are perfectlysatisfactory for color TV.

Certain modified log type anten-nas are also acceptable for colorreception. Remember that the goalin selecting an antenna is to findone with good directivity anduniform broad response.

Installing the antenna also re-quires greater care than installinga B/W antenna. If at all possible,the final antenna direction andheight should be determined by thequality of a color broadcast. Thisleads to some interesting problemsin the final installation which manyof you haven't bothered to concernyourself with in B/W installations.


After It's on the Roof

After it's been determined that aparticular location is the area ofstrongest signal and least ghosting,many installations will just be get-ting under way. When the antennais rotated, for example, the set mayoverload and obscure the true pic-ture condition. The AGC controlsmany be misadjusted, or the signalmay be too strong. In the absenceof a field strength meter, the onlyway to determine this is to adjustthe set's AGC and signal strengthreception controls. If the overloadcondition dissappears, the antennamust be rotated again until an opti-mum picture is obtained. When thefinal antenna position is determined,the set controls should, of course,be readjusted.

In the event that the set's controlsdo not correct the overload condi-tion, attenuation pads should be in-stalled. Simple 6, 12 and 18 dbpads are shown in Fig. 1. If a fewof these are made up in advance,much time will be saved during theinstallation of either B/W or colorsets in strong signal areas. The padgiving the strongest signal withoutset overload should be used.

The lead-in

The most neglected part of aB/W installation becomes one ofthe most important ones in colorTV antenna installations: the lead-in. Many types of lead-in are avail-able and the technician owes it tohis customer and himself to installthe best lead-in for a given instal-lation.

The difference in price of a sub-standard and a high quality trans-mission line for a TV installation isvery small. And contrary to whatyou might think, if the antenna ortransmission line needs maintenanceor repairs within a year or two afterthe initial installation you probablywon't get the business anyway. Soselect a line that will last four orfive years in your locality. Specialleads are available for almost everynormal environment which will lastat least five years.

Many twin leads are on the mar-ket which are so poor that the in-sulation becomes cracked and use-less in less than a year. These leadscause fluctuating impedances and

signal losses which result in poorcolor or not uncommonly, completeloss of color.

Where a distribution system willbe used with the antenna system,it may be desirable to use 75 ohmcoaxial cable in place of 300 ohmtwin lead. This will make the in-stallation easier and at the sametime eliminates noise or interferringsignals from entering the lead-in.In apartment houses where noisemay be more prevalent, this maybe the only answer.

If 75 ohm line is used, matchingtransformers must be employed atthe set and at the antenna. .Depend-ing on the make, matching trans-formers may also be necessary atthe input, output or both when 75ohm line is employed.

Any amplifier should be thor-oughly checked to be sure that itwill handle a color signal. Most ofthe units perform satisfactorily, butsome do not. Don't buy blindly andfind out later that it was a bad buy.You're simply wasting your time.

Set Location

Set location will play a part inthe antenna installation. When in-stalling a B/W set, the customerusually will tell you to "put it rightthere." Color TV, however, hassome peculiarities that call for morecare in selecting the set's location.In order to properly install an an-tenna, set location must be one ofthe first decisions.

Applying a few simple rules is allthat is required to properly locatethe TV.

First, by design, the color sethas a picture which has consider-ably less brightness than the stan-dard B/W TV. Consequently, view-ing the set in a bright light is verydifficult and sometimes even impos-sible. Also, colors which are satur-ated tend to take on a pastel appear-ance in bright light. To preventthis from happening, the set mustbe located so any outside light doesnot fall directly on the TV screen.

Artificial lighting causes the sameproblems and is usually easier tocope with since it can be moved orturned out. If artificial lighting isportable, it is best employed to theside or rear of the set.

Where the TV room is so "win-dowed" that the set cannot be lo-

cated out of direct sunlight, gener-ous use of heavy curtains or shadeswill be required. The customershould be informed of these facts sothat he will not move the set acrossthe roof and splice lamp cord tothe antenna lead for an extension.

When the set location is deter-mined, the best way to run the TVlead to the set must be considered.Unless it is not practical, the short-est routing should be employed asthis will keep losses to a minimum.

After the set and antenna are in-stalled, the line should be checkedfor standing waves. Most installa-tions will have standing waves pre -

The conical antenna performs very well onstrong .ignals where ghosts are not a prob-lem.

The in-rne type antenna is most sJitable forcolor reception where ghosts may be preva-lent.

AUGUST 1963 49

Antenna Installations Continued

sent, either from the antenna design,the tuner design or from reflectionsin the lead-in because of the capac-itance between the line and sur-rounding objects.

To check for standing waves,wrap a piece of aluminum foilaround the lead-in and slide it backand forth on the line. If a changein the picture is noted, standingwaves are present. The foil shouldbe left where the picture is best.

One final precaution: don't letyour customers try to get alongwith "rabbit ears" or a built-in an-

tenna. These antennas are simplynot acceptable for color reception.

Sets employ a built-in antennaas a sales feature - to competewith other manufacturers. In someareas, these are acceptable for B/Wreception. In no case, should theybe used for color, however.

Color is still new enough thatevery color installation you makewill be viewed by many people. Iffor no other reason you shouldmake the installation good enoughso that the picture speaks for thequality of your work.

Fig. 1 (Al-A six db attenuator for signalshat overload the receiver only slightly. IBI-A 12 db attenuator for strong signal over-loads. ICI-An 18 db attenuator for ex-eptionally heavy overloads. One of thesehree attenuators should be suitable for any

overload condition.

TO VIDEOMP

PLATE OCT.

VERT.SYNC

Diagram of Zenith's automatic "Fringe -Lock"circuit.

Among the changes in Zenith'snew color TVs is the use of a 12-GN7 frame grid video amplifiertube with a Gm of 35,000 µmhos.This makes it possible to obtain awider video bandwidth and to ter-minate both ends of the delay line.

Another circuit includes a con-trast control of the video amplifierwhich is said to eliminate bouncingof brightness when the contrast con-trol is rotated.

New Circuits forCOLOR SETS

Current color sets also incorpo-rate the automatic "Fringe -Lock"circuit. Before the automatic fea-ture, the degree of noise immunitywas determined by the adjustmentof a control known as the "Fringe -Lock" control located in the noisegating grid of the AGC and syncclipper tube. This "Fringe -Lock"control was to be set by the service-man to suit local signal conditions.In some instances, where bothstrong and weak signals exist, thenoise protection of the weak sig-nal needed to be compromised sothe "paralysis" or "split phase" con-dition would not occur when switch-ing to a strong signal channel. Anautomatic "Fringe -Lock" controlsystem was developed which util-izes a voltage dependent resistor in-tead of the adjustable control.

As the signal level to the detec-tor decreases, the video screen de-creases in potential. Since the VDR

is connected to the video screen,less potential is applied across theVDR increasing its resistance. Thisaction is the same as adjusting the"Fringe -Lock" control. Therefore,the noise protection required by aweak station can be obtained with-out compromise. Furthermore, eachset no longer needs to depend uponcorrect adjustment by the factory,the television technician or the setowner.

Another change is the use of apotentiometer in the focus controlcircuit. This potentiometer is insul-ated above ground and is operatedwith only dc applied within theratings of the control. This pro-vides a smoother focus adjustmentthan the previously used tuned cir-cuit, where the slug in the coil wasrotated to vary the focus voltage.This is not to be confused with ap-plication of a pulse voltage to thecontrol used in other receivers.


FCC's technical requirements for transistorized 'ban-tam' units must be maintained by repairing technicians

Servicing Hand -Held CitizensBand Transceivers

Public response to Citizens Band2 -way radio has been little short offantastic. Sales doubled in 1962 andmay repeat in 1963.

It is difficult to determine howmany hand-held units are beingused today. Designated to operatewith not more than 100 mw inputpower they do not require licensing.A partial list of CB hand-held trans-ceiver applications appears in Ta-ble I.

Although no license is needed touse 100 mw CB equipment, cer-tain official requirements must bemet:

1. Input power to the transmit-ter's RF output stage mustnot exceed 100 mw.

2. The RF carrier must be be-tween 26.975 and 27.225 Mc.This prohibits its use on chan-nel one of the 23 -band CBspectrum.

3. Spurious radiations must beat least 20 db below the car-rier.

4. Total length of the antennamust be less than 60 in.

Manufacturers, of course, meetthe aforementioned requirementsat the time the units are producedbut it would be embarrassing totechnicians if a unit did not main-tain these requirements after re-pair.

Typical Transistorized Unit

The block diagram of a typicalbattery -operated, fully transistorizedCB transceiver for channels 2-23,is shown in Fig. 1. This particularunit can also receive standardbroadcast stations. It can be seenthat the audio voltage is developedby the speaker, which functions asa microphone. The signal is am-plified by the speech amplifier driverbefore it is used to drive the outputmodulators. The audio signal isthen applied to the final amplifierwhere it causes the carrier signalto be amplitude modulated. Theamplitude modulated RF signal isthen radiated by the antenna. Let'shave a look at circuit operation.(See complete schematic in theTEKFAX section.)

Since switching plays an im-portant part in a transceiver's per-formance, operation of the springloaded, push -to -talk switch, SW1A,is important. The following occurswhen the push -to -talk switch ispressed to the transmit position:

The telescoping antenna is con-nected to the final amplifier outputstage B - operating voltages con-nect to the transmitter oscillatorstage, TR8. The speaker voice coil isconnected to the driver stage, TRS.The speaker is now used as a micro-

phone. The modulation winding ofT6 is connected to the transmitter'sfinal amplifier tank circuit, TR9.It also supplies the dc operatingvoltages to TR9. The voice coil isconnected to SW1C.

Speech Amplifier & Modulator

The speech amplifier is a straightforward transistor voltage amplifier.Its job, whether transmitting or re-ceiving, is to amplify the audio sig-nal applied to it. Whether transmit-ting or receiving, the output mod-ulators also amplify the audio sig-nal applied to them. They operateas a conventional transistorizedpushpull power amplifier. The mod-ulation stages have a biasing diodein the base circuit. This diode addsvoltage and temperature stability tothe modulator stages.

As shown in the schematic, theplus or cathode end of X3 is con-nected to R26 which in turn is con-nected to -11 v. Current flowsfrom the -11 v. line, up throughR 26 and X3 to ground. Since theresistance of X3 is small in the con-ducting direction, only a small volt-age will be developed across it. Thissmall negative voltage across thediode is applied through the second-ary of T5, to TR6 and TR7 tran-sistors' bases-providing them witha fixed bias.

AUGUST 196351

Hallicrafters CB -4. Lafayette HE -66L.

Transceivers Continued

Johnson Personal Messenger.'

Diode X3 is also a temperaturesensitive device, chosen to have heatcharacteristics similar to transistorsTR6 and TR7. If the transceiver'stemperature goes up, the resistanceof diode X3 goes down and thevoltage across it decreases. The for-ward bias of TR6 and TR7 tran-sistors therefore becomes less. Asthe current through the transistorsincreases because of heat, their for-ward bias becomes less because ofthe diode action, reducing the cur-rent, and the effects of heat arecounter -balanced or neutralized.

Another type of stabilization in-troduced by addition of diode X3is supply voltage regulation. In theevent battery voltage drops, as it

Heathkit GW-31.

does under normal use, the tran-sistor's emitter and collector volt-ages decrease, lowering the transis-tor's gain. But the voltage acrossdiode X3 also decreases, therebydecreasing the transistor's base volt-age. Decreasing the base voltage inproportion to the lowered collectorand emitter voltages, permits thestage to continue to operate linearly.In short, diode X3 provides anautomatic bias control on TR6 andTR7.

Osillator

Since the transmitter and receiverused to communicate with eachother operate on a single frequency,it is important that both are fixed

I

Cadre hand-held CB transceiver.

exactly to that frequency. To obtainthis accuracy, crystals are used.Crystal pairs for Channels 2 to 22are usually available and it is notnecessary to make adjustmentswhen crystals are changed.

Final Amplifier Modulation

Since RF carrier modulation ac-tually takes place at the final ampli-fier, it might more appropriately becalled either the modulation stage,or final amplifier. Hence the finalamplifier's task is two -fold. One isto amplify the carrier signal gener-ated by the crystal oscillator; theother is to combine this carrier sig-nal with the audio signal to obtainan amplitude modulated carrier.


This is accomplished by what iscomparable to conventional platemodulation, where an RF ampli-fier's plate voltage is varied at anaudio rate. In the transceiver, thefinal amplifier's collector voltage isvaried at an audio rate.

It can be seen on the schematichow modulation is accomplished.With SW1D in the transmit posi-tion, -12 v is applied to the finalamplifier's collector (TR9) throughthe 11512 modulation winding ofT6. Assuming the audio voltage in-duced into this winding is an 8 vsine wave, depending upon its po-larity, it would aid and oppose the-12 v supply. So the actual voltageapplied to the final amplifier's col-lector will vary from a maximum of-20 to a minimum of -4 v. Thusthe final amplifier's collector voltageis varied at an audio rate, causingthe signal to be amplitude modulat-ed before it is radiated by the an-tenna.

Receiving

Essentially, the receiver operatesthe same as a regular AM broad-cast receiver except it has a fixedreceiving frequency.

Let's follow the signal throughthe receiver. SW1 and SW2 areshown in the CB receive positionon the schematic. Two crystals forchannel 11 operation are installed-a 27.085 Mc transmitter crystal

Fig. 1 - Block dia-gram of typicalhand-held transistor-ized citizens bandtransceiver. Tnis par-ticular unit is de-signed to receive theregular broadcastband.

vRECEIVE

tiSViIA A

TRANSMITB

MIXER IT I F 25P1 F

SW2C

27.540 MCFIXED OSC.CIT. BAND

VAR OSC.BROADCAST

BAND

DETECTOR

SPEECHAMP

DRIVER

HOUTPUTMODULATOR

HOUTPUTMODULATOR

RANSMITOSCILLATOR

BTRANSMIT

RECEIVESWIG

FINALAMP

and a 27.540 Mc receiver crystal.The 27.085 Mc signal is picked upby the antenna, heterodyned in themixer with the crystal controlled27.540 Mc oscillator, producing a455 kc IF frequency. The IF signalis passed through two amplifierstages detected and fed to thespeech amplifier. The audio signal

is then fed to a pair of transistorsin push-pull, and then finally to thespeaker. To make the receiver cap-able of tuning the AM broadcastband, a variable oscillator can beswitched in by SW2C. When theselector switch is placed in thebroadcast position, SW2C switchesin the tapped tank circuit oscillator

CHART I

TROUBLE 551Symptom - Set does not work on citizens band receive only.Isolation - Switching the selector switch to R shows that the

broadcast receiver operates normally.Conclusion - Entire broadcast section of the receive, is OK,

which means the common stages are OK IIF stages to thespeaker). Trouble must be in the citizens band receiveroscillator circuit.

Possible Defect - Receive crystal XI defective.NOTE: Crystals are delicate devices and cannot be subject toabuse. If set shows signs of rough handling, it's advisible tocheck crystals thoroughly.

TROUBLE =2Symptom - Set doesn't receive citizens band or broadcast

stations.Isolation - Check the transmitter by pressing the push -o -talk

button and check against a receiver or field strengthmeer. Transmitter works OK.

Conclusion - The transmitter working means the audio stages,TR5, TR6 and TR7, are probably OK. Barring a cefectiveswitch, the trouble must be in the mixer or IF stagessince these stages are common to both CB and BC.

Possible Defect - Open IF can T3.

TROUBLE 553Symptom - Set doesn't trarsmit.Isolation - Checking the unit's other operations, by placing

the selector switch, SW2, in either receive positions,shows receive sections OK.

Conclusion - The orly stages the receivers don't have incommon with the transmitter are the transmitter oscillatorand final amp. Trouble is probably there.

Possible Defect - R31 open.

AUGUST 196353

coil, T8, and the local oscillator isa Hartley -type variable oscillator.

Troubleshooting & Repair

When troubleshooting, it is nec-essary to note that the oscillatortransistors, TR2 (receive) and TR8(transmit) are slightly reverse -bi-ased. With a tube -type oscillator, aquick check calls for measuring thenegative voltage on the control gridto determine if the tube is oscillat-ing. There is also a quick check forthe transistor oscillator.

As seen on the schematic, thetransmit oscillator transistor (TR8)base is one tenth volt less negativethan the emitter and is therefore re-verse -biased. For a PNP transistorto be forward biased the base mustbe more negative than the emitter,of course. The quick check of theoscillator stages then, is to see thatthe base is reverse biased by beingslightly less negative than the emit-ter.

Since TR8 is reverse biased, onlythe more negative portion of thecrystal output signal will cause TR8to conduct. The crystal is vibratingat 27.085 Mc and supplies energy

the tank circuit, T7, at this rate.The tank circuit, in turn, ,rings oroscillates at its resonant frequency,in this case the same frequency asthe crystal. The same can be saidof the receive oscillator transistor,TR2.

Two stages use average gaintransistors. One is the transmittersection, TR9, and the other is thereceiver section, TR3. When re-placing these transistors, only av-erage gain transistors should beused. When TR3 replacement isnot an average gain transistor, over-all receiver sensitivity may be af-fected.

If receiver gain increases consid-erably and the receiver goes intooscillation when TR3 is replaced,the 150 K damping resistor R12,across T3 primary, should be de-creased in value. Experimentallyselect a value between 150 K and100 K until the receiver becomesstable and sensitivity becomes ad-equate.

If receiver gain decreases con-siderably when TR3 is replaced,then R12's value must be increased.Substitute a value between 150 K

and 330 K until receiver sensitivityis satisfactory.

When replacing the final ampli-fier transistor, TR9, an average gaintransistor must be used. To insurethat final amplifier input power doesnot exceed 100 mw and also thatthe input power is adequate, thefollowing check can be made:

1. Remove the shorting bar,CCP2 shown in diagram near

the battery symbol.2. Connect a milliammeter (0-10

ma) in its place, observingpolarity.

3. Press the talk button, SW1.4. The final amplifier current

should be 6.5 ma.Adjustment of the drive control,

R30, and the final tank coil, L3,should bring the final current to6.5 ma.

If TR9 is replaced and the finalcurrent is low and can't be adjustedto 6.5 ma by L3, T7 and drive con-trol R30, then resistor R29 must bechanged. By experimentation, sub-stitute a value for R29 between 33and 15 1/, so that the final currentcan be adjusted to 6.5 ma.

If the final current is high andcan't be brought down to 6.5 maand by adjusting L3 then R30, R29must be increased in value. Tryvalues between 33 and 56 1t untilthe final current can be adjusted to6.5 ma.

Some interaction may be notedbetween the adjustment of R30 andL3. To adjust properly rock bothadjustments.

With TR8's collector current setto 6.5 ma, the final amplifier's input power is about 78 mw.

It must be remembered that withthe numerous contacts involved intwo switches, SW1 and SW2, theyshould be considered when isolatingdefective stages.

When the set is completely in-operative, after a quick power sup-ply check, the most logical placeto look for a defect is the audiostages. These stages are common toall functions, receive and transmit.This should be regarded as a quickisolation check because it doesn'trule out the possibility of two ormore defects in separate sectionsof the receiver.

Further troubleshooting informa-tion would be too repetitive since

the set in the R (broadcast receive)position is a conventional high qual-ity AM broadcast receiver.This article was based on information furnish-ed by Westinghouse's TV -Radio Division.

TABLE ICB APPLICATIONS1. Plan security patrols2. Roving supervisory personnel3. Crane operators in steel industry4. Materials handling in intro -plant5. Materials handling to yard &

fork-lift trucks6. Departments to inventory ware-

house7. Inside shipping department8. Guided tours9. Dispatcher to loading platform

10. Ves pocket annunciator11. Plant engineer to maintenance

superintendent12. Emergency backup for regular 2 -

way communications systems13. Model shop to tool crib14. Warning systems, dangerous loca-

tions15. Steel mill control console to work-

ers on floor16. Quality control to production17. Plant engineer to boiler room18. Coordinating testing19. Lumber mill to field logging20. Oil field to rig supplies21. Looms to raw fiber supply22. Multi -level printing presses23. Quarry

ery24. Sales office to mobile salesman25. Lumber stock record to kilns or

yards26. Inventory to purchasing27. Pipeline maintenance - field to

central office28. Bridge construction29. Building construction30. Siding to sugar mill batch feed31. Dispensary to factory floor32. Hangar to airfield office33. Drafting room to drafting storage34. Drafting room to prototype design35. Chemical processing to laboratory36. Dam power inspection to office37. Rail siding to receiving and ship-

ing38. Drydock it shipbuilding operations39. Fire fighting coordination40. Farmhouse to planting, cultivating

and harvesting equipment in field41. Geological surveys an prospect-

ing42. Land surveys43. Road construction operations44. Power and telephone line mainte-

nance45. Large building maintenance super-

intendent -to -personnel46. Radio interference location opera-

tions47. Antenna orientations and field

strength measurement operations48. Civil defense49. Campers and hunters50. Search -party operations in woods


For strength,long life

Want TV Masts and Towers That Sell?

Want TV masts and towers with special features that are easy to sell?Masts and towers of Armco ZINCGRIP® Steel Tubing are strong-resistwind and snow loads. And they're protected with a durable zinc coat-ing to fight rust. Get names of manufacturers who make TV masts andtowers of this strong, rust -resisting steel tubing. Fill in and mail coupon.

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- for more details circle 11 on post cardAUGUST 1963

55

TOUGH DOG CORNER

Difficult Service Jobs Described by Readers

Booster Generates Hum BarI recently made a call on a 14-

YP3D Admiral portable. The cus-tomer complained about a fainthum bar that was creeping its wayfrom the bottom, up and out of thepicture. As soon as the bar dis-appeared another one would startslowly creeping up and out again.

The customer complained thatanother technician had worked onthe set a few weeks before and itwas only since then that this troublebecame evident. It looked like asimple case of poor filtering to meso I could hardly hold anything hedid responsible for this problem.I explained this to the customer;feeling satisfied that this was abrand new condition, the customeragreed to let me take the set to theshop.

I've serviced this type of capac-itor before and it has usuallyturned out to be a leaky filter con-denser. The B + filters and thevertical output tube cathode filterare generally all parts of a mul-ti -section filter can. When the di-electric seperating the sectionsbreaks down, a small portion of thehigh ac pulse voltage makes it wayover to the vertical output tube andshows up as a faint hum bar slow-ly creeping through the picture.

Before I completely dismantledthe receiver, I thought I wouldcheck my diagnosis by taking ascope check at the vertical outputcathode. This receiver is the dou-ble-decker chassis variety so I firstswung the printed circuit IF chas-sis down on its hinges, plugged anine pin test socket into the ver-tical sweep tube socket. After rein-serting the vertical tube, I connect-ed the scope to the cathode ter-minal. When I finally turned thereceiver on, much to my dismay,the hum bar was gone.

I operated the set this way for

two days hoping the hum bar wouldreappear, but it didn't. I removedmy test setup and screwed the IFchassis back in place and placedthe set aside to cook some more.When the switch was turned onagain, I was surprised to see thatthe hum bar was back again.

I swung the set around to facethe shop mirror and proceeded toswing the IF chassis down and outof the way once more. Again I

noticed that with the chassis swungdown, the bar disappeared. Thesolution suddenly became clear.

The serviceman before me in-stalled a picture tube booster. Thisbeing a very tight set with limitedroom, he tucked the booster rightup against the picture tube neck.Being so close to the kine gun, thesmall transformer inside the boost-ed was modulating the beam with60 cps filament voltage. When Ifirst lowered the IF chassis, thebooster pulled away from the kineexplaining why I lost the bar. WhenI reassembled it, I made the samemistake as the other fellow andtucked the booster up tight again.I relocated the booster a little fur-ther away from the kine and theproblem was solved. - Frank A.Salerno, Long Island City, N. Y.

CRT Causes Reduced B+I was called on to service a Mo-

torola RTS 525A-03 chassis with"no raster." Close observation ofthe screen in a dark room revealeda faint picture. The high voltagearc looked good. However, I de-cided to supply a plate drive pulsefrom my sweep analyst to the platelead of the 6B06. This failed toproduce a raster improvement. Sub-stituting a new 1B3 did not help.A check of B + showed it to be low,so I replaced the selenium rectifiers.

This broughtvived the set.

Thinking my troubles were over,I replaced the chassis in the cabinet.The original trouble had returnedwith dividends; in addition to a dimraster, the horizontal oscillator wasoff frequency! After adjustmentsand a few other checks failed toshow any promise, I pulled the chas-sis and took it back to the shopfor more extensive checks.

At the shop, voltage checks re-vealed that things were OK alongthese lines. I tried a new yoke,but this did not cure the trouble.I studied the schematic very care-fully noting that the boost voltagewas also fed to pin ten of the21YP4. I decided to try my sub-stitute picture tube. The set wasback on frequency and a perfectpicture appeared. Replacing the21YP4 picture tube completed therepair. - P. R. Savage, Jr. Decatur,Ala.

r

up the B + and re -

TOUGH DOGS WANTEDsio 00 paid for acceptable items. Use

drawings to illustrate whenever neces-

sary. A rough sketch will do. Photo

graphs are desirable. Unacceptable

items will be returned if accompanied

by a stamped envelope. Send your

entries to "Tough Dog" Editor, ELEC-

TRONIC TECHNICIAN, 1 East First St.,

Duluth 2, Minnesota.


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Provides Accurate NTSC-Type Signal-Color phaseangles are maintained in accordance with NTSCspecifications.Makes Convergence and Linearity AdjustmentsEasy-Highly stable crystal -controlled system with

vertical and horizontal sync pulses, assures the ultimatein line and dot stability.Simplifies Demodulator Alignment-The type of colordisplay produced by this instrument provides the ulti-mate in simplicity for precise demodulator alignment.Provides Automatic Deconvergence-Eliminates thenecessity for continual static convergence adjustments.The instrument automatically deconverges a white into acolor dot trio without digging into the color set to mis-adjust the convergence magnets. It also deconverges awhite horizontal or vertical line into red, green and blueparallel lines. This greatly simplifies dynamic convergenceadjustments.Provides Exclusive Color Gun Killer-Front-panelswitch control makes it easy to disable any combinationof the three color guns. Eliminates continuous adjustmentof the background or screen controls, or connection of ashorting clip inside the receiver. The switch also selectsthe individual grids of the color tube and connects to afront -panel jack to simplify demodulator alignment.Provides Switch -Selected R.F. Signals-Factory-tuned, for channels 3, 4, and 5-for open channel use inyour area.

Model 850 also includes other features thatit invaluable for home and shop use. Net,

See Your B&K Distributoror Write for Catalog AP21-T

B & K MANUFACTURING CO.Division of DYNASCAN CORPORATION

1801 W. BELLE PLAINE AVE. CHICAGO 13, ILL.Canada: Atlas Radio Corn., 50 Wingold, Toronto 19, Ont.Expert: Empire Exporters, 253 Broadway, New York 7, U.S.A.

- for more details circle 12 on post cardAUGUST 1963 57

SHOP HINTSTIPS FOR HOME AND BENCH SERVICE

Eliminating Noise on "Seeker"Tuner

On some auto radios with touch -tuners objectionable noise developswhile the searching motor is oper-ating (seeking station). To correctthis condition, obtain some three -in -one oil and mix with equal partsan oil additive known as "STP."Carefully apply this oil mixture toboth bearings (front and rear) ofthe search tuner motor, one dropwill usually do the trick. This mix-ture is also great for Generatorsand other small Motors, Tape Re-corder bearings and anything thatrequires a long lasting lubricant.- Floyd A. Roberts, Kearney, Ne-braska

Cleaning Tube PinsI find cleaning tube base pins

with contact fluid when I have themout for testing improves perfor-mance of many sets; especially theminiature tube pins. - H. E. Barta,Hepler, Kansas

Solder RemoverSolder can be cleaned from points

with a special tip. The old tip ofthe iron is removed and replacedwith a 13/4" length of 3/16" coppertubing, flare one end slightly andthread the other end to fit the heat-ing element. Drill a small vent holenear the threaded end as shown.

To clean a solder connection ap-ply the hot iron tip to the connec-tion and the molten solder is drawnup into the hollow tube by capil-lary action. When the tube becomes

full it is emptied by merely shakingthe iron while hot. - Robert L.Howell, Berlin Heights, OhioSarasota, Fla.

Network ReplacementTo replace transistors, or resist-

ors - capacitor networks with longwire leads - cut the leads in a

Multiple wire PC networks can be installedeasily if leads are stagger -cut.

"step" fashion. Then by heating theback side of the printed board eachwire can be pushed through sep-arately.- Ivan Ruggles, Lubbock, Texas

Rivet RemoverOne of the best time savers we

have in the shop is a set of threevari-shaped grinding bits for ourelectric drill. There's no faster wayof getting off riveted componentslike interlocks, than by touching thewhirling burr to the heads of therivets. They come off in no timeand avoid damage trying to remove

PENCIL SOLDERING IRON

3/447 V2 W FLARE END

SLIGHTLY

3/16° COPPERTUBING

Modified solderingiron tip for printedcircuit work.

Grinding bits speed removal of rivets.

them by drilling, etc, especially inclose -in work. The burrs are inex-pensive, last a long time and areobtainable in hardware stores andhobby shops. - Harry I. Miller,Sarasota, Florida

Liquid Lock WasherWhen assembling components

destined for a mobile rig in a joun-cing vehicle, we've found it veryuseful in preventing prematurebreakdown, to dip the threads ofmounting screws, nuts and bolts ina bit of ordinary shellac.

The shellac makes the screwsstay put indefinitely. This is of spec-ial value on screws too short for alock washer. - Harry S. Miller,

SHOP HINTS WANTED

$3 to $10 for acceptable items. Use draw-ings to illustrate whenever necessary. Arough sketch will do Unacceptable itemswill be returned if accompanied by a

stamped envelope. Send your entries toShop Hints Editor, ELECTRONIC TECH-

NICIAN, Ojibway Building, Duluth 2,

Minn. The hints published in this columnhave not necessarily been tried by

ELECTRONIC TECHNICIAN editors and

are the ideas of the individual writers.


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Time -Saving, Money -Making Instruments Used by Professional Servicemen Everywhere

Model 960 TransistorRadio Analyst

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B & K MANUFACTURING CO.Division of DYNASCAN CORPORATION

1801 W. BELLE PLAINE AVE. CHICAGO 13, ILL.Canada: Atlas Radio Corp., 50 Wingold, Toronto 19, Ont.Export: Empire Exporters, 253 Broadway, New York 7, U.S.A.

- - - for more details circle 35 on post cardAUGUST 1963 59

NEW PRODUCTSFOR MORE INFORMATION CIRCLE PRODUCT NUMBERS ON POST CARD FOLLOWING PAGE 82

SEMICONDUCTOR TESTER 200A VOM specifically designed for

semiconductor testing, Model 630-Loffers two special low power Ohms

circuits on the x 1 and x10 ranges.These ranges have been designed forsafe testing of semiconductor cir-cuits. The maximum open circuittest voltage is onlypared to 1.50 in conventionalOhmmeter circuits. This allows test-ing below the breakdown voltageof the transistor or other semicon-ductor without damaging overloads.Maximum power dissipation in thesemiconductor under test is lessthan 420 /2,w. Triplett Electrical In-strument Co.

STEREO TAPE DECK 201A 3 -speed stereophonic tape deck

and preamp combination is claimedto offer utmost versatility and beideal for rack mounting or custominstallation. Featuring an integrateddual preamplifier, it permits 4 -trackstereo and mono record/play; 2 -track stereo and mono playback;and facilities for sound with sound

recording. Other outstanding fea-tures include: two separate VU me-ters, individual volume controls foreach channel, digital tape indexcounter, automatic tape shutoff andfast forward and rewind control,Precision Apparatus, Inc.

SPEAKER KIT 202A pre -finished loudspeaker kit

reportedly can be constructed bythe novice in less than twenty -minutes - without tools. Christen-ed the Coronet, the system com-bines an 8 in. extended -range loud-speaker with a ducted -port acousticphase -inverter enclosure. Three ver-sions are available: the Coronet I,which includes the enclosure kit and

an 8 in. MC8 Michigan loudspeak-er; the Coronet II, including enclo-sure kit and a Wolverine LS8 loud-speaker; and the Coronet III, whichincludes enclosure materials and anSP8B. The Coronet I will sell toaudiophiles for $39; the Coronet II,for $43.50; and the Coronet III, for$54. (Prices, west of the Rockies,are slightly higher.) All systemsfeature exterior surfaces of selecthardwood veneers, pre -finished inoiled walnut. The design whichmakes possible "the industry's firsttool -less loudspeaker system kit,"is said to be the system of inter-locking tongue -and -groove joints,further secured by four threadedrods which extend vertically throughthe unit, fastened by wing -nutswhich are recessed into wells in thebottom. Strips of adhesive -backedgasket tape, of polyurethane foam,

are used to line the joints, assuringtight, rattle -free construction. Elec-tro-Voice, Inc.

FLYBACK TRANSFORMER 203Four exact replacement flyback

transformers are now available.When used in the following applica-

tions, no circuit or chassis altera-tions are required. HO -345 re-places Philco 32-8855-1, -2, -5, and-8 in 76 models and chassis. HO -349 replaces Philco 32-8993-3 in47 models and chassis. The HO -350replaces Admiral 79D83-4, -5, -7,-8 and -10 in 32 models and chas-sis. The HO -351 replaces Admiral79E77-11, -14, and -15 in 36models and chassis. All these unitsare now being stocked by distribu-tors. Stancor Electronics, Inc.

RADIO CONTROL 204A complete radio control system

for automatic remote operation ofdoors, lights, signals, motors, etc.,the Model RT-400, has a suggesteduser price of $99.50. Operating isup to 500 ft. when used outdoorsin unobstructed areas. Indoors, dis-tance will vary from 50 ft to severalhundred ft, depending upon thestructure of the building and the


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AVAILABLE WITH REVOLUTIONAR rNUVISTOR COLORTRON AMPLIFIER...

Now, through continuous Winegard research, a new, im-proved Electro-Lens yagi has been developed-the NEWWINEGARD COLORTRON-PERFECT ANTENNA FOR COLOR TV!

Colortrons have a flat frequency response (plus or minusih DB across any 6 MC channel), no "suck -outs" or "roll -off"on end of bands . . . accurate 300 ohm match (VSWR 1.5 to1 or better) . . . unilobe directivity for maximum ghost andinterference rejection. They deliver today's finest color recep-tion, give a new picture quality to black and white. Colortronsare the only outside antennas that carry a WRITTEN FACTORYGUARANTEE OF PERFORMANCE.

And Colortrons are built to last. High tensile aluminumtubing for rigidity and stability, insulators with triple mois-ture barrier, GOLD ANODIZED for complete corrosion -proofing.

There are 4 Colortron models to cover every reception need,from suburbs to distant fringe areas . . . $24.95 to $64.95 list.

New Winegard Colortron twin-nuvistor amplifier perfectlymatches Colortron antennas. Gives added gain and sensitivityon both color and black and white. Ultra -low noise, hieh

1F

MODEL C-44

GOLD ANODIZED 564.95

---

4' 24-, .s,

NUVISTOAMPLIFIER

gain Colortron Nuvistor Amplifier can easily drive 6 or moreTV sets.

With revolutionary twin-nuvistor circuit, Colortron ampli-fiers can handle up to 400,000 micro -volts of signal withoutoverloading. This is 20 times better than any single transistoramplifier. The Colortron Amplifier will bring the weakestsignals up out of the snow, yet strong local TV & FM signalswill not overload it. A special life saver circuit gives the twonuvistors a life of 5 to 8 years.

This amplifier is completely trouble free and the finestperforming antenna amplifier you can own.

Completely weather sealed, nothing is exposed to corrodeand cause trouble . . . has all AC power supply with 2 setcoupler. (Model No. AP -220N, $39.95 list). Twin transistormodel also available up to 80,000 micro -volts input. New typecircuit protects transistor from static electricity built up inlightning flashes. (Model No. AP -220T, $39.95 list).

Colortron Amplifier can be added to any good TV antennafor sharper, clearer TV reception.

Ask your distributor or write for technical bulletin.

v.:41MODEL C-43

1GOLD ANODIZED 551 9

;E17DE1.111C-42OLD ANODIZED 534.95

7 -MODEL C-41

ANODIZED 524 95

1111 -Winegani ANTEN NA SYSTEMS 3)19-8 Kirkwood Burlington, Iowa

1.803.4 ity and performance in every Winegard product.

- - - for more details circle 34 on post cordLONG ISLAND 1:171 (p. N. 1.. 1:11 1-1100

frorolitori .4 rea nictriburt,

NEW PRODUCTS

'Al

presence of metal obstructions, suchas wiring conduits p i p i n g, ductwork, columns, etc. The systemconsists of a portable pocket sizedtransmitter with self contained an-tenna and battery, and a receivercontained in a metal enclosure withflanges for wall mounting. Perma-Power Co.

TUBE PULLER 205The TP-1 tube puller was

designed for removing nuvistortubes, too small to be removed withconventional tube pullers. It is

designed with an internal springmechanism that firmly grips thetube without danger of denting,scratching, or other damage, themanufacturer says.Cinch Manufacturing Co.

SQUEEZE PACKS 206Instant squeeze packages of sili-

cone are available for the encapsul-ation of electronic components. Theunit packages contain preciselymeasured amounts of silicone RTC'resin and catalyst. The two com-ponets are kept separate by a heat -seal barrier until ready for use.Intermixing is accomplished bysqueezing the resin compartment tobreak the seal. The componets arethen mixed by massaging the pack-age for approximately one minute.A funnel tip is provided for dispens-ing the catalysed resin, which curesinto a solid rubber at room tem-perature in five minutes or less.The Instant Rubber packages areclaimed to eliminate any chance oferror in measuring and mixing thecomponents, thereby simplifyingquality -control procedures. Stand-ard packages of Instant Rubber

List Price $149.50HALLMARK 512UNEXCELLED IN PERFORMANCE, STYLING

AND RUGGED RELIABILITY!Today's best selling CB from Hallmark features dual -power. 12 channelcrystal -controlled, push to talk operation. Sensitivity better than 0.30for 10 db S N ratio. Selectivity better than 30db. RF power over 3.2watts. Audio power 3 watts. Top-quality components in rugged hand -wired chassis. 26.965 to 27.255 mc. High-level modulation, improvedlow -noise front end. "S" meter and neon modulation indicator standard.

NOW FROM HALLMARK, NEWEST ADVANCE INIMPROVED MULTI -PURPOSE

e$ 49 50 I TRANSCEIVER TESTERS!A precision instrument designed to assist

11-1I

the technician in installation and servicingof low power transceivers. Measures: RFpower (absolute) 0-5 w.; 0-120% amplitudemodulation: VSWR; Produces a 100mw carrier(with or without amplitude modulation of a1000 cps tone) for checking receivers: Useas a field strength meter.

HALLMARK INSTRUMENTS6612 DENTON DRIVE, DALLAS 35, TEXAS


contains 1/2 oz of resin and catalyst.Price for a box of 10 units is $5.25.Laguna Labs.

AUTO 'HOME STEREO 207An auto/home stereo set may

also be installed in pleasure boats,trailers, and airplanes. The in -carinstallation includes the basic Model100 set having 4 -in. speakers, twoin back and two in front. The setnestles beneath the dash or otherconvenient location. It has 10 tran-

NOW . . .

a convenient, sturdy binder for yourELECTRONIC TECHNICIAN Schematics!

54.95 EachPostage Paid

Here's a sturdy book binder designed specifically for technicianswho want to file away the ELECTRONIC TECHNICIAN Tekfaxschematics fo' easy reference. KING-SIZED. 11" x 15".Your schematics lay flat, no folding necessary. EASY TO USE.Just press back the special spring clamp and slip your newschematics into place. No holes to punch. STURDY. Hand-some, reinforced binding. Tough duty fabric cover. SAVETIME. With This convenient binder you'll be able to locateyour schematics quickly, easily. You'll be able to protectthem, carry them conveniently with you on your service calls.

- - -ORDER. TODAY - USE THIS CONVENIENT FORM- - -

ELECTRONIC TECHNICIANDEPT. B -B OJIBWAY BUILDING, DULUTH 2, MINNESOTA

Please Rush Me Schematic Binders at $4.95 each

I am enclosing $

Name

Company Name

Street Address

City Zone State


Prices effective January 1, 1963

Tarzian offers

FAST, DEPENDABLE

TUNER REPAIR

SERVICE (MAALKLES)

of

It just makes sense that a manufacturer of tuners shouldbe better -qualified, better -equipped to offer the most de-pendable tuner repair and overhaul service.

Sarkes Tarzian, Inc. pioneer in the tuner business,maintains two complete, well-equipped Factory ServiceCenters-assisted by Engineering personnel-and staffedby specialized technicians who handle ONLY tuner re-pairs on ALL makes and models.

Tarzian-made tuners received one day will be repairedand shipped out the next. Allow a little more time forservice on other than Tarzian-made tuners.

Tarzian offers a 12 -month guarantee against defectiveworkmanship and parts failure due to normal usage. And,compare our cost of $9.50 and $15 for UV combinations.There is absolutely no additional, hidden charge, for ANYparts except tubes. You pay shipping costs. Replacementson tuners beyond practical repair are available at low cost.

Tarzian-made tuners are identified by this stamping.When inquiring about service on other tuners, always

give TV make, chassis and Model number. All tunersrepaired on approved, open accounts. Check with yourlocal distributor for Sarkes Tarzian replacement tuners,replacement parts, or repair service.

3 \-T-ISARKES TARZIAN, INC.Bloomington, Indiana

MANUFACTURERS OF TUNERS . . . SEMICONDUCTORS . . . AIRTRIMMERS ... FM RADIOS ... AM/FM RADIOS ... AUDIO TAPE ...BROADCAST EQUIPMENT

ONLY

INCLUDING

ALL PARTS(except tubes)

I and LABOR

24 -HOUR SERVICE

1 -YEAR WARRANTY

TWO SERVICE CENTERSTO SERVE YOU BETTER

See your distributor, or use theaddress nearest you for fast fac-tory repair service

537 South Walnut St.Bloc mington, IndianaTe I : 332-6055

10654 Magnolia Blvd.North Hollywood, Calif.Tel: 769-2720

AUGUST 1963 3

ALL TAPE HEADSWEAR OUT!

HERE'S HOW AND WHY!

Magnetic tape itself is thereal cause of head wear!

The abrasive action of tape as it passesover the head face gradually wearsaway the depth of metal left on a newhead after final polishing (see above).Because wear is nearly always uneven,craters or ripples are also formed onthe face as wear progresses, thus mak-ing it impossible to achieve goodcontact between the head gap and theall-important signal recorded on thetape. The severe high frequency lossesand erratic output resulting from poortape -to -gap contact are very annoyingto the ear. Head wear should NOT bepermitted to reach this point - muchless go beyond it to the limit where thegap actually begins to open up.

By replacing the worn head with anew Nortronics professional type oflaminated tape head you will obtainimproved high frequency response overthe original head, plus the added fea-ture of longer life since laminated headshave 50% more depth of metal at thegap. Nortronics manufactures bothlaminated and solid -core heads, butrecommends the use of the laminatedtypes for up -grading of your customer'srecorder.CHECK into the profit -packed NortronicsTape Head Replacement Program NOW!

This new program offers you the opportunityto get in on the ground floor ... Replacementof worn tape heads is profitable - is easy - isever-growing in demand. it your local repre-sentatives can't help you - write Thor John-son, Distributor Sales Manager.

"Music sounds best on Tape -Tape Sounds Best

with Nortronics Heads"

-71oAdizonic4- e8133 10th Ave., N.

Minneapolis 27, Minn.- - for more details circle 25 on post card,


NEW PRODUCTS

sistors, a 12-v system that willoperate on 9 to 14 v, drawing lessthan 1 amp. Cost of the set in-cluding installation approximates$150. The standard home adapterincludes a converter element whichhouses the auto/home stereo andtransforms 110-120 v, 60 -cps ac to12 v plus/minus 2 vdc; plus twowalnut speaker housings that sit ontable or hang on wall. Cost of thisoptional home adapter assembly isabout $70. Diamond Electronics,Inc.

CAR RADIOS 208A line of custom

cludes 24 exact -fit, custom -lookmodels. Features include a built-in

',Kier control for push-buttonmodels. In addition to the custommodels, the company also offersthree Universal model auto radiosfor installation in sports cars.foreign cars, trucks and boatsTenna Corp.

FM STEREO TUNER 209Equipped for stereo reception,

the new 310E FM tuner utilizes

time -switching multiplex circuitryfor achieving optimum stereo sep-aration. Features claimed for the310E include: sensitive, illuminatedtuning meter for optimum orienta-tion and station selection; conven-ient front -panel recorder outputjack; laboratory -type precision ver-nier tuning control; auto -sensor cir-cuitry for fully automatic operation;and mode control with FM mono-phonic, FM stereo, and FM stereoautomatic positions. The 310E car-ries a net price of $279.95.H. H. Scott Inc.

SOLDER REMOVER 210Soldapullt is a portable hand tool

for component rework. It is saidto be a convenient method of de -

soldering radio and television com-ponents on printed circuit boards.It features a high impulse of 25 in.of Hg vacuum and a self cleaningtip. It reduces solder splash andoverheating of solder connectionsand simplifies removal of multi -component terminal connections,expediting component replacement,claims the manufacturer. EdsynEngineering.

CB TRANSCEIVER 211

A 10 -channel citizens band trans-ceiver employs a solid state fre-quency synthesizer so that the same

crystal can be used for transmittingas well as receiving. Supplementingthe 10 crystal -controlled channels,the unit is equipped with a tunablereceiver covering all frequencies

within the 27 Mc citizens band.This enables users to monitor anychannel and to pinpoint clear chan-nels. In addition to the frequencysynthesizer said to cut crystal costs,the TWR 3 features a sensitive RFstage. This coupled with exception-ally low internal noise levels issaid to make unit particulary effec-tive for receiving distant and weaksignals. High electrical efficienciesproduce 3.2 w output from the max-imum input permitted by the FCC.The suggested list price is $219.95.Raytheon Co.

COMM SYSTEM 212A transistorized two-way com-

munications system aimed at homeor business use, the Interphone, hasbeen introduced. Designated asModel 6555, the transistorized in-terphone is battery -operated. Lightand compact, it can even be hung ona wall. Either unit, master or slave,can initiate calls. The master unitcan be set to insure privacy, yet can

be buzzed at any time. A volumecontrol feature is included. Listprice is $34.95. Channel MasterCorp.

FUSE PACKAGING 213The Visual -Pak, a package of

glass tube fuses, has a clear plasticbottom with a metal slide top. Thiscombination is said to make thetop firmly grip the bottom and sec-urely lock, thus eliminating the dan-ger of the top coming off and spill-ing the fuses. The new type metaltop has a flat end so that the typeand size of fuses can be shown inlarge clear letters. Bussman Mfg.

AUGUST 1963

try this with any other cartridge(at your own risk)

No way to treat a cartridge, for sure-That is, any cartridge except the Sonotonemodels featuring the new Sono-FlexT needle No more bent or broken needleshanks caused by flicking off some lint, dropping the arm, or scraping it acrossthe record.

The newly developed Sonotone Sono-FlexT. needle to the rescue! Gripped in aresilient butyl rubber mount. you can flex this needle shank in a 360 -degree orbitwithout breaking. Pluck it-flick it-bend it-bump it-it will continue to performas good as new.

Moreover, the Sono -Flex brings advantages in performance never before offeredby any replacement cartridge: Higher compliance, wider and flatter frequencyresponse, lower IM distortion, and longer needle and record life.

Sonotone Sono -Flex° increases your profits two ways Sonotone cartridges are better than ever, easier to sell, because they're betterperformers. Further, you el,minate callbacks because of broken needle shanks.Sono -Flex needles are standard right now in these Sonotone cartridges models:9TAF, 16TAF, 916TAF and the Velocitone Mark I I.

Sono -Flex opens up lucrative needle replacement business for upgradingthese Sonotone cartridges models: 9T, 9TA, 9TV, 9TAV, 16T, 16TA, 16TAF and916TA, original equipment in over a million ahonographs. Replacement is fast,simple-requires no tools-assembly snaps 41to position easily, and gives im-med ate proof of better performance plus abuse -proof, longer needle life.

See your listributor today and ask for Sonotone cartridges with the Sono -Flex needle.

SONOTONE CORPORATION Electronic Applications Division Elmsford, New YorkIn Canada: Atlas Radio Corp., Ltd., Toronto cartridges speakers batteries

microphones electron tubes . tape heads hearing aids headphones- - for more details circle 31 on post card

65

NEW PRODUCTS

TAPE RECORDING HEAD 214A triple -action, one component

tape recorder head that records,plays and erases has been marketed.

The all -metal faced head can eraseone track at a time or both trackssimultaneously. Its tapered designis said to prevent incorrect insertionof reels or tapes. Michigan Mag-netics Inc.

PLAYBACK SYSTEM 215A longer -play Symphonaire Mu-

sic System is offered with playback

The Serviceman'sAlways

Right . .

When He Uses

QUIETROLEThe happiest customers are serviced byrepairmen who use Quietrole . the amaz-ing lubricant that so effectively silencespesky, noisy controls and switches on radios,TV sets and electronic instruments. If youwant to leave your customers smiling, you'lldo what good servicemen do everywhere ...USE QUIETROLE!

Now, with FREEEXTENDER TUBEfor aerosolcan to easilyreach the mostremote places.The bestdistributorseverywhere arepleased to sellQUIETROLE!IN SPRAY CANSor 2, 4, 8 oz.BOTTLES

manufactured by

COMPANYSpartanburg, South Carolina

In Canada: CROSS CANADA ELECTRONICS12 Laurel Street, Waterloo, Ontario

- - - for more details circle 27 on post cord

equipment which provides fourhours of continuous general back-ground, mellow moods, show tunes,dinner music, industrial and specialselections by leading musicalgroups, without repeating. To sup-port the 4 -hour service feature, anew direct drive repeatable tapetransport has been designed. Na-tional Sound System.

ANTENNA SYSTEMS 216Three indoor antenna systems

have been introduced. The Twinshown consists of two spearate an-

tennas coupled to a common feedline. The Color Master may be usedas a color television antenna, ablack and white television antenna,an FM monaural and stereo anten-na, and a master distribution tele-vision and FM amplifier system, themanufacturer says. The Discovered,for broadcast and short wave fre-quencies, has a built-in, fully trans-istorized preamplifier, which in-creased the strength of the signal atthe receiver. Gallo ElectronicsCorp.

MONITOR RECEIVER 217A crystal -controlled VHF -AM

monitor receiver for the 100-150Mc/s range, the AMR52-X can,according to the manufacturer, beequipped for receiving on any fre-quency in the following bands: 108:

135 Mc/s aeronautical band; 136-137 Mc/s earth -space band; 143.91 Mc/s and 148.41 Mc/s CivilAir Parol land and mobile channels;and the 144-148 Mc/s (2 -meter)amateur band. The AM receiveris available in single and multi -chan-

nel types. Hammarlund Manufac-turing Co.

MULTI -TESTER 218The VOM-22 is a miniature mul-

ti -tester said to have a sensitivityof 20,000 ohms/v dc and 15,500ohms/v ac and 18 different mea-surement ranges. Equipped withthumb -operated ohms adjust, ex-ternal zero adjust and detachableleads, the multi -tester has five dif-ferent ranges for ac voltage, five fordc voltage, four for dc milliamperesand four for resistance. Complete

with leads and batteries, it is pricedat $36.90 International Instruments,Inc.

INDOOR ANTENNA 219The FM 1000 Indoor antenna is

said to have been engineered and


perfected exclusively for FM multi-plex, stereo and Hi Fi. It fea-tures a combination of matchedcomponents, special noise filteringcircuit, and 12 -position directionfinding switch. The unit is fair tra-ded at $6.95 retail. All ChannelProducts Corp.

COLOR TV TUBES 220Two tubes for use in color tel-

evision circuits have been intro-duced. Designed particularly to

4iN

handle the higher dissipations andvoltages of color TV receivers, thenine -pin 6DW4A is a heater -typediode for use as a horizontal fre-quency damper. A filamentary di-ode designed as a high voltage fo-cus rectifier in color TV receivers,the 1AU2 is directly replaceablefor the 1V2. The tubes have asuggested unit list price of $2.10 forthe 1AU2 and $3.70 for the 6DW4-A. Raytheon Co.

CB ANTENNA 221This tuneable mobile CB an-

tenna is a copper -sheathed fiber -

0

glass rod encapsulated in a water-proof plastic sheath. It is 48" high.New-Tronics Corp.

SPEAKER LINE 222A multi -impedance replacement

speaker line utilizes multiple -wind-ing voice coils. The multi -imped-ance speaker line boasts the alum-

inum voice coil plus extra -heavywindings claimed to handle maxi-mum power without overheating orloss of efficiency. Oaktron Indus-tries.

MICROPHONE HOLDER 223The No. 65-525 magnetic micro-

phone holder need not, the com-pany says, be permanently mounted,but relocated time and again onany metal surface to suit the de-sired availability of the user. Themagnet is said to have a holding

INSTALL and SERVICE

COLOR TV in the HOME

ELECTRONICS

cf2T>

FAST -SIMPLE

COLOR andBlack & WhiteSERVICING

ONLY

EST PATTERNGENERATOR

Designed for low cost color servicing . . . on location!Light -weight, compact, GC's new Color Test PatternGenerator eliminates lugging heavy, bulky equipmentinto the customer's home-allows Color set-up, finalconvergence and purity checks to be made quickly,easily ... economically!

Simple to operate . . . easily connected, the generatorproduces 3 different patterns, each with a specificfunction, including individual switching for any com-bination of three color guns . . . for fast purity orconvergence checks without upsetting color controls.

PLUS ... many more features! Complete specificationsare available from your GC distributor or by writing GC.

No.36-613 Complete in rugged,handsome carrying case Net $59.50

GENERATES THESE PATTERNS

...

DOTS HORIZONTAL VERTICLEBARS BARS

Write for the all new

GC 340 page Master

catalog . . . with the

complete Test Equip-

ment line and over

12,000 other products.

GC ELECTRONICS CO.)IVISION OF TEXTRON ELECTRONICS, INC., 400 5. WYMA4 STREET, ROCKFORD, ILLINOIS, USA

- - - for more details circle 18 onAUGUST 1963

post card67

NEW PRODUCTS

capacity up toprice of $.99.Co.

12 lb. It has a netG. C. Electronics

OSCILLOSCOPE 224This compact and lightweight

general-purpose oscilloscope has a3 in. flat face CRT and mu -metal

neck shield. It features direct con-nection to vertical deflection plateswithout need of removing and re-placing shorting links or wires.Test leads are simply plugged intorear jacks and the switch is turnedfrom amplifier to direct plates. Thelist price for the kit is $65.95. Wiredit is $99.95 Eico Electronic Instru-ment Co.

PEN OILER 225The plastic Oil -Mite pen oiler

has an extending retracting "needle -thin" stainless steel tube. With fin-ger tip control, the special instru-ment oil is easily dispensed throughthe tube a drop or fraction of a

drop at a time, the manufacturersays. The over-all reach is over9". Armite Laboratories.

UHF -FM EQUIPMENT 226The Model 684 Ultra Basecom

and the Ultra Fleetcom (shown)mobile units are said to provide aUHF radio system featuring hightransmitter powers for extendedrange. The Model 684 Portacom isavailable in a hand -carried case withself contained speaker and controlsfor installations requiring frequent

moving of the radio equipment fromvehicle to vehicle, or vehicle to base.Communications Co.

CATHODE TUBE 227The 8408 harp cathode tube uti-

lizes a frame grid. It features apower output of 6w at 500 Mc withan instant heating warm-up time ofless than 0.5 sec, the firm claims.The tube is a push-pull tetrode de-signed for use as an RF amplifieror frequency multiplier in transistor-

ized vehicular transmitters. Amper-ex Electronic Corp.

PUSH-PULL CONTROL 228Fourteen new items have been

added to the Fastatch II replace-ment control system for use in theconstruction of push-pull controls.Among the items are a KR -8 push-

pull line switchthe rear of any dual concentricFastatch II control; a universalpush-pull, snap -in shaft and 12 ex-act replacement push-pull shafts invarious sizes for use with KR -8.Central ab

which snaps onto

SOLDERING IRON 229A tiny lamp, built into the handle

of the Sentry Model KC 1200Bsoldering iron gages tip temper-ature and wattage. The lamp burnsbrightly on 50 w and dimly on 40

w. The iron is hot when the lampis lit. It lists for $2.50. Electron-ic Ideas, Inc.

TABLE RADIOS 230Model 6500 is a 6 -transistor table

portable radio that retails at $19.95.Model 6520 shown is an 8 -transis-tor cordless AM table portable thatfeatures an RF amplification stage.It has a list price of $49.95. Model


3

6536 is an FM/AM clock alarmradio. List price is $99.95. Chan-nel Master Corp.

TRANSISTOR TESTER 231The Model 4 in -circuit transistor

tester tests semiconductors installedin circuits. Circuit resistances downto 20 ohms may be balanced forevaluating low medium and highpower transistors and diodes, thefirm reports. It is said to measuresaturation voltage and forward re-sistance in -circuit with 5% accuracy

at 5, 50 or 500 ma by a simple2 -step sequence. Test EquipmentCorp.

THREE YOKES 232Fhree yokes have been an-

nounced. They are Part No. #Y -54A, which replaces 7 Philco yokesin 5 chassis and 32 models; DY-56A, a replacement for 4 Zenithyokes in 7 chassis and 58 models;and DY-51A, which replaces 2Packard Bell part numbers in 21

chassis and 45 models. StancorElectronics, Inc.

AM/ FM PORTABLE 233A new Toshiba AM/FM port-

able has been introduced by Trans-istor World Corp. to retail at $59.95complete with batteries and ear-

" phone. The Model 10TL-655FAM/FM portable is said to incor-porate advanced circuitry using 10high frequency transistors, 6 diodesand a 31/2 -in speaker. The set ispowered by 4 C -cells held in a side -

POWER LINE CORD 234A power line cord, Model 1480

consists of two insulated Safe-T-Klips, each incorporating a typeAGX-5 fuse. Connected to these

NMI 0opening battery compartment. Itretails at $59.95. Transistor WorldCorp.

Tilukt oly

Raba -TV

-hose who use Those who use

GUAMreplacement loudspeakers replacement loudspeakers

We're proud to say thatthis group is bigger*

other brands of

* According to the findings of Brand NameSurveys, Chicago, Illinois in March and April1963, more servicemen prefer Quam speakersthan all other replacement brands combined.Major reasons stated for the preference:Quality! Availability! Performance!

QUAM-NICHOLS COMPANY226H E. Marquette Road, Chicago 37, Illinois


69

if NEW PRODUCTS

fused clips is a 6 -foot length ofNo. 18 SPt-1 black line cord com-plete with strain relief and moldedplug. Industrial Devices, Inc.

PREAMPLIFIER 235The Model SPM-102 Super-Pow-

ermate 2 -transistor preamplifier issaid to handle up to 700,000 µA,

011/40.10

output. Super-Powermate workswith any antenna, the companyclaims. The list price is $44.95.Jerrold Electronics Corp.

TUBE TESTER 236The Model 98 tube tester is de-

signed for analysis of TV and ra-dio tubes and filament rectifiers. It

includes a replaceable socket chas-sis. The replaceable socket chassisis available with special sockets up-on request. Seco Electronics, Inc.

UHF TUNER 237Model 100 UHF tuner is furn-

ished with a direct drive shaft. Mod-el 100-V is supplied with a 6:1planetary ball reduction drive at-tached. The Oscillator tube type

is a 6CW4 nuvistor. The mixer -diode is a specially selected low -noise component. Gavin Instru-ments, Inc.

Transmission Lead-ins

For Color TVReitemet 71teraele eutel Ret6e,re Shade

Electronic 3roduct EngineersBelden Manufacturing Co.

For years snow, smearing andghosts which were merely annoyingin black and white, have been ig-nored. But these defects are in-tolerable in color.

Obtaining crisp picture detail inall types of weather requires thatmaximum signal be transferred fromthe antenna to the tuner withoutpicture smearing reflections. An allweather transmission line must havefeatures not found in the "fairweather" flat ribbon twin -lead.

Little difference exists in attenu-ation characteristics of differenttypes of twin -lead when clean anddry. The important difference oc-curs when the lines are wet asshown in the accompanying chart.

When dirt and moisture accum-ulates on the surface of a flat lineor when the line is routed near me-tallic or lossy objects (such as masts,gutters, downspouts, roofing or wetlumber,) part of the electro-magnet-ic field surrounding the lead-in ex-tends into these objects, creatingeddy currents and increasing atten-uation losses. These conditions alsolower the characteristic impedanceof the line resulting in losses due tomismatch and signal reflections.

The most annoying defect in col-or TV reception is ghosts whichcan be caused by the transmissionline system as well as by reflectionfrom large objects. Energy is reflec-ted from the receiver back to theantenna and then again back to thereceiver if the characteristic im-pedance of the lead-in has beenlowered because of surface depos-its. This reflected signal produces

a ghost image which appears on thescreen as a multiple image or assmearing.

A solution to the problem ofloss creating deposits and loweredimpedance is transmission linewith the critical field zone occupiedby a low -loss insulating material.Now that transmission lines speci-fically designed for color TV areavailable you cannot justify down-grading the performance of an ex-pensive color TV set by installingan inferior ribbon -type lead-in.

The best designed lead-in willnot function properly unless it is in-stalled correctly. We should vis-ualize the transmission line as hav-ing a diameter of twelve inches (thetwin -lead plus the surrounding elec-tro-magnetic field). Then we canappreciate the need to keep the twin -lead at least six inches away fromall objects.

This twelve -inch pipe concept willkeep us from making the followingerrors:

1. Taping the line to gutters,downspouts, masts, towers,etc.

2. Entering the building thruholes drilled in metal windowframes or jamming the leadbetween the window andframe. A better method ofentering the building is thruan insulating feed-thru tubeinstalled to prevent entry ofrain water. Another goodapproach is to install a plexi-glass panel in a windowframe and route the lead-inthrough the panel center.


3. Bending the lead-in sharply.Sharp bends in the line pro-duce impedance discontinuitiesdue to distortion of the fieldsurrounding the lead-in there-by creating ghost images.

The lead-in should be routed inthe shortest way possible usingstand-off insulators which are atleast six inches long. Stand offswhich encircle the lead-in with ametal ring should not be used. Se-lect stand offs which have been con-structed to keep metal parts as farfrom the transmission line and as -

"That wasn't what I meant when I said I

hadn't got all the bugs out of it yet."

MOVING?Be sure to let us

know your new ad-dress at least 6 weeksin advance. Andplease enclose a com-plete address labelfrom one of your re-cent issues.

ELECTRONIC

TECHNICIAN1 East First Street

Duluth 2, MinnesotaRA 7-8511

sociated electro magnetic fields aspossible. The proper line balanceshould be maintained by twistingthe lead-in at least one completerevolution every two feet insuringthat both conductors are equallyexposed to outside influences. Hor-izontal runs should be avoidedwhere possible. The signal from thetransmitting antenna is horizontallypolarized and is therefore easilypicked up by the horizontal por-tions of the lead-in, which results inghost images and also picture smear-ing.

WET

WET

80

WET

40'WET

8NI DRY DRY DRY20gDRY

II 1. M i0

--,

i,

tic

1

Atteruation of various transmission lineswhen wet and dry.

1962-63TV Replacements

Lead Stancor'sXI

'11-)Dr P 1418SStancor exact replacement transformers for 1962and 1963 television sets are now available from yourdistributor. For the first time in the history of thetransformer replacement market, parts are in stockfor sets the dealers are selling today. These brand-new units are among the more than 90 yokes,flybacks, powers, and vertical output transformersadded to the Stancor line so far this year.

This 1963 Stancor Parade ofParts dramatizes our continuingprogram of providing an exactreplacement transformer for yourevery need, available throughyour electronic parts distributor.

You can rely on him . . . and on ST ANCORELECTRONICS, INC.3501 W ADDISON CHICAGO 18, ILL.

AUGUST 1963 71

Do you still find transistor circuitstoo hard to repair? It may be be-cause you are using the wrong me-ters. If this seems as obvious an er-ror as using a screw driver in placeof a nut driver, better take anotherlook.

The use of the wrong meter orrather a meter with an unsuitedrange is due to several wrong con-ceptions many service technicianshave in regard to transistor circuits,and in regard to meter accuracy rat-ings.

The voltages involved in trans-istor .circuits are usually low. Thecollector voltage ranges from say 3to 12 v and the bias may be on theorder of 0.1 v. Some techniciansfeel that because the voltage is smallit is not particularly important. Thisimpression is substantiated whenthey make a voltage test on a func-tioning circuit with the wrong meterand find that the voltage indicatedis far from what the circuit maycall for.

How does this happen? Read on.Assume that the voltage under testis exactly 0.10 v. The meter usedis a voltmeter with a range from 1to 10 v. The needle, if it moves atall, is in that portion of the totalscale that is least accurate. (Fig. 1)In addition, because of the positionof the needle, and because of thewidth of the needle in relation tothe scale markings, it would bephysically difficult to read the point-er with accuracy. Add to this thebasic error of the meter itself.

Many bench test meters have abasic accuracy of plus or minus 5percent or less. This is a far greater

Transistors Require

accuracy than that demanded formost bias circuits. It would seemthen that the meter is entirely ade-quate for its task. Actually, thismeter is just a mite better thanworthless for this measurement.

All service grade instruments, asdistinguished from laboratory in-struments, are calibrated to an ac-curacy that is a percentage of fullscale deflection. This is usually ex-pressed in a plus or minus percent-age figure. When a meter with a±5 percent accuracy is operated onits 0 to 10 v scale, the statementmeans that the pointer may be 0.5 vaway from the actual voltage undertest. We are assuming the averageaccuracy. When the meter is op-erated at its low end, the error isgreater; and in our example that iswhere it is being used.

When we endeavor to measure0.1 v with a meter having a scale of0 to 10 v, and having an accuracyof ±5 percent, the minimum errorthat we can expect will be five timesthe figure that we seek to measure.It now becomes quite obvious whytransistor servicing can be so diffi-cult. It also becomes obvious whymany technicians who have troubledto analyze circuits that operate satis-factorily with the wrong instrumentshave come to the erroneous conclu-sion that transistor bias is not tooimportant.

A better grade instrument is notthe solution. If the meter were ac-curate to ±2 percent, the minimumerror we could expect would be 0.2v, or twice the figure we are seekingto measure. We could, of course,buy a meter with a log scale, but

4 wax ,4

there is a cheaper solution. Use aninstrument with a scale that is morethan two or three times the voltageyou want to measure. Since thereare few service instruments havinga voltage range of 0 to 0.2 or 0.3vdc, we have to make -do with whatis available - meters with a 0 to1.0 or 1.5 v range. A 5 percenterror on a 1 v scale amounts to0.05 or 0.075 v. This could change0.1 v to appear as 0.15 v, or 0.05v, and should be kept in mind. Atleast our instrument error is nowless than the voltage we are measur-ing.

Along the same line of thought isusing the wrong milliammeter formeasuring emitter current in a trans-istor output stage (Fig. 2). Themeter that should be used must nothave an internal resistance higherthan 0.5 12. If it does, the result isthat when the meter is removedfrom the emitter circuit after the

A high resistance milliammeter in the emitter circuit will establish an incorrect bias.


Proper Meters

Transistor radios are a standard itemnow and transistor TVs are findingtheir way onto the bench. Still sometechnicians have trouble because theycan't get voltage readings to check out

bias on the output stage has beenadjusted, the bias will be incorrect.The emitter circuit resistance of anaudio output stage is usually on theorder of a few ohms. The resistorin the emitter lead is frequently un-der one ohm in value, and the out-put transformer has a resistance ofthree or four ohms. If a 5 S2 milli-ammeter, for example, is placedhere, the total resistance is morethan doubled. When the bias is ad-justed with the meter in the circuit,it goes off when the meter is re-moved.

Ohmmeters can also generatetrouble for the unwary technician.Most of us are aware of the neces-sity of removing the transistor whenattempting to make circuit resistance

measurements; what is often over-looked is the fact that some portionsof the circuit place the transistorsin parallel, so that when an ohm-meter having an internal 221/2 v bat-tery is used, care must be exercisedto make certain that all the transis-tors in the circuit are disconnected.By the same measurement, we maysay, the electrolytics can also beruined.

A VTVM can also cause similardamage. On occasion they developtransient voltages that are highenough to cause transistor damage.This is rare, it is true, but withoutprecautions, how can you use theseinstruments and know for a certain-ty that you are making a repair andnot damaging the receiver?

AREA CCLEASTACCURACY

AREA OFGREATEST

ACCURACY

AUGUST 1963

The hatched zone isa visual representa-tion of the area ± 5percent accuracywould cover. Therewould be no way ofknowing whether theactual voltage was5 percent tbove thepointer, or 5 percentbelow the pointer, oranywhere in-be-tween.

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NEW CADRE C-75CB TRANSCEIVER

The new Cadre C-75 1.5 -watt, 2 -channel trans-ceiver is 15 times too powerful for youngsters(under 18 years of age) to operate, accordingto FCC regulations. Clearly, it's not a toy. It'sdesigned for serious CBers who need 'big set'performance that can be used anywhere.The new C-75, weighing less than 2 Ibs: providesclear, reliable 2 -way communications up to 6miles and more. All solid state design creates anextremely rugged transceiver to absorb roughhandlir.g, stays on frequency. Two crystal -con-trolled channels spell perfect communicationscontact everytime. Sensitive superhet receiver(1µv for 10 db S/N ratio) brings in signals inpoor reception areas. Powerful transmitter hasone watt output to the antenna. Adjustablesquelch silences receiver during standby. AGCassures proper listening level. In a word, theC-75 has all the features you'd look for in aquality full size CB unit.The C-75 has all the portable conveniences you'dwant, too: operates on alkaline or mercury pen-lite cells (S -hour rechargeable nickel -cadmiumbattery available): earphone and antenna jacks;built-in retractable antenna; jack for base oper-ation while recharging.Use the Cadre C-75 anywhere in the field, forvehicle, office, boat or plane. Use it constantlytoo, because its all -transistor modular circuit(11 transistors and 2 diodes) is virtually main-tenance free. ;109.95. Recharger and 2 nickel -cadmium Mittel-les $31.85.

- -Cadre also offers a complete line of 5 -watt alltransistor transceivers and accessories.See your Cadre distributor or write

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73

Servicing Transistor Amplifiers

in Hybrid Auto Radios

Don't let a blown fuse -resistor throw you

If you see a technician, who isnormally mild mannered, cussingsoftly to himself over the car radiohe has on the bench, you can besure that the transistorized outputstage is the cause. Even though thehybrid, with its customary transis-torized output, has been widelyused sice 1958, it is still misunder-stood and troublesome. Why is this?To find the answer let's take a closerlook at a typical circuit, examine thecommon troubles and the methodsused to locate them.

We all know that the transistor isa current rather than a voltage am-plifying device. What is not alwaysfully understood is how service pro-cedure must be changed because ofthis.

A schematic of the output stagein the Chevrolet car radio model987727 is shown in Fig. 1. Thiscircuit uses a Delco 2N278 transis-tor as the final audio amplifier. Thistransistor is capable of handling apeak power collector dissipation of55 w. As used here, however, thecollector power dissipation is about1.5 w.

As with any electronic devicewhich technicians service, it is im-portant to understand "exactly"how it works. In other words, wemust understand circuit theory if weare to quickly and efficiently locatedefects.

The audio signal is still primarilya function of voltage at the 2ndaudio amplifier plate - the 12K5.

If we connect a scope to this pointwe see an audio signal of about 1 vP -P.

The signal is fed to the plateload - the primary of the impe-dance matching transformer T1.Note that T1 is a step-down trans-former with a turns ratio of fifty toone.

Remember we have stepped ouroriginal 1 v signal down in the ratioof fifty to one, plus losses. Whenwe connect the scope to the emitterof the transistor, we will not be sur-prised to find either a very smallsignal or none at all - if you usean expensive scope. If you cannotpick up the audio signal at the emit-ter and doubt that the audio signalis being passed by the matchingtransformer, lift the transformerlead from the emitter. This donethe signal will again be strongenough to display on the scope.Transformer T1 matches the impe-dances but it should be noted thatit also changes the audio signal froma voltage to a current function. Ofcourse, the audio current is nowpart of the base emitter current.

Moving our scope from the emit-ter to the collector we find that theaudio signal is about 1.5 v P -P.Note that there is very little voltagegain between the 12K5 plate andthe transistor collector - about 1.5possibly 2.

From the collector the audio sig-nal is loaded across the audio out-put transformer T2. The audio

4 faek Stavtega

signal taken from the tap on T2goes to the speaker.

We have carefuly traced the audiosignal through a typical transistor-ized audio output stage of the largesignal type but we have said nothingabout how the dc voltages are de-veloped at the transistor terminals.This is very important as consider-able difficulty is often encounteredbecause of mis-interpretation on thispoint.

Watch That Fuse -Resistor

According to the schematic (Fig1) a positive 11.3 v is on the emit-ter. If we trace the emitter circuitback, we can see that the voltagecomes from the on/off switch, SW1,through the choke, L10, continuingthrough the fuse resistor, R22, tothe emitter. But here is where thedifficulty comes in, suppose the fuseresistor, R22, burns out. At firstglance it would seem that the emit-ter voltage would be reduced tozero. It's simple logic, since theemitter voltage flows through thefuse resistor, and R22 is now blown,of course, the emitter must nowhave zero volts on it.

The "logic," however, is a bit toosimple. With a blown fuse resistorwe find that instead of having theexpected zero volts the emitter nowhas a little over 12 v on it. Thereare two reasons for this.

When the fuse resistor blows, itdoes not open completely, butchanges its resistance from a frac-


tion of an ohm (.27, .33, .47) to amuch larger value which may be assmall as two or three hundred ohmsto five or six thousand ohms. Whenthe fuse resistor burns, the core onwhich it's wound also burns -turning the core material into car-bon much the same as partiallyburned wood has a layer of carbonon it. Carbon, of course, conductselectricity.

Suppose the fuse resistor burnsand changes its value to 1500 ohms.Under these circumstances, theemitter would have the 12 v on itthat we measured earlier. But the1200 ohm resistor in the emittercircuit stops the transistor fromdrawing any appreciable amount ofcurrent.

Even if the fuse resistor doesopen completely or if you discon-nect the emitter from the circuit,we find that we still measure about12 v at the emitter because the me-ter itself completes the circuit.

With the emitter disconnected wehave a circuit equivalent to thatshown in Fig. 2. If transistors wereperfect, we could not measure avoltage difference between emitterand ground while in this circuit -the transistor base -to -emitter circuitis back biased. But transistors arenot perfect and they have someleakage current. The dc resistance

of this particular transistor, underthe conditions shown in Fig 2, isapproximately 5000 ohms and is thereason why the emitter still readsslightly over 12 v even disconnected.

The 1.7 collector voltage is theonly terminal voltage left for con-sideration. The emitter collectorcurrent flows from the on/off switch,SW1, through the choke, L10through the fuse resistor, R22,through the transistor, and throughthe output transformer, T2, toground thus completing the circuit.Transformer, T2, with the emitter -collector current flowing through it,of course, develops a voltage acrossit in proportion to its dc resistance- in this case 1.7 v.Use The Milliammeter

It's obvious from the foregoingthat servicing a transistorized outputstage with a VTVM can becomevery confusing. If the transistor inthis particular circuit is not conduct-ing, no voltage will appear at thecollector. But many transistorizedoutput circuits are used that havegrounded collectors - hence novoltage appears on them - evenwhen working. As a result, thebest initial instrument to use whenservicing these output stages is amilliammeter. A milliammeter inconjunction with a scope or a good

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75

OUTPUT

Fig. 1-Schematic of C he v role t model987727 output stage uses a Delco 2N278transistor.

signal tracer will tell us almosteverything we need to know aboutconditions in this stage.

As mentioned previously, themost common trouble is the fuseresistor blowing. The symptoms ofa faulty fuse resistor will vary de-pending on resistance of the burnedfuse resistor. If it has a resistanceas low as two or three hundredohms, then the radio will soundweak and distorted. Under theseconditions, the transistor will drawabout 30 to 35 ma. If the burnedfuse resistor has a large resistance,then the transistor will not draw anappreciable amount of current andthe radio will be dead.

In either case, if we connect amilliammeter in series with the emit-ter or the collector (which ever ismore convenient) the drastically re-duced current tells us that one ofthe three (emitter, base, collector)current -paths are open or havehigh resistance. The current in theemitter or in the collector circuit isnot dependent to any extent uponthe 12K5 audio signal.

Simple continuity checks in thethree branches will quickly disclosewhich current path is at fault. Ifyou find the fuse resistor bad, besure to check the transistor forshorts before replacing the fuse.Often a short between the transistoremitter and the collector is the causeof a burned fuse resistor. At othertimes the fuse resistor seems to justgive way for no apparent reason.

Another common trouble, al-though not so much with this par-ticular circuit, is the burning or

2 N278

10VDC BLUE TI GRN

12 K5C18

0535n -

REDCIA1000

1,f

R23

I Iv

E

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R24 1001:2W

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220

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T2

SPEAKER

opening of the bias pot, R2. Inthis circuit when R2 opens thesymptoms will be extreme distortionand a reduction in gain. Of course,our milliammeter in the emitter orcollector circuit would clearly showthis.

Bias Pots

In the output circuit shown inFig. 3. Mopar model 848 - aburned bias pot is common. If thepot opens in this circuit, the symp-tom will be a dead radio - the biaspot is in series with the base cir-cuit. Of course, being in series,the entire base current flows throughthe bias pot and if the transistordevelops a base and collector short,the bias pot will be destroyed. Whenthe bias pot is destroyed, the bias isremoved from the base and the tran-sistor will not draw current - re-sulting in a dead radio.

If you connect the milliammeterin the collector circuit and find itOK but no audio signal is present,the only thing to do is trace thesignal through the stage as we didearlier. Few parts in the circuit,however, can go bad without affect-ing collector or emitter circuit cur-rent. If the emitter or collectorcurrent checks OK, you can usuallybet the stage is good.

A very simple method of pin-pointing a defective transistor out-put stage is listen for a "pop" inthe speaker when the set is turnedon. If this "pop" is not heard, thenyou definitely have trouble in theoutput stage, providing the set isreceiving power. If you do hear

Fig. 2-Checking emittor current with mil -

Hammier.

this "pop," it's best to look for thefaulty stage elsewhere.

Before turning the set back tothe customer, always adjust the biaspot for proper collector or emittercurrent, this will assure maximumgain with minimum distortion. Ifyou have the milliammeter in theemitter circuit, remember that thebase current is also flowing throughthe emitter and make allowances inyour readings.

Many output circuits are in com-mon use today. Each has its ownpeculiarities which have to belearned. One of the best ways tounderstand a circuit is to carefullyanalyze and check it out. This canbe done with a radio after repairsare made. By checking circuitscarefully while a set is working,you'll learn what to expect whentrouble develops. And you'll havelittle trouble isolating it.


Fig. 3-Schematic of Mopar model 848 transistor output stage.

COL OR VIEWS-

At Press Time

John K. West, a vice president ofRCA, believes 750,000 color setswill be sold in 1963 - doubling1962 sales. RCA announces a$11.6 -million expansion programfor its Lancaster, Pa., tube plantfor color TV CRT engineering andconversion tube operations.

Exact Replacement,.

for Original

tutu Radio Equipment

10'4111111?b,\

Olympic Radio & TV Divisionof Lear Siegler announces a stereo-phono/color-TV combination for$449.95.

Curtis Mathes brings out a tablemodel color set for $399.95-meet-ing Admiral's price.

Motorola is using its new 23 -in.rectangular CRT in eight of its1964 -line sets.

RCA is working on a 25 -in. 90°rectangular color CRT - expectedto be ready in about a year.

A report from Buffalo, NewYork, says that Sears, Roebuck andCompany is selling a color TV setin that area for $369. It was saidthat the set has a 21 -in. round CRT.

RCA group executive vice presi-dent W. W. Watts, says color TVsales for June 1963 were 170 per-cent above the same month in 1962.

By the time you read this a Jap-anese color set, by Toshiba, with a16 -in. round CRT, will probably beon US market.

(at. No. Use O.E.M. Part No.

BelltliN6501 262 kc I.F. 2090237.16502 262 kc I.F. 2090237.26503 262 kc I.F. 2090237-36504 262 kc I.F. 2090237-46505 262 kc I.F. 2090237-56506 262 kc I.F. 2090239-16507 262 kc I.F. 2090239-2

1111111110. 6508 262 kc I.F. 2090239-36509 262 kc I.F. 2090907-26510 262 kc I.F. 2090908-36511 262 kc I.F. 2090907-36513 262 kc I.F. 2090908.46514 262 kc I.F. 2090907-56515 262 kc I.F. 2090908-5

Delco6540 262 kc I.F. 12212536541 262 kc I.F. 1221255

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General Replacement6581 455 kc I.F. Output with Diode Filter6582 455 kc I.F. Input6583 455 kc I.F. Output6584 262 kc I.F. Input6585 262 kc I.F. Output with Diode Filter

Available through your local distributor

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AUGUST 1963for more details circle 24 on post card

77

Auto Radio Reverberation

TV -radio shops who do auto ra-dio work are now being called uponto install and service reverberationunits. It may prove helpful if thetechnical characteristics and instal-lation techniques are known for atypical system.

Reverb Unit

This system employs two electro-mechanical transducers with dualspring assembly. The original pro-gram received on the auto radio isfed into the "transmitting" trans-ducer which vibrates the sound intothe springs, in a torque fashion, sothat the vibrations travel the fulllength of the springs. The "receiv-ing" transducers pick up the delayedsound and amplify it to a secondspeaked (rear seat). Spring assem-blies are slightly different in lengthto allow for a smooth transition ofdelayed sound and are wound in

different directions to cancel out for-eign vibrations - bumps on roughroads, for example.

A capacitor couples a portion ofthe original sound to the r ea rspeaker. An under -dash fader con-trol allows switching reverberationoff the rear speaker, if desired. Aschematic of the system is shownhere.

Because of the various types ofplug assemblies used on car radios,the manufacturer of this unit hasremoved the plugs shown on origi-nal installation guide diagram. Ca-bles should be connected as follows:

1. Cut lead going from radio tofront speaker.

2. Select two wire cable labeled"front speaker."

3. Connect the green and theblack leads to the front speaker.

4. If either one of the voice coilterminals is grounded to the speaker,

r

E

FRONT SPEAKER

RADIO

C

GC 640

E C

B

GC 641

0I /YU. ONI 11111T.

14

I3.2VCD

CAUTION- LEAD MUST BECONNECTED TO POSITIVE 1+)SIDE OF POWER SUPPLY, ORUNIT WILL NOT OPERATE ANDDAMAGE TO COMPONENTS MAYRESULT.

CONDUCTORCABLE

T2

_J

Schematic of Tenna Corporation's Model RU -1017 auto radio reverberation unit.

this connection must be insulatedfrom the ground.

5. Select the other green andblack cable.

6. Connect the green lead markedradio output to the ungrounded leadgoing to the radio.

7. Connect the black le admarked ground to other lead goingto the radio or to ground.

According to the manufacturerthe system will operate through abattery supply range of 10.5 to16.0 v. Amplifier sensitivity is ratedat 2 w output at 400, 1000 and3000 cps with .070 v applied tothe amplifier input through a 2µfcapacitor.

The speaker is reported to be 6x 9 in. with a 1.73 oz capped mag-net. Speaker impedance is 8 O.Distortion at the 2 w output leveldoes not exceed 12 percent at 400,1000 and 3000 cps, according tothe manufacturer.

Installation Tips

System should be installed incars with negative ground only.Lugs must not touch metal partsof car or other electrical wiring.Transistor must not touch metal ofcar. Unit must be mounted so thatits side, with transistor, is verticalor it will not operate satisfactorily.Unit uses one 2N1379 and one2N250 transistor. Current drain is0.7 amp.

. . . TEST EQUIPMENT

Continued from page 47

Bench Production

We consider bench productionas completed chassis per day. Ourshop payroll, overhead, etc. remainsfixed. If we turn out a lot of chassisin one day our cost per chassis islow. If we turn out a low numberduring a dog day the sets are ex-pensive. Naturally we strive to turnout the TVs as quickly as possiblewithout sacrificing our quality.

The right test equipment keeps


production high. I can't stress howimportant this is. The point wasbrought startlingly home to me onceagain a few weeks ago.

I was working on the bench on asquashed in thin line portable. Therewas not enough high voltage. Mynormal approach to this problemis roll the centered table that myflying spot scanner is mounted onup to the TV and begin substitutingcircuits. My signal sub unit permitsme to substitute for the tuner, IFstrip, video amps, sync circuits,vertical circuits and horizontal cir-cuits. It has rolled many milesaround the shop.

This particular day the sub ma-chine was sitting idle. It had openedup a width coil and we were await-ing delivery of the part.

Without the use of my electronicright arm I was back using antiquat-ed techniques. Wearily I checkedthe screen grid of the horizontaloutput tube. It was + 145 as itshould be. I checked the controlgrid and it read -20 which wasabout 5 v low. I went into the oscil-lator. Voltages were near normal.I checked the damper. The platewas normal and the cathode a bitlow. My conclusion, trouble couldbe anywhere from the horizontaloscillator grid to the CRT well. Ap-proach: Start testing componentsone by one.

I decided to quit the hassle andwait for my sub machine to getback into action.

The next day the width coil ar-rived. Before all else I dropped itinto the signal substitution gener-ator.

After awhile I was back to thethin line portable. I plugged thesub's probe into the control grid pinof the horizontal output tube's sock -

Base diagram for 90P4.

et. There was a whine and thebristling of high voltage in the pic-ture tube shell. I looked in thescreen. The repair was almost com-plete. A perfect keystone shonebrightly. A new yoke replacementcleared all.

One Step Beyond Equipment

A must reason to purchase newtest equipment, is when new TVsand radios appear on the scenewith components and circuits thatjust won't be tested with existingapparatus. You must buy spankingnew gear designed expressly for aparticular purpose. Among suchnew test units are pieces for colortroubleshooting, transistor testingand instruments to analyze all thepicture tubes that are installed inthe new TVs.

No matter what you purchase youcannot cover one hundred percentof all eventualities per set, but ifyou do keep yourself in up-to-dateequipment, you can wiggle out a re-pair in a pinch if you add one morething to the test gear: Your owningenuity.

Like this emergency nine inchHotpoint that belonged to a localmotel account of ours. He had tohave the TV for the weekend. Itwas Saturday late afternoon. Alldistributors were closed. Thetrouble was no raster.

I tested the high voltage. It wassupposed to be 5.5KV and thatwas exactly what my VTVM equip-ped with high voltage probe read.

I suspected the picture tube. Itwas a strange little job. A 9QP4.The high voltage was injected notinto a well, like ordinary tubes butin through pin number six, normallya focus anode.

I pulled out my latest CRT test-ing machine. I looked up 9QP4.No listing. I pulled out some otherpicture info that I keep.

No Listing

After searching around, the onlyinformation I had was on the sche-matic sheet, but there was no fila-ment voltage listed. At least I hadthe pin numbers.

Fortunately the filaments, cath-ode, control grid and screen gridwere identical to regular tubes al-though there was another addition,pin three evidently was focus anode.

I installed the CRT tester, care-ful to keep the filament voltage of

IT PAYS TO USE AEROVOX !

Let's face it... this radioTV.electronicsserking business is a highly demandingbusiness. Your customers demand goodservice at a fair price. Your work at thebench or on service calls requires skilland efficiency. The rapid pace of new cir-cuits and equipment demands time tokeel up with the industry. And how wellyou know that time means money! That'swhy you can't afford costly callbacks orcustomer complaints due to prematurecomponent failures. When it comes to ca-pacitors, you know you can depend onAercvox. You see, at Aerovox there's abso-lutely no compromise with quality. Sincethe early days of radio, Aerovox engineershave pioneered capacitor improvements.Take electrolytics, for example. YourAercvox distributor stocks the most dependable and complete line of exact replacement types in every rating co:=3;you need...a few of the most -4111>0popular types are shown here.Get all the facts,..ask him for afree copy of the new Aerovox TVElectrolytic Capacitor Replace-ment Guide AFG-462. Neil

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AUGUST 1963- for more details circle 10 on post card

79

the machine at its lowest settingaround 2 v. Good thing I did forat that voltage the tube lit normally.The emission was zero.

I contacted the set owner andbroke the bad news. He was nice,but explained he had to have it forthe weekend. We could have it backon Monday to install a new replace-ment.

I hung up the phone and wentback to the TV. I attempted re-juvenation measures since I nowknow the correct dial setting. (Thefilament voltage should have been4.68 v, though the emission wasstill very low.) Between my re-search and the capabilities of thenew tester I was out of a tight spot.The resurrection took beautifully.

He picked up the TV. The onlything that happened is the TV isstill playing merrily and this incidenttook place four months ago.

Anyway, test equipment doesvery well for us. We do not skimpor cut costs in that direction. Rath-er we are constantly examiningand purchasing the gear we feel willincrease our efficiency and sales.

It is not an expense but inactuality is part of your profit mak-ing. You actually earn money bystudying your needs and satisfyingthem.

That doesn't mean buy every-thing that shows itself in the market-place. It does mean buy every-thing you feel will help you properlyoperate on the receivers you arecommissioned to repair.

New Test Equipment SurveyNew test equipment to a techni-

cian has tremendous appeal. Givenan unlimited budget we would buyeverything we saw.

However, from a practical stand-point we must buy not one moreitem than we need. Here is a listof questions I ask myself beforeeach major purchase.

1. Do I need it?2. What are its features in com-

parison to other brands?3. In my labor time saved, how

long will it take me to get mymoney back? (Figuring timeat $5.00 an hour.)

4. Will this apparatus obsoleteany existing equipment? (Ifso is it advisable to trade inthe old equipment?)

5. How fast can I depreciate it?6. Can my business afford the

investment.

NEW BOOKS

BASIC MATHEMATICS. By Nor-man H. Crowhurst. Published byJohn F. Rider Publisher, Inc. 556pages, hard cover. $14.50.

This is a one -volume binding ofpreviously published paperbackvolumes 1 through 4. It is a four-part course that makes it easier tolearn mathematics. Since most peo-ple find it difficult to learn math-ematics, the author worked out thissystem after his teaching experi-ences at two leading technical col-leges. The text embraces a newconcept in teaching arithmetic, al-gebra, geometry, trigonometry andcalculus. The complete course pro-ceeds step-by-step, in easy stages,from simple arithmetic on to cal-culus.

NEWSOF THE INDUSTRY

FM -Stereo Gets BoostFM -stereo reception capability

was contained in just a shade under50 percent of all radio -televisioncombinations and radio -phonographcombinations produced during thefirst quarter of this year.

During the first quarter of 1963,production of radio -TV and radio-phono combinations totaled 411,-252, of which 205,217 had FM -stereo capability. A total of 24,465radio -TV combinations out of the62,816 produced could receive FM -stereo broadcasts. Of 348,436 ra-dio-phonos produced, 180,752 wereequipped to receive the signals.

As previously reported by theElectronic Industries Association,nearly 46 percent (767,539) of the1,677,385 combinations producedduring the entire year of 1962 werecapable of receiving FM -stereotransmissions.

Speed All -Channel TV ProductionThe country's TV set manufac-

turers are stepping up the tempo oftheir changeover to full productionof all -channel TV receivers, al-

though the effective date of a newlaw requiring that new sets receivethe complete range of 82 channelsis still 8 months away, according toan EIA report.

G -E Lowers Color -Set PriceA color TV receiver has been in-

troduced by General Electric whichwill sell for about $450, or about$45 below the lowest priced set inits line. The price partly meets Ad-miral's previously established priceof $400.

Hallicrafters Enters 2 -Way FMField

Hallicrafters Co. announces plansto enter the FM two-way radio mar-ket with a complete line of unitsfor business and industrial applica-tions. Units are designed to operatein the Business Radio Service or inany of the other available land -mo-bile services.

Parts Distributor Sales RiseThe national Credit Office re-

ports an increase of 9.9 percent intotal volume of electronic parts dis-tributors during 1962 over 1961.Sales exceeded $1 -billion for thefirst time.

Zenith Reports Record OrdersL. C. Truesdell, president of Zen-

ith Sales Corporation, announcedthat orders for new products placedby distributors at the company'ssales convention were the highestin history. Truesdell said that therecord -breaking orders for new1964 Zenith instruments were sub-stantially ahead of orders for thesame period last year and more than28 percent ahead of orders for thesame months in 1961. He said thatthe company's entire production ofcolor TV was sold out throughAugust and initial production sch-edules have been increased, sub-stantially through September.

CRT Implosion ProtectionCorning Glass Works announces a

low-cost implosion protection sys-tem for YV picture tubes. The newsystem, approved by UnderwritersLaboratories, eliminates the needfor a glass safety plate by surround-ing the tube face with a steel shell.


The lightweight shell fits like a rimaround the tube' faceplate edges. Astrip of pliable gasket material andan alcohol -base bonding resin arealso used.

Sylvania's Acheson RetiresMarcus A. Acheson, chief engin-

eer of Sylvania Electric Productsradio tube division, retires after40 years of work in electronic de-velopment. He was responsible forthe redesign of many tube types andincreased tube reliability.

Harmon Resigns from JerroldSidney Harman, president and

chief executive officer of the JerroldCorp, has resigned. It was under-stood that policy differences betweenMr. Harman and Milton J. Shapp,chairman of the board, led to theresignation.

Stancor Increases Yoke LineStancor Electronics announces

the addition of three new yokes toits "Parade of Parts," program.Part No. DY-54A replaces sevenPhilco yokes in five chassis and 32models; DY-56A replaces four Zen-ith yokes in seven chassis and 58models, and DY-51A replaces twoPackard Bell yokes in 21 chassisand 45 models.

Stark Merges With HickokStark Electronic Instruments,

Ltd., of Ontario is merged withHickok Electrical Instrument Co.of Cleveland. Terms were not an-nounced. Hickok purchased all out-standing stock of Stark.

April Phono Sales DipPhonograph sales in April dip-

ped under March totals by nearly100,000 units at the distributor leveland better than 88,500 at the fac-tory, according to the ElectronicIndustries Association. The EIAsaid the declines failed to offsetcumulative gains over last year'ssales, however. April sales were246,730 units compared to 346,152recorded for March. A year ago inApril, 201,192 phonos were sold.Cumulative sales for 1963 stood at1,239,379 at the end of April, anappreciable increase over last year's959,597.

FREE LITERATURE

TAPE RECORDERS 300This color brochure contains de-

tailed specifications of the Model801-A battery powered portabletape recorder. In addition it pic-tures five Model 801-A accessories.Superscope Inc.

TOOLS CATALOG 301A 24 -page catalog, No. 10, cov-

ers a line of special pliers andtweezers designed for aerospace re-quirements. Also included is a se-lection of clean -room hand cover-ings and white -room accessories.Techni-Tool, Inc.

RESISTOR LITERATURE 302Bulletin 104 announces a line of

wire -wound, vitreous enameled re-sistors. The bulletin is arranged tosimplfy ordering, and is said toconstitute a technical aid to thoseconcerned with naval equipment.Ohmite Manufacturing Co.

TRANSFORMERS CATALOG 303A 48 -page catalog lists 1500 re-

placement transformers and coilsfor television, radio, high fidelity,and stereo applications. The bookcontains specifications and addition-al information to aid the technicianin the selection of the proper unitfor his application. Stancor Elec-tronics, Inc.

RESISTOR INFORMATION 304A short catalog covers three styles

of deposited carbon, fixed filmresistors and one wire wound series.Published in the form of 3 -holepunched data sheets printed in twocolors, the 8 -page short catalog pro-vides information on dimensions,design and construction, electricalcharacteristics, derating curves, per-formance and environmental char-acteristics where pertinent. PennResistor Corp.

CAPACITOR CHART 305The Ceramics Selector, a 17" x

22" wall chart was designed to aidengineers select ceramic capacitors.Twenty different ceramic capacitortypes are listed with line drawingsand dimensions showing form fac-tors and actual sizes. Cornell -Du -biller Electronics

HEATHKIT COLOR BAR & DOTGENERATOR ... YOUR BEST BUY INA COLOR TV SERVICE

INSTRUMENT! ... ONLY $64.95

Crystal -controlled accuracy & stability

Produces six different patterns forpicture adjustments

10 vertical color bars-spacial shading bar pattern

Perfect for color or B & W TV servicing

Another outstanding value from the world'slargest kit manufacturer! The HeathkitIG-62 Color Bar & Dot Generator at only$64.95 is unmatched in the industry for per-formance, quality and value! Provides choiceof six different patterns for color or B & WTV picture adjustments ... all with crystal -controlled accuracy and stability. No syncleads required, internal sync pulses lock thepatterns firmly on the TV screen, withoutjitter or crawl for fast, easy servicing. Onesimple connection to the antenna terminalsof the TV set is all that is required. Outputis on Channels 2 through 6. Color bars pro-duced by the offset -carrier method allowAFC, phase and matrix alignment of colorsets and adjustable video output permitschecks of color hue and sync at differentsignal levels. Crosshatch, vertical & hori-zontal bars, dots, and special shading barpatterns simplify convergence, linearity andbackground picture adjustments. Order thisfine instrument for your test bench now!Save with Heathkit!Kit IG-62...13 lbs....no money down, $7 mo.

$64.95WIDE BAND 5" TV SWEEP

OSCILLOSCOPE 10-12 GENERATOR IG-52$76.95 $67.95

-.11114;;;Immiri.C

*

Professional styling &features at low cost Full5 mc bandwidth for colorTV seivicinq Heath pat-ented sweep circuit -10cps to 500 kc Push-pullvertical & horizontal am-plifier .

Complete FM & TV cov-erage -3.E to 200 mc. Stable all -electronicsweep circuit Built-incrystal & variable markeroscillators Versatile,easy to operate, reliable.

rHEATH COMPANYBenton Harbor 24, Michigan 49023

0 Please send free Heathkit test equipment catalog.

NAME (Please print)

ADDRESS

CITY ZONE STATE

AUGUST 1963- - - for more details circle 2' on post cord

81

. . . COLOR TV SIGNALS


portions of the picture, there are noR -Y, B -Y and G -Y color signalsbecause they were not transmitted.The -Y signals, up to 4.2 Mc, stillappear on the cathodes of the CRTguns, however, and merely causein unison gun conduction to producewhite when they are at saturation,the gray scale when they are be-tween cut-off and saturation, andblack when they are at cut-off. Re-fer to Fig. 4B.

On the black -and -white program-ming; there are no R -Y, B -Y orG -Y color signals. The full fre-quency range of the Y signals willtherefore cause in unison conduc-tion of the guns reproducing thepicture in black -and -white.

It should be noted that on a blankraster, in the absence of any signals,all guns are conducting in unisonwith no change in electron flow; onmonochrome programming or toreproduce the higher detail black -and -white portions of a color pro-gram, the guns are conducting inunison but the electron flow ischanging in accordance with the in -

NEWYORK'S

e.y.cit'avg East Sag 4-lotelcomfort, convenience, luxury at

reasonable rates . . . from $8.85single, $11.85 double, including TV

and air-conditioning ... plus free swim-ming in Olympic pool on

Special family, week -end andgroup rates . Convenient

to 5th Avenue, Grand CentralStation, Air Line Terminals,Mid -Town Business Appoint-ments . . . All good reasonsfor wide acceptance by busi-ness and pleasure travelers

the

premises.

HotelLexington Avenue48th to 49th StreetsTEL. Plana 5-4000

YEAR 'ROUND POOL

stantaneous brightness values of theY signals; and finally, to reproducethe color portions of a scene, theguns are changing conduction withrespect to one another in accordancewith the actual instantaneous colorpresent.

. . . THE NEON TESTER


but serves only as a quick and easyshort-cut tester to help techniciansanalyze the trouble. For example,in checking for RF in the HV cage,much time used in checking or sub-stituting tubes can be saved. At thesame time, the presence or absenceof RF will indicate what furtherchecks need to be made.

B -plus Checks

It is a simple matter to use theneon tester to determine if B + ispresent at any point in the supply.Place one test lead from the supplypoint and the other to ground orB-. If B + is present, the neonlamp will glow, and if absent, thelamp will not glow. (The testerwill indicate either ac or dc fromapproximately 50 to 600 v.)

The B + check is useful in locat-ing open resistors in B + circuits bychecking from either side to ground.Also, primary windings of audiooutput transformers, IF transfor-mers, vertical output transformers,blocking oscillator transformers -and RF chokes in the B + circuits- may be checked in the samemanner. B + fuses may also bechecked the same as ac line fuses.ac line capacitors used in selenium,silicon, or germanium power sup-plies may also be checked to deter-mine if ac is passing through themin the same manner used to checkresistors. Rectifier output may alsobe checked from output point toground. Plate and screen suppliesin excess of 50 or 60 v dc may alsobe checked in a like manner.

The neon tester does not measurevoltages, but only indicates theirpresence. To determine the amountpresent, a voltmeter must be used.Also, the neon tester in no way re-places the voltmeter as this wouldnot be feasible; it is used, as pointedout before, to provide quick prelim-inary checks in helping to analyzetroubles.

Technicians servicing two-way ra-dio communications transmitters will

also find the tester is a ust, ul in-strument in checking antenn- load-ing, resonating various stag. 3, etc.For example, if RF is pre nt inthe antenna, the neon lar. ) willglow (it might be necessary t 'f'hthe test leads to the antennaionization and then removeThe amount of load or m. mumload is indicated by maxims bril-liance of the neon lamp what a fixed position near the ; .abase while the transmitter outputand coupling are being tun( RFin the "tank" circuit of a trar flittercan also be determined by . &lingthe neon tester lamp near tl coil.Maximum RF is indicated b: max-imum brilliance of the lamp.

Many other uses for the neontester can be found in servicir elec-trical appliances and circuits.

ADVERTISERS INDEX

Aerovox Corporation 79

Armco Steel Corporation .5

B & K Manufacturing Company 5 , 59

Blonder -Tongue 3rd -peer

Bussmann Manufacturing Company

Cadre Industries Corp.

Delco Radio, Division of General Motors

EICO Electronic Instrument Co., Inc.

GC Electronics Company , 1

General Electric Company 34.4

Hallmark Instruments 62

Heath Company 81

Hickok Electrical Instrument Company2nd Cover

Imperial Inn 75

J. W. Miller Company 77

Nortronics Company, Inc. 64

Quam-Nichols Company 69

Quietrole Company 66

Radio Corporation of AmericaRCA Electronic Components and Devices

4th Cover

RCA Sales Corporation 20

Sarkes Tarzian Tuner Service Division 63

Seco Electronics, Inc. 24

Sencore, Inc. 29

Shelton Towers Hotel 82

Sonotone Corporation 65

Sony Corporation of America 25

Sprague Products Company 23

Stancor Electronics, Inc. 71

Winegard Company 61

- - - for more details circle 30 on post card82 ELECTRONIC TECHNICIAN

Blonder -Tongue increases the UHF profit zone

First all -channel UHF Booster-the U -BOOSTThe fabulous new Blonder -Tongue can add up to 15 miles toyour city's UHF reception range. It turns TV viewersformerly beyond the range of UHF into profitable UHFcustomers-prospects for UHF converters, UHF antennas,all -channel TV receivers and the U -Boost itself. The U -Boost.will also clean up and improve reception for viewers in poorsignal areas-More money in your pocket!The U -Boost (gain 10 db)-triples the antenna signal volt-age. Teamed up with a UHF converter, or added to an all -channel receiver, the U -Boost improves picture contrast onall but the "hottest" TV sets or with deluxe converters. Just aturn of the dial pinpoints any desired channel from 14 to 83and brings it in sharp and clear. TV picture quality is alwaysexcellent with the U -Boost because it has a lower noise figurethan most existing TV sets or UHF converters. This meansa better signal-to-noise ratio, resulting in less snowThe U -Boost is easy to install: convenience AC receptacle;

Canadian Div

patented 300 ohm stripless twinlead terminals. And finally,the modern U -Boost styling matches the new Blonder -TongueUHF converters - making combination sales easy. Sell aBlonder -Tongue converter and a U -Boost together. They're"profit -mates". U -Boost, List $39 -95 -

BLONDER -TONGUE TOTAL SALES POWER SPELLS BIGGEST UHF PROFITS

1. World's finest UHF converters performance tested in2,000,000 homes.Model 99-S for prime signal areas. List $27.95.BTU -2T for weak signal areas. List $44.95.

2. New U -Boost to increase your UHF profit zone.3. Powerful merchandising program back-ing up every Blonder -Tongue product.Look to the leader in UHF.Contact the Blonder -Tongue distributorin your area now.

engmtimrect and manufactured by

BLONDER TONGUE. 9 Amng St. NewerIc2 N

Benco Television Assoc., Ltd., Toronto. Ont./home TV accessories closed circuit TV community TV UHF converters master TV

- - - for more details circle t3 on post card

ALL YOUNEED FOR

RCA Color-Bar/Dot/Crosshatch GeneratorLow-cost, lightweight, porta-ble instrument that providesall essential Color -TV testpatterns. Simple to operate:only 3 controls. RF outputleads connect directly to an-tenna terminals of receiver;no external sync leads re-quired. Crystal -controlled sig-nals assure rock -steady pat-terns, free from "jitter" and"crawl." Extra -wide -rangechroma control. Generates: Color -bar pattern: ten bars

of color, including R -Y, B -Y,G -Y, I and Q signals spacedat 30° phase intervals forchecking phase and matrix-ing, and for automatic fre-quency and phase align-ment. Permits accuratealignment of the "X" and"Z" demodulators whichare used extensively in RCAVictor and many othermakes of color TV receivers

Crosshatch pattern: a grid -like pattern of thin sharplines for adjusting verticaland horizontal linearity,raster size, and overscan

Dot pattern: a pattern ofsmall sized dots facilitat-ing accurate color converg-ence adjustments

$189.500 with output cables.

User Price (Qptional)

RCA 5 -Inch Oscilloscope

for Color -TVA wideband scope excellentfor checking colorburst sig-nals and general troubleshoot-ing of wideband color circuitsand other electronic equip-ment. Muilt-scale calibratedgraph screen makes measure-ment of peak -to -peak voltageas easy as with a VTVM. New 2 -stage sync separa-

tor assures stable horizon-tal sweep lock -in on com-posite TV signals

Dual bandwidth: 4.5 Mc at0.053 volt rms/in. sensitiv-ity. 1.5 Mc at 0.018 voltrms/in. sensitivity

Continuously adjustablesweep frequency range: 10cps to 100 Kc

3 -to -1 voltage -calibrated,frequency -compensatedstep attentuator for "V"amplifier

Simplified, semi -automaticvoltage calibration for si-multaneous voltage meas-urement and wave -shapedisplay

Vertical -polarity reversalswitch for "upright" or"inverted" trace display

$249.50*, including direct/low capacitance probe andcable, ground cable, and in-sulated clip.

RCA Television FMSweep GeneratorSpecifically designed for vis-ual alignment and trouble-shooting of color and black -and -white TV receivers, andFM receivers. The RCA WR.69A has pre-set switch posi-tions for all VHF TV channels,FM broadcast band, and TVvideo, chrominance, and IF

frequencies. The WR-69A hasthese important features: IF/Video output frequency

continuously tunable from50 Kc to 50 Mc

Sweep -frequency band-width continuously adjust-able from 50 Kc to 20 Mcon IF/Video and FM; 12 Mcon TV channels

Output level -0.1 volt ormore

Attenuation range:TV channels, 60 dbIF/Video, 70 dbFM, 60 db

Return -trace blanking Two adjustable bias volt-

ages on front panel$295.00* including all neces-sary cables.

RCA RF/VF/IFMarker Adder

Designed for use with a mark-er generator (such as RCA'sWR-99A) and a sweep gener-ator (such as RCA's WR-69A),this instrument is used forRF, IF, and VF sweep align-ment in both color and black -and -white TV receivers. Invisual alignment techniques,it eliminates distortion ofsweep response pattern.Important features:

Choice of four differentmarker shapes provided byfront panel switch for dif-ferent types of sweep -response curves and forpositive and negative sweeptraces

Provides very high -Q mark-ers of high -amplitude andnarrow bandwidth

Complete front panel con-trol of marker shape, mark-er amplitude, marker polar-ity, sweep amplitude, andsweep -trace polarity

$74.50* complete with cables.

RCA Crystal -CalibratedMarker GeneratorSupplies a fundamental fre-quency RF carrier of crystalaccuracy for aligning andtroubleshooting color andB&W TV receivers, FM receiv-ers and other electronic equip-ment in the 19-260 Mc range.Combines functions of mul-tiple -marker generator, re-broadcast transmitter, andheterodyne frequency meter. Highly stable output May be calibrated at 240

separate crystal checkpoints-accurate calibra-tion provided at 1 -Mc and10 -Mc intervals

Matched -impedance pad -type attenuator and doubleshielding of the oscillatorprovide effective attenua-tion of all frequencies

Most -used IF and RF fre-quencies are specially in-dicated on the dial scale

Sound and picture carriermarkers available simulta-neously

$242.50* complete with out-put cable and phone tip.

RCA ELECTRONIC COMPONENTS AND DEVICES, Harrison, N. J.

The Most Trusted Name in Electronics

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