may 1967/75 cents roadeast engineering...

A HOWARD W. SAMS PUBLICATION

MAY 1967/75 cents

roadeast Engineeringthe technical journal

[of the broadcast-!

communications industry

When you're in command of a Riker switcher,you've got the video right where you want it.Under control. You can select or mix yourvideo sources with new ease and flexibility.

A button. A dial. A lever. And video thingshappen. Like additive/nonadditive mixing.Special effects by the score. Film control/tapestart -stop. Automatic double re-entry.And lots more.

High performance in differential phase, gainand frequency response ensure excellent picturequality. Switching speeds in the nanosecondrange during the vertical interval result insmooth, invisible transitions.

If you're interested in building the switchingand quality control capabilities of your station,write or call Riker-the one company in the TVbroadcast industry offering a complete line ofall solid-state instrumentation for videoanalysis, simulation and control.

**40 SOO .01.

00041011w.141P-PIPIPS Plet

1111111111111111111111111111111.111110

no otherswitcher letsyou do so muchwithyourvideo

1111111KLIMIFItPRODUCTS FOR Viet° ANALYSIS, SIMULATION & CONTROL

RIKER VIDEO INDUSTRIES, INC. 100 Parkway Drive South, Hauppauge, Long Island, N.Y. 11787 (516) 483-5200

Circle Item 1 on Tech Data Card

1

"Encoded COLOR camera chain for 530,000.But don't hold your breath for delivery...right?"

Wrong! Cohu delivers in 30 days.

You heard us right, friend.$30,000 buys our 1000Series tri-vidicon camera- complete with solid-state camera control unitand NTSC video encoder.Less lens and cabling, ofcourse. And we do deliver

in thirty days.

For your mobile unit, $31,000buys the same chain with our 61/2 -

inch electronic viewfinder. Camerawith finder weighs a mere 58 pounds.

Prices are FOB San Diego. Additionalexport charge. Place purchase ordersdirect with your nearest Cohu engineer-ing representative. Or, call Bob Boulioat 714-277-6700.TWX 910-335.1244.Box 623, San Diego, California 92112.

t___EC-ri=tc7,rviCS., INCSAN DIEGO DIVISION

Circle REM 2 on Tech Data Care

May, 1967 3

DESIGNED FOR THE STATION OPER-ATOR: This new series of Mark IX Videoand Pulse Distribution Amplifiers wasdesigned by Ball Brothers ResearchCorporation especially for color studiooperation. Constructed with the stationoperator's needs in mind, each unitprovides the high performance andreliable operating standards requiredof broadcast studio equipment.

BUILT FOR SERVICE AND CONVEN-IENCE: The Mark IX modular units in-corporate solid state circuitry, de -ratedcomponents, and self-contained, regu-lated power supplies. Up to 10 videoor pulse amplifiers, or any combina-tion of the two, can be plugged intothe Mark IX chassis to provide as manyas 40 isolated signal outputs at onecentral distribution point.

BBRC

MARK IX VIDEO DISTRIBUTION: Nohigh frequency adjustment is requiredon the Mark IX Video Amplifier be-cause of its built-in wideband fre-

MARK IX VIDEO -PULSE DISTRIBUTION AMPLIFIER

quency response characteristics. Dif-ferential gain and phase measurementsare shown for all input signal condi-tions at 0.25 percent and 0.25 degrees,respectively. Convenient test pointsare provided for signal monitoring andservicing.

MARK IX PULSE DISTRIBUTION: TheMark IX Pulse Amplifier has highlyisolated signal outputs with an impe-dance of 75 ohms terminated at thesending end. Each amplifier hasbridging or looping input drive signalprovisions. The active circuitry main-tains constant pulse rise times of lessthan 50 nanoseconds and is compen-sated for possible component replace-ment. Pulse delay of less than 50 nano-seconds is measured at the output.

Prices: Video -Pulse Amplifier, $255 ea.;Electronic Housing, $275. For full spe-cifications and equipment details con-tact BBRC, Video Marketing, Boulder,Colorado 80302. HI -FREQUENCY RESPONSE FAST PULSE RISE TIME BRIDGING INPUTS BUILT-IN/REGULATED POWER SUPPLY ISOLATED OUTPUTS

BALL BROTHERS RESEARCH CORPORATION P.O. BOX 1062 BOULDER, COLORADO 80302 TEL 303/444-5300 TWX 910-928-0141

4

Circle Item 3 on Tech Data CordBROADCAST ENGINEERING

Hw do youmeasure loudness?

First, you listen a lot...

And that's exactly what we did!For the past several years, scien-tists at CBS Laboratories havebeen using the rigorous tech-niques of psichoacoustic testingto determine the nature of sen-sory loudness as it applies tobroadcasting. From this researchhave come significant new dataand methods for measuring sen-

sory loudness with respect to fre--quency content, combinations ofcomplex signals, the "ballistic"response (including impulse andduty -cycle considerations), thesignal peak factor, and other re-lated phenomena.

A sensory loudness indica-tor and a new automatic controlfor limiting excessive loudness

are now undergoing field tests.Write to us for further in-

formation on CBS Laboratories'loudness indicator and auto-matic loudness control.

PROFESSIONAL PRODUCTS

LABORATORIESStamford, Connecticut. A Division ofColumbia Broadcasting System, Inc.

May, 1967Circle Item 4 on Tech Data Card

5

publisherHoward W. Sams

general managerDonald W. Bradley

editorWilliam E. Burke

managing editorJames M. Moore

associate editorHarold E. Hale

regional editorsGeorge M. Frese, NorthwestHoward T. Head, Wash., D.C.

Robert A. Jones, MidwestAllen B. Smith, North Central

Martin J. Taylor, Southwestand Latin America

research librarianBonny Howland

productionE. M. Rainey, Manager

Paul A. Cornelius, Jr., Photography

circulationPat Osborne, Manager

advertising sales officesHugh Wallace, Sales Manager

central and midwasternRoy Henry

Howard W. Sams & Co., Inc.4300 West 62nd St.

Indianapolis, Ind. 46206291-3100

easternAlfred A. Menegus

Howard W. Sams & Co., Inc.3 West 57th St.

New York 19, New YorkMU 8-6350

southwesternMartin Taylor

P.O. Box 22025Houston, Tex. 77027

713-621-0000

westernLOS ANGELES OFFICE

G. R. (Jerry) HoltzThe Maurice A. Kimball Co., Inc.

2008 West Carson St., Suites 203-204Torrance, California, 90501

320-2204SAN FRANCISCO OFFICE

The Maurice A. Kimball Co., Inc.580 Market St., Room 400San Francisco 4, California

EX 2-3365

foreignLONDON W.C. 2, ENGLAND

John Ashcraft, Leicester SquareWHitehall 0525

AMSTERDAMJohn Ashcraft, Herengracht 365

Telefoon 24 09 08PARIS 5, FRANCE

John Ashcraft, 9 Rue LagrangeODeon 20-87

TOKYO, JAPANInternational Media Representatives,

Ltd., 1, Kotohlracho, Shiba,Minato-Ku, Tokyo

(502) 0656

Copyright * 1987by Howard W. Sams & Co., lac.

BROADCAST ENGINEERING is publishedmonthly by Howard W. Sams & Co., Inc., 4300West 62nd Street, Indianapolis, Indiana 46206.SUBSCRIPTION PRICES: U.S.A. $6.00, oneyear; $10.00, two years; $13.00, three years.Outside the U.S.A., add $1.00 per year forpostage. Single copies are 75 cents, backissues are $1.00.

the technical journal of the broadcast -communications industry

*Broadcast EngineeringMkt:

Volume 9, No. 5

CONTENTS

Features

May, 1967

Rejuvenating Disc Recorders Larry J. GardnerThere are a number of ways in which an olddisc recorder can be used when it has been

restored and modified to cut LP's.

Planning and Building theNew CKAC Studios Len Spencer

An analysis of the programming and technicalrequirements which led to the construction

of this station's new studio complex.

13

16

A Frequency -Measurement System Robert L. Zuelsdorf 20

The design coisiderations and details of asystem built for compliance with Paragraph

73.690 of the FCC Rules and Regulations.Part 1 of two parts.

1967 NAB Convention ReportHighlights of the Exhibits

Highlights of the Engineering Conference

Departments

Letters to the Editor

Book Review

Washington Bulletin

News of the Industry

This disc recorder is used by Jan EdenRecording and Sound, Inc.. Indi-anapolis, to cut LP discs. To see

how older machines can be used forthis purpose, read ''Rejuvenating

Disc Recorders" on page 13of this issue.

12 New Products

49 Engineers' Tech Data

51 Classified Ads

60 Advertisers' Index

3241

64

73

77

78

ISr ia ca.! I:nine:4.i :is

1Your enthusiastic response and acceptance of ournew lines of solid-state equipment at the NAB wasmost gratifying...and the only way that we know ofshowing our appreciation is to continue to developand build the finest and most advanced equipment.If you didn't have the opportunity to discuss yourspecific requirements with us, due to the crowds orother time limitations, please write or call us now.

TRANSMITTER

DEMODULATORS

TV STATIONBREAKPROGRAMMER

AUDIO

)111:biliP

AUDIO

AMPLIFIERS

VIDEO

SWITCHING

SYSTEMS

l:1 I

SYSTEMS

TRANSMITTER

PHASE

EQUALIZER

WARD ELECTRONIC INDUST:iiii

May, 1967

142 CENTRAL AVE., CLARK, N. .. 07066 (201) 382-3700Circle Item 5 on Tech Data Card

7

55 reasons why

Lenkurtis the largestindependentmanufacturerof video, voice,and datatransmissionsystemsin the world.

LEA/111/117 ELECTRICSUBSIDIARY OF

GENERAL TELEPHONE & ELECTRONICS GTE

OPEN WIRE CARRIER SYSTEMS32E . . . 3 or 4 channel toll trunksystem. Coordinates with WesternElectric's type C systems overshort, medium, or long haul routes.33A . . . 1 to 3 channel stackabletoll trunk system used in shortand medium haul routes, espe-cially for drop channel operation.45A . . . 12 channel toll trunk sys-tem. Coordinates with WesternElectric's type J systems overshort, medium,or long haul routes.

45C . . . 4 to 16 channel toll trunksystem. Coordinates with WesternElectric's type 0 systems overshort or medium haul routes.T -FM . . . 1 to 10 channel transis-torized subscriber line system.

CABLE CARRIER SYSTEMS45BN ...4 to 24 channel exchangeor toll trunk system. Coordinateswith Western Electric's type Nand ON systems.46B . . . 2 to 24 channel transistor-ized toll trunk system. Works end -to -end with Western Electric'stype N3 system.

*46C . . . 60 to 600 channel transis-torized coaxial cable system.47A/N1 & N2 . . . 9 to 12 channeltransistorized exchange or tolltrunk systems. Work end -to -endwith Western Electric's type N1and N2 systems.81A . . . 12 to 24 channel transis-torized short haul exchange trunksystem.

*82A . . 1 to 6 channel transistor-ized station system for use over asingle exchange grade telephonecable pair. Provides one, two, orfour party service per channel.

*83A . . . Single channel transistor-ized station system providing anadditional subscriber circuit overan existing exchange grade tele-phone cable pair.

*91A . . . 24 channel transistorizedPCM carrier system. Works end -to -end with Western Electric'stype T1 system, equipped with D1channel banks.X . . . 4 to 20 channel transistor-ized subscriber line or exchangetrunk system. (Special equipmentoptions provide a 4 or 8 channelopen wire system, or a 20 channelradio multiplex system.)RADIO MULTIPLEX SYSTEMS34A ... 2 to 24 channel, stackable,transistorized system.45BX ...12 to 264 channel system.47A . . . 12 to 72 channel transis-torized system.

8 BROADCAST ENGINEERING

46A (AN/FCC-55(V))**... 1 to1260 channel transistorized sys-tem. Compatible with CCITT orWestern Electric's type L system.AN/FCC-17** & AN/UCC-4(V)**... 12 to 600 channel transistor-ized class of military multiplexersused for fixed office or tacticalmicrowave radio relay or tropo-spheric scatter systems.

MICROWAVE RADIO SYSTEMS

71 ... Class of FM systems, oper-ating in the 150, 300, 400, 450, and900 MHz bands, handling up to 24or 48 v -f channels.

71F ... Transistorized FM system,operating in the common carrier,Government and industrial bandsbetween 1700 and 2300 MHz, han-dling up to 120 or 300 v -f channels.

74B (AN/FRC-84)** ... FM sys-tem, operating in the commoncarrier, industrial, and Govern-ment bands between 5925 and8400 MHz, handling up to 300 v -fchannels.75A... Transistorized FM system,operating in the 6000 MHz com-mon carrier band. System usesTWT output amplifiers and IF re-peaters, handling up to 1200 v -fchannels or one video and pro-gram channel.75B ... Transistorized FM systemoperating in the 6425 to 7125 MHzindustrial and STL bands. Systemuses TWT output amplifiers andIF repeaters, handling up to 1200v -f channels or one video andprogram channel.

*75C ... Transistorized FM systemoperating in the 7125 to 8400 MHzGovernment band. System usesTWT output amplifiers and IF re-peaters, handling up to 1200 v -fchannels or one video and pro-gram channel.76A and 76D . . . TransistorizedFM systems operating in the 6000and 11000 MHz common carrierbands. Systems handle up to 300,600, or 960 v -f channels or onevideo and program channel andare compatible with Western Elec-tric's type TH-TM and TJ-TL sys-tems.76B and 76E . . . TransistorizedFM systems operating in the 6575to 6875 and 12200 to 13250 MHzindustrial bands, handling up to300, 420, 600, or 960 v -f channels,or one video and program chan-nel.76C(AN/FRC-109(V))**... Trans-istorized FM system operating inthe 7125 to 8400 MHz Governmentband, handling up to 300, 600, or

960 v -f channels or one video andprogram channel.76 for TV ... Transistorized FMsystem operating in the commoncarrier, industrial, STL, and Gov-ernment bands between 5925 and13250 MHz. System provides ahigh -quality black -and -white orcolor video and program channel.73 ... Transistorized FM systemoperating in the 3700 to 4200MHz common carrier band. Sys-tem is capable of handling up to1800 v -f channels, or one videoand program channel, and is com-patible with Western Electric'stype TD -2 and TD -3 systems.44835... FM terminal assembly,providing baseband to IF modula-tion and IF to baseband demodu-lation for long -haul IF repeatermicrowave radio systems hand-ling up to 1200 v -f channels or onevideo and program channel.

TELEGRAPH AND DATATRANSMISSION SYSTEMS25A ... Transistorized FSK sys-tem used to multiplex up to twen-ty-five 75-b s or eighteen 110-b 'stelegraph signals, or up to seven200-b s data signals and four 110-b s signals, for transmission overa single v -f channel.26C (MD-701/UY)**. . . Transis-torized Duobinary FSK systemused to convert a 150-, 300-, 600-,1200-, or 2400-b s data signal fortransmission over a single v -fchannel.27A (AN/FYC-9(V))**... Transis-torized Duobinary FSK systemused to convert a 1200-b s or2400-b s data signal for transmis-sion over an HF radio facility.960A ... Transistorized pulse -duration FSK system used toconvert analog sensor signals re-ceived from railroad hot -box de-tectors to tones suitable fortransmission over standard com-munications facilities.970A ...Transistorized data mod-ulator used to convert one 24 or40.8 kilobit per second data sig-nal for transmission over a wide -band channel of a carrier ormultiplex system.

SUPERVISORY CONTROLSYSTEMS

936 . . . Class of transistorizedalarm and control systems usedto monitor and control test func-tions at unattended or remotecommunications facilities.937A ... 6 channel system usedto monitor and control protectiverelaying functions, associated


with electric power transmissionsystems, over standard communi-cation facilities.AUXILIARY AND TESTEQUIPMENT52A ... Video order wire system.53C (RT-824/UCC)**... Transis-torized order wire and tone sig-naling system used with radiotransmission facilities.57B ... Transistorized one -for -three standby diversity protectionsystem with baseband switchingfor use with microwave radio sys-tems handling up to 1200 v -fchannels or one video channel.57C ... Transistorized two -for -sixstandby diversity protection sys-tem with IF or baseband switch-ing for use with microwave radiosystems handling up to 1200 v -fchannels or one video channel.565B, C, & D ... Universalweather-proof communicationsequipment cabinets for outdoorinstallations.601A & B F1A and C -messageweighting networks.921A ... Schedule A or B pro-gram channel.927A ... Transistorized multi -option in -band signaling system,compatible with Western Elec-tric's type E in -band signalingsystem.931B ... Echo suppressor.940A1 Baseband regulator.971A & 30231 ...Adjustable delayequalizers.5090B Compandor.5203/5204... Noise loading testsets.5249A... Speech plus data panel.26600 (AN/TSM-86**)... E & Mand loop -dial signaling test set.31041 ... 4 -wire terminating unit.37455/37418 ... Portable testmodem for microwave radio IF re-peaters.

CUSTOMER SERVICESEngineer, Furnish, and Install, pro-viding complete turnkey installa-tions; Customer MaintenanceTraining School, tuition free; Fac-tory Repair and Replacement forall products; Engineering andMaintenance Publications Infor-mation.

'under development**military designation

Lenkurt Electric Co., Inc.San Carlos, California.Offices in Atlanta, Chicago,Dallas and Stamford, Connecticut.

May, 1967 9

Solid State Color STABilizing AMPlifierwith A.G.C. model VI -500

Ultra Stable Circuitrythrough complete and accuratetemperature compensation

AUTOMATIC VIDEO LEVEL CONTROLMaintain video peaks constant to a preset level, withreference to blanking.

CLAMPINGSync tip clamps remove hum, tilt and other low frequencydisturbances. Where excessive negative spikes or tran-sient -noise are present, additional noise immunity is

available with an external pulse generator at $300.00SYNC LEVEL

Sync level is maintained at a constant amplitude despitelarge variations in input.

EQUALIZATIONAccurately compensates for losses in up to 1000 feet ofcoaxial cable.

REMOTE CONTRCLSAutomatic/Manual video gainSync LevelWhite ClipChroma ControlBy-pass switch

WHITE CLIPAdjustable sharp white clip remains fixed with respectto blankings.

CHROMA CONTROLChroma response continuously adjustable 4db. fromunity.For Automatic chroma feature to assure constant burstlevel, add $200.00.

WHITE STRETCHStretch adjustments provide a high degree of flexibilityto compensate linearity characteristics of transmitters ofall ages.

NON -COMPOSITE COLOR OUTPUTMono or Color non composite output board in lieu ofwhite stretch for additional $100.00.

APPLICATIONAt the input to all transmitters (VHF, UHF. 2500 MHz)and remote inputs to your station. You may use the noncomposite output (color or mono) and bring it into yourswitcher for mixing with local signals. You may use it atthe input and output of VTR's including helical scanrecorders. At the line output of your switcher, at theinput and output of microwave equipment and for airpick-ups.

Price for the VI -500 still $1,750.00 Remote controls $150.00 . . . One out of 3 stations in thealready enjoys the benefits of this stabilizing amp.

GOOD ENGINEERING IS VITALWrite for complete information and specifications.

VITAL INDUSTRIES

country

3614 SOUTHWEST ARCHER ROADGAINESVILLE, FLORIDA -PHONE 372-7254

10 Circle Item 7 on Tech Data Card BROADCAST ENGINEERING

When engineers get together,the conversation turns to pickups.

It's an irresistible topic.Especially since Stanton came out with the Model 5(X) stereo cartridge.That's an engineer's pickup, if there ever was one.Beautiful curve-within 1 (Whom 20 to 10,(XX) Hz, 2 db from 10,000 to 20,0(X) Hz.Fantastically small moving system.to trace the wildest twists in the groove.Light weight (only 5 grams!) to take advantage of low -mass tone arms.And, of course, Stanton's legendary quality control.No wonder engineers use the Stanton 5(X) for critical broadcastingand auditioning applications.And to impress other engineers with their pickupmanship.

(Available with 0.7 or 0.5 -mil diamond, $30; with elliptical diamond, $35.For free literature, write to Stanton Magnetics, Inc., Plainview, L.I., N.Y.)

KlaISIT()11


New FAIRCHILD 42 input TV Network Mixer.

FAIRCHILD MASTERTAPE IMPROVEMENT SYSTEM

FAIRCHILD MTIS with "focused -gap"head design reduces bias -induced noiseto a point where it is no greater than 2db than the noise of virgin or bulk -erasedtape. FAIRCHILD MTIS has an S/N ratioof 72 db on one track of a 4 -track 1/2"tape. FAIRCHILD MTIS increases the re-cording level by 4 db over present stand-ards, with the lowest harmonic, intermod-ulation, and cross -modulation distortionof only .5%. Only the FAIRCHILD MTIScomes in a compatible, convertible pack-age allowing you to update your presenttape transports to the highest quality"state of -the -art" recording standards.

FAIRCHILD CONAX

The world -accepted standard to controlhigh frequency spillovers due to pre -emphasis. Maintain high levels even withbrass and crashing cymbals in FM andrecording.

THE REVERBERTRON

The new compact rever-beration system whichgives your station thatreal big voice. With theReverbertron you canhave that Carnegie Halleffect as close as thegain control on the Reverbertron. Andthere's the added plus of an increase inapparent loudness of your station sounddue to reverberation, as originallydescribed by Dr. Maxfield.

FAIRCHILD COMPACT

COMPRESSOR MODEL 663

Allows creation of those up tight levelsthat contribute materially to presenceand loudness combined withoverload protection. The FAIR-CHILD Model 663 CompactCompressor produces no dis-tortion despite the amount ofcompression used ... nothumps, no noise. The 663 pro-vides adjustable release timeand up to 20 db of compres-sion. Model 663 N Lcomes withunity gain and additional gainif needed with +18 dbmoutput.

FAIRCHILD PROGRAM

EQUALIZER MODEL 664NLAn ideal no loss equalizer forbroadcast and recording. TheFAIRCHILD Model 664NLallows the production of the"hot, solid commercial" soundstandard with major recordingstudios; transforms any con-ventional console into 'BigBoard sound'. 11/2" x 51/4" highunit provides equalization up

to 10 db at 4, 6, 8, 10, or 15 KHZ and lowend equalization up to 10 db. Rolloffs alsoprovided. The Model 664NLB has equal-ization at 2, 3, 4, 5, and 7.5 KHZ for mo-tion picture demands. The FAIRCHILDProgram Equalizer contains equalizationplus 18 dbm amplifier output. Put life intoyour sound with the FAIRCHILD Equalizer.

FAIRCHILD LIMITER MODEL 670

Fast attack StereoLimiter (50 microsec-onds) with low distor-tion and absence ofthumps. Sum anddifference limiting po-sition eliminates float-ing stereo image. In-cludes regular channel A and B limiting.Dual controls, dual meters provided.Used throughout the world. Flexible re-lease times make it indispensable instereo recording and broadcasting.

Write to FAIRCHILD - the pacemaker in professional audio products - for complete details.

FAIRCHILD RECORDING EQUIPMENT RT10 40 45th Ave, Long Is landCOCity 1,PORA NIONY.


LETTERS

to the editorMIN 11=1 II= MINI =II II=

DEAR EDITOR:I have received many requests for

information concerning the type ofamplifier used in my redundant remoteamplifier (February 1967 BROADCASTENGINEERING, page 28). The redun-dant arrangement can be used withalmost any type of amplifier, and theamplifiers do not have to be identical.The article was written on the assump-tion that the builder would use what-ever units were available to him.

I am using Round Hill Associates'Model AA -200. In this amplifier, thevolume control is also the collectorload resistor, and changing the settingwill cause a gain bounce. Therefore, Imade the modification shown in theaccompanying diagram. These unitshave a 50 -ohm balanced input and a500 -ohm balanced output. The powersource is a 9 -volt battery. A word ofcaution is necessary: This amplifiermust be terminated at all times. Thesupplier suggests that a 1000 -ohm re-sistor be placed across the output (500 -ohm) terminals. I would suggest thatthe line pad be used. The amplifierwill "run away" and burn out the out-put transistors if not terminated.

Since the amplifier can draw asmuch as 100 ma at 9 volts, I suggestthat a large battery be used. I amusing two 4.5 -volt batteries.

This amplifier is available with orwithout metal case from Round HillAssociates, 434 Avenue of the Ameri-cas, New York, N. Y. 10011.

CHARLES D. SEARSNew Whiteland, Indiana


REJUVENATING

DISC RECORDERS

Somewhere in the back room ofmany a radio station lurks a discrecorder. It may date back to theinfancy of radio, or it may be amore recent type, but almost al-ways it is considered to be a use-less antique, rendered obsolete bythe advent of magnetic tape. Al-though present-day radio and tele-vision stations don't use the prod-ucts of these machines very often.there is a waiting market for disc re-cordings, and making discs can bea profitable sideline. If your stationhappens to have one of these ma-chines, restoring it to operation andupdating it to cut microgroove discsmay be well worth your while.

The MechanismPull the old machine out of the

closet and blow away the dust. Itmay need a lot of cleaning, andsoap and water won't hurt it if usedcarefully. Clean the turntable, lathe,drive system, and cabinet. Then,following the instruction book, ifyou can locate it, be sure all therotating and sliding parts are prop-erly lubricated. Only a few dropsof oil are necessary in most cases.When the machine appears to beready to run again, turn it on anduse a strobe disc to check the turn-table speed. These machines wereseldom used for a great manyhours, as compared to a play-back turntable, and the motors areusually in good condition. Mostdrive troubles can be traced to im-proper lubrication or incorrect ad-justment. Usually only 78- and331/2 -rpm speeds are available, butyou probably will be making only331/2 -rpm recordings.*President, Gardner Electronics Corp., andBE Consulting Author.

by Larry J. Gardner*-You can put this neglectedpiece of equipment back to work.

APPROX 50

CUTTER HEAD

CHUCK SCREW

DISC SURFACE

STYLUS

Fig. 1. Correct angle for cutting stylusis essential for good disc recording.

When you are satisfied that theturntable is running properly, checkthe cutting lathe. Be sure there isno stylus in the cutting head, andthen put the carriage in its operatingposition and check the cutter feed.You should be able to hand crankthe cutter across the disc, or let itfeed by itself. In most cases, thecutter is driven by a blade whichrides on the leadscrew, and the con-dition of the blade determines howevenly spaced the grooves will be.The blade should be clean andsharp, and it should mate properlywith the groove. It can be sharp-ened with a small, round file, butyou must be careful not to get it tooshort.

The cutting angle should now beadjusted. Position the cutting head sothat the stylus is approximately 5°from vertical as shown in Fig. I.' Usea microgroove sapphire stylus, shortor long shank as recommended bythe manufacturer. Steel or Stellite

Editor's Note: Some authorities recommendthat the stylus make an angle of 90° ±2 or 3°with the record surface. In the final analysis,the angle used will be the one that gives thebest results with the machine being used.

styli are satisfactory for standard -groove work, but the sapphires willsave money in the long run, es-pecially for microgroove cutting.

You are now ready to make atest cut. Use a new blank disc (anyold ones left over from the "goodold days" will be too hard to becut, a microgroove stylus, and anyleadscrew you happen to have. Withthe turntable running, and the cut-ting head disconnected (so that youdon't record amplifier noise), gent-ly lower the cutter and watch thecut groove. It should be verysmooth and shiny, and no soundshould come from the cutter. Ahissing sound indicates either thatyou are cutting too deeply, the re-cording stylus is bad, or the cuttingangle is incorrect. After cutting afew grooves, stop the turntable andexamine the chip (thread) cut fromthe grooves. It should be slightlysmaller than a human hair, almoststraight, and shiny. A course, kinkychip indicates too deep a cut or adry disc, and a very fine chip whichlooks dull indicates too shallow acut (this, also, could be caused bya dry disc). When a pitch of 120lines per inch is used, the ratio ofgroove width to the width of the"land" between the grooves shouldbe about 60/40. For a finer pitch(over 120 lines per inch) the ratioof groove to land should never ex-ceed 70/30, which can be easilychecked with a microscope. (Stand-ard microscopes for this purposeare available.) A 60-40 ratio at 120lines corresponds to a groove depthof about .002 inch. The depth ofcut is usually adjusted by means ofa tension spring attached to the cut-ter. Increasing the tension of this

May, 1967 13

+20

+15

+10

+5

0

-5

-10

-15

-20

2 3 4 5 6 7 8 9 120 100

2 3 4 5 6 7 8 9 11000

FREQUENCY (Hz)

2 3 4 5 6 7 8 9 110000

2

20000

Fig. 2. Standard recording characteristic shows roll -off of low -frequency signals and boost of high -frequency signals.

spring reduces the depth of cut, andvice versa.

Many older lathes, designed for78 -rpm operation, do not have lead -screws for pitches finer than 120lines per inch. Although excellentrecordings can be made at thispitch (which is used on many 45rpm commercial records), the re-cording time is somewhat limited;only about ten minutes can be ob-tained per side on a 12 -inch discat 331/2 rpm. Leadscrews for 136,148, 160, 190, 210, or more linesper inch are available from mostmanufacturers, and the finer pitcheswill give a proportional increase inrecording time. Older lathes, how-ever, are designed for coarserpitches and sometimes do not feedwell at pitches over about 210 linesper inch. Using the 120 -line screwfor 45 -rpm work and the 210 -linescrew for 331/2 -rpm work shouldgive satisfactory results with mostlathes, however.

If you can't get leadscrews fromthe manufacturer, any good pre-cision machine shop should be ableto make one for you. Be sure they

understand the purpose of the screwand the shape of the threads. If youtake one of your screws in as asample, they should be able tomake a screw for just about anypitch.

You may want to cut 45 -rpmdiscs on a 331/2 -78 -rpm lathe andneed a means of driving the turn-table at 45 rpm. How this can bedone depends to a large degree onthe construction of the turntable.Check first with the manufacturerand see if he has a conversion. Onrim -drive turntables, this conversionis simply a sleeve which slips overthe 331/2 -rpm drive surface of themotor shaft. On gear -driven turn-tables, it is necessary either to re-place the 78 -rpm gears with newones of a suitable ratio, or to drivethe turntable at 45 rpm with a sep-arate rim or belt drive. If you wantto do the conversion yourself, havea machine shop make the parts. Ona rim -drive turntable, you some-times can have the 78 -rpm drivesurface ground down to size for45 rpm, which corresponds to45/78 times the original diameter

(this, of course, eliminates the 78 -rpm speed). Alternatively, you canadd a belt drive around the cir-cumference of the turntable, usinga pulley on a separate drive motor.If you grind down the existing rim -drive shaft, be sure there is suf-ficient metal left after machining tohold the set screw or screws firmly.If not, you can make a separatedrive shaft for 45 rpm. This ap-proach does have a big disadvan-tage: it requires a shaft changeevery time you change speeds.

If changing speeds is a really bigproblem, a good playback turn-table can be pressed into service asa cutting table, provided the mo-tor has sufficient torque to over-come the drag of the recordingstylus. You will have to add adriving pin for the recording blank,and the center pin will have tomatch the driving disc of the feedmechanism.

Amplifiers

To make good recordings, youwill need an amplifier with a mini-mum of about 30 watts output and


good performance specifications.Many ordinary monitor amplifiersor hi-fi types are acceptable. Choosean amplifier with an output im-pedance that matches the cutter youplan to use, and avoid using a

matching transformer between theamplifier and the head. Losses insuch a transformer degrade thedamping factor of the amplifier,and good damping is especially im-portant in disc recording. Some ofthe newer transistor amplifiers withvery high damping factors are ex-cellent for this purpose, and are attheir best with a low -impedance re-cording head.

The amplifiers originally usedwith older disc recorders are ca-pable of excellent performance, butusually are not equalized to thecurrent NAB or RIAA curve, andshould only be used in the "flat"response position of the equalizer.

Equalization

Equalization is used in disc re-cording to permit a higher record-ing level by attenuating the lowfrequencies and to lower objection-able surface noise by accentuatingthe high frequencies. Currently, theaccepted standard curve is the NAB(or RIAA) curve, shown in Fig.2. This curve may be most easilymatched by using two networks,one in series wth the cutter headitself for frequencies below 1000Hz, and another in the amplifierinput circuit for frequencies above1000 Hz. The low -frequency net-work is a simple series resistor fora low -impedance head (8-16 ohms)and a parallel RC network for a500 -ohm cutter, as shown in Fig.

in parallel with a 400 -ohm, 30 -wattresistor, and it is adjusted in thesame manner as the low -impedancenetwork. Remember that the seriesresistance of the amplifier outputis also part of the circuit, so youmay find that only a few ohms ofthe external resistor is used, de-pending on the power capabilities ofthe output transformer. If it is notpossible to get correct low -fre-quency response because of this,use a lower -impedance tap on theoutput transformer.

After wiring the low -frequencynetwork, you should check the low -frequency response. Connect anaudio generator, set to 1000 Hz,to the amplifier input and adjustthe gain for about 2 volts acrossthe amplifier output for a low -im-pedance cutter, or 15 volts for a500 -ohm cutter. Be careful not toapply excessive power to the cut-ter at any time, especially if youare using a high -power amplifier.Many recording amplifiers can de-liver in excess of 100 watts, whichcould easily damage the cutter.Keeping the amplifier input levelconstant, record a few seconds oftones from 1000 Hz down to 50Hz. Then, check one of your turn-tables against a test record such asthe 1965 NAB disc. If your play-back is properly equalized, the discyou have just recorded should pro-duce response flat within about 2dB from 50 Hz to 1000 Hz. If not,adjust the series resistor on thecutter and try again.

The high -frequency equalizationnetwork should be inserted in a600 -ohm line feeding a 600 -ohmbalanced input on the recording

3. For a low -impedance cutter, aseries resistance of from one toten ohms is required. Because ofthe inductive nature of the cut-ter, the portion of the output volt-age across the resistor is greater atlow frequencies than at high fre-quencies, and by adjusting theresistor the low -frequency roll -offmay be adjusted. For any low -im-pedance cutter, a ten -ohm, 30 -wattresistor with a slider should besuitable for close matching to thecurve. Increasing the resistance de-creases response below 1000 Hz.

6000INPUT

270 0

.01 mfd

270

For a 500 -ohm cutter, the low -frequency network consists of a

10Q30W

AMPLIFIER CUTTER

(8-16 S2 OUT) (8-16

(A) Low -impedance cutter

400 CI

30W

AMPLIFIER(500 CI OUT)

CUTTER

(500 DI

(B) High -impedance cutter

Fig. 3. Low -frequency equalizatior is

provided by simple output networks.

amplifier. The circuit for a suitablenetwork is shown in Fig. 4. If theamplifier does not have a 600 -ohmbalanced input, a matching trans-former (600 ohms to grid) shouldbe used. The 250 -ohm potentiom-eter is used to adjust the high -fre-quency boost for the cutter andspeed used, although a compromiseshould be made between a cut madenear the edge of a 12 -inch disc andone near the center. The construc-tion of the equalizer is not critical,but the 10-mhy coil should be atoroid if you can get one.

To adjust the high -frequency Please turn to page 58

.033 mfd

0

8 10 mhy

270

MA.-270 Q

.033 mfd

600 0

OUTPUT

4-mfd paper or oil -filled capacitor

May, 1967

Fig. 4. Equalizing network for highs is placed ahead of recording amplifier.

15

PLANNING AND BUILDING

THE NEW CKAC STUDIOS

Although the structural design ofradio studios would seem to fall inthe province of the architect, theactual layout must be made by thestation chief engineer or consultant.The controlling factor in studio de-sign is, of course, programming,both present and future. Thereforethe full cooperation of the manage-ment, program, and engineering de-partments of the station is essential.A logical decision, however, is noteasily reached when one has toforesee the future of radio program-ming. For example, at x dollarsper square foot, is it sound busi-ness engineering to provide a stu-dio suitable for a 16 -piece orchestrajust in case it might be requiredin the future? Is there a trendtoward more telephone call -in pro-grams? What about complete auto-mation? Will there be more or few-er remote broadcasts, on -the -spotnews pickups, or sports programs?How about forum -type programs,and will they be with or withoutaudience? Is intercity and interna-tional news to predominate? Theseand many other questions must beconsidered in the light of presentand expected rental, construction,and equipment costs. It is the pur-pose of this article to describe the

Chief Engineer, CKAC, Montreal, Quebec,and BE Consulting Author.

by Len Spencer*-New studio facilities and some of the con-siderations that went into their design.

design and layout of a four -studiocomplex suitable for the present-day operation of an independent50 -kw station in a major market.

Preliminary Requirements

The CKAC studio project had tobe completed within a building al-ready in existence, so it was notpossible to build from the groundup. Fortunately, the building didhave a clear ceiling height of 10feet.

It had been decided, during thepreliminary discussions, that theproduction department should beon one floor. Available space, how-ever, did not permit inclusion ofthe record library in the produc-tion area; it is situated on thefloor below, along with the work-shop and engineering department.

Fig. 1 shows the top -floor layoutas finally developed. Included arefour studios, master control, re-cording, remote -equipment storage,the news department, and the re-mote -broadcast department. Thetop floor was chosen to get as faras possible from street noises andvibration and to preclude the neces-sity of soundproofing the ceiling tokeep out noise from above. Thebuilding had one wall without open-ings, and this wall was used as abase line from which to begin the

Table 1. Determination of Absorption

Material

Plaster on wooden studsLinoleumPerforated

pressed fiber boardSmall grand pianoPlate glassPerson

Absorption Area AbsorptionCoefficient (Sq. Ft.) Units

.039 800 31.2

.03 390 11.7

.76 390 296.4.6 .6.025 48 1.2

4.7 (4) 18.8

359.9

preliminary layout. From past ex-perience, the location of the mastercontrol room was chosen so that theoperators could see into as manystudios as possible.

Acoustical Considerations

An important characteristic ofa studio is its reverberation time.Studio A measures 24' x 16' 3"x 10'. The reverberation time ofthis studio can be calculated fromthe formula'

where,

T =-

V=

A=

a =

T=.05 VAa

reverberation time in sec-ondsvolume of the studio incubic feetsurface area of the studioin square feetcoefficient of absorption

Since the studio is composed ofseveral materials having differentabsorption coefficients, product Aais determined as shown in Table 1.The reverberation time is then cal-culated to be

T .05 3360900

= .54 sec

Table 2. Studio A Reverberation Times

Hz 125 250 500 1000 2000 4000

Sec 1.2 .9 .7 .7 .75 .8

Table 3. Studio B Reverberation Times

Hz 125 250 500 1000 4000

Sec 0.6 0.5 0.5 0.5 0.5


PROGRAM DIRECTOR

RECEPTIONIST

ELEV

CLERICAL

REMOTE

EQUIP

ANNOUNCERS

STUDIO A

REMOTE

DEPT

NEWS

DIRECTOR

STUDIO B

MASTER

CONTROL

NEWS ROOM

STUDIO C

RECORDING

& CONTROL

NEWS

STUDIO D\ I

ICONTROL

TAPE MONTAGE

FOLDING DOORS

Fig. 1. Floor plan of the CKAC production area. Note sound locks and use

This value is acceptable for a stu-dio intended primarily for speechuse. If necessary, the reverberationtime could be increased easily bythe addition of reflective materialto the studio surfaces.

The actual readings taken in stu-dio A are shown in Table 2. Theoptimum reverberation time for asmall broadcast studio (4000 cubicfeet) is considered to be about .72sec at 512 Hz.'' The optimum timeincreases with decreasing freqency;at 125 Hz it is about 1.02 sec.

But there is another criterion inacoustical design that is very im-portant. Consider the reverberationtimes measured in studio B (Table3). This would seem to indicate anacceptable response time for a:

speech studio, but in actual factbroadcasts from this studio soundedterrible, and we had to resort to allsorts of tricks to make it usableuntil a correction could be applied.

The trouble was caused by aphenomenon well known to radioengineers: standing waves, or re-flections that were in phase withthe original sound at certain fre-quencies. From Fig. 1, it can beseen that studio B has one solidback wall with observation win-dows on the three other sides.Where glass is installed in oppositesides of a studio, it has been found

of offices and hall for sound isolation.

judicious to install the panes atan angle of 12° (Fig. 2); this pre-cludes reflections at the higher fre-quencies by directing the soundtoward the ceiling. But in studio B,despite the 12° angle of the win-dows, reflections came from therear wall. Had it been possible toslant one wall to avoid the "squarebox" effect, it might have been pos-sible to eliminate the reflections.However, in this case the cure wasto install highly sound -absorbentmaterial opposite the reflecting sur-face, but not enough material to

change the overall reverberationtime drastically.

At first glance, it would seem that252 square feet of glass in studioC would have created both rever-beration and reflection problems,but the wisdom of building wallsthat are offset, whenever it is pos-sible, is shown by the actual meas-urements in Table 4. Because ofthe 12° slant of the panes, the jux-taposition of four observation win-dows resulted in no reflection prob-lems. The measured reverberationtimes were for the studio with only

WORM I MGM I MGM a leF.Ist14,11fit

ACOUSTICALTILE

3

WE I

APANWAVAPYANWATAVANdrArAffirtirdrAftriPAM

Fig. 2. Basic window dimensions. Angle of glass reduces reflection problems.

May, 1967 17

4' CORK ATLOOR & CEILING

2" THICKGLASS FIBER

SOUND BLANKET

Fig. 3. Cross-sectional view of topof wall shows soundproofing method.

the control table in place. Whencartridge racks, a second desk, anda coat rack were added, the rever-beration time was reduced to about0.5 sec; this was proved satisfac-tory by the final criterion: "Air"listening.

Contruction Details

Fig. 2 also shows the preferredcontrol -room dimensions. The ob-servation window has a 12° slopefor sound reflections and to reduceglare. The panes are 1/4 -inch thick,set in medium soft rubber; thisthickness of plate glass at 51/2 -inchbottom separation gives good soundinsulation for the type of programscontemplated.

The equipment room and allstudios are built with double "bal-loon" type soundproof ( - 60 dB )

HONEYCOMB DOORWITH 114"

PLYWOOD PANELS

r' CORK PANEL

RUBBER WEATHERSTRIP, TOP AND

BOTTOM OF DOOR

(A) Cross section

walls. It should be understood thatthe isolation obtained is only goodenough for locations not subject toheavy vibrations or high sound lev-els such as might be found on astreet with heavy truck traffic, orclose to a railroad or airport. InFig. I, notice that except for stu-dio D, which has a special windowtreatment on the outside wall, thecontrol rooms and studios are pro-tected from outside noises by officespace and walls plus the 14 -footwidth of the passageway.

The rather complicated entrancesto the recording department andstudio D serve a double purpose.First, a sound lock is provided be-tween the news room and the stu-dio, and second, access is permittedto the studio without the necessityof going through the news room.The door across the passagewayacts as a sound lock for studio Cand the recording department.

A double folding wall allows therecording room to act as a controlroom for both studio C and studioB if the need should arise. Atspeech levels, which is all studiosB and C are designed for, experi-enced operators could operate re-cording equipment without appre-ciable sound interference.

Control room A -B can functionas designated, and studios A andB are protected by their individualsound locks. The master controlroom has visual control of all stu-dios in the station.

For operation under the aboveconditions, the wall constructionshown in Fig. 3 has proved quitesatisfactory. The uprights are erect-ed on 4 -inch cork strips that are6 inches wide to allow the plasterboard to butt against them at ceilingand floor. A two- or three -inch -

DOOR

SOFT RUBBER

RECESSED BOLT

HARDWOOD STOP

JAMB

(B) Seal detail

Fig. 4. Doors combine absorbent materials with seals for soundproofing.

Table 4. Studio C Reverberation Times

Hz 62 125 250 500 1000 2000 4000 8000

Sec 0.9 0.8 0.8 0.8 0.7 0.7 0.8 0.8

thick glass -fiber blanket is suspend-ed from the ceiling so that thereis no contact with the walls. Theblanket is hung from 1" x 2" fur-ring strips; it is of sufficient lengthto hang loosely and be at-tached to the floor. The furringstrips do not touch the 2" x 4"uprights. A false floor was builton 2" x 3" runners, which weremounted on rubber pads placed sixinches apart.

If there is need of acousticaltreatment, perforated acousticalpaneling can be mounted on 1" x 3"furring strips, and glass -fiber battsmay be installed behind the panels.If the studios are larger and thesound problems more severe, theservices of a sound specialist willbe required; for the smaller stationwhere programs are mostly at voicelevels, a "cut -and -try" method mayprove satisfactory. Panels withoutthe acoustical batts are installedopposite those that are backed with2" fiber batts to balance out re-flection areas against absorptionareas.

Soundproof doors are a specialproblem; visits to six different sta-tions provided six different solu-tions. Some studios were providedwith lead -lined 4 -inch -thick doorsequipped with pressure edges thatlock into the door jamb. Thesedoors are nearly airtight and arequite effective when newly installed,but their weight may cause themto sag after a few months of heavyuse. Another solution is a doubledoor frame using two padded doors.This allows a six-inch separationbetween the doors, and if they closeagainst soft rubber they can bequite efficient. Another type ofsoundproof door (for use with asound lock) consists of a 1 -inch -thick honeycomb core with a1/4 -inch plywood skin on which areglued 4" cork panels (Fig. 4 ). Pro-vision must be made for a narrowpane (double) of glass in each doorso that collisions can be avoided.Also, we provide a continuouslyilluminated 60 -watt light in every


sound lock. With rubber strippingapplied to the door and door frame,and with a rubber draft stopper,these sound locks are quite satis-factory.

Most engineers prefer some sortof sound lock, which basicallymeans that enough room must beprovided for one door to close be-fore the second one opens. Thiscosts floor -space rental, and it ispreferable to use existing and neces-sary passageways for this purpose.Notice in Fig. 1 that the doormarked "X" is for the use of themaster -control operator under emer-gency conditions and therefore isnormally in the closed position.The entrances to studios A and Bmake use of existing passageways,as does the entrance to the record-ing room and studio D. The only"waste" space is between the mas-ter control room and the controlroom for studios B and C.

Other Sound Problems

It is of course most importantthat the master and other controlrooms have good acoustical prop-erties and that the monitor am-plifiers and speakers have goodresponse curves. In some stations,it is found that mediocre repro-duction systems are used in con-trol rooms in a mistaken attemptto economize. This only results inpoor on -the -air monitoring and badmicrophone placements.

Air conditioning ducts are a spe-cial problem as a source of un-wanted sound transmission - notonly noise from the air-conditioningmachine itself, but also leaks be-tween studios and control rooms.Adaquate reduction of this noisegenerally results from the use of1/2 -inch-thick glass -fiber linings inall supply ducts, specially designed4 -inch -thick noise -suppressor padsat the output from the machine, andbaffles at each outlet. For this workit is wise to rely on qualified soundengineers for the installation.

In cases where there is trans-mission of high audio frequencies,such as noise from electric motorsor fans supplying the air, the useof glass -fiber batts applied to thecork linings for a few feet fromthe outlets has proved helpful insome cases.

"Air rush," when the pressure or

movement of the air itself is toogreat, has been reduced by theuse of curved baffles mounted afew inches from the outlets, but inmany cases only the reduction ofair flow was completely satisfac-tory. This trouble is most oftenfound in small studios where themicrophone is quite close to the airsupply. An empirical approach tothese and related problems is theonly solution, and the "on -air" re-sult is the final criterion.

In cases where there are heavysmokers on the announcing staff,a fan -type exhaust is very oftennecessary to clear the air beforevisitors or nonsmokers enter theroom. This is generally needed inbuildings not constructed especiallyfor radio. The smoke exhaust is,of course, in addition to the regularair supply.

Provision must be made for wir-ing ducts between the several stu-dios and the control and recordingrooms. Where there is a danger ofsound leakage, conduits are pref-erable, and when larger conduitsare installed for future expansionthey can be blocked at each endwith oakum.

Conclusion

In an ideal case where it is pos-sible to design a studio complexfrom the ground up, or where thereis sufficient space available in anexisting building, studios can bebuilt to textbook specifications. Forthose engineers who have to workon small budgets using what theyhave at hand, it is hoped that thesenotes will be useful. A

References

1. Ulrey, Harry F., Architects andBuilders Guide, Theodore Audel &Co., Indianapolis, 1964, page 261.

2. Davis, Don, Acoustical Tests andMeasurements, Howard W. Sams& Co., Inc., Indianapolis, 1965,page 67.

3. Elder, J. Gordon, "Introductionto Studio Acoustics," BROADCASTENGINEERING, September 1965,page 14.

4. Watson, Floyd Rowe, Acoustics ofBuildings (Second Edition), Chap-man and Hall, London, 1930.

5. Olson, Harry Ferdinand, Elementsof Acoustical Engineering, D. VanNostrand Co., Princeton, N. J.,1957.

Control area for studios A and B.

Announcer at studio C control unit.

View of CKAC recording facilities.

Studio B; note large rear wall area.

Studio B from Recording and Control.

May, 196719

A FREQUENCY -MEASUREMENT SYSTEM

by Robert L. Zuelsdorf*

The design and construction of equipment formeasuring TV carrier frequencies is described.

Part 1 of two parts.

Television frequency -measurement requirements havechanged. For many years it was sufficient to have onlyfrequency monitors on the station premises, and cali-bration checks usually were made by having a frequen-cy -measurement service pay semiannual visits. But withthe coming of the requirement for once -a -day checksand once -a -month calibration, these methods are nolonger adequate. The daily requirement may still be metwith the station frequency monitor, but it is now a nearnecessity to possess a system capable of performing themonthly calibration check. This article deals with thephilosophy of design of such a system and describes aset of equipment and its operation. Sufficient informa-tion is presented to enable the broadcast engineer toduplicate these units or to modify the design to suithis own tastes.

" Engineering Supervisor, 11' '<A/W AM -TV, Madison, Wis.

Method of Measurement

Nearly all frequency -measurement systems compare,either directly or indirectly, the frequency in questionwith the output frequency of a stable reference oscilla-tor. The method to be described starts with a 1 -MHzoscillator, and dividers and multipliers provide har-monics and subharmonics for the actual frequency com-parison.

From the block diagram in Fig. 1, it can be seen thatthe three triplers in the frequency standard produce anoutput at 27 MHz. A diode multiplier generates har-monics in the UHF range which are mixed with thecarrier frequency. At WKOW-TV, operation is onChannel 27 with a - 10 -kHz offset. The 20th harmonicof 27 MHz is 540 MHz. If this is mixed with the549.24 -MHz visual carrier, a 9.24 -MHz difference fre-quency results. This difference signal is picked up on a

1

4 10 4 10 MHz 3 MHz 9 MHz 27 MHz 27 MHz MULTIPLIER TRANSMITTER

COUNTER COUNTER xrAL OSC TRIPLER TRIPLER TRIPLER MIXER SAMPLE

100kHz

BEAT

OUTPUT10kHz 1 MHz

fMARKEROUTPUT

COMBININGNETWORK

WAN

COMMUN I CAT IONS

RECEIVER

Fig. 1. System block diagram shows how multipliers and dividers produce the desired reference and marker signals.


communications receiver tuned to 9.24 MHz. There willalso be a harmonic of the 10 -kHz frequency -standardoutput at 9.24 MHz; if these two signals produce azero beat, the visual transmitter is exactly on frequency.An aural frequency check is made in the same manner,except that the receiver is tuned to 13.74 MHz, thedifference between the 553.74 -MHz aural carrier andthe 540 -MHz harmonic.

Master Oscillator

A frequency standard can be no better than its masteroscillator. Quite naturally then, stability is the primeconcern in the design of this unit. There are a numberof parameters which affect frequency stability of acrystal oscillator. Among the more important of theseare the transistor terminal impedances, operating level,and variations of supply voltage and temperature.

For analytical purposes, an oscillator may be brokendown into an amplifier and a feedback network. Ifamplification exceeds losses and the phase shift aroundthe loop is zero at a given frequency, oscillation willresult at that frequency. Any phase instability occurringin the circuit will cause a shift in the frequency at whichzero phase shift around the loop exists. The problem,then, is to minimize causes of phase instability.

Consider a transistor amplifier coupled to a feedbacknetwork, or resonator. An impedance, Z, could bemeasured across one of the couplings. With a changeof voltage, a change of capacitance, AC, would occurbecause of variation of the base -collector depletionregion. A change of temperature would produce achange of transistor beta, giving rise to a similar ca-pacitance variation. For small angles, the phase changedue to AC is 1:

A 4 = - ACwZ

This indicates that a low -impedance coupling is desir-able to reduce the effects of AC and thus keep A assmall as possible. Or putting it another way, the valuesof swamping capacitance should be as large as possibleto minimize the effects of intrinsic capacitance changes.This is particularly true of the relatively large and un-stable base -emitter capacitance.

The amplitude of the waveform in the collector cir-cuit will also have an effect on stability. A shift of beta,such as might be caused by a temperature variation, will

vary the amplitude of the collector current. If the circuitis entirely linear, no change of phase shift will occur.However, a transistor driven beyond the linear rangewill not have a sinusoidal output, and exact analysisnow becomes complex. It is evident, though, that achange of waveshape such as that caused by a shift ofthe clipping level can produce an effective change ofphase around the loop. Keeping the output nearlysinusoidal will tend to minimize this problem.

A Colpitts oscillator circuit was chosen because itreadily permits a high -stability design. Large values ofcollector and base swamping capacitance make upthe feedback network ( Fig. 2). The precise valueschosen are a compromise between swamping, feedbackamplitude, and output frequency. The values shownallow the oscillator to be set to exactly 1 MHz. Feed-back amplitude is sufficient for reliable starting, but lowenough to avoid severe clipping. Substitution of anothertype of crystal would probably require some adjustmentof the capacitance values.

The frequency adjustment system is unique in thata combination of fixed and trimmer capacitance isemployed in conjunction with a voltage -variable ca-pacitance diode. The 4-25 pf capacitor (C5) is ascrewdriver adjustment used to set the oscillator to1 MHz, while front -panel control of the voltage acrossthe diode permits a ±10 -Hz adjustment of frequency.High impedances are used to isolate the diode fromground to minimize degradation of crystal Q.

The high value of base -emitter swamping capacitancecontributes to stability for the reasons mentioned pre-viously. Output is taken from the base and fed to theclass -A buffer through R3. This isolation resistor islarge compared to any variation in buffer input imped-ance, and thus oscillator loading remains constantdespite possible fluctuations of buffer parameters.

The simple biasing method used is suitable becauseof the low Ie. of the silicon transistors. The values ofR2 and R6 were selected to give DC voltages of 8 to12 volts on the collectors of Q1 and 02. R3 allowsenough drive to reach the base of Q2 to develop 6volts peak -to -peak of 1 -MHz signal at the collector ofthat stage.

The objective of this frequency standard is short-termstability of a high order. The crystal and frequency -adjustment capacitor C5 are located in an unheated

The finished frequency standard is shown in front view.

May, 1967

Bottom of multiplier chassis: output left, input right.

21

N O O n m m

RI

1011

R2

R3

1.5K

C8

R6

.001

R7

1DK

200K C

l

r --

II NP

OC

2

300

pf

NP

O

r

1 M

Hz

CR

YS

TA

L r-

miz

05C

212N

834

C3 I(15

0 pf

670

4-25

pf

C5

6750

I

riI

.__F

H4 25

14

'

OV

EN

)R

4

C55

.15

D_

C56

m

3.

1506

C9

6750

C6

.001

1600

R17

1615

15

18V

114A

T1

256

IA

ST

AN

CO

R P

6469

IR 6

.8S

C 2

0

R13

00 m

fd

R5

NY

* 4

160K

104

C12

,001

BU

FF

ER

2N83

4Q

2 C7

001

R14

2'20

R13

RE

G

2N1

500

010

5C6/

1615

15

RIO

A WH

RD

16:1

51

E0

WH

GN

CLI

P -

AM

P

Q3

2N70

6

018

- Y

e" 39K

FR

EQ

UE

NC

Y 8

25K

WH

OR

B(

159I

'ILK

100

4 IO

N

1.13

" 1

03 m

fd25

9

011

RI2

R9

5.6

056

056

0 0

CII

,X'2

4vlo

o -t

oo1N

3029

B

C10

1 -

r -t

."-

500

mfd

mkI

SaR

T

1

5DV

IF

750

CE

RA

MIC

SE

T T

O 8

00

R19

E-F

OLL

1311

2N

706

5.1K

C15

R20

PI

R2

022

2.2K

CLI

P A

MP

2N70

604

2.2K

1MH

z

C16

- .0

1

101k

Hz

CI7

39 p

f

2.2K

R24

25K

R26

56K

6.5I

K

C17

111_

.

CI9

11

429

pfto

o,H

, SIL

VE

R M

ICA

MV

B

Os

2N38

4Q

6 2N

384R

27

2.2K

R30

15K

R32

# 3

9K11

3156

KC

2I

1001

1

012N

384

C20

C23

5Orr

tfd

R28

25V

1E0

0

220

0

C24

5 O

m(

d

361

MH

z22

01M

Hz

200p

1006

1

C

2211

,,I

. 003

3S

ILV

ER

R33

Q9

2N38

4

C51

27K

946

106H

2R

49 1K

1674

9O

UT

PuT

AM

P2N

706

2N36

38A

518

017

C52

2.5K

15K

MA

RK

ER

LE

VE

L

R50

MA

RK

ER

C53

OU

T

.001

HI Z

C54

f--0

.001

LO Z

R5

2.1K

C26

1 (2

pC

311

.30

0f

2300

pi

Tr;

100

PI R

,

Q12

©50

0 pf

3©3

I5K

2NQ

1

:73:

1

§C

33

100C

OS

AM

PR

38

1K

C28

TR

IFLE

Rr

3

2N70

6*--

li--

2 0

*18V

MO

LT O

N

R36

27K

11-2

8 tu

rns

No.

28

on 3

/e"

slug

-tu

ned

form

(M

iller

440

0)L2

-8 tu

rns

No.

28

on 3

/8"

slug

-tu

ned

form

(M

iller

440

0)L3

-4 tu

rns

No.

20

on 3

/8"

slug

-tu

ned

form

(M

iller

440

0)L4

-4 tu

rns

No.

20

on 3

/8"

slug

-tu

ned

form

(M

iller

440

0)L5

-62

p.h

Mill

er 4

630

L6-1

00 A

th M

iller

6'1

12

1.80

040

120

0

C36

iI1

C41

II --

.1r4

,C

47 I

2300

pf

atio

pi

MU

LTIP

LIE

R L

EV

EL

Cb

4T-L

-2i3

1:4.

-15

0...

..8

lop

= §

CO

O'M

H27

:r1.-

pfL2

c,

piL3

TR

IFLE

R1

cmie

2N21

02

Q14

©10

-100

p8

fL7

-20

lah

Mill

er 6

152

L8-2

0 ,u

h M

iller

615

2

5.04

- C

34 0.1.

L7

Cha

ssis

boa

rd-V

ecto

r 42

F22

C2

sink

s-W

akef

ield

NF

207

Cry

stal

-Int

erna

tiona

l Cry

stal

F60

5

TR

IFLE

R

2N02

1510

245 27

pf

R42

HO

;

C44

3.6V

LB

C39l

1800

pf

(

/c.s

ai2.

71a

1'

100

MH

z ...

1C

46

R

8L4

-...

C50

FA

m;

7-45

pf

2NQ

1262

19

Hi

C49

20 p

f

943

680

2.4V

-L c

45

MO

LT O

UT

OF

ig.

2.C

ompl

ete

sche

mat

ic d

iagr

am o

f the

solid

-sta

te fr

eque

ncy

-mea

sure

men

t sys

tem

sho

ws

osci

llato

r, m

ultip

liers

, div

ider

s, o

utpu

t sta

ges,

and

reg

ulat

ed p

ower

sup

ply.

I

oven atop the counter chassis. A 21/4 " X 21/4 " X 5"box encloses the rest of the oscillator and buffer cir-cuitry. The oven is a piece of plastic foam material cutin half and hollowed to accept the components. It islocated at the edge of the chassis away from sources ofheat and provides excellent thermal isolation. The un-heated oven is ideal in terms of short warmup time; iflong-term stability were the goal, or if the unit were torun continuously, a heated oven would be chosen.

Of course the crystal itself should not be overlooked.A low -temperature -coefficient type is essential forstability; the one selected is a low -drift AT -cut crystal.Also, some transistor types are more suitable thanothers.2 The 2N834 used here is an epitaxial mesa type,which has the low intrinsic impedances desirable foroscillator usage. Typical drift figures are 0.25 Hz in 1

hour from a cold start, and 0.6 Hz at the end of an8 -hour period.

Multiplier ChainThe multiplier chain is used to provide output of the

proper frequency and amplitude to drive the multiplierdiode. It is desirable to be able to develop at least 5ma of diode current; this level is necessary to producehigher -order harmonics of sufficient amplitude. Theseharmonics, when mixed with the transmitter signal, mustgenerate beat products strong enough to be picked upclearly on the receiver. The amplitude should be ad-justable to enable the operator to optimize for maximumbeat output. The following paragraphs indicate howthese things are accomplished and go on to describe themultiplier circuit in detail.

Most broadcast engineers are aware of the advantagesof conservative design. When active and passive com-ponents are but moderately stressed, increased reliabil-ity and longer life can be expected, and additional driveis available to offset the effects of component aging. Themultiplier chain was designed with these considerationsin mind. Gain stability, always an important factor insolid-state circuits, was provided for in the circuitry.Dissipations are kept to a conservative level, while out-put is more than adequate.

Output Stage

The multiplier chain consists of a 1 -MHz pulse am-plifier, three triplers, and a 27 -MHz output amplifier.The output stage bears first consideration. An output of250 mw will provide more than enough drive for themultiplier diode. A 2N2219 was chosen for the outputtransistor, since it has adequate capabilities at the fre-quency in question. If ideal class -B operation is as-sumed, the collector current and voltage waveforms willbe as shown in Fig. 3. The collector voltage is:

-2

( - sin 0) + E.

E + 1/2 Er, sin 0 -1/2 Ewa. sin 0

and

= Ip sin 0

describes the collector current during the conductionintervals.

Emax

CC

Emin

0

TT

27T

Fig. 3. Collector waveforms for a Class -B output stage.

Transistor power dissipation is given by

t T

131, = i,. ee dt

t=o

In this case, time is expressed in terms of electricalangle 0. Since a full cycle must be considered in deter-mining PD, the factor 1/T becomes 1/27r, but sinceconduction takes place only during the first half cycle(It, = 0 for the second half cycle), the limits of inte-gration are 0 = 0 and 0 = r.Therefore:

PD1

(Ip Eee sin 0 + 1/2 Ip Emto sine 00

-1/2 I, Lux sine 0) dO

= 217r E,, ( - cos 0)

+ 1/2 Ip Lin (1/2 0 - IA sin 2 0)

1/2 I, E, (1/2 0 -1/4 sin 2 0)]

1p E Ip mnE E,;,7T 8 8

May, 1967 23

LA.!

< Emax

oEcc

(-) - E.m

0

CUTOFF

< wco

-JCL >

Tr 2Tr

Fig. 4. Tripler-stage base, collector voltage waveforms.

PD = .318 I, Eec - .125 I, (E,a,, - Ern,.)

For an average collector current (It) of 35 ma, I, =110 ma. If E. = 16 volts, 4 volts is a realistic valuefor

PIN = I.E = (.035)16 = 560mw

PD = (.318) (.11) (16)- (.125) (.11) (28 - 4) = 230mw

Po PIN - PD = 560 - 230 = 330mw

This gives an efficiency of 59% and an output wellabove the target value of 250 mw.

Triple,

In general, the tripler may be handled in the samemanner, but owing to the more complex waveforms theanalysis also is more complex. The base and collectorvoltage waveforms are shown in Fig. 4. It is noted thata 60° conduction angle is required for ideal tripleraction. Considering the collector voltage waveform,

e, = E -1/2 Ernin sin 3 0

IP

0

Fig. 5. Collector current waveform is clipped sine wave.

= I, sin 0 - sin 011 - sin 0,

where 0, is the angle at which conduction begins. For aconduction angle of 60°

= I, sin 0 - .8661 -.866

= 7.47 I, sin 0 - 6.47 I,,

from to27r

3 3

The power dissipation is found as before; the limits ofintegration are the times that conduction begins andends.

PD =

27,73

21.7r(7.47 I, E sin 0 - 6.47 I, Et,

17-/3

+ 3.74 I, E. sin 0 sin 3 0 - 3.24 I, E. sin 30

- 3.74 I, E,ir, sin 0 sin 3 0 + 3.24 I, sin 30) d0

217[ - 7.47 I, E cos 0 - 6.47 I, E, 0

+ 3.74 19 E,,,( sin: 0

+ 3.24 I, E, ( 1/2 ) cos 3 0

sin 2 0 sin 4 0- 3.74 I,k 4 8

sin 4 0 \8 )

1/2 E. sin 3 02,13

Fig. 5 shows the collector current waveform. It is no - 3.24 I, Em,n (1/2 ) cos 3 0longer a complete sine function, but rather the clipped J '7713

top of a sine wave. In general, within the conductioninterval PD = .115 I, E - .042 1p (EMaXE,,,,,,)


YOU WON'T FIND A PANIC BUTTON

ON A MAGNECORD!

PANIC BUTTON

When Magnecord engineered a long list ofsafety factors into their professional line of taperecorder/reproducers . . . they engineered theemergencies out! A sturdy die-cast mainplate,supporting the transport in every model, insuresprecise location of internal parts under theroughest operating conditions. Rigid die-casthead mounts eliminate alignment problems.Professional quality hysteresis synchronous

capstan motor and individual reel drive motors are heavyduty models, and the capstan shaft assembly is re-inforcedfor extra strength and longer life.While you are taping, safe -guard operating features protectyour thinnest tapes. With Magnecord you get top-notch per-formance and superb fidelity to keep your taping facilityoperating at maximum capacity, even after years of constantuse. Ask a broadcaster who uses one . . . Magnecords arebuilt to take it!Write now for the full story on the complete line of durablequality Magnecord tape instruments.Magnecord 8+ Reels now available from Audiotapel. See your local dealer.

MAGNECORD MODEL 1021Fully transistorized professionaltape recorder/reproducer formonaural operation. For use inmain or production control room.

t"

t*k k' '-

MAGNECORD MODEL 1022Fully transistorized professionaltape recorder / reproducer twochannel (stereo) for use in mainor production control room.

1

MAGNECORD MODEL 1028Professional quality 2 channel(stereo) tape recorder / repro-ducer for recording mastertapes. (101/2" reel capacity)Available in 1/2- or 1/4 -track.

CrVIAGNECORDtape recordersCON0. T,ON

9600 ALDRICH AVENUE SOUTHMiNNEAPOLIS, MINNESOTA 55420

MAGNECORD MODEL 1048Professional 2 channel (stereo)recorder/reproducer for use inmain studio, production studioor conference recording (101/2"reel capacity) Model 1048 isavailable in 1/2- or N -track.


BROADCAST ENGINEERING 25

Now. A 100 KW UHF -TV Transmitter.

21 0"

26 0"

ATJUSTABEE LO,ER /TR NLE T

HEAT ExCHAN.A.

NEAT EXCHANGER

WATERTANK

WATERPUMP

SPARETOME

ANOCIRCO T

?\/VISUAL

AS, iF IER

RE PATCH L DUMMY LOACSRARE

[P't - 44- A HYBRIDPv -16- A HAR FILTERREELECTOMETERS

- CAFERHEAD -THIS AREA -

Al DUAL

ANPL, ER

NOvu. TALE

PLATE

BREAKER

P1 - 45- A MAPLE 'CEA- OVERHEAT -THIS AREA -

AURAL

ASIPE,P ER

DRIVER

ECX.P IER

-VA

SWITCH

vkal VOLTAGEEHELOSHRE

OUTSIDE Au -DEO

REACTOR

(Inquire how 5 megawatt ERP canbe provided with this transmitter.)

These GE transmitters willmeet the most sophisticatedrequirements for UHF tele-vision service.

15 KW, Type TT -56-A30 KW, Type TT -57-A50 KW, Type TT -59-A60 KW, Type TT -61-A100 KW, Type TT -62-A

Minimum suggested station floor plan layout, GE Type TT -62-A, 100 KW UHF transmitter.


Honest.

PY-47 Vestigial Sideband Filter inserted between the driver and thevisual amplifiers assures maximum filter stability.

Now you can get a 100 KW transmitter that is a 100KW transmitter. From the ground up. The GE TT -62-A.

It took all the engineering know-how we keep talk-ing about to package it into five standard cubicles.With a modern 100 watt exciter. And four -cavityklystron tube amplifiers. The 50 KW klystron tubesused in the visual amplifiers have been in broadcastservice since 1965. Check the minimum floor spacerequirement-it's another GE first. Now you can getfull 100 KW output on any channel from 14 through83. Day in and day out. With easier tuning, fewer tubes,more efficiency and easier maintenance. And it willcost you less to install and operate.

If you'd like to know more about it, just ask yourGE representative. He has all the answers. Honest.

General Electric Compary, Visual CommunicationProducts Department, Electronics Park, Syracuse,New York 13201. GE -44


May, 7967GENERAL ELECTRIC

27

Po = 525 - 280 = 245mwIP

CUTOFF

I

_,Fig. 6. Peak -to -average current ratio can be determined.

The next step is finding the ratio of peak to averagecollector current. It is found by comparing the area in-side the conduction curve (A1 in Fig. 6) with the totalarea (A1 + A2) between sin 01 and I, from 0 to 27r.Referring to Fig. 6 and considering the peak sine -waveamplitude as unity,

Al

2'713

= f sin 0 dO - ir \/-3-

5T/3

3 2

277-

= [- COS 0113 7r V-5-

6 = .092/Is

Al + A2 = 27r (1 - 3/2) = .842

.842/.092 = 9.15, the ratio of I, to I, for a 60° con-duction angle.

Consider a tripler operating as follows:

E = 15 volts I, = 35ma

E,, = 5 volts I, = 320ma

Conduction angle = 60°

PIN = (.035)(15) = 525mwPD = (.115) (.32) 15 - (.042) (.32) (25 - 5)

= 280mw

RL-°- Cl

®

°

Fig. 7. "L" coupling network is used between multipliers.

.245 X 100 = 47%71 .525

An efficiency of 47% seems surprisingly high for atripler. The prime reason is the 60° conduction anglechosen to give ideal tripler action. In practice a 60°angle is difficult to achieve because of the high drivelevel required; 90° is a more realistic conduction angle.Recomputing for a 90° angle gives

PD = .169 Ip - .045 1 (E. - Emin)

Ip = 6.05L

For the 90° conduction angle:

PD = (.169)(.212)15 - (.045)(.212)20

= 348mw

Po = 525 - 348 = 177mw

The efficiency is 34%, still a high-sounding figure fora tripler. In the idealized tripler, the collector voltageand current pulses were of the same width, giving highthird -harmonic output with a resonant tank circuit.With a 90° conduction angle, a portion of the currentgoes into generation of second and other harmonics. AFourier analysis of the collector waveform, with a tank -circuit Q of 5, indicates that 8% of the output will con-sist of unwanted harmonics, thus lowering the collectorefficiency to about 30%. Coupling -circuit and miscel-laneous losses amount to another 3 to 5%, giving thestage an overall efficiency of 25 to 27%.

Coupling

The pi network is perhaps the most widely used de-vice for interstage and output matching. Being basicallya low-pass filter, it provides excellent suppression ofhigher -order harmonics but poor rejection of subhar-monics. Thus it is not the most suitable coupling net-work for use with frequency multipliers. Adequate sup-pression of the fundamental and second harmonic wouldbe difficult to attain. For better performance, a type of"L" network, as shown in Fig. 7, was chosen as acoupling device. Because this network has a high-passcharacteristic, it gives improved rejection of the lowerfrequencies.

To find tank -circuit and coupling values, the formulasgiven below are applied.3 The 2N2219 output circuit isworked out as an example.

RLE2 - (E, - Emin)22P0 2130

122 - 206 ohms2 (.35)

Select a loaded Q of 5;

RL - 206 - 0.24 pb(00,..eL 27r (2.7 X 107) 5


Three months of competitive'in use' tests is the reason Paramount chose

Altec Audio Controlsfor their new solid-state console.

Good Reason.

Paramount Pictures Corporation is justifiably proudof their new re-recording console. It has the latest ofeverything, including some firsts. Such as the con-stant air pressure flowing from inside the unit to keepout smoke and dust.

It also has a complement of Altec amplifiers andaudio controls that practically covers our entire cata-log. With good reason. Bruce Denney, Paramount'sAssistant Sound Department Head, took three monthsto test competitive products under actual use. Theend result is rewarding.

Here's the list of Altec products used:36 each SM8272-01-GG Straight Line Mixers36 each 9611 Escutcheon Plates

4 each RA8400-01 Unbalanced CalibratedAttenuators

30 each 9470A Preamplifiers5 each 9550A Power Supplies

30 each 9850A Trays5 each 9852A Trays6 each 9800A Rack Mounting Frames

36 each 9701 Plug-in Mounting Frames4 each 7160 VU Meters1 each 9060A Microphone Equalizer5 each 9061 A Program Equalizers7 each 9073A Graphic Equalizers6 each 9069A Variable High Pass F Iters2 each 90688 Variable Low Pass Fibers4 each 9066 Fixed Filters

60 each LP8004-00 Fixed Loss PadsMonitoring and playback speakers:3 each A4X "Voice of the Theatre' Systems1 each custom monitor with A7-500 system

componentsOur components were supplied by California SoundProducts, Inc., an Authorized Altec Distributor.There's an Altec Distributor in your area who wouldbe happy to discuss your custom -console needswith you. Give him a call, or write Dept. BE -5for our complete Audio Controls catalog. There arelots of good reasons to do it now.A Division otLIY C Ling Altec, Inc.

Anaheim, California 92803 .

ALTEE

May, 1967


29

1

wOROR.

1 ) 11/2Ro

1 - 67 pf27r (2.7 X 10') 50

50206-1) 1/2

RoCl =()DI' - C, 1 -

RLcooxi,

5

27r (2.7 X 10') (2.06 X 102)

- (6.7 X 11-11) (1 - 50206= 92 pf

A Q of 5 is adequate for the output stage, since therejection of harmonics of 27 MHz is not important. Forthe multipliers, a Q of 10 to 15 is used to improvefurther fundamental and second -harmonic rejection.

The interstage coupling networks may be handled inthe same manner. However, an unknown quantity mustbe dealt with first. This is the input impedance. If plotsof yie vs collector current are available for the frequencyin question, the solution is simple. In many cases, how-ever, the only input information available is- hie vscollector current. This is not sufficient for an exactdetermination of input impedance, but fortunately aprecise result is not necessary. For an approximation, itis found that

where,

FThief°hte

RfNh

fe hi,,) 2/3FT

FT

' fehfe

= gain -bandwidth product at I, and Emin= input resistance at I,= input frequency= low -frequency beta

This approximation is sufficiently accurate up to aboutf. = 1/2 FT.

As previously mentioned, the frequency -multiplierchain consists of five stages. There are a 1 -MHz pulseamplifier, Q12; three triplers, Q13, Q14, and 015; anda 27 -MHz output amplifier, Q16. Pulse amplifier Q12 isforward biased by R36 and R37, and the stage is drivento cutoff by the 1 -MHz input pulse. Its output is coupledto the first tripler through 500-pf capacitor C28, whichis resonant with L5 near 1 MHz. The rest of the cou-pling circuits are of the type previously discussed.

Decoupling

Waveforms observed on the supply side of the 2300-pf feedthrough bypass capacitors indicated they wereinadequate by themselves. Addition of the 0.1-mfdcapacitors in parallel greatly reduced RF on the B +line. Lead lengths are kept short, and components arepositioned to minimize interaction of ground currents.The copper -clad chassis board helps simplify grounding

and shielding. Adequate bypassing is essential if stabil-ity of cascaded stages is to be achieved.

Thermal Considerations

The entire chain uses 135 ma at 18 volts DC, for atotal input of 2.5 watts. The last three stages dissipate80% of this power. Thermal considerations require thatjunction temperatures be kept below the rated maxi-mums and that measures be taken to insure gain stabil-ity. Emitter bias is used for stabilization. Although itwould not be satisfactory for a single-sideband ampli-fier, this method works nicely for cw. It is a means ofnarrowing the conduction angle, and emitter bias alsoprovides a convenient means for checking the emittercurrent and thus determining stage input.

Emitter current indicates the 3 -to -9 MHz tripler isoperating at an input of 540 mw. For conservative de-sign, the input power is considered as dissipation whenmaking heat -sink calculations. The 2N2102 has a maxi-mum operational junction temperature of 200°C anda thermal resistance of 35°C/watt. Wakefield NF207heat sinks were selected for cooling. With natural con-vection, these units allow a temperature rise of 49°C/watt. The maximum allowable ambient temperature

Tmax = 200 - (49 + 35) (.540) = 155°CThis is far above the anticipated maximum ambienttemperature.

Adjustment

To tune up the multiplier chain, it is best to use aselective absorption wavemeter coupled to the collectortank coils. An RF probe or a high -frequency scope mayalso be useful, but unless a selective device is used toidentify proper frequencies, it is easy to arrive at max-imum output on 21 or 24 MHz instead of 27 MHz.Each stage should be peaked with the wavemeter, start-ing with LI and proceeding to L4. Trimmers C38 andC44 permit touching up the drive to the proper levels,while C50 allows output -stage matching adjustments.

A calibrated RF probe may be used to measure out-put from the multiplier chain. Transistor Q16 producesan output of 320 mw with an input of 535 mw, for anefficiency of 60%. This compares with a calculatedefficiency of 59%. Factors reducing efficiency whichwere not included in the calculations include tank andcoupling -circuit loss, harmonic loss, and collector -bodyresistance loss. On the other hand, the conduction anglehas been reduced somewhat, from class B into class C.which tends to increase the efficiency. Neutralizationwas not necessary, but it could be incorporated byadding two turns to the cold end of L4 and a 1-10 pfpiston trimmer back to the base.

The concluding portion of this article will appear innext month's issue.

1.

References

"Oscillators," Sec. 5-1, Selected Semiconductor Circuits,Nayships 93484, Dept. of the Navy.Pullen, "L -C Oscillators" Sec. 10-0, Handbook ofTransistor Circuit Design.

3. Texas Instruments, Inc. Engineering Staff, TransistorCircuit Design, New York: McGraw-Hill Book Co.,1963, p. 351.


THE KING

OF NO

BREAKDOW

FRONT VIEW10 KW FM

CCA SALES ARE Ubecause

TRANSMITTER BREAKDOWN

TIMES ARE D 0 Iv*

HOW CAN CCA PRODUCE THE

TRANSMITTERS AT 20% LESS?VEST

SLAVE LABOR NOSKIMP ON PARTS - - - - NOINFERIOR MATERIAL- - NOPOOR WORKMANSHIP NOOLD FASHION DESIGN - NOLACK OF SERVICE - - - - NO

CCA'S

INGENIOUS ENGINEERING.FMCCA 3rd generation, zero bias grounded grid design results in absolutelyno requirement for neutralization; complete absence of troublesome RF bypass capacitors, screen and bias supplies; exceptional life on inexpensivetubes; perfect stability and reliability. In addition, the modern direct FMexciter with a solid state modulator and integrated circuits assures lowdistortion, high fidelity, stable, stereo and SCA operation.

AMCCA Electronics AM designs utilize conventional, field proven high levelpate modulation - no marketing gimmick circuits - All components aresuper reliable with tremendous reserve and accessibility; 10,000 hours oftube life with inexpensive tubes and distortion of less than 1%; largest mod-u.ation components available assure responses from 30 to 12,000 cycles.

CCACCA ELECTRONICS CORPORATION716 JERSEY AVENUE, GLOUCESTER CITY, NEW JERSEY 08030 AREA 609-456-1716SPECIALISTS IN BEACON, BROADCAST, COMMUNICATION & AIRPCRT TRANSMITTERS

Civet* Item 13 on Tech Data Card

May, 1967 31

1967 NAB Convention Report

Part 1 Highlights of the Equipment Exhibits

As always, there was much to seeand hear in the exhibit area. Perhapsthis was not a year for electrifyingnew breakthroughs, but if the Conven-tion -goer took more than a quickglance, he saw many interesting andsignificant developments.

Through sheer force of size andshowmanship, the television exhibitscommanded first attention. Each majormanufacturer of color cameras con-ducted live demonstrations, engineered(and in several cases choreographed)to emphasize the performance of hisparticular camera design. The debateover color camera systems seemed notto have subsided in the slightest.

There was other TV equipment ondisplay, too. A new color/mono-chrome film scanner was shown, andinterest was high in video recordingequipment. A lightweight, backpackVTR and companion camera were ondisplay. Also of interest was the pres-ence of transmitters and antennas forproducing the maximum power onUHF channels.

A definite trend, in radio as well asTV, was exemplified by a demonstra-tion in one booth: TV antenna patternswere being plotted (over teletype lines)by a computer. Another manufacturerpresented a synchronizing generatorincorporating computer -type circuitryfor improved stability.

There were new items in otherareas as well. Several manufacturersintroduced circularly polarized an-tennas for FM. There was a demon-stration of an automatic loudness -con-trol device. Interesting, too, was the

apparent increase in the use of slider -type audio attenuators.

New and established models ofequipment were shown in almostevery area familiar to the broadcastengineer: automation and automaticlogging, and video equipment,recording and reproducing equipment,transmitters, towers, antennas, micro-phones, wire and cable, test and meas-uring equipment-far too many tocatalog completely. Even the armedservices were represented with somenonbroadcast hardware possibly not sofamiliar to the broadcast engineer whois not also a recent veteran. And, whileCATV is anathema to some broadcast-ers, it is a second business to others;this fact was evidenced by the size andnumber of CATV exhibits.

A person could have spent muchmore than the time available in ex-amining the literally thousands ofitems on display. However, to providean overall picture of this year's ex-hibits we offer the following summaryof highlights.

Addressograph Multigraph Corp.

Equipment for duplicating pro-motional material, logs, or otherprinted matter made up this exhibit.

Advance Industries

Information about a line of towers,microwave reflectors, and prefabri-cated buildings was featured.

Albion Optical Co., Inc.

Featured were Rank Taylor HobsonVarotal zoom lenses, with ranges upto 16:1. Also occupying a prominent

position in the booth was the Pantilt520 servo controlled pan and tilt unit.

Alford Manufacturing Co.

Antennas and related products forVHF TV, UHF TV, and FM were ondisplay.

Altec Lansing

Prominent in the display was theModel 9200 audio console, whichmakes use of modular amplifiers, at-tenuators, etc., and blank panels topermit custom design for a given ap-plication. Also shown were micro-phones, speakers, and other audioequipment.

Ameco, Inc.

Featured by this manufacturer ofCATV equipment were the "Chan-neleer" heterodyne headend unit,"Pacer" line extender, "Pacesetter"series of amplifiers, "Courier" multi-channel closed-circuit TV systems,"Amecoax" aluminum -sheathed cable,and a line of Delta Electronics MATVequipment.

American Electronic Laboratories, Inc.

AEL placed emphasis on its AM -50K A 50 -kw AM transmitter, AM-5KA 5 -kw transmitter, Model 2203solid-state stereo generator, and Model2202 solid-state direct FM multiplexexciter. Also in this booth were twoBelar Electronics Lab. FM monitors,the Model FMM-1 baseband monitorand the Model FMS -1 stereo unit.

American Pamcor, Inc.

Representative of this company's


product line were multiple -circuit andcoaxial connectors and a videoswitcher.

Ampex Corp.

One of the highlights of the Ampexexhibit was the Model VR-3000 bat-tery -powered portable video tape re-corder, which together with its com-panion camera weighs 50 pounds;both are designed to be carried by asingle operator. Other new productsincluded: Model 7500-C color videotape recorder for closed-circuit use;the HS -100 high -band color recordingsystem which uses metal discs forinstant replays in slow motion andstop action; the Multilock system forsynchronizing separately recordedsound with the picture output of avideo tape recorder; a head -alignmentaccessory for adjusting video headcompensation in VR-2000 machineswithout external test equipment; solid-state video and pulse distributionamplifiers for closed-circuit and broad-cast use; and the Mark II Editec sys-tem for timing control of electronictape editing and cueing with VR-1200and VR-2000 recorders. A full com-plement of tape, audio recorders, andamplifiers was shown.

Also in the Ampex area was theMarconi television studio set, wherethe company's Mark VII color camerawas demonstrated.

Andrew Corp.

Included in this exhibit were coaxialtransmission line, elliptical waveguide,coaxial switching equipment, and co-axial fittings.

Arriflex Corp. of America

An array of professional film cam-eras, projectors, magazines, and ac-cessories made up the display.

Audio Devices, Inc.

For those involved with audio re-cording, Audiotape and the Audiopaktape cartridge were shown.

Ball Brothers Research Corp.

Included in the company's line ofspecial -effects generators, AGC ampli-fiers, and other video equipment was anew waveform oscilloscope, the Mark21. This unit is designed primarily forthe educator.

Bauer Electronics Corp.

A new FM transmitter, available intwo models, was introduced; Model603 has 3000 watts output, and Model603-5 delivers 5000 watts. Other itemsincluded audio consoles, Log Alarmautomatic transmitter logging equip-ment, and vidicon camera chains.

Beckman & Whitley

The Model CM 16 professional 16 -mm motion -picture camera and itsaccessories formed the heart of the ex-hibit.

Borg-Warner/Ingersoll Products

An assortment of Emcor equipmentracks and cabinets for broadcast con-trol -room applications was presentedin this booth.

Boston Insulated Wire and Cable Co.

Cables and connectors to mate withall major European and Americanbroadcast television cameras werefeatured. Included was the TV -85C85 -pin connector, designed for posi-tive alignment and protection of mat-ing parts.

Broadcast Electronics, Inc.

On view were models from the com-plete line of cartridge recording andplayback machines, cartridge winders,remote amplifiers, and audio distribu-tion amplifiers.

CBS Laboratories, Div. of CBS, Inc.

A sound, color film showed mobilecolor TV units, which can be built onorder for any customer. Demonstra-tions were given of image enhance-

ment equipment, and the AudimaxIII automatic level control, Volumaxand FM Volumax automatic peak con-troller, and Model 600 wide -rangeprogram monitor were highlighted. Ofspecial interest were demonstrations ofthe new loudness monitor and auto-matic control, and a new digital dis-play system for presenting vote totals,scores, etc., for on -camera pickup ina TV studio.

CCA Electronics Corp.

Transmitters included power levelsof 1 kw, 3 kw, and 10 kw for FM and1 kw and 5 kw for AM. Other high-lights of the display included a "DualReliable" combiner, circularly polar-ized FM antenna, stereo and SCAgenerators, and AM monitoring equip-ment.

Central Dynamics Corp.

Among the featured products werethe Type 67NAD switcher, includingType 2071 nonadditive/ additive mix-ing amplifier; processing amplifiers,Types 2085, 2081, and 2080; and theD-6500 International Standard Day-light photometer.

Century Lighting, Inc.

A line of studio lighting equipmentand lighting control devices made upthis exhibit.

Chrono-Log Corp.

Shown in the Riker Video Industriesbooth was the Step system for TV sta-tion -break automation.

Cleveland Electronics, Inc.

Deflection components for vidiconsand image orthicons in both black -and -white and color applications werefeatured.

Cohu Electronics, Inc.

In the Cohu booth were a color en-coder, a color film chain, a synchroniz-ing generator, and video distributionsystems.

May, 1967 33

41ittlit Otal

iii111111111111111I 111011killi *

Collins Radio Co.

In the Collins exhibit were the fol-lowing: Model 831D-1 2 -kw FM trans-mitter with stereo generator; Model830E- I A 10 -kw FM transmitter;Model 820D-1 1 -kw AM transmitter;Model 820E-1 5 -kw AM transmitterwith remote control; Model 900C-2FM modulation monitor, includingstereo and SCA functions; Model54N-1 FM frequency monitor; Model54Z-1 AM frequency monitor; threeaudio consoles, Model 212T-1 (tele-vision), Model 212S-1 (stereo), andModel 212M-1 (mono), all employingphotoconductive switching; and Model37CP circularly polarized FM an-tenna.

ColorTran Industries, Inc.

A large selection of items from theColorTran catalog of lighting equip-ment and accessories was available forinspection.

Conrac Div., Giannini Controls Corp.

Black -and -white monitors in a rangeof sizes, and color monitors with rec-tangular and round CRT's wereoffered. Among these were the ModelRVB 17/C (17") and RVB 23/C(23") transistorized monitors.

Continental Electronics Mfg. Co.

In addition to Prolog automaticprogramming and logging systems, thismanufacturer showed the Type 315C/316C 5/10 -kw AM transmitter andthe Type 317C 50 -kw AM transmitter.

Cooke Engineering Co.

Model 22B Cojax, Model 22T Co -term, Models 2-2 and 2-2A Copatch,and Models 105-23 and 105-24 co-axial jacks were in this display ofcoaxial switching devices.

Cummins Engine Co., Inc.

A full-size cutaway model of adiesel -powered generator set was thecentral feature of this exhibit, thetheme of which was standby or auxil-

t«CAW

Owl WM..,

iary power sources for broadcast appli-cations.

Davis & Sanford Co., Inc.

Camera -supporting devices were thefeatured products in this manufactur-er's exhibit.

Delta Electronics, Inc.

Measuring equipment included theModel OIB-1 and Model OIB-2 oper-ating -impedance bridges, the ModelCPB-1 common -point impedancebridge, and the RG-1 receiver/gener-ator. Also shown was the Series RVIhigh -current rotary variable inductor.

Dresser Crane, Hoist, and Tower Div.

Photographs and other descriptivemeans were used to present the com-pany's towers for television and radio.

Dynair Electronics, Inc.

Video and audio/video switchers,video and pulse distribution amplifiers,audio/ video modulators, the Model TS100B sideband analyzer, the MINI -Series of CCTV equipment, and Equa-Dyn video cable transmission equip-ment were among the numerous itemsfor CCTV, CATV, and other applica-tions that were shown.

Eastman Kodak Co.

Film for professional use was fea-tured by this manufacturer of photo-graphic supplies and equipment.

Effective Communication Systems, Inc.

Several items of television equipmentwere shown, but emphasis was placedon a new Telemation color synchon-izing generator. Making use of com-puter technology in its design, this unitcombines a high -frequency "clock"with fast -rise logic circuitry to provideimproved time -base and subcarrierphase stability.

Electronics, Missiles &Communications, Inc.

Equipment for the Instructional Tel-

evision Fixed Service, and UHF andVHF translators were featured. Theexhibit was titled "The Profit Improve-ment Clinic," and emphasis was placedon the use of translators to improvecoverage by television stations.

Entron, Inc.

A comprehensive display of equip-ment for CATV systems was shown.

Fairchild Recording Equipment Corp.

The Conax for preventing high -fre-quency overmodulation by FM sta-tions, reverberation systems, and audioconsoles were among the audio prod-ucts offered to broadcasters.

Filmline Corp.

In keeping with the swing to colorfilm for local newscasts, Filmline wasshowing its professional 16 -mm colorfilm processor.

Fort Worth Tower Co., Inc.

Visual representations of towers forradio, TV, CATV, etc., and troposcatter antenna systems were includedin the display.

Gates Radio Co.

New consoles included the ModelM-6546 portable television audio con-sole with 12 mixing channels and threemaster or submaster channels, theDualax II for the AM/FM stereo/SCAbroadcaster, the Gatesway II, and theStereo Statesman. A line of FM trans-mitters, with outputs from 250 to20,000 watts, is based on the modelTE-1 solid-state exciter, in whichmodulation occurs at the carrier fre-quency. Also introduced was theDual -Cycloid circularly polarized FMantenna.

Three automatic programming sys-tems by the Automatic Tape ControlDivision of Gates were shown. Thesewere the "Automate 244," which ac-commodates 24 events from foursources; the "Automate 484" whichaccommodates 48 events; and the


"Automate 1007," which handles 1000events from seven sources.

General Electric Co.

A stage for live performances formedthe heart of demonstrations of thePE -250 live camera and other GEcolor equipment. The demonstrationsincluded various lighting effects (in-cluding a luminous backdrop bathedin black light), color moving againstcolor, and chroma keying. Also in thislarge exhibit was the TT -62-A 100 -kwUHF transmitter, which can be usedwith six sections of the TY-95-C an-tenna to develop 5 megawatts erp. TheModel BC -31T is a large, new audioconsole for television applications.Transmitter logging facilities and nu-merous other equipment items forboth broadcast and closed-circuit TVwere included in the exhibit.

In one corner of the area was ademonstration in which TV -antennaparameters were fed, by teletype, intoa distant computer center. The patternwas computed and printed out aspoints for a polar plot by the teletypeprinter.

A front projection system for colorTV, a product of Front ProjectionCorp., was demonstrated in the GEexhibit.

Gotham Audio Corp.

This booth was filled with audioequipment and devices. Among themwere: turntables, earphones, attenua-tors, Neumann condenser microphonesemploying FET circuitry, the EMT140st reverberation unit, EMT Vid-E-Dit electronic video tape editor andsplicer, the EMT 159 FM stereo faultalarm, EMT -160 microphone polaritytester, Eltro Mark II information ratechanger, and Gotham ME -101/102solid-state wow and flutter meters.

The Grass Valley Group, Inc.

Among the items on display were avideo insert keyer, color -lock equip-ment, and video processing equipment.

4$. 111111L ttnLftNr

NATIONAL ASSNIATIONOF

IWOADCASTERS

The Harwald Co.

Film -splicing equipment and sup-plies were shown, including the MarkX film editor with facilities for clean-ing, inspecting, and editing 16 -mmmotion -picture film.

Hewlett-Packard Co.

Test equipment included voltmeters,a square -wave generator, test oscilla-tors, an oscilloscope, a multimeter, awaveform monitor, a time -domain re-flectometer, an automatic distortionanalyzer, and a video monitor.

Houston Fearless Corp.

In this exhibit were the Colormasterfilm processor, and the PD -8 (studio)and PD -16 (field) pedestals for tele-vision cameras.

International Good Music

Automation systems for radio broad-cast stations were presented. In thegroup were the Models 362 and 363program loggers, Model 50-3 random -select memory, and the Series 500 andSeries 600 control systems.

International Nuclear Corp.

Model TMA2 video mixer, ModelTSC2 sync comparator, Model TDA7video distribution amplifier, ModelTVM2 video modulator, and othervideo processing and switching equip-ment shared the spotlight with theModel TS2 weather satellite processor.

Jampro Antenna Co.

Antennas for television (includingzig-zag and bat -wing types), FM, andinstructional television service wererepresented in the Jampro booth.

Jerrold Corp.

An extensive selection of CATVheadend and distribution equipmentwas shown by Jerrold, which stressedthe concept of "Total Turnkey Re-sponsibility."

Johnson Electronics, Inc.

Johnson -A ire solid-state equipmentfor the receiving function in multiplexSCA systems was displayed.

Kaiser -Cox Corp.

Another of the major manufacturersin the CATV field, Kaiser -Cox had anextensive display of equipment forcable -TV applications.

Klieg! Bros. Lighting

In addition to a line of quartz -iodineluminaires, a new preset plate for con-trol of studio lighting was a featureditem.

Lenkurt Electric Co., Inc.

The Type 76 and Type 75A micro-wave systems, and their uses in broad-cast applications, were featured in thisexhibit.

MaCarTa, Inc.

Tape -cartridge equipment, includingthe new Model 593 record/delay play-back unit, was shown. Rotary -maga-zine machines for tape cartridges, andracks for cartridge storage were amongother items and accessories in thebooth.

Marti Electronics

Audio and special systems, remote -pickup and automatic relay equipment,and 950 -MHz STL and intercity relaysystems were represented. Some indi-vidual items were: M -PRE -OP (phon-ograph) and M -PRE -OM (microphone)preamplifiers, AC -22 power supply,M-PGM-18 program amplifier, SCG41/67 subcarrier generator, RMC-1Cremote control consolette, RMC-2Aremote control system, and PA -1 150 -MHz remote -pickup antenna.

McCurdy Radio Industries, Inc.

A wide range of audio equipmentwas shown by this Canadian manu-facturer. Among the units on displaywere audio consoles, a single -channel

May, 1967 35

remote amplifier, and a four -channelremote amplifier.

McMartin Industries, Inc.

Frequency and modulation monitorsfor FM stations, and equipment forreceiving SCA multiplex transmissionswere well represented in this exhibit.A featured item was the Model LX -600 mixer -preamplifier.

Memorex Corp.

Type 78V tape, for use with high -band video tape recording systems,was shown by this manufacturer.

Microwave Associates, Inc.

Emphasis this year was placed onnew and diverse applications, such asairborne pickups, for the company'ssolid-state microwave equipment. Alsoshown were microwave components,including a 2.5-gHz transistor ampli-fier and a "Sugar -Cube" Series tunnel -diode amplifier for the 1.9-13.2 gHzrange.

D. B. Milliken Co.

The Model DBM-64A camera forvideo film recording was on displayin this exhibit.

Miratel Electronics Co.

Solid-state general-purpose videomonitors, solid-state professional black -and -white monitors, and color mon-itors were exhibited by Miratel.

3M Company

A full line of video tapes and ac-cessories was shown. Emphasis was onNo. 399 tape for high -band quadru-plex video recording.

Mole -Richardson Co.

Lighting equipment and accessoriesof interest to television broadcasterswere shown.

Moseley Associates, Inc.

Among the items on display werethese: Model SCS-1 8 -channel status/

control system, for a single wire lineor radio circuit; Model WRC-10T (forsingle DC control pair) and ModelPBR-21 (for single AC control pair orSTL) solid-state remote control sys-tems; Model SCG-4T all silicon solid-state SCA subcarrier generator; ModelPCL-303 all -solid-state aural STL; andModel ADP -101 automatic dataprinter for transmitter logging.

North American Philips Co., Inc.

Philips Broadcast Equipment Corp.,a newly formed subsidiary and succes-sor to the former Studio EquipmentDiv., maintained an extensive studiodemonstration area. Hourly demon-strations of the Norelco PC -70 colortelevision camera were centered aboutfour dancers who performed a panto-mime dance routine timed to a recordedsales presentation. The dance was de-signed to present in an attention -com-pelling manner the basic technical con-cepts behind the Norelco color camera;emphasis was placed, of course, on theabsence of a fourth tube. Fast -actionsequences and various lighting levelswere included in the routine to demon-strate the performance of the cameras.

In addition to the PC -70, on displaywas the Model EL -8530 color camera,for applications where a viewfinder isnot needed and light weight and re-mote -control capability are advanta-geous. Test equipment for both mono-chrome and color was also featured.In a nearby booth, CCTV equipment,microphones, and other items wereshown.

Nortronics Co., Inc.

This company presented its exten-sive line of replacement heads andhead -mounting devices for magnetictape recorders, both cartridge andreel-to-reel types.

Optical Imports

Optical products available from thecompany were represented in thisbooth.

Perfection Music, Inc.

Automated presentation of recordedmusic was demonstrated.

Power Optics, Inc.

A major item of the display was theServo -Pak, a control system designedfor use with all zoom lenses.

Q -Tv Sales 8, Distributing Corp.

Equipment included the "Q -Prompt-er," "Grafic" Q -Crawl (vertical move-ment), and "Q -Dispatcher" (horizontalmovement) moving -title machineswhich use tape with white -on -blacklettering prepared by the Q-Typer type-writer.

Quick -Set, Inc.

A number of tripods, dollies, pedes-tals, and heads for use with televisionand motion -picture cameras were ex-hibited.

Radio Corp. of America

The RCA Broadcast and Communi-cations Products Division maintainedstudio sets for demonstration of itslive color cameras. In addition to anew version of the TK-42 studio cam-era, the company introduced the TK-44, a camera designed for field use. Amodel football stadium was especiallylighted to show the performance ofthis camera in the presence of lateafternoon shadows. In addition to thelive cameras, two film islands usingTK-27 cameras were in operation.

Other video equipment included theTP-77 slide projector with 120 -slidecapacity; two new solid-state televisionswitchers, the TS -50 video distribu-tion switcher and the TS -51 produc-tion switcher-they mark the first useof integrated circuits in RCA videoswitchers; the solid-state TA -19 videoprocessing amplifier; and the TR-70high -band color TV tape system. Otheroperating RCA TV tape equipmentwas converted to high -band color withfield conversion kits.

The Type TTU-110A 110 -kw UHF


transmitter is designed for erp's up tofive megawatts (on channels 14 through50) in combination with pylon or panelantennas.

A full line of "Professional Televi-sion" equipment for closed-circuit andbroadcast ETV systems was shown.

Other items included monochromeTV cameras, FM transmitters, TV an-tennas, BFC circularly polarized FMantennas, and stereo cartridge systems.Audio equipment included the BN-26battery/AC remote amplifier, the BA -43 program amplifier, BA -45 AGCunit, BA -46 limiter, and BA -47 peakclipper.

In separate booths, the ElectronicComponents and Devices Division ex-hibited microphones, solid-state de-vices, camera tubes, and power tubes,while the Magnetic Products Divisiondisplayed its tape line in the mainexhibit.

Raytheon Co.

Dage television cameras and con-trol equipment were shown in additionto the Raytheon line of microwavesystems for STL, intercity relay, ETV,and other applications.

Reeves Soundcraft Div.,Reeves Industries, Inc.

Video tapes on display were Type303 for high -band color recording, andType 302 for monochrome use.

Riker Video Industries, Inc.

Some of the items from this com-pany's full line of video and test equip-ment were: the Model 5619 Colorizer,for adding several color effects tomonochrome transmissions; an En-coded Color Keyer; a color encoder;and a Title Inserter for adding titleswith white letters and black borderor black letters and and white border.An audio mixer and video special -effects equipment were also shown.

Rohde & Schwarz Sales Co. (U.S.A.), Inc.

Items from this company's range of

test equipment for television systems,including its new Type UPSF videonoise meter, were to be seen in thebooth.

Rohn Systems, Inc.

Information was available concern-ing towers, microwave reflectors, towerlighting equipment, and accessoriesfor AM, FM, TV, CATV, and com-munications uses.

Rust Corp. of America

Highlights of this exhibit included:the Model RC -2400D (single DC pair)and Model RC -2400F (microwave/voice line) push-button remote -controlsystems in which control is achievedby coded -pulse -width signals; dial -op-erated video/audio remote switchingsystems; and a new strip recorder forthe company's transmitter logger -24hours of recorded readings can be seensimultaneously.

Sarkes Tarzian, Inc.

Regular demonstrations of the com-pany's color -camera chains were givenin the Tarzian display area. Live mod-els performed in two colorful sets toshow live -camera performance, andcolor film chains also were in opera-tion. In addition to the cameras, thisexhibit included solid-state microwaveequipment and the APT 1000C com-puter programmer.

Schafer Electronics

Switching and program automationequipment was highlighted by a com-plete, operating stereo tape system.

Seeburg Music Library, Inc.

Model SABMC-2 disc automaticbackground music equipment, and anautomatic stereo music center wereshown.

Shibaden Corp. of America

The Model SV-700U video taperecorder, Model VS -100 video tape

splicer, and Model FP -107 televisioncamera were in this booth.

Shure Brothers, Inc.

A number of professional audioproducts were included in this display.Among them were microphones,phonograph cartridges, tone arms, anda microphone mixer.

Sony Corp. of America

Video tape recorders for broadcastand other applications were includedin this display. along with color adap-ters and electronic editing devices foruse with the company's VTR's.

Sparta Electronic Corp.

Reel-to-reel and cartridge tapeequipment, audio consoles, and turn-tables were presented, along with Vegawireless microphones and solid-statecompressor/limiters. One highlight ofthis booth was the introduction of theTeac Series R-310 professional taperecorder, available in mono and stereoconfigurations.

Standard Electronics Corp.

Highlights of the exhibit included aVHF television transmitter (output 5kw visual, 1 kw aural) that employsseveral transistor stages; other itemswere an FM transmitter and auxiliaryequipment for TV and FM.

Studio Television Products Sales Corp.

A balanced camera pedestal waspresented in this company's booth.

Sylvania Electric Products, Inc.

Sylvania's array of equipment in-cluded tungsten halogen lamps; tele-vision cameras, for both live and filmapplications; a video control console;and a helical -scan video tape recorder.

Tape-Athon Corp.

Audio automation equipment usingmagnetic tape as the program sourcewas exhibited.

May, 1967 39

Tapecaster Electronics

Solid-state tape -cartridge equipmentfor use by broadcast stations wasfeatured.

Tektronix, Inc.

Oscilloscopes and related productsincluded the Model 453 oscilloscope,Model 549 storage oscilloscope, Model1S2 time -domain reflectometer, andtelevision waveform monitors.

Tele-Beam Div., The Kalart Co., Inc.

The Tele-Beam large -screen tele-vision projector, and a Kalart/ Victor16 -mm motion -picture projector werein operation in this booth.

Telecontrol Corp.

This exhibit was centered aroundthe Unicon automatic controller fortelevision programming. This equip-ment incorporates a magnetic corememory.

Telemet Co.

Among the items in this booth weretest signal generators, processing am-plifiers, clamper amplifiers, video andpulse distribution amplifiers, syn-chronizing generators, special -effectsgenerators, color -bar generators, colorstandards, monitors, encoders, andsubcarrier regenerators.

Telequip Corp.

Items from Telequip's line of tripodsand heads for TV cameras, reels forelectrical cable, and television light-ing equipment were featured.

Telesync Corp.

Horizontal and vertical crawls forblack -and -white and color, conversionsfor color slide projection, and promp-ter mounts for color cameras wereamong the products shown.

Television Zoomar Co.

Highlights here were the News -breaker 400 automatic color -film proc-

essor, a zoom -lens drive (providingzoom and focus controls) for the GEPE -250 camera, and the Gardner TVColor Guard.

The Telex Corp., Magnecord Div.

Magnecord tape recorders, ear-phones, and other acoustic productswere exhibited by this manufacturer.

Tiffin Scenic Studios, Inc.

Cycloramas and related products foruse in television studios were on view.

Toshiba America, Inc.

Video switching equipment and theModel IK-37 color television camerawere available for examination.

Townsend Associates, Inc.

Transmitters for FM and UHF tele-vision broadcast were featured. TVequipment included Model TA-55BT55 -kw UHF transmitter, Model TA-lOBT 10 -kw UHF transmitter, andModel TA -1000 TLA 1 -kw translatoramplifier.

Tracor, Inc.

Equipment for synchronization oftelevision signals from different sourceswas featured in this company's ex-hibit.

Trompeter Electronics, Inc.

A selection of items from theTrompeter line of connectors, patch-ing systems, switches, and matrixeswas shown.

Utility Tower Co.

Base insulators, operating towerlights, and sample sections of towersin several sizes were in evidence inthe Utility booth.

Varian Associates

Eimac power tubes, Microlink 2500 -MHz Instructional Television equip-ment, and master -antenna distributionequipment were displayed.

Viking Industries, Inc.

Turnkey systems were featured inaddition to an extensive line of equip-ment for CATV applications.

Visual Electronics Corp.

Adjacent to the Norelco color studiowas Visual's large display of equip-ment for television and radio.

The new Fernseh flying -spot scan-ner for color or monochrome moving -picture film was shown; the machineadvances each frame, during the verti-cal blanking interval, by pneumaticaction rather than with a claw mecha-nism. A companion slide scanner alsowas shown.

New production units of the Visual/Allen high -band color video tape re-corder line, Models V/A 100 andV/A 50, were presented; these fea-tured state-of-the-art electronics anda precision video head and transportmechanism. Also stressed, in the post -Convention seminar, was the Visual/Allen rebuilding program for con-verting existing recorders to high -band operation.

In the area of video switching, theLS -18 switching system was intro-duced; the system provides for tennoncomposite and eight separatecomposite inputs. Also introduced wasan added facility for the VAT thumb -wheel preselection system: event dura-tion can now be preset into the sys-tem in addition to the video source,audio source, and transition. Anothernew system was the VS/AS-12, a 12 x1 solid-state video and audio switchingsystem.

Many other items of interest totelevision broadcasters were included.A line of ELCON matched color tubescame from English Electric Valve,Ltd. Solari digital clocks were repre-sented, along with AC -operated Tele-indicator digital display modules forthe display of election returns, sportsscores, etc. The Visual/VideographModel 990 character generator per -


forms digital to video conversion of64 different alphanumeric and specialcharacters; the techniques employedin this generator are all -electronic,making use of integrated circuitry.

Radio equipment included the newModel AM -50K -A 50 -kw transmitterand the Model AM -1K -A 1 -kw unit.The FM line featured a new 10 -wattsolid-state direct FM exciter, theModel DFM-3K-A 3000 -watt trans-mitter, and the Model DFM-20K-B20 -kw transmitter.

Vital Industries

The Model VI -1000 solid-state proc-essing amplifier incorporates auto-mated features, including automaticcorrection of a number of common

Part 2

faults in television video signals. Otherequipment on display included a colorstabilizing amplifier and video andpulse distribution amplifiers.

Vitro Electronics

Nems-Clarke equipment includedthe Type 112 solid-state phase moni-tor, Model HFM harmonic field -in-tensity meter (1.6 to 5 MHz), the solid-state Model FIM-135 field -intensitymeter for the 540 to 1600 kHz band,and stainless -steel patching equipmentfor video and RF applications.

Ward Electronic Industries

A new TV switcher, Model TS -206,utilizing a solid-state double re-entrysystem was presented. Other equipment

included a TV station -break program-mer, transmitter demodulator, trans-mitter phase equalizer, audio consoles,audio amplifiers, and intercom sys-tems

Wilkinson Electronics, Inc.

Transmitters included the FM20000D 20 -kw FM model and theAM3 3000/1000 -watt AM unit.Other featured items included the S-lAline -surge protectors, Model 4N1 field -intensity meter, TAC-1B solid-stateaudio console, ARF-1A RF amplifier,AMM-1A AM modulation monitor,TAGC-1 solid-state AGC amplifier,FM -10D FM exciter, SG -1D stereogenerator. and replacement siliconrectifiers.

Highlights of the Technical Sessions

For broadcast engineers, the radio/television technicalsessions are the heart of each NAB Convention. The exten-sive displays and demonstrations, the "hospitality" suites,and the opportunity to get together with old friends, thougha part of the show, are for the most part of transistoryvalue. The real reason we gather in a distant city andspend a dozen hours a day on our feet is, hopefully, tofind concepts, techniques, or equipment that will makebroadcast operations more efficient or easier to maintain.

While no technical conference could, in its entirety,provide everything each engineer needs, some part of thepresentation interests almost everyone. This 21st Engineer-ing Conference had no spectacular, industry -revolution-izing breakthroughs, but no one who attended the threedays of technical sessions could have come away entirelyemptyhanded.

Monday, April 3Radio/Television Session

The first technical meeting was called to order bychairman James D. Parker, CBS -TV, New York, who in-troduced NAB president Vincent T. Wasilewski. The NABPresident welcomed all engineers to the 45th Annual Con-vention and recalled the significant contributions madeby the Engineering Conference to the health and wealthof the broadcasting industry. He gave particular weightto the establishment of the NAB Engineering Seminarsheld in 1965 and 1966 at Purdue University and announcedthe Third Annual Seminar, to be held during November1967. Purdue once again will host the meeting, under thedirection of NAB Vice -President and Director of Engineer-ing George W. Bartlett.

Before the technical papers were presented, reportsfrom two NAB Engineering Advisory Committees weregiven. Clure Owen, ABC, New York, session coordinator,told of the FCC denial of NAB's petition requesting rulemaking for remote control of VHF transmitters. (Furthercomment on this topic is given in the report on the Wednes-day technical session.) He also commented on NAB re-action to FCC Docket 13598 concerning sharing of VHFchannels 2 through 13 with the land mobile service. TheNAB Advisory Conrunittee reviewed all exhibits presented

by proponents of the measure and concluded that suchsharing was not feasible. The Commission was informedof these findings. FCC tests to determine what interferencemight occur under such sharing will be conducted soonon channel 6 in Washington, D.C. and channel 8 in LosAngeles, Calif.

The Advisory Committee also petitioned the FCC againstthe 10 -kw reliability requirements for remote control. FCCaction followed, and a rule change was filed.

In another petition, the FCC was told of NAB opposi-tion to the 2 -hour inspection requirement for phase meas-urements on directional antennas. NAB recommendedthat such measurements be made during normal engineer-ing procedures, and the Commission has the commentunder consideration.

Plans also were announced for publication of a newSixth Edition of the time-honored NAB Engineering Hand-book.

The second committee report was from the AdvisorySubcommittee on Loudness. John T. Wilner, Hearst Corp.,Baltimore, Md. read the report which dealt with NABefforts to provide means and procedures to assist broad-casters in complying with the FCC statement of policyon loudness (dated July 12, 1965). NAB guidelines aredescribed in two tutorial papers on automatic audio -levelcontrol, and implemented with standard -loudness tapes,ET's, films, and video tapes. This material is, or soon willbe, available from NAB Engineering Division offices.

Loudness Meter

In the first of the technical papers, Benjamin B. Bauer,CBS Laboratories, Stamford, Conn., described the signifi-cant work performed in developing an effective equal -loud-ness contour for the design of a loudness monitor. Thecontour of the CBS -developed curve lies between that ofthe established Fletcher -Munson 70-phon contour and theCBS Labs 70-phon octave -band contours for noise. In-formation for the design of the new loudness contour wasobtained through a psychoacoustic testing program using aselected panel of listeners who made thousands of sound -level comparisons against standard volumes in a controlledenvironment.

Effectivness of the monitor (calibrated in Loudness Units-LU's-, rather than Volume Units-VU's) is supported

May, 1967 41

by the fact that its readings correspond within 1 dB tothose determined by the subjective analysis of the psycho-acoustic panelists. In other words, the loudness monitorresponds objectively, within 1 dB, to the same soundsobserved subjectively by a panel of listeners.

The monitor is a fairly complex instrument which splitsthe audio spectrum into eight separate bands through theuse of filters. Each band of frequencies is processed inaccordance with the newly developed CBS loudness con-tour for that band, and then the bands are recombinedinto a single waveband. A ballistic network, to compensatefor the manner in which the meter needle responds tosignals of differing frequency and duration, is located be-tween the signal -processing network and the meter itself.This ballistic compensator produces an attack time of 0.1sec and a decay time of 0.5 sec. The effect of the com-posite circuitry very closely approximates the overall re-sponse to loudness of the average human ear in typicallistening environments.

The loudness monitor is now available for field testing,and work is progressing satisfactorily on a companionloudness controller to guard automatically against loudnessvariations in program material from various sources andwith different kinds of "enhancement" and other signalprocessing applied.

Demonstration tapes played during the presentation ofthe paper showed excellent results, especially consideringthe deviation in the convention hall from recommendedenviromental conditions for "average" listening.

EBS System Activities

This paper, prepared by Arthur Barriault and presentedby W. Elmer Pothen of the National Industry AdvisoryCommittee, was nontechnical. Mr. Pothen described workdone by NIAC in cooperation with various governmentalagencies and the military to set up and operate the systemwhich, in time of national disaster, must go into effectautomatically. He described methods of implementing re-quirements of the EBS and encouraged cooperation ofall engineers in working out compliance with the operatingrules established for the system.

VHF Radiation -PatternMeasurements by Helicopter

Kear & Kennedy, Consulting Engineers, prepared apaper on determining radiation patterns in both verticaland horizontal planes by making measurements from ahelicopter. The ability of the rotary -wing aircraft to risevertically over a check point on the ground and to flyslowly over a circular route to ensure an accurate pathmakes it particularly suited to this purpose. Neil M. Smithof Kear & Kennedy presented the results of several pat-terns measured in this manner.

For most measurements, K & K mounted a Nems-ClarkeModel 107 field -intensity meter and an Esterline-Anguschart recorder in the aircraft. The equipment was poweredby a storage battery mounted in the luggage section. Astandard dipole was used for most measurements, and it wasmounted on a mast capable of being lowered into positionaway from the craft during flight.

Based on considerations of transmitting antenna aper-ture, radius distance measurement errors, altitude measure-ment errors, possible radiation hazards, and ground re-flections, most analyses were made using a radius of ap-proximately 1.5 miles. Altitudes generally were the mini-mum required by the FAA.

To provide several sets of data for averaging out meas-urement errors, three to four flights were made over thecircular path in each direction. The permanent recordobtained on the chart recorder was analyzed to give specific

field -intensity figures for each azimuth reference. This in-formation then was averaged for all runs and plotted toobtain a final pattern chart.

Measurements made at WNDT, channel 13, Newark,N. J., WPIX, channel 11, New York, WPRO-TV, chan-nel 12, Providence, R. I., and WCBS-TV, channel 2, NewYork, have provided highly satisfactory measurements ofboth horizontal and vertical patterns. Best results were ob-tained at the high -band frequencies, but even low -bandchannels permitted measurements better than had beenobtained using conventional ground -based measurementtechniques.

Similar helicopter -airborne measurement techniques alsohave been used to select sites for head -end equipment forCATV systems. Sites selected in this manner have provedto be quite satisfactory.

IC's for the Broadcaster

R. N. Hurst, of RCA, gave an interesting view intowhat broadcast engineers soon will be seeing in newequipment designs using integrated circuits. He also pre-sented several examples of how modern solid-state tech-nology has progressed in a very few years from simplediodes to complex multiple -component circuits in a singleTO -5 transistor case.

To give an example of how solid-state electronics hasaffected the design of equipment for broadcasters, Mr.Hurst pointed out that a vacuum -tube version of RCA'slatest video recorder would require at least 14 six-footracks of equipment. The new tape unit, the TR-70, isroughly 3' x 5' x 5'. IC's most likely will result in equip-ment of greater capabilities and sophistication rather thanin smaller equipment, according to M. Hurst.

Most of this paper was concerned with manufacturingand design features of IC's, rather than with equipmentor circuit applications. For many of the engineers in thistechnical session, this was their first introduction to themarvelous, almost magical, world of fabricating siliconchips into functioning electronic circuits.

In making a final educated guess about what mightfollow IC's, the RCA engineer suggested that large-scaleintegration (LSI) would probably lead into molecular elec-tronics. In this area of circuit miniaturization, all theelectronic circuitry for an entire camera or sync generatormight be contained on a single silicon chip, one not muchlarger than a postage stamp. Once we get over the shockof ". . . dropping a faulty sync generator into the nearestwastebasket and plugging in another one, LSI couldchange the industry even more radically than the transistordid," according to Mr. Hurst.

Tuesday, April 4Radio Session

A troublesome engineering problem, several new itemsof equipment, and a discussion of standby power sourceswere the subjects of this session. William S. Duttera, NBCNew York, was session coordinator, and Leslie S. Learned,MBS New York, presided.

Spurious Signals in Radio

That spurious signals can be a problem to both AMand FM broadcasters was made evident by the first twopapers. First, Fred L. Zellner, of ABC New York, re-lated experience with low -frequency signals generated bybeats of the signal of WABC (770 kHz) with those of WINS(1010 kHz) and WHN (1050 kHz). The beats were foundto be originating in the final stages of the WABC 10 -kw and50 -kw transmitters, and the solution to the problem was toinstall a bandpass filter between the transmitter and the


antenna. A passband of 250 kHz centered on 770 kHz waschosen, and a three -section filter was used together with amatching network. Following adjustment, field measure-ments showed the spurious signals to be in the noise levelwhen either transmitter was operated at full output.

Eldon Kanago, of KICD, Spencer, Iowa, showed thatspurious signals can be even more troublesome-anddifficult to eliminate-when the FM band is considered.The problem here is largely one of harmonic interferenceto high -channel VHF television stations and to aviationcommunications and navigation systems. Case historieswere given to show how interference problems can arise:Preamplifiers for TV receivers clipped a strong FM signal,producing a square -wave signal rich in second -harmonicenergy (solution: change the FM -station frequency);spurious outputs originated in the final -tube socket of theFM transmitter; a station's AM and FM transmitters pro-duced a beat in the aviation band (solution: better shieldingand grounding to prevent mixing in the FM exciter); othercases showed an increase of spurious outputs as the finaltubes aged.

The speaker stated that the problem is serious, and itwill get worse. He observed that better airborne equipmentwould help the aircraft situation and pointed out fourmajor problem areas: A greater number of better engineersare needed at stations; better assignment of frequencieswould avoid many problems; better shielding and groundingat the stations are needed; and, perhaps most important,better understanding and communication among the FCC,FAA, stations, and manufacturers is essential.

Fault Alarm for FM Stereo

Stephen F. Temmer, of Gotham Audio Corp., nextdescribed equipment for detecting and warning of faults inFM stereo transmissions. The equipment, known as theEMT -159, detects total loss of modulation, loss of rightchannel, loss of left channel, loss of difference signal, andreversal of polarity of one channel. With the aid of slides,Mr. Temmer explained the circuit operation for eachfunction. Readout is by means of indicator lamps, andexternal relays may be connected in series with the lamps ifdesired. Prolonged or repeated failures must, of course, beverified by the operator, but the system is intended to makeunnecessary continuous subjective monitoring of the stereosignal, which can be both costly and tiring.

Automation From Program Through BillingJ. L. Smith, of Collins Radio Co., discussed the use of

automation in the programming, equipment operation, andaccounting phases of station operation. He hastened to pointout, however, that automation is not a panacea, nor does itrelieve the broadcaster of his responsibilities; it is instead atool with which to do a better job.

The operation of an "automatic" radio station wasdescribed. Sales, promotion, and community -relations func-tions must be done "manually," but sales information canbe entered into the system data storage, for example inthe form of punched cards. This information, combinedwith the program information, is interpreted by the auto-matic programmer, which puts the desired program ma-terial on the air and logs it. The punched cards are thenstored for use in billing and bookkeeping.

The automatic program equipment must be capable ofmaintaining the station image, be familiar to the broad-caster, and be priced within his budget. Different degreesof program automation are possible. First, there is "total"automation, the so-called "background sound." This canbe modified by the addition of periods of manual operationto give "fractional" automation. A type of "tailored" auto-mation uses prerecorded intros, etc., on a "tie-in" tape cor-

related with the music tape. This system gives most of theadvantages of full-time personalities with part-time an-nouncers, but it involves more effort and requires care inmaintaining the proper tape sequences. A fourth possibilityis the use of an external source (network or program serv-ice) with local insertions controlled from the externalsource.

All of this leads to the heart of the paper, the automatic,self -monitoring transmitter plant. As envisioned, the mon-itoring system would sense the important parameters at twolevels, an alarm level which would signal station personnelthat an out -of -tolerance condition is approaching and re-medial action is needed, and a second level at which thetransmitter is automatically shut down. A three -time re-cycling feature would be incorporated to allow for transientout -of -tolerance conditions. Override provisions and a fault -location display would be included for maintenance andtroubleshooting purposes. Alarms would be located at thetransmitter and at the point where the maintenance man islocated.

A block diagram of a self -monitoring FM station wasshown. A load -power monitor was added to the transmitterto control power output; control of modulation and meansfor detecting distortion were included. One interestingaspect of this operation would be the lack of need for anoperating log; only the carrier on and off times would belogged (automatically).

Before the fully automatic radio station becomes areality, much work remains: some types of equipment stillare needed, some definitions need to be made, and FCCapproval must be secured. (In the case of FM stations,Collins has applied for the latter.) Mr. Smith concluded hisremarks by asking for comments from broadcasters.

Circular Polarization for FMA paper describing one approach to the design of circu-

larly polarized FM antennas was presented by Dr. MattiS. Siukola, of RCA. A vertical component of radiation isdesirable because of the increasing use of automobile -mounted and other vertical receiving antennas.

The speaker first listed some of the drawbacks of dual -polarized antennas (as opposed to circularly polarizedtypes). Dual types are more complex and expensive, andtheir use may be restricted by the physical capabilities ofan existing tower. In addition, the horizontal and verticalportions have different radiating centers, so the verticaland horizontal radiation components may arrive at thereceiving antenna with other than an optimum phaserelationship. If the signals are in oblique phase, ellipticalpolarization results, and the position of the receiving an-tenna determines the amount of signal received. If thesignals are in phase, linear polarization at 45° results; anantenna oriented at 135° theoretically would receive nosignal. For a 90° phase difference, and a 1:1 "axis ratio,"however, the orientation of the receiving antenna makesno difference, so long as it is perpendicular to the direc-tion of radiation.

The derivation of RCA's circularly polarized antennafrom two dipoles at right angles was shown. The result wastwo half -wave dipoles, formed into one -turn helices andinterlaced. A one-sided delta -match is used as a feed, andno balun is required; a variable input transformer is pro-vided for a 1.1 VSWR. The elements are welded to a back-bone, and the entire assembly is pressurized. High currentthrough the elements provides a de-icing capability.

The antennas may be stacked. Gain can be statedtwo ways: with respect to input power at one polarization,gains correspond to those of other antennas; with respect tototal input, the gain is approximately one-half as great.Power handling capability is 10 kw per layer.

May, 1967 43

On -Carrier Direct FM

A new Gates Radio Co. FM exciter was the subject of apaper by Hardin G. Stratman. This is a solid-state unit, inwhich direct frequency modulation of the oscillator takesplace at carrier frequency; no multiplication is used. Theentire oscillator circuit is enclosed in a shock -mountedoven, and the mono or composite stereo input is appliedto the bases of the oscillator transistors. Two diodes (volt-age -variable capacitors) act as frequency -control elements;SCA input is applied to these diodes through an isolationnetwork. These separate program and SCA feeds are usedto reduce crosstalk.

AFC is accomplished by comparing the output signalwith the third harmonic of a reference crystal oscillator.The 200-kKz beat -frequency signal is processed through achain of circuits which produces a train of equal -width pulses for application to an AC -DC converter; theconverter provides the correction voltage.

The stero generator uses a linear balanced modulator, anda crystal oscillator is the 19 -kHz source. The subchannelsecond harmonic is fed back into the circuit 180° out ofphase to reduce crosstalk. Oscillators at 941 and 967 kHzare beat with a 900 -kHz oscillator to produce the SCAsubcarriers. SCA muting is provided.

Modular construction is used in the exciter, and cablesare provided so that modules can be operated out of thecabinet. The cabinet is supplied wired for SCA and stereo,and these modules may be added at any time.

Emergency Power System

The subject of emergency power sources has alwaysbeen important to broadcasters, but interest seems to haveincreased in the last few years. James J. Strathmann, ofCummins Engine Co., delivered a talk on this subject.

The speaker observed that the broadcast industry hascreated a need for reliable continuity of information,especially in emergencies, and the industry is better pre-pared than most to cope with power emergencies. He saidthat 1965 was the year that standby power became popular(there were ten major failures that year). Some states haveenacted laws regarding standby power.

In general, three types of systems are available: A fullyautomatic system can be in service in five to ten secondsafter sensing a failure; such a system would be used, for ex-ample, at an unmanned transmitter site. A semi -automaticsystem is less costly; it starts automatically, but the loadmust be transferred manually. For many applications,however, a manual system is adequate even though start-ing and load transfer may require from two to ten minutes.

Cost is usually one deciding factor in selecting a genera-torset, but other factors relating to dependability must beconsidered as well. It was recommended that the buyer setup performance specifications (NEMA generator specs canbe used as a minimum) and consult with several suppliersbefore buying. A key decision is choosing a qualified sup-plier; factors to consider are location, facilities, qualifiedmechanics, parts inventory, field service, and sales per-sonnel (they will be your advisers).

Some comments about operating and maintaining gen-erator sets should be of interest: Be careful of freezing ofthe coolant. As a starting aid, keep the coolant heated;combustion is better and lubricants flow more quickly andeasily. Fuel should be replaced (through use) every six totwelve months. The system should be exercised under load-a no-load test is almost meaningless. The equipmentshould be inspected annually by qualified personnel.

The speaker touched on some of the differences amongengines, fuels, etc. However, he stressed this advice forprospective purchasers of standby power equipment: Con-

sult several suppliers, and then decide what equipment (andwhich supplier) will best meet your needs.

Television Session

This meeting covered several topics of interest to TVengineers, from million -dollar mobile studios to test filmsand slides. The session was coordinated by Dick F. Engh,KTNT AM -FM -TV, Tacoma, Wash., and presided overby Robert W. Flanders, WFBM Stations, Indianapolis, Ind.

Designing Mobile Units for Color

Faced with increased demands for mobile TV produc-tion in color, the three major networks have undertakenextensive design, development, and construction projects toprovide comprehensive mobile capability. Costs range to$1 million or more per system and, as for the twin -unitABC studios, weights can be as much as 60,000 pounds perunit. Typical size of these new -generation behemoths is:length, 50 ft; width, 8 ft; height, 12 ft, 6 in.

Panelists for this presentation were representativesfrom all three major networks and an independent station:

James R. Baker, ABC-TV, New York, N. Y.Robert Zagoren, CBS -TV, New York, N. Y.Allen Walsh, NBC-TV, New York, N. Y.Charles Blair, WJZ-TV, Baltimore, Md.

John T. Wilner, Hearst Corp., Baltimore, served as moder-ator.

While individual differences, too numerous to evaluate ina brief report, were obvious in the course of the descrip-tions given by the speakers, all mobile studios were char-acterized by extraordinary complexity. Each of the sys-tems, including even the independent station's unit, ex-ceeded in many ways the comprehensive facilities of apermanent production studio.

One area of fundamental difference in concept led ABCand NBC to choose a tractor/trailer combination for eachof their two -unit mobile studios, while CBS and WJZchose self -powered van -type chassis. CBS, like its networkcompetitors, required two units to contain the equipmentand support subsystems, while WJZ, through lesser equip-ment requirements, managed to house necessary items ina single van. All units carry comprehensive environmentalconditioning units, including air conditioning, heating,humidity control, and electrostatic dust precipitators.

All engineers presenting papers during this meeting an-nounced their willingness to make available their observa-tions and findings to engineers undertaking major mobile -

studio construction projects for color production.

Color-Newsfilm Handling

Sigmund Bajak, NBC New York, described the exper-ience of the NBC news department in switching to the useof color film for all hard -news coverage. He related earlyuse of Eastman type 7255 color film, and the final choice,when it became available, of improved -type 7258 sound-striped color emulsion. With good fundamental film speed(tungsten 125, daylight 80 with Wratten No. 85 filter) anda useful forced -processing speed increase of three fullstops, the single emulsion gives the desired capability forshooting almost all possible assignments.

Mr. Bajak also noted the necessity of providing supple-mental 3200° Kelvin quartz -iodine lighting units in thekits carried by newsfilm cameramen. NBC also recom-mends that their film teams always provide the requiredcolor balance (3200° K) through the use of set-up lighting,rather than use filters to compensate for other tungstenlighting or fluorescent lighting.

Other procedures required by the switch to color filmwere added refrigerated storage for film, modification of


film -path rollers and guides in the Auricon cameras usedfor sound filming, and constant review of color -film qualityto maintain the exposure values necessary for high-fidelitycolor newsfilm.

Color & Brightness Contrasts in TV Production

The Operations Department of CBS -TV, New York, hasproduced two outstanding color films for their productionand creative people. These films, "Color and BrightnessContrasts" and "Color By Design," present in highly un-derstandable terms reasons why filming in color for use inTV is different from filming for theater presentation.

The first film, on the two different types of contrast-color contrast and brightness contrast-clearly demon-strated the effects and control of these important funda-mental concepts. Pure white, for example, never shouldbe used in color sets or in costumes, or the brightness -range (20:1) capability of film and equipment will be ex-ceeded. Maximum brightness of "TV White" should notexceed a reflectance of 60 percent. The film also demon-strates the effects of improper color use. Color disharmony,lack of color contrast, use of too much color, or failureto use color accents all adversely affect the end -result TVpicture.

The second film showed the difference in how cameras(TV or film) see color and how people see color as theyexpect to see it-the subjective response. Necessary use ofmakeup, for both men and women, was demonstrated.Proper selection of fabric types (lames, brocades, silks arebetter than velvets and velours, as a rule) also was covered.

The two films were presented in person by the film nar-rator, E. Carlton Winckler, CBS -TV, New York.

SMPTE Color TV Reference Test Film

Those unable to view the excellent CBS films describedabove will, when production prints become available thisSummer from SMPTE, be able to purchase for their ownuse a test film which does in a less polished, but equallyeffective, way what the CBS films do. John M. Waner,SMPTE, New York, showed the film soon to be suppliedto TV stations as a standard color -film reference for equip-ment setup and production comparisons. Varied lightingsituations demonstrate the brightness and color -contrastparameters of color films for TV use. Color problems inharmony and accent also are described. These films, ac-cording to Mr. Waner, should be available from SMPTEby the middle of the summer. A series of slides to assistin equipment set-up and evaluation also will be available.The full program will be described in a forthcoming issueof the SMPTE Journal.

New Developments in Color Cameras-Image Isocon

In related papers, Robert L. VanAsselt and Dr. H. N.Kozanowski, of RCA, presented information on an image -

orthicon type camera tube with a greatly improved signal-to-noise figure. Although it is not a new tube in concept,recent development of new electronic/optical techniqueshas made production of the type feasible.

In describing the image isocon, Mr. VanAsselt says, "Theimage isocon has the same image section as an imageorthicon. The essential difference between the two tubesis in the scanning section. To discuss this difference it isnecessary to recognize two kinds of electrons in the returnbeam. These two classes of electrons originate at the target.When an electron in the primary beam approaches thetarget, one of three events occurs: The electron may notquite reach the target and be specularly reflected; the elec-tron may strike the target with finite energy and be scat-tered; or the electron may enter the target and neutralize a

positive charge. Thus, the return beam consists of twocomponents, the reflected electrons and the scatteredelectrons. In the image orthicon, the entire return beam isdirected into the multiplier. In the image isocon, the re-turn beam is split, and only scattered electrons are directedinto the multiplier."

The result of this fundamental difference gives the imageisocon tube the following characteristics: The signal-to-noise ratio is superior to an equivalent IO; beam setting isless critical than for an IO; there is very low noise in theblacks, permitting required gamma correction with smalladded noise; and resolution, sensitivity, and knee character-istic are very similar to the IO.

Following Mr. Van Asselt's description of the tubecharacteristics, Dr. Kozanowski described the RCA TK44 camera, a color camera intended primarily for outdooror remote TV pickup. The camera uses a 3 -inch imageisocon in the luminance channel of the four -tube circuit.The chroma tubes are vidicon types, which will be avail-able with lead -oxide surfaces to attain improved sensitivity.

The TK 44 is said to have an exposure characteristiccompletely linear from black to the knee, beyond whichthe signal rises only very slowly with increased light.

An operator of the new camera is required only to aimand focus the lens. All other set-up adjustments which arenot automatic or completely regulated and preset are madeby the camera -control operator.

Color -Image Enhancement Techniques

In the final paper of this technical session, Charles E.Spicer, of Visual Electronics Corp., described a method ofcompensation for the image -softening horizontal- and vert-ical waveform rounding common to all camera tubes as aresult of aperture distortion. By the use of delay lines andfilters, the contours of the horizontal and vertical wave-forms are reshaped to provide sharply defined waveformedges.

In a color system, to obtain control of the contourbeing enhanced, the contour may be taken from the greenchannel within the camera itself. This approach takesmaximum advantage of the fact that the signal-to-noiseratio of the green channel is significantly lower than thatof the red and blue channels or the matrixed signal. Thegreen contour also can be matrixed, after enhancement,into the red and blue channels before encoding. The effectof misregistration in the red and blue channels is thenreduced.

"Contour -out -of -green" enhancement, then, uses verti-cal and horizontal aperture corrections integrated into athree -tube color camera. It achieves reduced noise andprovides increased sharpness in the color signal. There alsois increased tolerance to misregistration of the three colorimages.

Wednesday, April 5Radio/Television Session

The final meeting of the 21st Annual Engineering Con-ference was held Wednesday morning. Glenn G. Boundy,Storer Broadcasting, Miami Beach, Fla., presided; JamesD. Parker CBS -TV, New York, was session coordinator.

Maintaining Video -Tape Program Quality

In the first paper of this session, Charles E. Anderson,of Ampex Corp., offered a straightforward program de-signed to help engineers get the most from their video-taperecording and playback equipment. Referring to video-tape

Please turn to page 55

May, 1967 45

Introducing the...

CHROM I NANCE

TEST GENERATOR(20T PULSE)

BY TELEMET

Model 3522 -Al

Recently devised method for measuringchrominance delay with respect to luminance.

Resolution accuracy within 10 nanosecondsread from calibrated dial.

E Matching receiver Model 3525 -Alavailable for remote readings.

'TELEMET COMPANYS 185 DIXON AVE., AMITYVILLE, NEW YORK 11701 PHONE (516) 541-3600



"New York's Great NewSound is WNEW-FM-'Where The Girls Are'backed up by ourScully 280's."

MAX WEINERChief Engineer

WNEW, New York

WNEW-FM is only one of a growing parade of broad-casters who specify SCULLY recording equipmentbecause its superior performance is proven by thetoughest test of all; the daily grind of schedules thatmust be met without a hitch. SCULLY offers thefinest solid-state instrumentation available plusexclusive plug-in construction . . . for minimumdown -time, fast, easy repair when necessary, nocomplicated wiring disconnects or desoldering.Relays, modular sub -assemblies, electronic chassissolid-state amplifiers are all plug in. WNEW has4 more coming.

'Seven Scully units in our FM controlrooms give our recording crew the pre-cision, flexibility and operational easethey demand."

Alison Steele, one of the three glam-our gals who make the new soundon WNEW-FM 14 hours daily.

Mr. Weiner, left, demon-strates Scully 280's to Pro-gram Director John Dale.

SCULLY RECORDING INSTRUMENTS CORPORATION480 BUNNELL STREET, BRIDGEPORT, CONN. 06607 TEL. (203) 335-5146

Makers of the renowned Scully Lathe, since 1919 symbol of precision in the recording industry.


May, 196747

It's lovely to look at, delightful to hold . . . and ruggedas can be! Small wonder that Shure's new SM60omnidirectional dynamic microphone was an instantsuccess with both producers and engineers in advancefield and studio tests and on subsequent programswith requirements as divergent as outdoor footballtelecasts and posh variety shows.There are at least four big reasons why:BEAUTY: Lustrous, non -glare matte metallic finish,classic simplicity of line, and tailored -to -the -hand di-mensions add up to stunning good looks and superiorhandability.STRENGTH: The case front is machined steel! You candrop it right on its nose with no danger of case dents or

I-4 V FR

damage to the internal structure. (In actual lab testswe drop the SM60's over and over from a height of6 feet.)PERFORMANCE: Built-in wind and "pop" filter elimi-nates or minimizes breath and wind noise. Windscreenand front end instantly removable for cleaning. Smoothand natural sound for both voice and music. Goesfrom stand to hand instantly.ECONOMY: Priced competitively with conventional"workhorse" microphones. Why not check one out now?See your Shure Professional Products Distributor orcontact Mr. Robert Carr, Manager of ProfessionalProducts Division, Shure Brothers, Inc., 222 HartreyAve., Evanston, III. 60204 - Phone 312 - 328-9000.

SIVI60OMNIDIRECTIONAL DYNAMIC MICROPHONE

SHURE STATION-TESTED AUDIO CIRCUITRY EQUIPMENTShure stereo equalizer and preamplifiers are praised as MAJORcontributions to upgrading station quality by broadcasters.

SE -1 Stereo Transcrip-tion PreamplifierProvides precise RIAA equaliza-tion from magnetic phono repro-ducers at line levels. Separatehigh and low frequency responsetrimmers. Lowest distortion, noiselevel, susceptibility to stray RFfields.

M66 BroadcastStereo EqualizerPassive equalizer compensatesrecorded frequency to threeplayback characteristics: RIAA,flat, roll -off. Provides preciseequalization from magneticpickup at microphone inputlevel.

48Circle Item 121 on Tech Data Card

BROADCAST ENGINEERING

BOOK REVIEW

Amplifier Handbook: Richard F. Shea,Editor -in -Chief; McGraw-Hill BookCompany, New York, 1966; 1504pages, 6" x 9", hard cover, $37.50

This volume may be described asa major attempt to provide an ency-clopedia of amplifier theory and cir-cuitry. Its scope ranges from tubes tolasers, and from ceramic and magnet-ic devices to complex integrated cir-cuits.

The work has been divided intothree principal areas, each comprisedof the elements essential for thoroughexplanation and illustration of theanalysis at hand.

Part one deals with the fundamen-tals of amplifier theory, including net-work definitions and concepts as theyrelate to amplifiers, necessary mat-rices, feedback, and noise. Treatmentextends to the detailed mathematicalanalysis and proof which are neces-sary to full comprehension of theprinciples involved.

The second part is devoted to thedescription of every significant formof amplifying device. This includestubes, transistors, tunnel diodes, othersolid-state components, and magnetic,ionic, and ceramic devices. The de-scription of each type extends to thefull range of its theoretical and prac-tical application, and includes expla-nation of the use and effect of thevarious materials employed in theirconstruction. For example, the chap-ter on electron tubes covers simplediodes, the more complex multiele-ment tubes, klystrons, and receivingand transmitting types.

Part three, and by far the largestpart of the book, is given to the pre-sentation of specific amplifier circuitsby their application. Included arechapters on audio, DC, high -power,magnetic, ionic, servo, tuned, non-linear, microwave, and induced -emis-sion (laser and maser) amplifiers,and the special requirements and lim-itations of integrated circuits. Withineach broad area, actual working cir-cuits are given the attention sufficientfor their full explanation and appli-cation in working devices.

This is essentially an engineer'shandbook, but its thorough treatmentof the subject permits its use by anyadvanced technician with a require-ment for more than an elementaryknowledge of a few basic circuits andprinciples. It should be especially use-ful to anyone who wishes to haveaccess to knowledge of amplifier cir-cuits not encountered in the ordinaryday's work A

!TEA-zsbnat T

BEFORE... so mall' qualityno

EVER BEFORE

M 11-10back models are Evadable

Serte-s R-310 Recerd &

t

and -wo or four tack star

half -)r full track

INTE 10 IIRack portably case or

sole cabinet moirting.

r.

Be among the fist to plife !yot under and take.advantage of out special NEVER HIORE - NEVERAGAII. offer!

Call or write Sparta -or full svcill;a:m and informatiof

%PA PtTALECTRONIC CORPCR4TION

5851 FLCRIN-PERKINS ROAD, 3ACRAMEN-C CALIF. 95828 (913) 3'13353

May, }967

Circle Item 15 on Ted. Data Card49

What's newat KABC-TV, KATV, KEMO-TV, KEPR-TV, KFMB-TV, KGGM-TV, KHET-TV,KHFI-TV, KHTV, KIMA-TV, KIRO-TV, KMED-TV, KMVT, KNBC-TV, KOAP-TV,KOLO-TV, KPIC, KPRL-TV, KQED-TV, KTCA-TV, KTCI-TV, KTVB, KTVH-TV,KVIE-TV, KVOS-TV, KWGN-TV, KWTX-TV, WABC-TV, WBMD-TV, WCNY-TV, WDIQ-TV, WEDH-TV, WEIQ-TV, WERO-TV, WGEM-TV, WHDH-TV,WHDO-TV, WITA-TV, WJCT, WLOS-TV, WNBC-TV, WOR-TV, WPRO-TV,WPTZ-TV, WRAL-TV, WROW-TV, WSCO-TV, WTIC-TV, WTWO-TV, WVTV,

WWTV, WCBS-TV,. KGGM-TV, ABC Network, CBS Network, NBC Networkand BELO HORIZONTE TV (Belo Horizonte, Brazil), CBC (Montreal,Can.), CFRN (Edmonton, Can.), CBC Newfoundland, BOGOTA TV (Bogota,Col.), CHSJ (St. Johns, N.B., Can.), CKLW-TV (Windsor, Ont., Can.), NRK(Norway), Radio Bandirantes (Sao Paulo, Brazil), RTB,/ BRT (Belgium), StaatsbedrijfDer Posterijn (Holland), Telefis Eireann (Eire), TV -2 (Panama City, Pan.), XEIP(Mexico City, Mex.), XET-TV (Monterey, Mex.), XEW-TV (Mexico City, Mex.), YNSATV (Managua, Nic.).

Read allabout it.

MA -2A and MA-7A.all-solid-state televisionmicrowave relay systems for high fidelitycolor and monochrome. For intercity re-lay, STL, or mobile TV pickup. No tubes.No high voltages. No thermionic devices.No relays anywhere in the system. Klystronreplaced by solid-state RF source for un-matched stability, reduced power require;ments. Send for free catalog S F-9501.

MICROWAVE ASSOCIATESBurlington, Massachusetts

Offices: Burlington, Mass.; 9911 Inglewood Ave., Inglewood, Cal.Hyde House, Edgware Rd., London NW9, England.

Subsidiary: Microwave Associates, Ltd., Luton, Beds, England.

Circle Item 16 on Tech Data Cara

May 1967

We interrupt this magazine to bring you...

Late Bulletin from Washington

by Howard T. Head

Radio Stations Warned on Commercial Practices

The Commission has renewed the licenses of seven Florida AM radio sta-

tions whose applications indicated commercial time of 20 minutes or

more in each hour as a regular practice (see December 1966 Bulletin).

In doing so, however, the Commission directed the licensees to report

to the Commission at the end of an 18 -month period regarding commercial

practices during that period, and to inform the Commission of any pub-

lic complaints or other adverse response to commercial time in excess

of 18 minutes per hour.

NAB Small Market Committee Studies Problems

The National Association of Broadcasters Small Market Committee has under

study the problems associated with the taking of FCC operators' license

examinations. Applicants in remote parts of the U. S. are often obliged

to travel several hundred miles to take the required examinations and

the Committee is attempting to persuade the Commission to provide moreconvenient locations. A survey is also to be conducted, through statebroadcaster associations, of the time and expense involved in sendingpersonnel to present examination locations.

The Committee is also studying the effect on daytime -only radio stationsof the new Federal law requiriig uniform observance of Daylight SavingTime (see May 1966 Bulletin). The Commission has reminded licenseesthat the new law does not affect sign -on and sign -off times, or in the

case of fulltime stations, the time of changing from day to night patterns;

these times will continue to be governed by Standard rather than Daylight

time. Minimum hours of operation for AM stations (Section 73.71(a) of

the Commission's Rules) are also established in terms of Standard time,

although this was not pointed out in the Notice.

Proposed Channel Searing Tests Advance

The joint Government -Industry Committee for Testing Sharing of TVChannels By'Land Mobile Services has approved plans for fieldtesting of land mobile/television channel sharing on Channel 6 inthe Washington, D. C. area (see December 1966 and March 1967 Bulletins),to start about June 1, 1967. The test locale had been shifted from LosAngeles to Washington, D.C. because of Mexican concern over possibleinteeerence to a Channel 6 station at Tijuana, B.C.

In approving the field test plans, the Committee noted the necessityfor laboratory testing in addition to the field testing, both toguide the conduct of the field tests and to permit analysis of theresults. Shortage of adequate laboratory data on receiver inter-ference has been one of the principal obstacles to a Commissiondetermination of the extent of interference to television receptionfrom land -mobile operation.

Negotiations Incomplete on New AM Treaty With Mexico

At the conclusion of a month -long second negotiating session betweenthe United States and Mexico, agreement still has not been reached ona new standard broadcast radio treaty between the two countries. Thepresent treaty will now expire at the end of 1967. At stake are suchissues as increased hours of operation on clear channels, and power in-creases for Class IV local -channel stations near the common border.

No date has yet been set for the resumption of negotiations. It ap-pears unlikely, however, that agreement will be reached, and ratificationeffected, before the present treaty expires.

Short Circuits

NAB has urged the Commission to authorize the establishment of a special-ized television -radio space satellite system for network relaying, withindividual broadcasters to own and control their individual ground re-ceiving stations (see September 1966 Bulletin).

. . The Commission hasdeclined to add a fifth commercial television channel to Charlotte,North Carolina (population: 230,000) on the ground of lack of need. .

A major FM -transmitter manufacturer has proposed that the Commissionauthorize the unattended operation of FM transmitters. . . A number oflicensees have been admonished for failing to exercise proper controland supervision over foreign -language broadcasts. . . The Commissionhas turned down a proposal for remote -control operation of VHF televisiontransmitters on the ground that it might lead to picture degradationand spurious radiation.

Howard T. Head . . . in Washington

Aim high

Target innovations inGE Pickup Tubes give you

a better picture.Shooting for the best possible picture? Set your sights on thenew generation of Image Orthicons and Vidicons from GeneralElectric!New innovations in GE Pickup Tube glass target technologiesnow permit higher signal-to-noise ratios and improved amplituderesponse in existing color or monochrome TV cameras. The newZ7899 10, for color remotes and monochrome VTR, and theZ7888 10, for studio color video taping-give sharper, quieter,better pictures. At medium to high illumination levels, theygive up to 3 to 5 times longer life than conventional glasstargets. Stickiness, loss of sensitivity, and burn -in are virtuallyeliminated.Let us prove-with your equipment, in your own studio-thatNEW IDEAS IN ELECTRONICS from General Electric will giveyou a better picture! To request a demonstration contact yournearest GE Sales Engineer:

Charles M. Liddic Charles Shields1330 W. Peachtree St., N.W. 3800 N. Milwaukee Ave.Atlanta, Georgia Chicago, IllinoisTelephone: (404) 875-6691 Telephone: (312) 777-1600

GENERAL

Type Target FeldMesh

Signal Noise@ 4.5 MC

Amplitude Response@ 400 TV Lines

Application

Z7899 New Electronic Min. Avg. Color Remote

Glass Target No 65:1 72:1 65% & MonochromeVTR

Z7888 New Electronic Studio Color

Glass Target Yes 65:1 72:1 65% Video Taping

OTHER GE PICKUP TUBES AVAILABLE

Image Orthicons Vidicons

5820A 8093A 6198A 7262A 77356 8572

4401 8092A 7038 7263A 8484 8572V

7293A Z7866 7038V 7697 8507 8573

7629A 7226 7735A 8541 8134V

Available From Your GE Camera Tube Distributor

Harold F. Boreiko200 Main AvenueClifton, New JerseyTelephone: (201) 472-8100

ELECTRIC

Fred A. SachsElectronics Park, Bldg. 6Syracuse, New YorkTelephone: (315) 456-2584


May, 1967 53

Overly builds doors to keep this out

What noises do you want to holdback? Overly makes a complete lineof certified acoustical doors - 13/4"to 41/2" or thicker, depending uponthe required sound reduction andsize. Full -flushed design, glazedunits, and a special louvered door.Overly units come complete: doors,frames, seals, hardware. STC loss

ratings from 35db to 53db - in tan-dem doors 62db-certified byRiverbank Acoustical Laboratory.

For lab test reports and informa-tion on how you can hold back un-wanted sound, write to: Managerof Product Development, OverlyManufacturing Company, Greens-burg, Pennsylvania 15601.

ilikirorly54



NAB Report(Continued from page 45)

design and operation as "sciences, not art," Mr. Andersonsuggested a five -point method for high -efficiency operation:1. Set up a planned maintenance and adjustment schedule,

then stick to it. Modify schedule only when betteroperation results.

2. Adhere closely to SMPTE recommended practices andstandards for TV magnetic -tape recording. This assuresgood interchangeability.

3. Take care to ensure proper signal levels in all phases ofthe recording process.

4. Set burst key to yield as many cycles of burst as is legal,and position burst properly.

5. Establish a training program for operators and main-tenance personnel.

The man -pack Ampex VR-3000, a portable recordinginstrument designed for news and remote coverage, alsowas described by Mr. Anderson. Slides showing the unitin operation with a two -man reporting team demonstrateda capability for making useful remote -location recordings.

New Video Noise Meter

A significant contribution to TV instrumentation wasdescribed in a paper presented by Rudolph Feldt, ofRohde & Schwarz. The complex design of the instrumentprecludes a detailed description of the circuitry. In brief,however, the unit processes the composite video signal toremove the sync and blanking pulses, leaving the videosignal. Compensation is made for duty cycle of the remain-ing video bursts to obtain measurement accuracies of betterthan 1 dB for remaining noise pulses.

The instrument is direct reading and indicates both theweighted and unweighted signal-to-noise ratio in both rmsand peak -to -peak values. A measurement range of 80 dB isavailable, and the gray level has no effect on the overallmeasurement. The gating pulses which blank the sync andblanking pulses are generated internally; external syncprovision also is made. Various filters are provided to allowmeasurements to be made within tolerances established byCCIR.

Tower Care and Maintenance

J. Roger Hayden, of Dresser Crane, Hoist & TowerDiv., gave engineers useful information on tower care.Drawing from years of experience on towers ranging fromlightweights to 1000 -ft -plus giants, Mr. Hayden showedphotographic examples of poor practice taken on actualrepair jobs. He also outlined a comprehensive list of itemsthat should receive special attention: lights and lightingsystems, feedlines, structural members, foundations, bolts,wedges, and guys.

A self-supporting structure often can be inspected ona two-year schedule, but guyed towers should have a yearlyinspection, according to Mr. Hayden. A self -supportedstructure also should be reviewed after any extremelyviolent storm and following a particularly severe winterwhen icing has been heavy.

While common sense suggests many obvious points forconsideration, says Mr. Hayden, a specialist should alwaysbe consulted for assistance in setting up a thorough main-tenance and safety program.

Advanced Manufacturing Methods forComplex Broadcast Equipment

The final formal presentation of a technical paper dealtwith the advanced quality -control concept General Electrichas developed to control tolerences during manufacture ofcolor cameras, signal -processing equipment, and other corn -

For a top job in broadcasting . . . get a

FIRST CLASS FCC LICENSE...or your money back!

YOUR key to future success in electronics is a First -ClassFCC License. It will permit you to operate and maintain

transmitting equipment used in aviation, broadcasting, ma-rine, microwave, mobile communications, or Citizens -Band.Cleveland Institute home study is the ideal way to get yourFCC License. Here's why:

Our electronics course will quickly prepare you for aFirst -Class FCC License. Should you fail to pass the FCCexamination after completing your course, you will get afull refund of all tuition payments. You get an FCCLicense ... or your money back!

And only CIE offers you new, up-to-the-minute lessons in allthese subjects: Logical Troubleshooting, Microminiaturiza-tion, Single Sideband Technique, Pulse Theory and Applica-tion, Boolean Algebra, and many more.You owe it to yourself, your family, your future to get thecomplete details on our "proven effective" Cleveland Institutehome study. Just send the coupon below for FREE book orwrite to Cleveland Institute of Electronics, 1776 E. 17th St.,Dept. BE -36 , Cleveland, Ohio 44114.

NEWS FOR VETERANSNew G. I. Bill may entitle you to Government -paidtuition for CIE courses if you had active duty in theArmed Forces after Jan. 31, 1955. Check box in cou-pon for complete information.

MAIL COUPON TODAY FOR FREE BOOK

CIE Cleveland Instituteof Electronics

1776 East 17th Street, Cleveland, Ohio 44114

Please send me your FREE book,"HowTo Get A Commercial FCC License."

Name(please print)

Address

City State Zip

Occupation Age

Veterans check here for GI Bill informationAccredited Member National Home Study CouncilA Leader in Electronics Training . . . since 1934 BE -36

May, 1967 Circle Item 19 on Tech Data Card55

claim:

proo

here'swhy:

Lcntilit.eatiaL

Our Type 317C is the most popularand most accepted 50 kw AM trans-mitter you can buy!

We delivered 15 type 317C transmit-ters to customers throughout the worldin less than 2 years! KWJJ, Portland;WCCO, Minneapolis; WKVM, SanJuan; WMOO, Mobile; WN AC, Boston;XETRA, Tijuana; Armed ForcesRadio; Diplomatic Wireless Service ofGreat Britain (2); Radio RumbosCaracas; Radio Barquisimeto Vene-zuela; Radio England (2); Radio Car-oline; Burma Broadcasting Service.

Our Type 317C is the most economical(82 kw @ 0% mod., 92 kw @ 30%mod., 120 kw @ 100% mod.); mostcompact (62 sq. ft., completely self-contained including blower); and hasthe lowest shipping and installationcosts.It's the most 50 kw for the money.Matter of fact, you cannot afford tobuy any other 50 kw!

For your brochure on the Type 317C, write CommercialSales Dept., Continental Electronics Mfg. Co., Box 17040,Dallas, Texas 75217.

ASUBSIDIARYOF AL,M 7 LEC7-1=1C)S3 ViE;TE/VI,



plex broadcast gear. An integrated policy, encompassingall phases of manufacturing from product evaluation tosales after service, the program of "Total Quality Control"includes environmental testing, shock tests, life expectancy,and ease of component interchangeability. Manufacturingprocesses and special training programs for assemblytechnicians have been designed to contribute to the con-struction of complex equipment. Automated test equipmentgives a means for rapidly evaluating circuit boards notonly for completeness, but for acceptable operation of eachcomponent.

The entire program, however, is far too detailed to re-view in its entirety. Engineers at the meeting did obtainan unusual insight into the extensive care taken to ensurethat the equipment they use every day is dependable andeasy to care for. The paper was offered by A. J. Strumar,of GE.

Industry/Government Technical Panel

To close off the three days of technical sessions, theconference committee assembled the following panel todiscuss questions of interest both to broadcast engineersand to FCC engineers in attendance:

Wallace E. Johnson, FCC Broadcast Bureau, Wash.,D. C.

Malcolm M. Burleson, Metromedia, Wash., D. C.Harold G. Kelley, FCC TV Applications, Wash.,

D. C.Philip Whitney, WINC/WRFL, Winchester, Va.Paul C. Schafer, Schafer Electronics, Chatsworth,

Calif.Harold L. Kassens, FCC Broadcast Facilities,

Wash., D. C.Clyde M. Hunt, Post -Newsweek Stations, Wash.,

D. C., was moderator.Verbatim transcripts of the session are not yet avail-

able, although they will be obtainable later from NAB.Topics, as might be expected in a free -form discussion,ranged widely.

Foremost, perhaps, was the comment from FCC engi-neers on the Commission's denial of the petition for remoteoperation of VHF TV transmitters. It was made clear thatalthough the petition was not felt to be adequate, thereshould be another petition filed later by NAB. The wordingof the denial, said Mr. Johnson, suggests the approach tobe followed in any forthcoming petition to assure adequatemaintenance of remotely situated transmitters.

Additional discussion touched on the need for clarifyingthe whole list of FCC rules and regulations to reflect theadvanced state of the art of electronics. Engineers alsolearned that field -office Radio Inspectors operate not onlyfrom the rule book, but also from field -office operatingmanuals provided by the Washington office to aid in in-terpreting the rules-a rule book for the rule book! Thissituation accounts for delays in implementing new rulesand indecision as to how they apply in specific cases. Othercomment concerned progress being made in securingagreement from international agencies (in Canada andMexico, particularly) to enable a new rule authorizing auniform sign -on time for daytime -only stations.

Summarizing

The Conference contained interesting information inmany particular areas of engineering operations. We have alot to look forward to, not only in terms of new equipmentand systems concepts, but also in the regulations underwhich we all function. Invaluable opportunity exists intechnical conferences of this sort to make known to manu-facturers, designers, and government engineers our needsand desires for bettering our profession.

Make tape heads, guides,capstans,3 ways cleaner

FLUSH OUT oxide build-up, dust, grit, greaseand oil quickly and efficiently with "FREONTF*" Aerosol Solvent Cleaner. Safe . . . evenon operating equipment. Has excellent wet-ting . . . gets into tiniest openings to replacesoils. Leaves essentially no residue. Pack-aged in 16 oz. aerosol spray cans with ex-tension nozzle for hard to reach areas.

CLEAN CRITICAL AREAS with TEXWIPE dis-posable lint- and static -free cloths. Non-abrasive and highly absorbent. Easy to use;wipe away all contamination which oftencauses malfunction of equipment. TEXWIPEis cut on a bias in convenient 9" x 9" squares.

ENTRAP DIRT PARTICLES with totally lint -free FOAM -SWABS that leave no contamin-ating fibers. Highly absorbent . . . Open cellstructure of urethane foam over absorbentcotton base soaks up and holds cleaningsolutions. Skeletal structure provides deepmaze for particle entrapment . . . assureseffective cleaning even in hard to reachplaces. Use as cleaning swab or applicator.Send for catalog *Du Pont Reg. T.M.

THE TEXWIPE COMPANYPhone 201 - 664-0555

HILLSDALE, NEW JERSEY 07642


57

Disc Recorders(Continued from page 15)

equalization, insert the equalizernetwork in the line feeding the am-plifier, set the audio generator to1000 Hz, and adjust the gain forabout 0.4 volt across the amplifieroutput when using a low -impedancecutter, or about 3 volts for a 500 -ohm cutter. This should give you arecorded level about 15 dB belowNAB standard reference level.Make a recording again, this timeusing spot frequency checks from1 kHz to 10 kHz, and play it backon your standard turntable. Whenthe equalizer is correctly adjusted,response during reproduction shouldbe essentially flat up to at least 7kHz, or, if you're lucky, as highas 12 or 14 kHz. If you're notwithin about 3 dB on the first try,adjust the 250 -ohm equalizer con-trol. Changing the resistance changesboth the high -frequency responseand the insertion loss. It will benecessary to readjust the input leveleach time the setting of this con-trol is changed. Don't try to checkthe high -frequency response of thecutter at a higher level than spec -

shed anove or you will rim( dam-age to- the cutter, since the am-plifier response rises with frequency.(Program material may be recordedat higher level because very littlehigh -frequency energy is present innormal music or speech.)

Once you get the high -frequencyequalizer adjusted, you should ad-just the gain control on the am-plifier for standard level. To dothis, play the standard -level cut onthe test disc, and adjust the turntablegain for a zero indication on theVU meter. Then, make a test re-cording of a 1000 -Hz tone withabout 2 volts across the amplifieroutput (15 volts for a 500 -ohmcutter). Play this back on the turn-table without changing the gainfrom the playback level of the testdisc. The reading of the VU meterwill now be your deviation fromstandard level. Adjust the record-ing amplifier gain and recheck un-til you are within one or two dBof standard level. Now, with pro-gram material reading the samelevel as the output of your audiogenerator, you will be able to makerecordings at NAB standard level.

ms is me standard normally useuon 331/2 -rpm records. Many 45'swill show levels several dB higherthan this, but unless you have avery high -power amplifier, don't ex-pect to match this level. With moststandard cutters, you run the riskof damage if you attempt to recordwith the power required to match"pop" 45's.

If you wish to make a frequency -response run on your cutter, besure you record levels no higherthan about 15 dB below NABstandard reference levels, since thehigh frequencies are boosted some20 dB by the equalizers. You maymeasure response at frequencies be-low 1000 Hz at standard level, how-ever.

ConclusionMaking good disc recordings

takes considerable practice, andyou may go through several discsand a stylus or two before you getthe swing of it. If you do a goodjob of rejuvenating your recorder,though, you should have a machinecapable of good performance-andwhich can bring you in some extramoney.

Operating remote control?Be safe and sure with the

AMENERI. AMA.

NEW! ALL EIL =3,TrzrE RFAMPLIFIER FROM WILKINSON!

Features of the Model TRF 1A: VERY LOW DISTORTION AND CARRIER SHIFT BROAD GAIN CHARACTERICTICS EXTREME STABILITY EXCELLENT SELECTIVITY ULTRA LINEARITY

For complete details write:

ILZ

PRICE: $ 395

1937 MacDADE, BLVD.

WOODLYN, PA. 19094

ELECTRONICS, INC. PHONE (215) 874-5236 874-5237

ROHN.Mighty bigin towers

CATV MICROWAVE COMMUNI-CATIONS BROADCAST HOME TV

AMATEUR SPECIALTY TOWERSRohn dominance in the tower field is

based on the concept of giving the cus-tomer more than he expects to get.

Every step - engineering and design,manufacturing, finishing, warehousing,turnkey tower erection service, acces-sories and equipment, world-wide repre-sentatives and service - all are dedica-ted to extra quality - extra satisfaction.

For further information contact

ROHN R Home OfficeP.O. Box 2000. Peoria. Illinois 61601Ph. 309/637.8416 TWX 309/697.1488

4itiitiLlaw


58



In 8 out of 10 cases.one of these STANDARD

consoles will meetCUSTOM console

requirements

Before ordering a custom installation for your control room,check your requirements against these features of Collins'standard 212T-1 and 212T-2 Audio Control Consoles:REMOTE CAPABILITY. Rack -mounted assembly containingamplifier cards can be located in an equipment room andlinked by cable to the audio control panel in the studio.Sensitive audio wiring is concentrated in a card cage awayfrom interference. Noiseless switching and audio level con-trol are accomplished by photoconductive cells which employa light beam to isolate control voltages from the audio circuits.COMPONENT ACCESSIBILITY. Plug-in etched circuit cardconstruction ends time -wasting troubleshooting. Attenuator,input switches, amplifiers, and amplifier output switches arereplaced by simply taking one card out of the rack -mountedassembly and plugging in another card.

The 2 I 2T Audio Control Consoles consist basically ofthree units:

CONTROL PANELS. The control panel constitutes the differ-ence between the two systems.

The 212T-1 control panel provides 28 inputs to 14 faders,2 program output channels, and 2 10 -watt monitor speakeroutputs. The overall dimensions are 153/4" high by 24" wide.

The 212T-2 control panel has 32 inputs to 16 faders. Thepanel is divided into two sections: The fader operatingcontrols are mounted on a panel 101/2" high by 19" wide; the

VU meters and monitoring controls are mounted on a panel51/4" high by 19" wide.

RACK -MOUNTED ASSEMBLY. The assembly contains 16 pre-amplifier cards. Quantity and types of cards depend uponindividual requirements. The assembly includes three pro-gram amplifier cards-one for cue and two for programchannels. Two amplifiers are for speaker monitors; twoswitching cards select monitor inputs. The rack -mountedassemblies for the 212T-1 and 212T-2 are identical.POWER SUPPLIES. Two power supplies are housed with therack -mounted assembly. One power supply provides vari-able illumination for meters and push-button controls.Another provides powering for cards, attenuators, ampli-fiers, switches, and photoconductive cells.

Most studio audio requirements can be met by adapting thestandard 212T-1 or 212T-2 Console through strappingoptions and minor wiring changes. Expansion and adapta-tion can be accomplished easily with additional space whichthe units provide for two extra preamplifier cards, two addi-tional program amplifiers, and two unwired spare cardreceptacles.

For a copy of a new descriptive brochure on the 212Tseries, contact Broadcast Marketing, Collins Radio Com-pany, Dallas, Texas 75207. Ph. (214) AD 5-9511.

COMMUNICATION COMPUTATION / CONTROL

liaaA\4141\144114\

COLLINS

COLLINS RADIO COMPANY / DALLAS, TEXAS CEDAR RAPIDS, IOWA NEWPORT BEACH, CALIFORNIA TORONTO, ONTARIOBangkok Be,rut Frankfurt Hong Kong Kuala Lumpur Los Angeles London Melbourne Mexico City New York Paris Rome WasMnglon Wellngton

Circle Item 24 on Tech Data CardMay, 1967 59

NEWS OF THE INDUSTRYINN II= NMI

To Build Earth Stations

Communications Satellite Corp. hasasked for fixed price proposals forfour large antennas and related earth -station equipment. The request forproposals (RFP), the largest singleearth -station procurement issued byComsat, was sent to 52 companies.Comsat filed the RFP with the Fed-eral Communications Commission.It included four 90 -to -100 foot pre -

IM IMO BIM NMI =II EMI BIM

cision-designed antennas, eight low -noise receivers (two for each station),and four sub -systems of ground com-munications equipment-all to be in-tegrated into reliable systems at eachstation site. The new equipment wouldbe supplied for installation at threenew high -capacity stations at sites tobe chosen in Puerto Rico, West Vir-ginia, and California, as well as foraugmenting the Hawaii station for in-creased Pacific service.

Multiple Cartridge Playback Units

Ten Spot Model 610B

6-0e 0 A41-41 41 41

Five Spot Model 605B

... bringing a new dimension topushbutton broadcastingSpotmaster Ten Spot (holding 10 cartridges) and Five Spot (holdingfive) will reproduce any NAB Type A or B cartridge instantly at the pushof a button ... at random or in sequence. They may be operated manuallyor incorporated into programmed automation systems, using one, two orthree NAB standard electronic cueing tones.

The Ten Spot is designed for 19" rack mounting while the Five Spotis available either in an attractive walnut -finished case or with a 19" frontpanel containing a cartridge storage cubicle. Both are backed by Spot -master's iron -clad full -year guarantee.

For further information about these and other Spotmaster cartridge tapeunits, call or write today. Remember, Broadcast Electronics is the No. 1designer/producer of broadcast quality cartridge tapeequipment ... worldwidel

BROADCAST ELECTRONICS, INC.1M=

8810 Brookville Road, Silver Spring, Maryland 20910; Area Code 301, 588-4983

Proposals for architectural and en-gineering services relating to the threenew station sites have been receivedand are being evaluated by Comsat.Construction is expected to get under-way at all four locations this year andbe completed in 1968. The new facili-ties will more than double presentearth -station capacity. Comsat cur-rently operates three earth stations, atAndover, Maine, Brewster Flat, Wash-ington, and Paumalu, Oahu, Hawaii.

Transactions

Subject to FCC approval, the assetsof Radio Station WRCR, Maplewood,Minnesota have been purchased byArmand Belli of Arlington Heights,Illinois for a total consideration of$115,000 on terms. WRCR operateson 1010 kHz with 250 watts.

Minnetech Laboratories, Inc., Min-neapolis manufacturer of automationequipment and industrial measuringdevices has been purchased by Nor-tronics Company, Inc.

Hans Trechsel will continue asgeneral manager of Minnetech, which

BROADCAST

EQUIPMENT

ALL SOLID STATE

AURAL

STLModel PCL-303

+ 8 watts at 950 MHz

+ True direct FM+ Silicon semiconductors

+ Sensitive receiver withratio detector

+ For all STL bands

MOSELEYASSOCIATES, INC.

135 NOGAL DRIVESANTA BARBARA, CALIFORNIA

(805) 967-0424

60



key better color

lijiALLENHIGH-BAND VIDEOTAPE RECORDER LINEVTR Designed and Built from the Operator's ViewpointNew Precision New PrecisionLong -Life High Tape TransportBand Video Head Full MonitoringNew Operations and PlaybackOriented Console ProcessingHousing Facilities

New "State -of -the -Art" VTRElectronics Systems

Simple, OccasionalMaintenance forRoutine ExcellentPerformance

Introducing the PRECISION High -Band VTR Video Head

To fulfill a long standing industry requirement this long -lifeVTR video head is designed and built as a precisioninstrument to provide a revolutionary new tool for the highestquality color VTR operation.

VISUAL ELECTRONICS CORPORATION356 west 40th street new york, n.y. 10018 (212) 736-5840

FIRST BY ANY STANDARD

May, 1967 61

1C111=P1.17341'11"1,..

MODEL SX 724

ELECTRONIC ADVANCES©Performance as yet unequalled

Two years proven Solid Statecircuitry

Extremely low noise electronicstEtched circuit modules

TRANSPORT ACHIEVEMENTSPatented Electro-Magnetic

Brakes never need adjustingComplete head accessibility

© Precision Construction© Low Wow and Accurate Timing

THESE AREJUST A FEW OF THE

OUTSTANDING FEATURESWHICH PROVIDETHE ULTIMATE IN-

QUALITYDEPENDABILITY

PERFORMANCE

MODEL SS822

Box 1000, Dept.BE-5Elkhart, Indiana 46514

MADE ONLY IN AMERICA


62

57db (@ 10Mc) orbetter cross -talk iso-lation. Gold-platedberyllium springs andgold-plated palladiumcontacts.

*licensed by C.B.S., Inc.

will be operated as a wholly -ownedsubsidiary of Nortronics. Minnetechwas founded by Mr. Trechsel in 1961.

New PlantA new plant at Hauppauge, Long

Island, New York has been occupiedby Riker Video Industries, Inc. Thecustom-built 20,000 square -foot struc-ture houses the company's manufac-turing facilities, executive offices, andNew York sales headquarters.

Expanded Plant FacilitiesAmerican Electronic Laboratories,

Inc., has acquired new plant space atMontgomeryville, Pa. The new facili-

ties, to be leased by AEL affiliateElectromagnetic Technology Corp.,will provide an area of approximately43,000 square feet. Current plans callfor doubling this space in the nearfuture.

Cable Facilities DoubledShipments have started from the

new Viking Industries, Inc., cable fa-cility at Freehold, New Jersey. The130,000 square -foot plant doubles thefirm's capacity for producing cable,and will be devoted primarily to serv-ing the needs of the CATV industry.The plant is managed by Hai oldRoveda.

VALUE Integrity Aviputnance.LET'S GET OUR HEADS TOGETHER . . .

EXCLUSIVEAll Adjustments

Made Topside!MMI Heads for Ampex 600/601 Series

MINNEAPOLIS MAGNETICS,INC2915 Huntington Avenue Minneapolis, Minnesota 55416


TEST

!APno circuit interruption, per-manent or temporary set-ups

SUPERIOR TV -10* JACKSDO ALL THREEWITH PLUG-IN SPEED

PA ICl/ and/or

replace or couple modules inseconds including use ofnon -adjacent normalled jacks

TERMINATE

1 operation patches1 circuit, loads another

Exclusive pick by leading TV networks for years. Used for a spectrum of 75 -ohm coax jacking requirements with virtually no cases of circuit degradationor failure. No measurable insertion loss from 1 to 40Mc while providing

Write for brochure. For full details, contact . .

SUPERIORManufacturing & Instrument Corp.36-07 20TH AVE., LONG ISLAND CITY, N. Y. 11105PHONE: 212 YE 2-1800 TWX: 710 582-2626



ALWAYS ON TARGET WITHSOLID STATE EQUIPMENTYears of technical experience in television broadcasting stand back

of the many new advances developed by Richmond Hill Laboratories

in this highly specialized field. Designed, engineered and manufactur-

ed in Canada, the wide range of RHL solid state equipment includes:

Studio Switching Equipment Synchronizing Pulse Generators

Video Test Signal Generators Special Effects Generators

Colour Bar Generators Video Distribution Amplifiers

Pulse Distribution Amplifiers Clamping Amplifiers

Digital Cue Generators Digit Generators

Clock System Driver Routing Switching Equipment (Audio 'Video)

All RHL products carry a 5 -year warranty, backed by skilled crafts-

manship, quality components and rigid control ... important factors

in building a fine record of service to the television broadcast industry.

FOR COMPLETE DETAILS AND SPECIFICATIONS WRITE

RICHMOND HILL LABORATORIES LIMITED1610 MIDLAND AVENUE, SCARBOROUGH, ONTARIO, CANADA/PHONE (416) 757-3631/TELEX RHL TOR 02 29803

Circle li.em 31 on Tech Data Card

May, 1967 63

AMMODULATION

MONITORThe Metron Model 506B-1 Amplitude Modula-tion Monitor is a high quality instrument, field -proven for several years.

FCC Type Approval 3-127

Compact-Only 51/4" high on astandard 19" rack

All solid state circuits-silicontransistors for greater reliability.

Low Cost-only $550.00.When you replace your present AM Monitor,buy the Metron 506B-1, your best value.

METRON INSTRUMENTS, INC.1051 South Platte River Drive Denver, Colo. 80223


NEWPRODUCTS

El EN NI MIII MN I=

For further information about any item, circlethe associated number on the Tech Data Card.

.4111=1111111111WIIIIItik.

to toor ti

0 eoi

Video Waveform Monitor(110)

A flat -face, rectangular, 5 -inchCRT with an edge -lighted IEEE -typegraticule is one feature of this videowaveform monitor for professionaland broadcast television systems.

The Ball Brothers Research Corp.Mark 21 monitor uses semi -conduct-ors throughout the electronic circuitryincluding the integrated circuitry.Since power consumption is low, con-

ajor co or s u lo goes to modern, reliablepatching equipment

ease of operation ease of maintenance more compactComplete line of patch panels, patch cords, looping plugsand other related hardware in either coaxial, twinaxial ortriaxial systems from Trompeter Electronics. For example:BNC connectors for Belden #8281 coaxial cable commonlyused on color systems.

Switching matrices inany format for switch-ing TV monitors and.video signals into videotape recorders,

TROMPETER ELECTRONICS, INC.8936 Comanche Ave., Chatsworth, Calif. 91311 (213) 882-1020


64

The soundest sound in audiois the new sound of Gates

Need a reallyportable

remote amplifier?One ... two ... three ... four! Youhave that choice of channels andmodels in Gates Solid Statesman re-mote amplifiers. All rugged, compact.Modern flightline styling. Choose amodel ideal for your needs. Write orphone (217) 222-8202 for off -the -shelfdelivery.

GATESHARRIS

INTERTYPE

CORPORATION

GATES RADIO COMPANYQUINCY, ILLINOIS 62301, U.S.A.A subsidiary of Harris-Intertype Corporation



If theElectro -Voice

Model 666picks up

sound here...

aThe holes in the top, sides andrear of the Electro-Voice Model

666 make it the finest dynamic cardioidmicrophone you can buy. These holesreduce sound pickup at the sides, andpractically cancel sound arriving fromthe rear. Only an Electro-Voice Vari-able -D® microphone has them.

Behind the slots on each side is atiny acoustic "window" that leadsdirectly to the back of the 666 Acoustal-boy® diaphragm. The route is short,small, and designed to let only highsget through. The path is so arrangedthat when highs from the back of the666 arrive, they are cut in loudness byalmost 20 db. Highs arriving from thefront aren't affected. Why two "win-dows"? So that sound rejection is uni-form and symmetrical regardless ofmicrophone placement.

The hole on top is for the mid-range. It works the same, but with alonger path and added filters to affectonly the mid -frequencies. And nearthe rear is another hole for the lows,with an even longer path and more

What are/all these

otherholesfor?

filtering that delays only the basssounds, again providing almost 20 dbof cancellation of sounds arriving fromthe rear. This "three-way" system ofports insures that the cancellation ofsound from the back is just as uniformas the pickup of sound from the front-without any loss of sensitivity. The re-sult is uniform cardioid effectiveness atevery frequency for outstanding noiseand feedback control.

Most other cardioid-type micro-phones have a single cancellation portfor all frequencies. At best, this is acompromise, and indeed, many ofthese "single -hole" cardioids are actu-ally omnidirectional at one frequencyor another!

In addition to high sensitivity toshock and wind noises, single -port car-dioid microphones also suffer fromproximity effect. As you get ultra -close,bass response rises. There's nothingyou can do about this varying bassresponse - except use a Variable -Dmicrophone with multi -port design*that eliminates this problem completely.

Because it works better, the E -V666 Dynamic Cardioid is one of themost popular directional microphoneson the market. Internal taps offer 50,150, or 250 ohm impedance output.Frequency range is peak -free from 30to 16,000 Hz (cps). Output is-58db.

To learn more about Variable -Dmicrophones, write for our free booklet,"The Directional Microphone Story."Then see and try the E -V 666 at yournearby Electro-Voice professional mi-crophone headquarters. Just $255.00 innon-reflecting gray, complete withclamp -on stand mount. Or try the sim-ilar Model 665. Response from 50 to14,000 Hz (cps), $150.00 (list pricesiessnormal trade discounts).

*Pat. No. 3,115,207

ELECTRO-VOICE, INC., Dept. 571V638 Cecil Street, Buchanan, Michigan 49107

gkere aka'Circle Item 35 on Tech Data Card

SETTING NEW STANDARDS IN SOUND

if you haven't seen these

all over the broadcast Hem..

it's lust because you

haven't been looking' /Rek-O-Kut has been a household word in the broadcast and re-cording business for a quarter century. You find them in broadcastoperations wherever you go. That's because a Rek-O-Kut is builtto perform . . . and maintain peak performance for years and years.

The Model B -12H and B12GH are in use in hundreds of radiostations. We send them a few parts once in a while, but you don'tencounter problems with either of these models. E Check thesespecifications. You'll discover you get measurably more froma Rek-O-Kut.

specifications: SPEEDS: 3313 rpm, 45 rpm, 78 rpm ['NOISE LEVEL: - 59 dbbelow average recording level (B-12GH: - 57 db) 0 WOW AND FLUTTER:0.085% RMS. (B-12GH: 0.09% RMS) 0 MOTOR: B -12H: custom-builtcomputer type heavy-duty hysteresis synchronous motor. B-12GH: highefficiency hysteresis synchronous motor, life -time lubrication 0 45 RPMHUB: removable P PILOT LIGHT: neon light acts as "on/off" indicator PFINISH: grey and two-tone aluminum 0 DECK DIMENSIONS: 14" x 1511/16'

Minimum Dimensions: (for cabinet installation) B -12H: 17%" wide x 16"deep x 3" above deck x 61/4" below deck. B-12GH: same as B -12H, but 43/4"below deck.

rek-o-kui by Koss electronics Inc.2227 N. 31st Street Milwaukee, Wisconsin 53208KOSS-IMPETUS II 2 Via Berna Lugano, Switzerland

vection cooling is employed; no fanis required. Electronically regulatedhigh- and low -voltage power sup-plies are employed for the purpose ofproviding constant trace brightnessand low -drift amplitude calibrations.

Three switch -selected vertical am-plifier response characteristics are in-cluded: FLAT-to 5 MHz; IEEE-roll-off; and CHROMA - high-passpeaked at 3.58 MHz. An internal am-plitude calibrator is provided for gainmeasurements. The 2H and 2V hori-zontal selections and expanded sweepsare switch -selected by a single con-trol. Automatic horizontal centeringon two-line, two -field, and expandedsweeps requires no adjustment whenswitching horizontal sweep modes.

Additional design features includeDC restoration on backporch of sync,sweep triggering from video or ex-ternal drives, and two high -impedancelooping video inputs.

Two models are available. One israck -mounted in 51/4 inches of ver-tical space; the other is available ina half -rack version. List price foreither model is $995.

Something to buy or Sell?Use the classified pages.

SPOTMASTERSolid -State Portable

REMOTEAMPLIFIER

The RA-4CA is a lightweight, four -channelportable mixer amplifier specifically de-signed for remote broadcast or auxiliarystudio use. It is completely self-containedand operates from either AC or batteries(switching automatically to battery opera-tion if AC power fails); runs as long as200 hours on low-cost "D" cells. It offersfour microphone channels with mastergain and P.A. feed, all controlled from thefront panel. Lightweight construction (just11 pounds with batteries), a convenientcarrying handle and a snap -on front covermean the RA-4CA can be easily set up tooperate anywhere. For further information,please write or call today:

BROADCAST ELECTRONICS, INC.8810 Brookville Road

Silver Spring, Maryland 20910Area Code 301 588-4983

Circle Item 36 on Tech Data Card66 BROADCAST ENGINEERING

TOTAL QUALITY CONTROL -ANOTHER REASON WHYCDC EQUIPMENT PERFORMSFROM THE INSTANTYOU TURN IT ON.

"Total" means just that. All our people, in engineering

production and administration, are trained to be quality controlconscious in their day-to-day operations. To this is added a complete

understanding of station operation by our systems engineers, who

will visit your studio if required. The result is that when your CDC

equipment is installed, it just can't help fitting naturally into your

station's operational environment. CDC video terminal equipment is

crafted in Canada to your specifications and serviced in the United

States by our own people.

CENTRAL DYNAMICS CORPORATIONHEAD OFFICE: 903 Main Street, Cambridge, Mass. 02139


May, 1967 67

V-52

his equipmentwn tarnish,

. V 4IP 111 S.6 gp :::-.11,

AA Aili141.11.4 A_ AILALAIL44700000000000000 _

alltAALAILAAIAAABLAIL111111111.

004100,000000000040000040000000000000000000000000000

AA AA AA AA AA AA AA AA Ai AA AAA&

..." .p. ,,F. Ale 116 AA 4.41, IR 0, 00 0,1* 1, 110 0w0 Or 000 0 0 0 0 fif PP 0

=-------Mt--

//' 4M,-.

\ 0

----.14,-.

9

stainless steel.Nems-Clarke stainless steel Video and RF Patchingsigned for the routing of RF and IF signals in receivertransmitter installations, and the distribution ofcomputer, telemetry, communication and TV installations.for use in 50 or 75 ohm installations, this equipmentreliability, longer operational life and better operatingthan comparable standard lines made of soft brass,Stainless steel doesn't tarnish or wear, and cannotround" by rough handling. Jack and plug combinationscontact pressure even after years of hard use,insertion loss. Write now for the free, 4 -pagedescribing the new Nems-Clarke stainless steel line.

Equipment is de-and low power

video signals in data,Designed

provides greatercharacteristics

silver and gold.be distorted "out of

provide uniformand maintain a low

illustrated data sheet

EQUIPMENT

585-1000477-6717

MT/ ELECTRONICSPRODUCERS OF NEMS-CLARKE

VITRO CORPORATION OF AMERICA919 Jesup -Blair Drive Silver Spring, Maryland 13011

2301 Pontius Avenue Los Angeles 64, California 1213)

CATV Converter(111)

For CATV systems whose custom-ers encounter ghosting problems be-tween a strong local broadcast signaland the cable transmission on thesame channel, Standard-Kolisman In-dustries Inc. has introduced a newconverter unit. The equipment con-verts the incoming cable signal to40MHz and then to channel 12 (otheroutput channels optional).

Features and specifications of theunit include: input frequencies, chan-nels 2 through 13; gain, 15dB onchannels 2-6 and 10dB on channels7-13; bandwidth, 6.0 MHz, with ad-jacent -channel carriers down 10dBminimum; noise figure, 10dB maxi-mum; input and output impedance75 ohms; input VSWR, 2:1 maximum;output VSWR 1.5:1 maximum; crossmodulation, down 55dB. A zener

YOU CAN GET MOREFROM YOUR CARTRIDGES

JOA gives you MORECARTRIDGE PERFORMANCE

. that's practical!MORE ENGINEERING TIME

... that's economical!Let JOA Cartridge Specialists reconditionand rebuild your worn cartridges and keepyour engineering personnel "engineering."-JOA will inspect, service and re-

load your cartridges with ANYLENGTH tape

NO MINIMUMNO EXTRA CHARGE FOR-

(a) FOAM TEFLON -FACED PRES-SURE PADS

(b) replacement of minor parts(c) VISIBLE SPLICE

ALL cartridges PRETESTED under ac-tual broadcast conditions

48 -hour Processing

Need NEW CARTRIDGES fast? JOA willship immediately . . . from stock . . .

any size Fidelipac, precision manu-factured NAB cartridge,

JOA-the cartridge service of author-ity-.serving the broadcast industry.

phone or writeCartridge ServiceP. 0. Box 3087

l'A O A Philadelphia, Pa. 19150AreaCode 215, TUrner 6.7993


68

Circle Item 40 on Tech Data Cord


WININF

Expanded production facilities and in-creased volume capacity at our factorymean superior JAMPRO quality anten-nas can now be furnished at thesenew low prices. Save up to 42% onyour FM antenna. Call Jampro today.

PRICES EFFECTIVE FEBRUARY 1, 1961JAMPRO No. of No. of . NEW

TYPE H. Bays V. Bays PRICE

J2B/2V 2J4B/4V 4J6B/ 6V 6J8B/ 8V 8J10B/10V 10

Prices apply to

24 $$42,015105..

6 $6,500.8 $8,900.

10 $11,100.antennas having equal

division of pow II bays.

For a complete tst of prices andspecifications, write or call JamproAntenna Co., today!

ANTENNAS MAY BE MOUNTED BACK to BACK or INTERPOSED to CONSERVE TOWER HEIGHT VSWR is better than 1.1 to 1 for ± 200 KC from carrier when properly installed. Antenna input connections are all 31/8" 50 ohms with EIA flanges. De-icers can be installed on horizontal bays at only $90 per bay. (250, 500, 1000 Watts) Prices are FOB Sacramento, Calif. and include suitable tower mounting hardware.

J A M PANTENNA

6939 POWER INN ROAD

R 0COMPANYSACRAMENTO. CALIFORNIA (916) 383-1177


69

owers too!For everyneedMoet comprehensive lineof Towers, Reflectors andpre -assembled aluminumbuildings anywhere. ForCA1V-FM-AM MicrowaveUHF - VHF. Designed, man-ufa:tured and installed byAdvance . . . the fastestgrowing company in theentire industry.

Lecse purchase plcn. CIV3 leble.

Write today for inmedia eestimate.

Advance industriesDept. BE

705 Douglas St. Sioux City, Iowa712 252-4475

regulated power supply and fine tun-ing of the preset, or memory, typeare used.

Overall dimensions of the unit are11.5" x 6" x 3.5'. Weight is lessthan five pounds.

Provision has been made for theaddition of a second tuner (channelselector), which may be included oradded later. This combination requiresa second cable, but it allows up to24 input channels.

Indoor SCA Antenna(112)

This indoor antenna, primarik, forSCA operators, is available fromMcMartin Industries, Inc. The unitcan also be mounted in a car. Builtinto the base of the A -72 -PA antennais a transistorized pre -amplifier witha 12 -volt power requirement. Thecylindrical antenna has a gray vinylcovering, is 221/2 inches long (in-cluding the connector), and has a 11/4 -inch diameter. Frequency alignmentto a specified frequency (within the88-108 MHz range) is accomplishedat the factory. The antenna assemblyhas been designed to be mounted any-where in a vertical, horizontal, or45° position. The antenna has a ratedgain of 8 dB. The item is shippedcomplete with coaxial connector andmounting bracket.

Head Conversion(113)

A kit to convert the new mono-phonic Wollensak and Revere tran-sistorized tape recorders from half -Hack to full -track recording is avail -

NEWMODEL CR-90

CARTRIDGE RACK

Holds 90 Cartridges Attractive Walnut -Formica Finish Large Openings for Easy Cartridge

Removal Rugged Interlocking Construction Compact 22 x 28 x 4

Net Price $35.

BROADCAST PRODUCTS CO.18804 Woodway Dr., Derwood, Md. 20855

(301) 942.1224


VEGAMICROPHONES

ALL NEW FROM VEGA!

Integrated circuits High power Solid state

Fully portable

ALSO... Bright, new ideas

in automaticaudio levelcontrol

I

Low cost capacitormicrophones

Visit Booth 306 at NAB

Write for free literature

VEGAELECTRONICS CORP.

1161 RICHARD AVENUESANTA CLARA. CALIF. 95050

I.0

Cncl, lt,m 44 on L..,11 Data Card

70



NEW

SOLID STATEPROFESSIONAL

AUDIO EQUIPMENTFor Broadcasting and

Recording Studios

Model 101SS

Fully Transistorized Plug -In PreamplifierFor Audio Consoles or MixersIdeal as microphone preamp or booster ampli-fier. Minimum wiring, negligible heat dissi-pation.

IN Noise level at output, input and output ter-minals -79 dbm Frequency response ±1db 20-20,000 Hz Size 11/2" wide x 31/e"high x 107/8" long

Model MSSCompletely Transistorized Plug -In LineAmplifier For Handling Broadcast -Recording ServicesFeeds line or distribution system. Low noisefigure makes it suitable preamp or boosteramplifier. Board mounted, all connectionsthrough single receptacle.

III Noise level at output, input and output ter-minals -67 dbm Frequency response ±0.5db, 15-50,000 Hz Size 11/2" x 31/8" x 107/8"

Model 136SS

Solid State Regulated Power SupplyFor Use With Audio AmplifiersAdjustable to accommodate various type am-plifiers. Rated 1.0 amp at 37 volts - suffi-cient for six 102SS Line Amplifiers or twenty101SS Preamplifiers.

Primary voltage, 115 volts AC, DC outputvoltage of 30 to 37 volts Taps movable forDC output voltage below 30 volts Fuse pro-tected. Remote sensing of error voltage isprovided

Model 120SS

Solid State Amplifier ForMonitoring & AuditioningSelf-contained power supply, stable operationover wide temperature range. Compact - fouramplifiers mount in 51/2 inches rack space.

Noise level at output max gain 61 db below1 watt output Frequency response ±1 db20-20,000 Hz IS Harmonic distortion at 20watts output, 8 ohm load - less than 0.5% Size 33/8" wide x 45/e" high x 101/2" long

AEROVOX CORPORATION1100 CHESTNUT ST., BURBANK, CALIF.

Selected commercial and military productsare available off -the -shelf from AuthorizedAerovox Distributors.


able from Nortronics Company, Inc.Called the WR-30, the conversionconsists of a full -track erase headand a full -track record -play headmounted on a brass plate to permitfull -track recording compatible withstudio -type tape transports. The as-sembly fits the new 1500SS1400AV Wollensak recordersthe older T1500 models. Themetal erase head has a doublefor complete erasure, while the

andandall -

gaprec-

ord -play head has laminated coresand a fine gap for good high -fre-quency performance.

Routing Clamps(114)

New clamps for temporary rout-ing of wires or for clamping of per-manent wiring have been added to

!if

NEW...LANG SOLID STATEPROGRAM EQUALIZER

Unsurpassed in design, performance andversatility, the new LANG SOLID STATE PRO-GRAM EQUALIZER PEQ-2 incorporates thefinest features found in quality equalizers,

PLUS THESE EXCLUSIVE FEATURES...

Eight low boost shelf frequencies Fourlow droop shelf frequencies Eight high boostpeak frequencies Six high droop shelf fre-quencies Frequency select switches andequalization controls for all boost and droopfunctions All controls and switches may beused simultaneously Low frequency peakboost by use of boost and droop controls Equalization "on" lamp indicates when equal-ization is taking place Engraved stainlesssteel panel blends harmoniously with otherequipment Plug-in transistor amplifier andPower supply cards Compact size: 31/ex19".

For complete details andnew Lang Catalog write.

LANGELECTRONICS INC.507 FIFTH AVE., N Y 17

For all your oudro needs - Look to Long!


Replace

857B

tubes

directly

with

lifetime

36-16 SiliconRectifier Stacks!Because... Wilkinson 36-16 Silicon Rec-

tifier Stacks virtually lastforever.

Immediately repairable inminutes.

Eliminate arc -backs, pre-heating and warm-up time.

Eliminate filament trans-former and auxiliary heaters.

Operate from -85° to+185°F ambient.

"Go -No Go" instantaneousproof of performance.

Only '475(less than the cost of a filament trans -former .. and you don't need them!)

SPECIFICATIONS: Model SR -36-16replaces tube type 857R PRV repet-itive 36 KV. PRV transient 42 KV. RMScurrent 16 amp. Surge current 1 sec.160 amps. Forward voltage drop 25V.

For complete details on Wilkinson Sil-icon Rectifier Stacks, write on yourcompany letterhead today to:

WILKINSONELECTRONICS, INC.

1937 MAC DADE BLVD. WOODLYN, PA. 19094TELEPHONE 12151 874-5236 874-5237


May, 1967 71

1 r,"" .:-.,.-.4,fir-,,,,f0,_..-el......-...-,,,....,--,el.. ,,,,L1 ,,,,4a t T,,.!...."-I''

- t, _ ,___s c- 44 --..4m-,..I.:----, ' -, r, 1:-11 k -t, """' 11P. r,.."*'

t -13 * 4114.

smeGi SWARMSTEREO

with Composite Output

and 100MHz FM Multiplex OutputThe versatile SMG1 generates a high quality stereo signal in

accordance with FCC standards for stereophonic broadcasting.Incorporation of the 100 MHz output, frequency modulated by thecomposite signal, eliminates the need for separate RF signal gen-erators in most applications. Thus the SMG1 serves as either acomplete stereo modulator or a multiplex FM station at your finger-tips - for development, production test and checking of stereoreceivers, adapters and systems.

Modulation is provided by the internal oscillator with a choice of80Hz, 1kHz or 5kHz - or by an external oscillator or completestereo -program source. The 19kHz pilot signal may be switchedin or out as required.

SPECIAL FEATURESFully transistorized and self contained

Both composite and RF outputs Pushbutton operation - quick and positive Modulation Operational Modes

Internal: R=L, R=-L, R ONLY, L ONLYExternal: R=L, R=-L, R+L, Stereo Program

Meter, Calibrated in % deviation, monitors compositeand 19kHz pilot signals

Standard 50 or 75 u sec. pre -emphasis - switchablein or out

Price: $1075 - Want all the facts? Write for booklet today!

THE LONDON COMPANY811 SHARON DRIVE WESTLAKE, OHIO 44145

RADIOMETER r-111COPENHAGEN L.

In Canada: Bach -Simpson Ltd., Box 2484, London, OntarioCircle Item 49 on Tech Data Card

the Thomas & Betts Co. Ty -Rap lineof harness fabrication products. Theclamps are locked closed by meansof slots which permit reopening atwill without damaging the clamp.They can be locked in either of threepositions to permit adjustability forvarying diameters.

The clamps are fabricated of nylonand are available in four basic sizes,1/2 ", I", 11/2 ", and 2" diameters. Eachsize has a variety of mounting con-figurations with or without an anti -rotation feature: adhesive -backed,threaded studs, push -in, push -in withantirotation feature, etc.

Crimped SolderlessUHF Connectors

(115)A line of fully crimped, solderless,

UHF connectors is being marketedby Kings Electronics Company, Inc.Called K -Grip Jr., the new units donot require hand soldering, and havebeen designed to increase the tensilestrength of cable connections.

With these connectors, cable trim-ming jigs and a crimping tool are fur-nished. The user trims the cablejacket and dielectric, crimps the cen-ter contact, and then crimps theconnector to the cable.

For only $550 your old Ampex 300/350 will be up-to-date in 1982 withnew Lang Record/PlaybackElectronics!

kett274_

MODELLRP

CHECK THESE ADVANCED FEATURES: ALL SOLID STATE COMPATIBLE WITHEXISTING HEADS LOW NOISE HIGH RELI-ABILITY FRONT PANEL SWITCHING DF MIC.AND LINE RECORD ALIGNMENT CONTROLSON FRONT PANEL PLUG-IN CONSTRUCTION BUILT-IN MICROPHONE PREAMPLIFIER HIGH OUTPUT RECORD ELECTRONICS LOWDISTORTION LINE AMPLIFIER SAFE RECORDSWITCH MONITOR JACKS COMPACT SIZE.

FREQUENCY RESPONSE:± 2 db 30-18 KHZ at 15 ips

2 db 50-15 KHZ at 71/2 ips2 db 50-7.5 KHZ at 33/4 ips

FOR COMPLETE DETA.L5 ANC NEA, LANG CATALOG WE FE

LANGELECTRONICS INC.SAT FIFTH AVENUE. NEW TORN N I 10017

For ail your auchoneecls LOOK ro LANG'


BROADCAST ENGINEERING72

Engineers'

TECH DATAOM MS MI I= UMW MO

ANTENNAS, TOWERS, & TRANSMISSION LINES

60. ANDREW-New 128 -page Catalog 25 features detailedproduct information and engineering data on antennasfor microwave, UHF and VHF communications, and tele-metry; flexible coaxial cables and elliptical waveguides;switching and pressurization equipment; and system ac-cessories such as radomes, positioners, and telescopingmounts.

61. CCA-Literature describes the FMA-7016R circularly polar-ized FM antenna.

62. FT. WORTH TOWER-Material covers towers, passive re-flectors, and equipment buildings.

63. GATES-Brochure is about the Dual -Cycloid FM antennawith circular polarization.

AUDIO EQUIPMENT

64. ATLAS SOUND-Catalog 566-67 lists public-address loud-speakers, microphone stands, and accessories.

65. BAUER-Model 910S eight -channel stereo console is sub-ject of new brochure.

66. CROWN INTERNATIONAL-Sheets provide technical dataand specifications for the SA30-30 60 -watt rack -mountedstereo monitor -amplifier.

67. NORELCO-Brochures give description, features, and otherpertinent information on professional microphones, com-mercial sound equipment, closed-circuit television equipment,motion -picture projectors, and color TV cameras.

68. PERMOFLUX-Subjects of brochure are monaural and bi-

CUSTOM 12"also available inSTANDARD 12" or 16"

Shhhh... Quiet Please!Today, critical listening is the name of the game.Audiences have become extremely "sound con-scious". So are QRK Professional Turntables."Sound Consciousness" is the reason a QRK hasonly 3 rotating parts and special vibration isola-tors. That's why a QRK offers a minus in rumblethat is far below NAB minimums. And, that's notall. Add ultra -acceleration, effortless control, sus-tained performance with practically NO mainten-ance and there's only one thing you can do . . .

Shhhh . . . just quietly see your Dealer today orwrite or call us for complete information.

ELECTRONIC PRODUCTS

2125 N. Barton, Fresno, Calif. 93703

Telephone: 209/255-8383 or 209/ 229-6128

'BEST

IN THE PATCH

FIELD . . . 'Al HarmonChief EngineerWTTG-TV,Washington, D. C., says:

"I'll recommend COTERM every time for itscompactness and dependability. With CO -TERM, we have no problems of open circuitsor noise from bad connections. Good designat the center -pin and the center connectorsinsure that."

COTERKU provides thebroadcast engineer with anew standard of depend-ability. With COTERM youhave normal -through co-axial circuits without theuse of patchcords. Whenthe load side is patchedthe source is terminatedautomatically in the properimpedance.

Active circuits may be tested without signalinterruption. COTERM is compact, permitting highdensity on the patch field - 22 jacks on the stand-ard 19" x 13/4" panel.

COJAX offers all the same advantages exceptself -termination of source when the load side ispatched. All COTERM - COJAX accessories arecompatible.

The unique snap lock featureallows easy insertion and removaleven in the densest patch field.Available for a wide range ofcoaxial cables and simple to at-tach with standard tools.

COOKEEngineering Company

735 N. Saint Asaph Street, Alexandria, Va. Telephone: 703-548-3889



73

naural headphones and dynamic microphones for headsetattachment.

69. QUAM-NICHOLS-Sound sheet deals with speakers andspecifications for use in public address, background music,intercom, and outdoor applications. Data on line -matchingtransformers is also included.

70. VEGA ELECTRONICS-Literature includes specificationsand prices on all -new, high -power wireless -microphonesystems and on new compressor/limiter for telephone use.

CATV EQUIPMENT

71. AEL-Technical data bulletins relate to plug-in modulesdeveloped for Colorvue series line amplifiers: CVT-AMautomatic -gain -control module, CVT-BM bridging -amplifiermodule, CVT-PM DC -powering module, and CVT-TM trunk -

amplifier module.72. SIGMA INDUSTRIES-New bimonthly bulletin presents in-

formation regarding cable -plant construction using thick -wall, heat -shrinkable splice covers and other products.

COMPONENTS & MATERIALS

73. BOSTON INSULA1E1) WIRE & CABLE-Information sheetrefers to the TV -85C color television connector with 85 pins.

74. CENTRALAB--22-page catalog contains detailed informa-tion and illustrations of line of push-button switches whichfeature modular approach to combining elements.

75. DIALIGHT New catalog L-204 is on the 913 -Series mo-mentary -action, push-button switches for mounting in 1/4" -

clearance hole on 19/32" centers.76. ELCO- -64-page guide describes and illustrates line of

printed -circuit connectors, enclosures, and installation equip-ment. Guide shows suggested applications, mounting data,PC -card layouts, and complete specifications.

77. STACO-Line of variable autotransformers and isolatedvariable transformers is pictured and described in six -pageVariable Autotransformer Product Guide.

78. SWITCHCRAFT---Bulletin 166 details new series of pushbuttons to fit firm's Series 21000, 22000, and 15000 illumi-

nated switches. Bulletin 169 is about a new 11/16"-square"Box Switch" (momentary -action push button) which canaccommodate up to four poles of switching.

79. TROMPETER-New Catalog T6 gives information on thecomplete line of patching equipment, connectors, etc., in coax,twinax, and triax.

80. VITRO- -Covered in four -page data sheet is the Nems-Clarke line of stainless -steel jacks, plugs, and jack panels.

MICROWAVE & STL EQUIPMENT81. MICROWAVE ASSOCIATES-The MA -2A and MA -7A all -

solid -state color television relay systems are illustratedand described in a new eight -page, short -form catalog.

82. MOSELEY ASSOCIATES- -The Model PCL-303 5 -watt, solid-state aural STL is subject of Bulletin 219.

MISCELLANEOUS83. WALLACH--Cabinets for disc recordings, transparencies,

filmstrips, and slides are covered in six -page brochure,which also includes information about the Reelmobile andmobile audio-visual center units mounted on wheels.

MOBILE RADIO & COMMUNICATIONS84. MOSLEY ELECTRONICS -1967 catalog lists line of Citizens-

band antennas.

RECORDING & PLAYBACK EQUIPMENT85. AMPEX- Features, specifications, and applications are list-

ed in brochures for the new AG -440 Series professionalaudio recorders, the VR-1100E and VR-1200E compact broad-cast Videotape recorders, and the line of products for TVbroadcast use, including Videotape recorders, cameras, andaccessories.

86. AUDIO DEVICES-Audiotape Formula 10 all-purpose, For-mula 14 low -print, Formula 15 low -noise, and Formula 17lubricated (for cartridge use) recording tape are describedin brochures.

87. AUDIO MAGNETICS- -"Magnetism and the Critical Dimen-sion" is the title of a booklet which explains magnetic tapeand its manufacture.

88. DOBBS/STANFORD-The Butoba MT225 all -solid-state bat -

0 TELEMATION, INC.

FIRST with an allDigital Color Sync Generator!AS SEEN AT THE NAB CONVENTION

TELEMATION, INC.

Check these exclusive features:

All pulses and transitions clock derived. No monostables - no delay lines. Integrated circuit reliability. Fast rise circuitry - 10 nsec. typical. Subcarrier vs. horiz. jitter better than

0.25 nsec. Pulse jitter better than 4 nsec.

throughout frame. Dual outputs - permit pulse

assignment with full standby. Color sync gen, color genlock,

bar/dot & sync changeover - allin 13/4" rack space.

Economical too! $1,000 mono,$1,500 color.

2275 South West Temple Salt Lake City. Utah 84115 / Telephone (801) 486.7564



tery- or AC -powered tape recorder is detailed in specsheet. Literature is also concerned with MB microphonesand headphones.

89. MAGNASYNC/MOVIOLA CORP.-Model DR -1 solid-statedisplacement recorder for 16 -mm, 100 -mil magnetic -stripemotion -picture film is covered by data sheet.

90. VIKING/MAGNECORD-Brochures illustrate and describethe Viking 230 and Magnecord 1028-1048 audio tape re-corders.

REFERENCE MATERIAL & SCHOOLS91. CLEVELAND INSTITUTE OF ELECTRONICS-Pocket-size

plastic "Electronics Data Guide" includes formulas andtables for: frequency vs. wavelength, dB, length of anten-nas, and color code.

TELEVISION EQUIPMENT92. BALL BROS-Illustrations, specifications, and general de-

scription about the Mark VI -A and Mark VI -AR specialeffects generators are given in four -page brochure.

93. CLEVELAND ELECTRONICS-A 52 -page quick -reference,step-down diecut catalog covers complete information onvidicon, Plumbicon, and image -orthicon deflection compo-nents. Included are photographs, specifications, technicaldata, and dimensional drawings.

94. COHU-3200 Series vidicon cameras, 1000 Series colortelevision system, and Model 9830-071 color encoder aresubjects of brochures.

95. COLORADO VIDEO-Data sheet tells about Model 405 scanconverter which translates oscilloscope patterns to TV formatwith storage.

96. COLORTRAN-Kits for adding adapter and specular ordiffuse intensifier to the Cine King or Cine Queen fixturesare outlined in specification sheet. Performance with boostedand non -boosted lamps is included.

97. DYNAIR-Offer is 26 -page, illustrated booklet "VideoSwitching Techniques." Described are various methods of

switching audio and video signals. Numerous diagran.show typical systems.

98. INTERNATIONAL NUCLEAR-Complete line of video equip-ment is presented in new Catalog 7A.

99. KALART-Four-page brochure "Large Screen TV Projection"and two -page information sheet show applications ofTele-Beam projector.

100. KAPPA NETWORKS-Essential factors which determinecost and size of delay lines, and product descriptions arefeatured in leaflet.

101. KLIEGL BROS.-Booklet titled "Lighting for the Plunge toColor" compares quartz -iodine and incandescent lightingfor color television; "Television Lighting for Quartz" andcondensed catalog present lighting products.

102. TELEMATION-Brochure about the Model TSG-2000 Seriestelevision synchronizing generators includes specifications.

103. TELEVISION ZOOMAR-Literature is concerned with News -breaker 400 portable color film processor for 16 -mm film,TV Colorgard Meter designed to reduce color monitor setuptime, and HTS studio equipment.

104. VITAL-Information is for Model VI -10A video distributionamplifier and Model VI -20 pulse distribution amplifier.

TEST & MEASURING EQUIPMENT

105. BARKER & WILLIAMSON-Specifications for Model 210audio oscillator and Model 410 distortion meter are givenin data sheet.

106. EICO-Firm's complete line of kits, factory wired equipmentand accessories, including those for test -instrument appli-cations is presented in new catalog. Special feature is com-pilation of dealers listed by state and city.

107. SECO-Offer is operating manual for new Model 107C tubetester with "constant -voltage" transformer and "eye -tube"indicator for grid -circuit test.

108. TRIPLETT-New test -equipment catalog Number 50-T isavailable.

SPOTMASTERThe all solid state AD1A

AUDIODISTRIBUTIONAMPLIFIER

s. h

g 6 6 6

Meet the AD1A, a solid state audio dis-tribution amplifier specifically designed forAM, FM and TV broadcast stations andrecording studios. The AD1A distributesaudio signals via five separate outputchannels (up to 25 with the addition ofADIA-X extenders), and incorporates afront -panel VU meter and monitor jack topermit visual and aural monitoring of theincoming signal at the output of the lineamplifier. Response is essentially flat from40 to 20,000 Hz, with low distortion andnoise, 60 db channel isolation and 12 dbpeak factor. For further information, writeor call today:

BROADCAST ELECTRONICS, INC.8810 Brookville Road

Silver Spring, Maryland 20910Area Code 301 588-4983

NEW

Ultra -Quiet Plug -In AmplifierNow available, a plug-in audio amplifier with anoise figure of -130 dbm.Essentially distortionless characteristics and high gain and out-put make the new 614A amplifier ideal for a wide range ofapplications, including: microphone preamps, line amps, play-back amps and record amps. It plugs into a miniature 9 -pintube socket.

The frequency response is flat from 6 hz to 100 khz with-.±0.25 db. Open loop gain is 57 db. Total distortion is less than0.5% at +22 dbm and the noise level is -130 dbm.

For technical data with typical application schematicscontact:

American Nucleonics Corporation1007 Air Way, Glendale, California 91201, (213) 245-0315or in Los Angeles area, contact: in New York area, contact:HAECO (213) 787-7733 CADDCO CORP. (914) 359-4434


75

1

del AA200

SOLID STATE AUDIO AMPLIFIERFrequency Response:±1db, 20 to 20,000 cycles at 100MW±2db, 20 to 35,000 cycles at 100MWHarmonic Distortion:Less than 1%, 20 to 20,000 cycles at 100MWLesS than 2%, 20 to 20,000 cycles at 200MWInput:50 ohms balanced (mu metal shielded,permalloy core transformer)

2,000 or 100,000 ohms unbalancedGain:70db, 50 ohm input, 8 ohm load65db, 2,000 ohm input, 8 ohm load15db, 100,000 ohm input, 8 ohm load

$345°Price:

Output: 500 and 8 ohms(grain oriented transformer)

Noise: Better than -70 dbCircuit: 7 transistors, 1 thermistorControls: Locking volume controlConnections: Barrier stripPower Supply: 9 volts DC, 100 MA(accessory power supply available)

Construction: Brown enamelledsteel case

Size: 9"L x 23/4"W x 31/4"HWeight: 28 ounces

1

Including complete Technical Data and SchematicFULL MONEY -BACK GUARANTEE IF NOT SATISFIED!Send check or money order-we pay postage.

ROUND HILL ASSOCIATES INC.A MILO ELECTRONICS SUBSIDIARY

434 Avenue of the Americas, New York, N.Y. 10011

Model PS -200

An all -transistor general purpose power supply, the Round Hill Model PS -200is particularly suited for use in applications requiring a stable, well -filteredDC source. It employs Zener referenced voltage regulation, and delivers 9volts DC at loads up to 200 MA with complete dead short protection. A lock-ing screwdriver -adjusted programming potentiometer permits the outputvoltage to be adjusted over a one -volt range.

Input Voltage: 105-125 volts AC,60 cycles, 5 watts

Regulation: Line + load 5 MVRipple: Under full load 10 MV, peak to peakOutput Voltage: 9 volts DC

(adjustable over 1 volt)Maximum Load Current: 200 MA

Controls: Locking programmingcontrol

Connections: Barrier stripConstruction: Brown enameled

steel caseSize: 9"L x 21/4"W x 3'/4"HWeight: 44 ounces

Price: 2450 Including complete Technical Data and SchematicSend check or money order-we pay postage.

ROUND HILL ASSOCIATES INC.A MILO ELECTRONICS SUBSIDIARY

434 Avenue of the Americas, New York, N. Y. 10011

Headphone -CordStrain Relief

by R. M. Kruse, Chief Engineer

WFHR AM -FM

Wisconsin Rapids, Wis.

We were bothered by a chronic prob-lem of headphone leads pulling open atthe earphone end. Since the eye lugsused on most headphone cords are simplycrimped on, any strain placed on the cordopens the connection. To solve the prob-lem, we made a hook by straightening apaper clip. One end of the hook is placedunder one of the screw terminals, and theother end is hooked through the sleevingon the cord. This arrangement absorbsthe strain. If desired, the exposed end ofthe hook can be wrapped with tape toconceal and protect the installation.

Headphone cords now last for almosta year, compared to a week or two beforethis method was adopted.

PUSH PAPER CLIPTHROUGH SLEEVINGAND BEND OVERTO MAKE HOOK.

4:0111tilksza, .::*".111)

PLACE HOOKUNDER ONESCREWTERMINAL

Tied up capital means limitingyour business expansion, post-poning promotion campaigns ordeferring other important equip-ment purchases. You can useyour present capital now for otherbusiness areas if you ..

j\" LEASE YOURBROADCASTINGEQUIPMENT!

Keep your funds liquid! Minimizeyour investment costs! Takeadvantage of special tax deduc-tions! Meet your other financialcommitments now! It costs lessto lease!

For complete details write today to:

LANG LEASING CORP.

507 FIFTH AVENUE NEW YORK, N. Y 10017TELEPHONE (2121 MU 2 7147


76



Professional Services

VIR JAMESCONSULTING RADIO ENGINEERS

Applications aid Field Engineering345 Colorado Blvd.

Phew (Area Cede 303) 333-5512

DENVER, COLORADO 80206Member AFCCE

JAMES C. McNARY

Consulting EngineerNational Press Bldg.

Washington 4, D. C.Telephone District 7-1205

Member AFCCE

CAMBRIDGE CRYSTALSPRECISION FREQUENCYMEASURING SERVICE

SPECIALISTS FOR AM -FM -TV

445 Concord Ave. Phone 876-2810Cambridge, Mass. 02138

AMPEX HEAD ASSEMBLY RECONDI-TIONING SERVICE for all Ampex pro-fessional model recorders. This profes-sional service features precision relap-ping of all heads for maximum head life.Your assembly is thoroughly cleaned andguides are replaced as required. Price in-cludes optical and electrical Inspectionand complete testing on Ampex equip-ment in our plant. Full track or halftrack assemblies . . . $35.00. One to twoday service. "Loaner" assemblies avail-able if necessary. LIPPS, INC., 1630Euclid Street, Santa Monica, California90404. (213) EX 3-0449. tf

CRYSTAL AND MONITOR SERVICE - Fre-quency change and repair service for AMmonitors including G.R., RCA, Gates, W.E.,and Doolittle; also H -P 335B FM. AM moni-tors bought and sold. What have you, whatdo you need? New or regrinding of AMcrystals for RCA, Gates, Bliley, W.E., andJ -K oven holders, repairs, etc. Fastest serv-ice, reasonable prices. Over 25 years inthis business. Eidson Electronic Co., Box96, Temple, Texas 76501, Phone 817 773-3901.

2-67-tf

VIDEO TAPE RECORDERAUDIO HEAD ASSEMBLY SERVICE

Precision relapping of all heads and sup-porting posts, including cleaning andtesting. Ampex head assembly with "cue"tracks, $75.00 complete. RCA units alsorelapped. One to two day service. LIPPS,INC., 1630 Euclid St., Santa Monica, Calif.90404. (213) EX 342449. tf

Kits serviced, shipped. Professional, reason-able. Also small broadcast rack and tableunits, carts, tuners, limiters. Write : 109Pinetree, Woodbridge, Va. 4-67-tf

Servicing arranged by mail on anythingelectronic. Flat fee. You know the costbefore you ship. Work prepaid before re-turned precisely repaired to factory speci-fications. $30 average. $20 handling on allcallbacks. VTVM's, SWL receivers, CB sets.FCC License. Limiters, Monitors, Stereo,Tuners, Test equipment. Busy? Why wastedays, dollars on trips to "quickie shops."Farm it t Ship! To: Mailtronics, 109 Pine -tree, Woodbridge, Va. 5 -67 -It

Classified11M1 !MI MI

Advertising rates in the ClassifiedSection are fifteen cents per word.Minimum charge is $2.00. Blind boxnumber is 50 cents extra.

EQUIPMENT FOR SALE

CO -AXIAL CABLE Heliax, Styroflex, Spiro -line, etc. Also rigid and RG types in stock.New material. Write for list. Sierra -WesternElectric Co., Willow and 24th Streets, Oak-land, Calif. Phone 415 832-3527 5-66-tf

Television / Radio / communications gear ofany type available. From a tower to atube. Microwave, transmitters, cameras,studio equipment, mikes, etc. Advise yourneeds-offers. Electroflnd Co., 440 ColumbusAve., NYC. 212 -EN -25680. 8-64 tf

Trimm 504 Audio Patch cords $4.00. Audiojack panels for 19" racks, 10 pair $8.95.Repeat coils 500-500 ohm flat to 20kc $4.00-Relay racks and equipment cabinets.Write for list. Gulf Electro Sales, Inc.,7031 Burkett, Houston, Texas. 4-66-tf

Audio Equipment bought, sold, traded.Ampex, Fairchild, Crown, McIntosh, Viking.F. T. C. Brewer Company, 2400 West HayesStreet, Pensacola, Florida. 3-64-tf

Everything in used broadcast equipment.Write for complete listings. BroadcastEquipment and Supply Co., Box 3141, Bris-tol, Tennessee. 11-64-tf

RADIO AND TELEVISION STATIONS forsale in all parts of United States. Qualifiedbuyers may receive further details bywriting to Inter -Media CommunicationsCorporation, 246 Fifth Avenue, New York,New York 10001. 1-67-121

G. E. Phono cartridges for broadcast use.Prompt service. Send for price list. RidgeAudio Co., 91 E. Lake Rd., Skaneateles, N.Y.13152. 2-67-4t

New Spotmaster cartridge equipment, OREturntables, all models available, will take inany trade regardless age or condition. Audio -vox, 4310 S. W. 75 Ave., Miami, Fla. 3-67-tf

CARTRIDGE TAPE EQUIPMENTCompletely reconditioned and guaranteed.Spotmaster Model 500 Record/Playbacks,$350.00. Model 505 Playbacks $250.00. 30 -day money -back guarantee on all equip-ment.

BROADCAST PRODUCTS COMPANY18804 Woodway Drive, Derwood, Maryland,

20855

(301)942-1224 3-67-121

U-shaped Broadcast Console, Collins 808-ARemote Console, 2 A.T.C. Playbacks, I Re-cording Amplifier. Meades, 10800 Dale St.,Space 715, Stanton, Calif. 3-67-5t

FOR SALE: Large assortment tube typetelevision equipment, cameras, switchers,sync generators, stab amplifiers, powersupplies, monitors, etc. Cox BroadcastingCorporation, 1601 West Peachtree Street,N. E., Atlanta, Georgia. 4=67-4t

"AUDIO EQUIPMENTneeds, check us first.pex, Altec, AKG, EV,Langevin, Rek-O-Kut,for equipment list."Inc., 2342 S. DivisionMichigan 49507.

- Whatever yourNew and used. Am -Fairchild, Neumann,Uher, Viking. SendAudio Distributors,Ave., Grand Rapids,

6-66-tf

HAMMARLUND FM50A (144-174 M.C.), 35watts, 6/12/110 transistorized power supply,10 units, purchased less than 11/2 years agoat $600 each; $240. ARC VANGUARD (144-174), 50 watts, 12v., w/secode all transistor-ized except transmitter, 2 units less than 1year old. Original cost $1000 each; $495. Allequipment top condition w/accessories.INTERNATIONAL DIVERSIFICATION, 1015Glenside Place; University City, Missouri63130. 314 991-1941. 5-67-1t

Two modified RCA TK-40A Color CameraChains in working condition. Exceptionalvalue. Immediate delivery. Write P. 0. Box18151, Tampa, Florida, 33609, or phone area813, 253-0447, Tampa. 5-67-21

One KW Collins transmitter. Extra parts.D. C. Stephens, Manager WPRT Radio Sta-tion, Prestonsburg, Ky. 41653. 5 -67 -It

"Arcturus" CatalogA Trusted Name in Electronics

Since 1925FREE Catalog. Electronic parts, tubes.Wholesale. Thousands of items. Unbeat-able prices.

ARCTURUS ELECTRONICS BE

502-22 street, Union City, N. J. 07087

EQUIPMENT WANTED

We need used 250, 500, 5K & 10K WattsAM Transmitters. No Junk. BroadcastEquipment and Supply Co. 1314 IturbideSt., Laredo, Texas 78040. 3-66-tf

EMPLOYMENT

Need general maintenance technician withfirst phone and some experience in broad-casting. Salary commensurate with 'radioand television maintenance experience.Send resume and phone number to GeorgeWussow, KHSL-TV, P.O. Box 489, Chico,California 95926. 4-67-3t

VIDEO CIRCUIT DESIGN ENGINEER . . .

Leader in audio, video, and instrumentationrecording engineering seeks Video Engineerwith BSEE or equivalent. Some TV stationbackground desirable. Smog -free location inone of So. Calif.'s garden spots just 45 min.north of L.A. Send resume: EmploymentMgr., Revere-Mincom Div., 3M Company, 300So. Lewis Rd., Camarillo, Calif. 93010. 5 -67 -It

MICROWAVE RELAY TECHNICIANS: Im-mediate and future openings at all experi-ence levels with fastest growing MicrowaveCommon Carrier in U.S. First or secondclass FCC radiotelephone license required.l'refer men with microwave and video ex-perience but will consider other relatedbackground. Work in New York and Penn-sylvania. Good pay, terrific growth oppor-tunities. Reply to: John Murray or AlanBurgess, Eastern Microwave, Inc., WSYR-TV, 1030 James St., Syracuse, N.Y. 13203.

4-67-21

(Help Wanted-Television-Technical)Established group -owned TV station in theSoutheast has opening for video operatorwith rst class license and potential forgrowing into -administrative duties assist-ing the Chief Engineer. This is a positionwith an aggressive fast-growing companyand has excellent possibilities. Send re-sume to Dept 174, Broadcast Engineering.

4-67-21

May, 1967 77

"First Class engineers, maintenance back-ground, no board work. Immediate open-ings. Excellent growth opportunity withindependent group. Bush reply by letter toC. Dingmen, WCTC, 385 George St.. NewBrunswick, N. J." 5-67-21

RCABURBANK, CALIF.

has an exceptional challengefor a

PROJECT LEADERColor TV Camera

This is a ground floor opportunityto enhance your career by joiningour select team of engineers in thedevelopment of TV systems for theInstructional Electronics field. If youhave experience as a Project Leaderin the development of color TVcameras and associated equipmentand a MSEE or equivalent, this posi-tion offers unusual professionalgrowth potential.RCA in Burbank is an engineeringoriented organization. Big enough sothere's room to grow. Not so big thatyou'll get lost in the shuffle. Yetbacked by all the resources of oneof the nation's largest electronicscompanies. We offer liberal fringebenefits including relocation allow-ances. To inquire, send your resumeto: Mr. Glen Seltzer, RCA Broad-cast & Communications ProductsDivision, 2700 W. Olive Ave., Bur-bank, Calif.

An Equal Opportunity Employer

The Most Trusted Namein Electronics

SYSTEMS

VIDEO

SWITCHING SYSTEMS

ENGINEERS

Our rapidly expanding volumeof business has created open-ings for systems engineers fa-miliar with vertical intervalswitching equipment. Respon-sibilities include provision ofwiring information on rackand control panel equipmentfor custom switchers. Some sta-tion experience and familiaritywith audio preferred. Pleasesend resume of experience orcall Mr. R. J. Rainey, 201-382-3700.

WARD ELECTRONICINDUSTRIES

142 Central Ave.Clark, N. J. 07066

5-67-1t

CATV FIELD ENGINEERSA well-known manufacturer and designerof CATV equipment, builder of turnkeysystems. and systems owner has severalcareer openings for qualified field engineersand technicians. Please forward a resumeof your background and experience, includ-ing salary requirements. All contacts willbe confidential. Our employees have beeninformed of this advertisement. Box 175,Broadcast Engineering. 5-67-1t

Job Headquarters for all Radio and Tele-vision Engineers. Immediate openings existin 9 western states and elsewhere for qual-ified engineer and technical personnel. Allcategories from trainees to experiencedtransmitter maintenance, chief, assistantchief, live color video maintenance andtechnical operations. Send us your com-plete resume now. The AMPS Agency, 3974Wilshire Blvd., Los Angeles, California90005. Telephone DU 8-3116.By Broadcasters-For Broadcasters 11-66-tf

TELEVISIONENGINEERS

We are interested in contactingStation Engineers capable of designor field engineering. Excellent oppor-tunities in TV Development Engi-neering and Systems Engineering withSarkes Tarzian, Inc., BroadcastEquipment Division.

TV station engineering experiencerequired, BSEE or equivalent desir-able. Send resume of experience, orcall, Mr. Biagio Presti, BroadcastEquipment Division, Sarkes Tarzian,Inc., Bloomington, InCiana, AreaCode 812, 332-7251.

IS.Symbol of iExcellence

InternationalAssignment

International Television Organiza-tion needing qualified engineersfor challenging position in Far East.Minimum of 5 years maintenanceexperience in such positions asChief Transmitter, Mobile Van andStudio Engineer.Job requires separation from de-pendents; however, periodic homeleave included as condition of con-tract.Salary and allowances commensur-ate with position.

BOX 176BROADCAST ENGINEERING

PERSONNEL

College student, 21, accounting major, seekssummer employment. Available June 9.Third -endorsed ticket. Experience w/NBCowned and operated, and others. HenryNavin. 9325 Beacon Avenue, Cleveland. Ohio.

5-67-1t

Advertisers' I nde)

Advance IndustriesAerovox Corp.

Altec Lansing, Div.LTV Ling Altec, Inc.

American Nucleonics Corp.Ball Bros. Research Corp.Broadcast Electronics, Inc. 60, 66Broadcast Products Co.CBS Laboratories, Div. of CBS, Inc. _

CCA Electronics Corp.Central Dynamics Corp.Cleveland Institute of ElectronicsCohu Electronics, Inc.Collins Radio Co.Continental ElectronicsCooke Engineering Co.Crown InternationalElectro-Voice, Inc.Fairchild Recording Equipment CorpGates Radio Co.General Electric Co. 26, 27,

International Nuclear Corp. CoveJampro Antenna Co.JOA Cartridge ServiceLang Electronics, Inc. 71

Lang Leasing Corp.Lenkurt Electric Co., Inc.London Co. 72Magnecord, Div. of Telex Corp. 25Metron Instruments, Inc. 64Microwave Associates 50Minneapolis Magnetics, Inc. 62Moseley Associates, Inc. 60Norelco 36, 37Overly Mfg. Co. 54QRK Electronic Products 73RCA Electronic Components and

Devices Cover 4Rek-O-Kut 66Richmond Hill Labs, Inc. 63

Riker Video Industries, Inc. Cover 2Rohn Systems, Inc. 58Round Hill Assoc., Inc. 76Scully Recording Instruments Corp. 47Shure Bros., Inc. 48Sparta Electronic Corp. 49Stanton Magnetics IISuperior Mfg. and Instrument Corp. 62Telemation, Inc.Telemet Co.

Texwipe Co.

Trompeter Electronics, Inc.Vega Electronics Corp.Visual Electronics Corp.

Vital Industries

Vitro Electronics Div.,Vitro Corp. of America 68

Ward Electronic Industries, Inc. 7

Wilkinson Electronics, Inc. 58, 71

7446

57

64

70

61

10


If your televisionstation ownec oneof our TS2Weather Satellite Signal

Processors and some other inexpensive equipment,your weatherman cou d do more than just talka3out the weather...

He coulc oicture it!

This ingenious engineeringfeat makes satellite weatherpictures available to any televisionstation. The basic equipmentneeded is sheer simplicity (our TS2,a Yagi antenna, an FMRadio receiver, a 5" oscilloscopeand a polaroid camera).

The system (we furnishdiagrams and specificationsfree) can give yourstation instant pictures ofweather for a 1000 mile square.It can put muscle intothe ordinary flabby job offorecasting or reporting weather.

Write or wire or phone collect:Ray Weiland, President

INTERNATIONAL NUCLEAR CORPORATION

608 Norris Avenue

Nashville, Tennessee

615 - 254-3365

"Transistorizingthe Television Industry"

Don't just talk about the weatherat your station. Do something.Write for complete informationabout our TS2 - anotherexample of the results ofInternational Nuclear'ssearch for a better way to do abetter job . . . in electronics.


flew RCA'41111111115k BIALKALI-PHOTOCATHODE

ELECTRONICALLY-CONDUCTING

GLASS TARGET

IMAGEORTHICONS

RADK) CORPORATIONOF AMERICAELECTNONtC

COMPONENTSAHD DE VI CES,

HARRISON,N J.

Don't forget to ask for yourcopy of catalog CAM -660.Available from your RCABroadcast Tube Distributor,

The Most Trusted Name in Electronics

may 1967/75 cents roadeast engineering...

Documents