67 - American Radio History

Transcript

BROADCAST BROADCAST .. .. BROADCAST BROADCAST BROADCAST WORKING FOR DEFENSE BRi:141úkt; I BROADCAST Vol. No. 67 JAN.-FEB., 1952 BROADCAST BROADCAST .A.t , P. 401,4,1. ,e. BROADCAST - MoMe BROADCAST ti r.., \.[,: R-1 BROADCAST w r4 sum mum .., BROADCAST w. #;/* /7/# sra*&,4&604.5- ... from your RCA nearest Sales Representative This 64 -page book is prepared specifically for TV station management, chief engineers, architects, consultants, and attorneys con- nected with station designing, planning, building, and operating. In a single reference it contains concise descriptions of RCA's entire line of TV transmitter and antenna equip- 200,000 Watts Power to Radiated for Any blidiulels 2 t ment- including transmitter plans and layouts, general application data, and cost charts. For your copy, get in touch with the RCA Broadcast Sales Representative nearest you: New York 20, N. Y. 36 W. 49th Street Telephone: Circle 6 -4030 Dallas 1, Texas 1907-11 McKinney Ave. Telephone: R -1371, 1372, 1373 Cleveland 15, Ohio 718 Keith Building Telephone: Cherry 1 -3450 3, Ga. Atlanta 522 -533 Forsyth Bldg. Forsyth and Lucide Streets, N. W. Telephone: Walnut 5946 K City 8, Me. 221 W. 18th Street Telephone: Victor 6410 Hollywood 28, Calif. 1560 North Vine Street Telephone: Hollywood 9.2154 San Francisco 3, Calif. 1355 Market Street Telephone: Hemlock 1 -8300 Chicago 11, Hl. 666 North Lake Shore Drive Telephone: Delaware 7 -0700 Washington 6, D. C. 1625 K Street, N. W. Telephone: District 1260 Boston 34, Mass. John Hancock Building 200 Berkeley Street Telephone: Hubbard 2 -1700 \-/ RADIO CORPORATION of AMERICA ENGINEERING PRODUCTS DEPARTMENT www.americanradiohistory.com CAMDEN, N.J. OUR COVER, as you hardly need be told, is a reprodaiti.m of the covers of all issues of BROAD. CAST NE%' from Vol. No. 1 (October 1931) to the last previous issue (Vol. No. 66). On the back cover (did you notice it ?) are the covers from 1931 through May 1941. These are arranged chron Broadcast News ologically, in rows, from top to bottom. On the front cover are all issues from September 1941 to date, similarly arranged. AM FM TELEVISION HISTORY OF BROADCAST NEWS is portrayed in picture and story, starting on Pg. 2. If the story seems to get a little sticky now and then, please forgive us. When we think of how the industry has grown, and our business (and BROAD. CAST News) with it, we get a little carried away by it all. Published by the RADIO CORPORATION ENGINEERING PRODUCTS DEPARTMENT AMERICA OF ... CAMDEN, NEW JERSEY THE INDEX, which we have been promising you for too I.u,g has finally been put in shape and appears oil Pg. 14-27 of this issue. Main credit for getting this done goes to Dick Newman of our broadcast transmitter sales group. Dick, who has been in Camden as Product Manager for Transmitters for the past two years, has now returned to his old stamping grounds in the San Francisco area. However, before he left he managed to get the index almost done and Norm Rivkees, who recently joined our group, has completed it. We hope you like it, and find it useful. But if you lind any errors, please write Dick, not the editor. JANUARY-FEBRUARY, 1952 NUMBER 67 Subscription Rates In continental U. In other countries JOHN M. L. P. S. A. - GASKILL, B. for for 12 issues issues 12 W. O. HADLOCK, Managing Editor TAYLOR, Editor E. 1;1.00 $5.00 - - MAY, E. C. MASON, W. R. COULTER, Associate Editors Contents by JOHN TWENTY YEARS OF BROADCAST NEWS P. TAYLOR 2 BROADCAST NEWS CHRONOLOGICAL INDEX 14 BROADCAST NEWS CONTENTS INDEX 15 BROADCAST NEWS CROSS- REFERENCE INDEX (by Subject Matter) BROADCAST AUDIO TRENDS IN IMPROVED TELEVISION PICTURE PERFORMANCE TELEVISION ON THE WING VERSATILE ANTENNA ASSEMBLY -LINE TV WRZE WHITE 28 34 49 by M. RETTINGER 50 by QUINTEN G. CUMERALTO 52 by E. T. JONES 54 ENLARGING THE TELEVIEWING AUDIENCE FOR by W. E. STEWART 49 STUDIOS BROADCASTING t' GEORGE KOFHLER AND E. C. MASON HAM FORUM 25 -KW CONVERSION . EQUIPMENT RECTIFIER TUBE PROTECTION . Copyright 1952 Radio Corporation of America RCA Victor Division Camden. N. J. 58 60 NINTH BROADCASTERS' TV TRAINING PROGRAM times more broadcast operating personnel than it would in any other place. To these men we owe a real debt -and we hereby acknowledge it. 23 by H. N. KOZANOWSKI APPARATUS ROSE BROADCASTING CO. FUTURE TALENT . . . TEST . ACKNOWLEDGMENT is also due here to all of tlu 1;1'.:\ engweer* who have given of their time ( usually their own, not the company's) to make BROADCAST NEws as interesting and technically accurate as it has been. In many, if not most, cases, they could have "sold" their material to outside magazines. However, because of their interest in the broadcasting business they preferred to see it in BROADCAST NEWS where it reaches several by M. L. GASKILL 62 by F. E. TALMAGE 64 by I.IAL MOBLEY, JR. 74 THANKS also to all of you station and network engineers-and not a few managers-who have taken time to furnish material for all the many issues of BROADCAST News that have rolled off the presses. It is your stories that have kept BROADCAST NEWS from becoming as one-sided as many house organs are. We hope you will continue to supply us with your material -and we'd not so even like to have a little more of it much the beaming face of your station manager and the pretty front of your new transmitter (although we have nothing against them), but rather more of the details of how you did it. Especially those little ideas that are your very own. Maybe you would be surprised how interested others would be in them. ... ANTENAPLEX, the community kind, comes in for a few kind words in the article starting on Pg. 54. RCA has developed and is marketing high-quality equipment suitable for serving communities in fringe areas of TV stations. As Ed Jones points out, such installations actually increase the audi ence of the station since, in most cases, they bring signals to homes which otherwise would have no service. Just how widely such systems will be used is still a matter of conjecture. However, the number of installations being made is such that coy erage will definitely be a factor in some parts of the country. BRJIDVIST NEWS 1411(1101.10041 mnl M1,OOi NX34 MAW. tovfvAOf-, Al.,. ItonOCAP [ane RCA Victor Company,lnc., Camden. N.J. IXILAB VOLUME NO. 1. October 1931, was a thin 12 pages, with a single color cover, which by today's standards looks a bit old-fashioned. Contents. however, were not too different from our most recent issues. The feature story was a description of KFI's then brand new RCA 50B installation -"the first 50 KW west of Texas" incidentally, is still going strong). In addition, there were two engineering "know how" stories: one of them on Microphone Placement by T. A. Smith, now Assistant General Manager of the Engineering Products Department; another on Field Intensity Measurements by the present editor. (which, - VOLUME NO. 21, July 1936, was much flossier. By this time BROADCAST NEWS had grown to a nice big 36 pages. The cover of this volume, a special Convention Number, was unusual in that it featured a picture of L R. Baker, who managed RCA's broadcast transmitter business from 1930 to 1943. It was Bake who formulated RCA's policy of building the best in broadcast equipment and of merchandising it with directness and honesty. BROADCAST NEWS. too, was Bake's idea -and certainly no one deserved more to grace the cover. However, such was his modesty that he was considerably irked when, without his foreknowledge, this cover appeared. VOLUME NO. 30. May 1939 marked a milestone in BROADCAST NEWS, when, for the first time, a piece of "commercial" television gear appeared on the cover. The TT -1A Television Transmitter shown on this cover, and described in following issues, was announced coincidentally with the start of "commercial telecasting" in New York. Although the "start" was somewhat premature it was an unmistakable portent of things to come, and of postwar issues of BROADCAST NEWS which have been more and more marked by the gradual ascendance of television as a main topic of conversation among non -TV broadcasters as well as present telecasters. TWENTY YEARS OF BROADCAST NEWS by JOHN P. TAYLOR Engineering Products Department BROADCAST NEWS is now in its twenty first year! The cover of this issue, which so proudly proclaims our 20th Anniversary, is actually a little late, for the first issue of BROADCAST NEWS was dated October 1931. Whether or not that impresses you, and how it impresses you if it does, will depend on how old you are and how long you've been in the broadcast business. If you were in the business in 1931 we don't need to tell you how different it was then. But if you were not, then we will have a difficult time convincing you. If you are statistically minded maybe we can do it by pointing out that in 1931 the total gross revenue of all the stations in the United States was only 56 million, about 8% of 1951's total gross revenue. That sounds as if broadcasting in 1931 was a small thing -and by today's standards it was. But this comparison tells only half the story. To complete the picture you must also note that only four years before, in 1927, the total gross of all the stations was less than five million dollars. In other words, in 1931 the industry was still an infant, dollar-wise, but it was a husky brat that had grown ten times over in only four years. So much for the statistics. If you are technically minded, and you weren't around then, maybe we can place it for you by telling you that all audio equipment was operated from storage batteries, a one kilowatt transmitter required a water-cooled tube, most plate power (as well as filament power) was supplied by motor -generators, the condenser microphone was the high favorite in the studios, radiating towers were only just coming into use, and directional antennas were only a subject of conversation. Of some 700 stations on the air in 1931 the great majority were of "composite" manufacture. Many of them were really "home- made" in the homiest sense of the word. This was not surprising, for many. 2 www.americanradiohistory.com if not most, of the broadcast stations taking the air during the twenties did so by the grace, if not the inspiration, of some aspiring amateur. However, by 1931, quite a few stations were making money (a development which originally came as something of a surprise). As the cash registers started ringing broadcasters stopped looking on their stations as hobbies, or prestige operations, and began running them like businesses. That's where we came in. RCA had started selling broadcast equipment in 1927, but did not aggressively go after the market until its manufacturing operation was established in Camden, N. J., in 1930. In the early part of 1931 there were just 30 RCA transmitters on the air. Six RCA transmitter salesmen were running themselves ragged trying to sell all the other 670 stations the advantages of RCA equipment. It soon became evident that in order to get information about our new equipment out to 700 stations in a hurry we would need some other means to augment personal calls. But how? WORKING FOR DEFENSE VOLUME NO. 37, September '.941 marked another important milestone. By this time BROADCAST NEWS covers had gone through several metamorphoses. (See outside front and back covers of this issue.) Only the masthead stayed reasonably constant. But it remained for this issue to strike a really different note. Although Pearl Harbor was yet to come, its shadow was on the land. BROADCAST NEWS, on cover and in editorial. recognized the state of national emergency. And, within months thereat ter, it, like everyone else, went to war. From this time until V.f Day, issues were few and far between. The answer we arrived at was BROADNEWS -our own magazine, for our own customers (and fair prospects). A magazine devoted to the interests of broadcasters-particularly those of a technical bent- and carrying only information of interest and usefulness to them. CAST The selfish purpose of BROADCAST NEWS, of course, was to present information on our equipment, its uses, its advantages, and its operation. We soon found, however, that this need not be a one -way street. From the very beginning we had sugarcoated our message by using at least half the page space for presentation of engineering "know -how" articles. To our delight station engineers all over the country received BROADCAST NEWS with obvious pleasure. Best of all, they sent in not only their kind comments, but also pictures of their installations, and articles on various ideas they had used successfully. Most of this material found its way into and thus the BROADCAST NEWS pages magazine became a sort of meeting place for station engineers. ... Naturally we were very happy with this development and have done our best to encourage it. Proof of this is found in the 1948 symbolized the post -war boom of the broadcasting industry and of BROADCAST NEWS. Now a big grown -up boy of 72 pages, with a four -color varnished cover, this issue of BROADCAST NEWS featured a detailed technical description of RCA's 5KW TV Transmitter, Type TT -5A. This is the transmitter which made today's television a reality. On the market, and available in quantity, long before any competitive make, it powered -and still powers most of this country's first one hundred television stations. It set the standard of today's television. VOLUME 68, March 1952. is, so to speak, a glimpse in the future. This - preview- of our next issue's cover shows BROADCAST NEWS still leaing the way in picturing new developments. This time it's UHF. Featured on the cover, and in the feature story, is RCA's new UHF antenna, now in production to meet the demand of post freeze stations in the new UHF bond. Also featured in this issue will be a description of RCA's completely new TV camera and camera control units. In addition, there will be the usual station and engineering articles which have featured every BROADCAST NEWS from the very first. fact that in recent years nearly half of the content material has been supplied by sources outside of RCA. We have not stopped there, however. In order to further supplement these engineering type articles we have enlisted the assistance of our own large corps of engineers. Nowadays almost every issue carries at least one article by one of these engineers. Ranking at the top of the profession, and working day -to -day on the newest and most advanced developments, they speak with authority, whether they write about theory, equipment design, or operation. issues from the very first chronological order. These covers, in themselves, tell most of our twenty -year history in the briefest, and probably most interesting, manner. Then, just above, we have reproduced some of our "milestone" covers with a few comments about their significance. Finally, in the pages immediately following we have collected a representative sampling of BROADCAST NEWS articles over the twenty -year period. This is just to refresh the memories of the old- timersand perhaps to slightly awe the new -comers (and Johnny-come -latelies). To these article by station engineers and our own engineers, we add station stories and equipment news stories written by our own technical staff. Then we throw in a few of our best and prettiest ads, and that's it. No cheesecake, no cartoons (well, not many), no company puffs; in fact, no extraneous material at all. Just broadcast engineering and operation- straight. That has been the continuing policy for twenty years, and, if we're here, it will be for another twenty. Starting on Pg. 14 will be found an overall index to all issues of BROADCAST NEWS to date. To those of you who have carefully hoarded your back copies this should be of some usefulness. To those who haven't it may still be a useful reference to material available elsewhere. VOLUME NO. 48. March On the outside cover of this Anniversary Issue we have reproduced the covers of all - -in - However, please note that we have a supply of only a few back issues. Those available are Nos. 42, 43, 44, 45, 46, 47, 48, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 63, 64. First come, first served as long as they last. Twenty cents each for handling and mailing. 3 www.americanradiohistory.com kOADCAST 1936 APRIL. NEWS 1ROADCAS1 A FIELD INTENSITY Top A Simple Method of Adjusting DlcEy5E5 W 193, SLIDE RULE Loaded and Sectionalized Antennas n BROADCAST NEWS . NOYFAIEI 193- LIGHTNING IS A MENACE tROADCAST NEWS . ...,,,,,, 113 MAY C LOGARITHMIC RECORDING OF FIELD A INTENSITIES Brief Survey JULY. 1935 etoADCAST NEWS of the Characteristics Broadcast S OR G SIMPLIFIED SOLUTION FOR ANTENNA IMPEDANCE MATCHING NETWORKS SIMPLIFIED /J,,;Ed;r,; Y.r r ., rl i,,..l. .,t .. 11 A/r...;/i.vl SUMUN13 .Irma. Slr..i_n IROADCAST NEWS. JANUARY 1 Twenty NEWS Years of !',..IrrrN,r... r,..rr,..r. A LAMONT 63.0ADCAST 111 rr of RCA YEAR, Fe, O.e. Ir..rl 913 DIRECTIONAL ANTENNAS rd.lr Irr hnd r. .. W0WN NETWORK SYNTHESIS arra 739 33^9. NEWS eROA DC AST Antennas N BROADCAST 9, .t vOtieNWr3DEA lN YOUNG NEWS r. , MARCH, PARALLEL MIXER CIRCUIT CALCULATIONS 1139 NrN.N, MECHANICAL DESIGN OF OPEN WIRE TRANSMISSION Jhi. /rrrprrJ,rnr ,¿,,.At I.',rRrrr.. r+ l+ LINES II GA At XI BROADCAST SUGGESTIONS 1930 JULY 'NEWS '-1sECC3S' 1 NEWS AUOUSy F OR To MEASURINGCOUPLING OF EQUIPMENT T.I.F. CALCULATION OF LOADS FOR TRANSMITTER E930 R -F CHARACTERISTICS NEWS ADCASt ER OVERHEAD 1931 MN, OF UNBALANCED TRANSMISSION LINES l.w.n.r.. ..._r- LINE TRANSMISSION SIX WIRE -r FM STATION FM AN GROUNDED-GRID Anylit'ers Own R30isf reeUenos Power Handle Wider Bandwidths AMPLIFIERS POWER CaÉ Sy aCie THE GROUNDED -GRID - At Hüner f revolves Comets Operate Covets Graunded.God TUSE And Can iRMEp A NON- FOR SITE A SELECTING AUDIO MEASUREMENTS with an AM RECEIVER I I Grounded -Cathode "n "lited C. Rik MOBILE pNENNp AMPLIFIER h3 WEBER E I F1Ett Dsc ILLOSCOPES BAND ZHE FM HOWbrTHo ST4RNTk AND VACUUM TUBE VOLTMETERS WHAT THEY DO YERE RAaDGAND UREMENjiNN 3. TECHNICAL ARTICLES on TECHNIQUES MEASURING FOR DISTORTION AND FREQUENCY RESPONSE AUDIO SPEECH INPUT SYSTEMS TRANSMITTING SYSTEMS FM lbeA I I ,. u..m nvrbrvl.E.,w. ..T . the Prn. ,...,. nl ., ., Ln.,,,- By REQUENCY RECORDING AND Fine GROOVE TECHNIQUE H. E. RANGE PREFERENCE SPEECH FOR by AND MUSIC By ROYS RSA MARRY i OLSON station operation have always been the most important part of BROADCAST NEWS. Many of these articles have emphasized the how.to -do-it angle. All have been chosen because of their direct usefulness to station engineers. In twenty years of publishing, BROADCAST NEWS has printed literally hundreds of such articles, most of them by the top men in the profession. The wide range of subjects covered by these articles is indicated by the headings in the columns MEASURED :HARACTERISTICS of the PYLON ANTENNA .,... r3,13313 i.. A r,` ' . 1 M. .r .r n1iW . . 43 R'N 4e' ',>RrM9.rm .'nRrr . ., .a.,w..Rr1 ,6+eriAt OrfCR1tT1ON Or 9. 1ww+iw.in.rr,a. .ST .emi.lnnWmr3 r. __ W.I. M R4 E-RVRW,'NO*. N.eMN.n SrT111 °: 13, °rI_': A METHOD OF DETER TRACKI NG THE CAPABILITIES ILITIES MI by OF A PICKUP EO óS . u3 " S393 33,31.33 , NAAR 3'. . 'A'^^... <.R.a... N. J. I,t vrlrr www.americanradiohistory.com - STrLUS at the left. Broadcast INTERESTING WGAR News DETAILS OF THE 50 -F TRANSMITTER ^Jw. ..l INSTALLATIONS AT THESE TWO RICHARDS' STATIONS, BOTH OF WHICH ARE NOW OPERATING WITH CLEVELAND re .^n1 sere, M. 50,000 WATTS , i 1 reel. I w..l.. . .1 :p' d1.1 1.. tom °petee le sm. ...As . KMPC I1.11sA' T.., el. LOS ANGELES .,. 1R i a At' h. r u: 9rAW x.A r n. w 10114 +mM. Ae Solos S.. IS e..w... 4 nl Y' A.... x° L .... °u....Mn,,., .Il-e, Ae r , Mn'^ n, L* seen. tonemeas N L.yMiensA A a. NI er mP VN A +-.p. IL.A Rr. , A. R:. +aAt. wee . ,,.. CAA-KGKO STUDIOS nut rrele neee lu Or- ;..Àer+d y. . ...r 4. + KOMG'S NEW 50,000 By F. STATION '\ DESCRIPTIONS have been a close second to technical articles in popularity as a BROADCAST NEWS feature. More than 200 station installalions have been described in detail. Many of these station stories have included detailed floor plans, schematic diagrams, and photographs showing details of construction, arrangement of equipment, etc. From these. station engineers have been able to learn "how the other fellow did it ". pick Yal er. 14Jr+,1 . 4 ° nsl . Y. 1 rk Ja,...a ,,. V r , ASV L n. ..... ..., ..... ... ,.,a.. N el, A Y w,a-p.: nl rww..r .. e. ^;` ..... wn.r. Iu . n 1 up KOMO BUILDS , Seattle Station, New Studio Aoridl,g Studio and Transmitting Equipment NEW A PLANT New 50.000 Wan transmitter Building and All One of the Conprvalon and equipmentFiner Anywhere full Derails In This Molle hT) \IO h LN 1. I.-a s l t .nove NI.. I 1 II Issue no e +.. AA. r4 M ?Aa.l.... bJ6 .S,1,, .m _° q . -' e1.. / N r m1 Ilvlhrnn.u.+a , e V rrT . ,,....1 Jrn w, ,..,i. té ideas they could use in planning their stations. y Tu ^r _gr . r. 7,.....-.7.,..., . 1 ,.. TRANSMI MIIIER ;1_17.-',....',7,,,,....----,.......-7,,,.--..- .., !. tl.y WATT BROTT uS,,.,r,dyÓ,.F. ,.r }M1 h l. / )'A w r.., .. . rl.. ..i -' R T,..,...,,., .. RCA PRESENTS TELEVISION TO BROADCASTERS TELEVISION TELEVISION RECEIVERS ARE HERE IS HERE rr.n-T, LT:71' .,! : k_........... DECEMBER 1936 issue described demonstration o RCA Television on November 12, 1936. Nearly 300 station executives attended. A part of firs large scale field test of TV, this demonstration was the first of RCA's "progress reports on tele- vision" to the broadcast industry. 1939 issue reported the introduction o commercial" television receivers in the New York market, noted the wild -eyed enthusiasm o crowds viewing television for the first time a the World's Fair. Some of the receivers shown (modified for 525 line operation) are still in use. JULY ' issue, proclaiming that "Television Is Here also announced the first TV Transmitter to be offered for general sale -the RCA Type TT -1A, predecessor of the RCA TT -5A Transmitter now used by nearly 100 TV stations. Also announced the first "commercial model" TV camera. JULY 1939 TELEVISION PIONEERING MILESTONES AS REPORTED IN TWENTY YEARS OF BROADCAST NEWS +v AONIR I. NBC's RCA TELEVISION FIELD PICKUP EQUIPMENT /MOT MYtOW R. SI EXPERIENCE with PORTABLE TELEVISION EOUIPMENT UMEU OEiWI COMP. fAMERR uMER. u1 UMEU m«raw uMOO. cAMER. .uuMn fEP ._... . EOnMOE EE:i UMIT vraq PULSE THREE CAMERA CA.' SYSTEM issue described RCA's new "Field Pickup Equipment ". This was the first commercial -type field equipment to be produced. It set a pattern for field units which is still being followed. Today's units, although using image orthicons instead of iconoscopes, are arranged in very similar manner. JULY 1940 O AUGUST 1944 issue carried this article on NBC's experience with the RCA Fielc Equipment (described in the July 1940 issue). The of NBC engineers with this, and other early equipment, formed the background of nearly all early post -war TV planning. prewar experience rh. TK -30A CAMERA with the RCA'S NEW REVOLUTIONIZES IMAGE ORTHICON HIGHSENSITIVITY CAMERA TELEVISION PICKUP TECHNIQUE JANUARY 1946 saw the first article describing the new RCA Image Orthicon, the camera pickup tube which obviated the need for extremely high light levels and thereby made possible today's TV techniques. BROADCAST NEWS was among the first to recognize the tremendous portent of this development. In a six -page article, complete with illustrations depicting televising by candle- light. the new tube was described in terms of near rapture. OCTOBER 1946 issue carried an eight -page picture story describing the new RCA TK -30A TV Camera --the first TV camera to use the image orthicon, and the first TV camera to be produced in quantity. An unusual engineering success, and an immediate hit, this camera has been the standard of the industry ever since. Today. some five years later, nearly 800 TK -30A Cameras are in use all over the world. - KSD -TV A POST -WAR TELEVISION by RORIRT Kre L. .3á3GS 12 2.61 Q.ta STATION COI .r..,.......w..:...ew»+. FIRST UHF TV TRANSMITTER SHIPPED Television Tranrminxr Installed at NBC . Experimental "Satellite' Station in Bridgeport, Connecticut RCA Type TTU -IA l, ,p11 ,..., . n o-.wt+4 MP.- Y^n ',t .l,n.t yti e,i v.. sswe arv^ mM ` n 1 s .ofi nPMUJP. AA.. v !P` Rat W..a mer1,.Mltu..If.JAW^,^ ,u.+rn TV STATION STORIES .have become an outstand. have g feature of almost every issue. Some 17 of these stories running from eight to twenty or more pages in length, have appeared since the first KSD -TV story (see Pg. 7). All have been accompanied by large numbers of photo. graphs showing, not only equipment, but also the design of studio and transmitter buildings, construction of studios, etc. KANSAS CITY'S = WDF-TV KANSAS CITY - .n:.:°«w.. a. , Co, .V ,. ws.. ` 1.Y ---S-- ? r. "Prf MISSOURI tertiAnut mittml `,- as .cn _ i sue: fi WOR -TV MASTER -..... te` t ç:...Ii ,j:--'iYj kti Nom" -.+i CIRCUIT DIAGRAM OF THE VIDEO SYSTEM LAYOUT Broadcast Yam News i ',pop u' :° ¡; ., :,., r` wwu., r 'Nrd., ,awa,; "aa;e.. ..m àµ; .. v irrhJ il arm* »e....,w,l n"".K`.ù M. or I+4e r.a .; ;I il Wwrire. u ...Om. k. .r.we...W,n .: ,w'Ia .,i.AA,,. _ I ni.. ewnl,4ln. . 'w`!I4..brpT x.4 NarTq,. y,4InI , W !....._ , . IwI,,iury; . ® I I an xW :41:414m.., . ._. .- ..11.1, un kW x "- I ,"- ti Y w . ___ , I N b ï Mm NG4rv.tup ..~` -------- _s_s9CIZA 24'.1.-- f reae9ex nwi a . ..yá u.lm.. J, 1 11f4 Iw.'4aew.,r.VI,.I`srNró:r k.I e. tl Niw. ~Ia,.aN xI y, Ieryer avail , ÿ' I'.,,.,,I I "°,lrv ,ru'64rt. 'a,hmu wave 4v dauE wu na p TV Mr' rao NüN,d °r. ,M .Y W w,I,+M' , m .a II , lmvl'N l.uL W r".44 M. nvn.4 W.tl.;a..wS Oa I I m.r,oW M.'t M : _ e..w.rl I SYSTGM. NOEa aafo,M II I t.w.AMd ad bi. uee ,Nau ^ m . w l nwuJ P°ruud^ .iM. whr ,weh^' cr, ud kre N ru.al, r . .,._ a.n.A^n r is ti SCHEMATIC ltVtll roe ..w.w^,°°.. DIAGRAMS showing extent and arrangement of audio and video circuits used in the TV stations described have been a part of most TV station stories. When related to the physical op eration of these stations. the description of these circuits serves to indicate to other station engineers the extent of equipment facilities required for various types and sizes of operations. Special By WOW-TV Designed "9System 9ineecs n ta r..,,a... ¡r : ,rw a`"n>rM ...,..,r . a ., ` --`^aL .,= _ - a, . WHAT THE VIEWER SEES AS THE CAMERAMAN "ZOOMS IN" ON VARIOUS PARTS OF THE FIELD Et" emesnt /MM.. WPIX Baseball 71, 01111, (MO.. .10 PI Apop HE . 1,1,,11.1$ 41.c. SELECTS ONE . OF THREE - IN TYPICAL SWITCHING - CAMERA PICTURES SEOUfNCE WPIX MIXES ZOOMAR SHOTS WITH - No.253 CLOSEUPS FROM CAMERAS FOR TRANSMISSION . In CAMERA SETUP ES TILE COLECTOR A ear SHOTS OE CROCE OF If NE WISHES HE CAN DO SWITCHING ZOOMAR A WHOLE SEQUENCE WITH CAMERA ALONE THE ON AN OUTFIELD HIT WPIX USUALLY FOLLOWS THE BALL OUT MD BACA WITH THE ZOOMAR COME NATURALLY BASEBALL TELECASTS COMMERCIALS ON WPIX t BASEBALL TELEVISING TECHNIQUES have been described number of baseball telecasts the early experience in this fieldin exhaustive detail in several issues of BROADCAST NEWS. Because of a large was considerable and could be used as a guide to other types of field operation. FOOTBALL TELEVISING TECHNIQUES, less standardized NEWS articles, was written especialy for this publicationthan baseball telecasts, were the subject of this article which, by an outstanding network engineer like many with direct personal experience BROADCAST in this field. Teieui4iss9. FOOTBALL FROM LOS ANGELES COLISEUM Ifilt O. 41.0W1LL 43 ?_11 www.americanradiohistory.com ' tali rrs, _HOW TV STOLE THE SHOW_ CONVENTION CONVENTION VIDEO - CBS' EQWPME VIDEO-LOCATION OF THE CAMERAS i .iYe;i //,h:,, CONVENTION CONVENTION CONVENTION AUDIO - THE VIDEO VIDEO - NBC'S EQUIPMENT ABC'S EQUIPMENT SETUP AUDIO POOL SETUP VIDEO CONVENTION 00.0.0 TeLECAM - WPIX'S CONVENTION NIL IS fan 110.-P00.0 Ttlf tS1 AUDIO THE "Non- Pooled" _...... FACILITIES _-°- -t _,..... =4my.____._ ....,....,,...., ,......... w.. ;k,(. 11 CONVENTION TELEVISING and copy, the equipment TECHNIQUES were exhaustively T setups IQdEb described in this Y each of the networks in coveringarticle which portrayed in photographs, the 1948 Political conventions for television. OTHER TV DEVELOPMENTS, in fields outside such developments that of broadcasting, seem to portend future have occasionally been developments in broadcast reported in BROADCAST TV equipment, NEWS. as, for instance, this story on evolutionThi s has been done only when of lightweight "airborne" TELEVISION'S AIRBORNE e d t ..- C _' Vatragar AN RCA by a Demonstrated and RING nososh Cul n Marsh ore the Anas t Navy and Me Nan o Airborne television a Work 'Ca Ten of m,nanon BLOCK This is I in the Bomb_ the Television Equipment 1 Equipment the Television Closeups o he Control Plane the the Bomb and used rim aw,n, Bomb looks This is what a Television , n: ;,4N` sm. .. r: -,._.."" TV. DEVELOPMENT RCA t w. .fir like- This is hew its course is Controlled.. "MIME " sIMPIIdlt hu $t SM+TLLER STILL THE NEW THIS IS EQUIPMENT AIRBORNE TELEVISION .e.e.r TMs Amyy°g1 un se. `d- Nlst th no awn h ohm "ROC" IS THE NIGN "IS ANGLE THE TELEVISION FOR WNICN GUIDED BOMB "WHO h hen n. MAS RESIGNED SETUP tier add IN1 EQ INTRODUCTION TO BROADCAST NEWS INDEXES WHAT IS INCLUDED I'he BROADCAST NEWS Master Cross -Reference Index is a handy guide for reference to the numerous articles which have appeared in the 66 volumes of BROADCAST NEWS since 1931. Representing a 20 year accumulation of technical information, the index has been composed in three main parts to facilitate its use. The first section is a "Chronological Listing of BROADCAST NEws" issues, showing issue or volume number, printing date, and an "index key number" (this is simply the volume number followed by two zeros). The second section is a "Master Table of Contents" which lists by title and author -according to volume and page number -every article printed in volumes 1 through 66. The third section is the "Cross- Reference Index" which includes every article, in volumes 1 through 66, listed categorically, under main and subheadings according to subject matter, uses, or other helpful classifications. WHAT THE NUMBERS MEAN The numbering system indicates the HOW TO The main headings are used to designate particular subject matter, in alphabetical order, within a particular alphabet letter group. In cases where one heading satisfactorily includes all pertinent articles, only one appears. Where it is necessary to break down further the main headings, two or more subheadings are used. These subheadings have been indented to show further breakdowns as needed. NEWS" USE IT l'he BROADCAST NEws Cross -Reference Index is easy to use, since practically every listing appears several times, under a different heading. For example, the user seeking information about "transmitting equipment" will find it listed "all- inclusively" under "E Equipment, and "T Transmitting Equipment. If it is desired to obtain data which applies only to a specific class of Transmitting Equipment such as AM, FM or TV, the user will find these listed "selectively" under "A" AM- Transmitting Equipment, "F" FM- Transmitting Equipment and "T" Television- Transmitting Equipment. Thus, it is not necessary to sort through information which is not pertinent to the user's immediate needs. "- WHAT THE "INDEX" HEADINGS MEAN "BROADCAST issue or volume number as well as the page number in the specific issue or volume. For the issues 1 through 9 all references are 3 digit numbers-the first digit designates the volume number and the second and third digits designate the page or pages in the particular issue. For the issues 10 through 66 the the same system is used, but references are made to 4 digit numbers. The first two digits designate the volume number and the third and fourth signify the page or pages in the particular volume. For example, 904 refers the user to page 4 of volume 9: similarly, 3521 refers the user to volume 35, page 21. "- BROADCAST NEWS -CHRONOLOGICAL LISTING Index Volume Date Date Key No. Volume Date Key No. 23 2300 2400 2500 2600 2700 2800 2900 3000 3100 3200 3300 3400 3500 3600 3700 3800 3900 4000 4100 4200 4300 4400 45 46 26 27 28 29 30 December 1936 May 1937 June 1937 November 1937 December 1937 June 1947 September 1947 December 1947 March 1948 May 1948 August 1948 October 1948 December 1948 February 1949 4500 4600 4700 4800 4900 5000 5100 5200 5300 5400 5500 5600 5700 5800 5900 6000 6100 6200 6300 6400 6500 6600 October 1931 2 January 1932 3 April 1932 100 200 300 4 July 1932 400 5 October 1932 6 January 1933 13 April 1933 August 1933 November 1933 February 1934 May 1934 August 1934 December 1934 14 February 1935 15 April 1935 June 1935 September 1935 December 1935 April 1936 June 1936 8 9 10 11 12 16 17 18 19 20 21 22 July 1936 October 1936 Index Volume I 7 Index Key No. 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 24 25 31 32 33 34 35 36 37 38 39 40 July 1938 January 1939 May 1939 July 1939 May 1940 July 1940 August 1940 February 1941 May 1941 September 1941 January 1944 August 1944 43 January 1945 June 1945 January 1946 June 1946 44 October 1946 41 42 14 www.americanradiohistory.com 47 48 49 50 51 52 53 54 55 56 April 1949 June 1949 September 1949 65 Jan.-February, 1950 ... March-April 1950 May -June 1950 July -August 1950 Sept.-October, 1950 ... Jan.-February, 1951 ... March-April, 1951 .... May -June 1951 July- August 1951 66 Sept.-October 1951 57 58 59 60 61 62 63 61 .... BROADCAST NEWS MASTER TABLE OF CONTENTS (Volumes Through 66) 1 INDEX NUMBERING (ISSUES KEY TO (A) First digit indicates "Broadcast News" volume or issue number. Index No. 102 106 107 108 110 Author Subject STATION KFI, LOS ANGELES MICROPHONE PLACING.... L. S. YULE AND I. R. BAKER RCA VICTOR PERSONALITIES WHAT IS YOUR "COVERAGE ". POLICE ALARM BROADCAST 602 605 606 Taylor 610 612 614 614 615 616 618 619 620 623 624 626 628 629 by J. P. Randall 202 204 206 208 210 MAINTENANCE MEANS MONEY.... 211 POLICE ALARM BROADCAST NEWS POLICE RADIO FROM AN ADMINISTRATION 212 213 214 219 STANDPOINT by E. K. Jett, Federal Radio Commission by T. A. Smith A NEW STATION FOR READING, PA... _.. KFGQ RUNS SIX HOUR DX TEST HOW ABOUT YOUR "MODULATION WANTED -A FREE WHEELING TYPEWRITER 302 304 306 312 314 318 320 322 324 402 404 406 408 409 410 411 411 412 416 416 by C. J. by C. L. Beach by A. H. Castor "' by J. P. PIONEER NBC STATIONS MODERNIZED by Raymond Guy _ by W. L. Lyndon 100 -250 WATT BROADCAST TRANSMITTER..... MERCURY VAPOR RECTIFIER RADIOTRONS by A. H. Castor and W. G. Moran RCA PERSONALITIES by Harold C. Vance _. ST. LOUIS POLICE RADIO_ _ by Harold C. Vance CHICAGO NBC STUDIOS by Henry Grossman PIPE ORGAN PICKUP BROADCAST FROM SPEEDING TRAIN by J. P. Taylor NEWS ABOUT YOUR FREQUENCY MONITOR NEW WCAU STATION NEARS COMPLETION SURGE IMPEDANCE AND SERIES RESISTANCE OF RADIO FREQUENCY TRANSMISSION LINES DIRECTIONAL BROADCASTING AT WFLA -WSUN ..... MODERN STATION AT WORCESTER, MASS. RADIO IN THE PALMY DAYS -(filler) WHAT IS IT, OLD TIMER? MILAN AND ROME STATIONS THE NATURAL MISTAKE LET'S GET ACQUAINTED POLICE ALARM BROADCAST NEWS 5 METERS.._ (with the Model ET -5000 HF Transceiver) GOING DOWN TO by _. R. B. Dome by 8. Adler by Ted Hill by Fred Muller by P. A. Anderson INTERNATIONAL EXPOSITION AT CHICAGO, 1933 by Hans Roder BROADCAST ANTENNAS by Albert Meyer UNDER VOLTAGE RELAY FOR TUBE TRANSMITTERS WLBG CHANGES HANDS A NEW INSTALLATION FOR WESTERN NORTH CAROLINA (WWNC) PUBLIC TO HEAR ORGAN IN SCHWAB MANSION ON RADIO 417 418 422 422 423 424 THE 502 506 509 .... by Earle J. WBT EXPANDS TO 25,000 WATTS.._ by Dr. H. F. THE VELOCITY MICROPHONE KOYL 10 YEARS OLD RCA BROADCAST TRANSMITTERS IN SOUTH AMERICA... by Fred STUDIO NOTES by Ralph L. INSULATION FOR VERTICAL RADIATORS by J. P. A NEW HIGH- FREQUENCY BROADCAST TRANSMITTER 510 511 512 516 518 520 521 524 525 526 528 529 532 536 540 Taylor LET'S GET Gluck Olson Muller Jenner Taylor ACQUAINTED by George Malcom Smith A NEW NETWORK FOR NEW ENGLAND WCAU USES DEAD END AND LIVE END STUDIOS WBEN -THE BUFFALO EVENING NEWS STATION by T. A. Smith INSTALLS NEW TRANSMITTER. __. WHAT IS IT, OLD TIMER? by Edmund A. Loport THE LINE TO THE ANTENNA. POLICE ALARM BROADCAST NEWS POLICE RADIO -MODEL ET -3670 RCAC DIVERSITY TELEPHONE EQUIPMENT AS USED by IN ITS ADDRESSED PROGRAM SERVICE BROADCASTING STATION WWSW, PITTSBURGH TRANSCEIVER BROADCAST FROM GLIDER by H. C. Vance H. Simpson, Jr. by M. J. Sartory by T. A. Smith S. 1 THROUGH 9) Next two digits indicate the pages on which articles begin Index No. by I. R. Baker by T. A. Smith EQUIPMENT BROADCASTING IN EUROPE........ TRANSMITTING RADIOTRONS LET'S GET ACQUAINTED (B) Subject Author WSM GOES ON HIGH POWER by George D. Hoy WHO BUT GEORGE CLARK COULD THE SELECTION OF SITES FOR BROADCASTING STATIONS by H. E. Gihring RADIO STATION WWL by Ben Adler PIONEER "LIVE -END, DEAD END" STUDIOS.. by C. Gordon Jones RADIO BROADCAST RESCUES NAVAL AIRPLANE FLEET OLD FAITHFUL (UV -864 TUBE) DID YOU KNOW ...... by W. S. Fitzpatrick LET'S GET ACQUAINTED INTERNATIONAL BROADCASTING WHAT IS IT, OLD TIMER? by RADIO'S DEBT TO CALVIN COOLIDGE NIPPER MAKES HIS BOW ON THE AIR THE NEW BEAT FREQUENCY OSCILLATOR POLICE ALARM BROADCAST NEWS A MINIATURE ULTRA -HIGH FREQUENCY RECEIVER 631 ORGAN REVEILLE (artist -Fred Feibel) 702 WCAU -A MODERN MONUMENT TO THE ART OF BROADCASTING.... .._. _. A VISITOR TOURS WCAU 710 716 F. Muller by Orestes H. Caldwell by J. P. Taylor by W. F. Diehl by P. A. Anderson by John G. Leitch by Kenneth W. Stowmon STRONG BROADCAST SIGNALS by Allred N. Goldsmith (Dr.) TWO GIRLS, TWENTY FINGERS LEON COLE, ORGANIST AND TECHNICIAN POLICE ALARM BROADCAST NEWS -The Baltimore Police Radio System 721 -1 RCA VICTOR DEMONSTRATES POLICE RADIO AT POOR RICHARD LUNCHEON 721.2 FRANCE ESTABLISHES POLICE RADIO SERVICE 724 THE INAUGURAL BROADCAST-A Tribute to the Advertisers 726 NEW RCA VICTOR EXECUTIVE 726 LET'S GET ACQUAINTED 730 VELOCITY MICROPHONE TEST CURVES by J. P. Taylor 735 DID YOU KNOW by W. S. Fitzpatrick RCA VICTOR LABORATORY TEST INSTRUMENTS 736 by William F. Diehl 742 WHAT IS IT, OLD TIMER? 742 HOG CALLER SHOOTS THE WORKS (WJAG) 743 -1 PRIDE GOETH BEFORE A FALL -AND SOMETIMES AFTER 743-2 NEWS FROM FOREIGN FIELDS A NEW MERCURY VAPOR RECTIFIER TUBE 744 THE BATTLE FOR 719 719 720 . 802 INCREASED POWER FOR WOC -WHO 806 814 818 THE ICONOSCOPE THE RCA 850 RADIOTRON by P. A. Loyer by Dr. V. K. Zworykin by H. F. Dart TURNTABLE WINS RECOMMENDATIONS NEW TRANSCRIPTION KTBS BUILDS OWN VERTICAL RADIATOR KTBS BUILDS OWN VERTICAL RADIATOR RADIO TELEPHONY ON THE SOUND MOVIE LOT GETTING HOT AT WLW 821 NBC BROADCASTS MAMMOTH ORGAN 822 DID YOU KNOW .. by W. S. Fitzpatrick MEASURING ANTENNA RESISTANCE 824 by L. F. Jones TRANSMISSION LINE FORMULAS 826 by L. F. Jones 827 LET'S GET ACQUAINTED 830 WCAM- CAMDEN, NEW JERSEY 831 STUDIO NOTES NEW STATION SERVES SOUTH CAROLINA -WFBC 832 by T. A. Smith UNIQUE LOW POWER STATION 834 by Peter Goelet TOWER AT WSM ._.. by George Dewey Hay 835 836 SOUND REENFORCING AND BROADCAST PICKUP _. AT ROBIN HOOD DELL by Kenneth W. Stowmon 837 STUDIO NOTES THE BALTIMORE POLICE RADIO SYSTEM 838 841.1 WILBUR RHODES 841-2 POLICE CHIEF QUINN BROADCASTS AS HOBBY NEW POLICE RADIO SYSTEM FOR EAST TENNESSEE... by Ben Adler 842 WHAT POLICE RADIO IS DOING FOR CENTRAL KENTUCKY 844 846 STATEMENT ISSUED BY W. R. G. BAKER 847 HIS MASTER'S VOICE OF THE AIR 848 WHAT IS IT, OLD TIMER? CITY MANAGER OF MIAMI RECOMMENDS POLICE RADIO 848 -2 819 819.1 819.2 820 ..... 15 BROADCAST NEWS MASTER TABLE OF CONTENTS- (Cont'd) KEY TO INDEX NUMBERING (ISSUES 1 THROUGH 9) KEY TO digit indicates "Broadcast News' volume or issue number. Next two digits indicate the pages on which articles begin. (A) First (A) (B) (B) Index Index No. 902 906 909 910 912 915 916 918 924 925 926 930 933 933 933 934 Author Subject KW TRANSMITTER UNIQUE NEW METHODS OF SOLUTION OF VACUUM TUBE PROBLEMS by 1 WSYR BROADCASTS DID YOU KNOW PRIZE L. 1002 1004 1007 1008 Jones and J. F. No, Young 1202 by loury G. Maloff 1204 E. by W. S. by Fitzpatrick F. Muller OPERATION AND MAINTENANCE OF A 1209 1210 LET'S GET 1207 1211 MODERN RADIO STATION KPO GOES TO 50 KW DICK LEIBERT LEADING A DOG'S LIFE AT THE WORLD'S FAIR LET'S GET ACQUAINTED A CATHODE RAY MODULATION INDICATOR LEW WHITE "RADIO CITY" ORGANIST NEW MOBILE TRANSMITTER FOR NBC by D. M. Stonier by Raymond F. Guy 1213 1214 1217 1221 by Ballantine C. E. 1224 1226 WITHOUT A DOUBT TERRA -WAVE POLICE RADIO SYSTEMS OF by A VISIT TO THE NEW WLW PROGRAM AMPLIFIER-1934 DESIGN WBRE AT WILKES -BARRE IS MODERNIZED BYRD ANTARCTIC EXPEDITION TO ORIGINATE Anderson A. P. ENGLEWOOD, N. J., GETS POLICE RADIO SYSTEM DEANS OF RADIO MEET AT CHICAGO CBS FIELD ENGINEER GETS BYRD EXPEDITION POST CHANGE NOTES by George ON TIME -A RAILROAD'S DAILY RADIO STUNT STATION IDENTIFICATION NAMEPLATES FOR THE NEW VELOCITY MICROPHONES 1230 1232 1233 F. McClelland Baker by Edmund Frost by I. R. 1034 WEBC AT DULUTH- SUPERIOR WHO'S WHO AT "RADIO HEADQUARTERS" 1036 1038 1042 1046 1047 1048 1049 - LET'S GET ACQUAINTED- BROADCASTING PERSONALITIES A 1934 MONITORING EQUIPMENT. by W. L. Garnett RCA VICTOR DEVELOPS NEW FIELD INTENSITY METER.... by Wm. F. Diehl AIR CONDITIONING AT THE RADIO CITY STUDIOS OF NBC by Oscar McClellan BABE GOES ON "THE AIR" WHAT IS ... AN "RA" TAG? 1051 1052 RADIO FROM STRATOSPHERE NEW MOBILE TRANSMITTER FOR RADIO CITY SERVICE HOLLYWOOD ON THE AIR by George Greaves 1102 FIVE HUNDRED KILOWATTS 1109 CONVENTION COMMITTEE -9TH ANNUAL 1110 1116 1118 1134 1138 1140 1142 1143 1145 1146 1149 1150 1152 1152 1157 1158 1159 1160 1161 1162 PIONEER BROADCASTING SYNCHRONIZATION NBC AT RADIO CITY RECORDINGS AND TRANSCRIPTIONS F. Jones IRE by George H. Clark .._. by C. W. Horn by C. L. Beach (Raymond Sooy and Charles Sooy) 1312 1314 1316 1318 1322 1324 1326 1327 1328 1329 1330 1331 1402 1404 1405 1406 1410 1414 1416 1418 1420 1423 1424-1 SHORT -WAVE RADIO... by H. H. Beverage THE OPERATION OF MERCURY VAPOR RECTIFIER TUBES by J. B. Epperson POLICE RADIO PROTECTION by George E. Anderson (RADIO) POLICE AT ENGLEWOOD GET TWO NOTORIOUS CRIMINALS NEW POLICE TRANSMITTER AT KANSAS CITY.. by Lt. Roy DeShaffen, Sr. 14242 LET'S GET ACQUAINTED 1430 1433 1434 1436 RCA GLOBE TROTTER PROGRAM POPULAR by Howard Allan Chinn by W. S. Fitzpatrick 1427-1 1427.2 1428 1429 1502 by George by Kenneth P. B. Hopkins Slowman by E. E. Taylor Barton W. Olandar B. S. Patterson Fitzpatrick by Kenneth W. Slowman "WHO'S WHO" AT RADIO HEADQUARTERS ROSELLE, N. J., "TERRA- WAVE" GETS ITS MEN A BRIEF SURVEY OF THE CHARACTERISTICS TERRESTRIAL MAGNETISM AND WM. A. GOLDSWORTHY, ORGANIST WHO'S WHO AT RADIO HEADQUARTERS THE COLUMBIA RADIO PLAYHOUSE DID YOU KNOW 50 YEARS OF PROGRESS -WSM RCA FREQUENCY MEASURING SERVICE NEW STUDIO EQUIPMENT FOR KOMO -KJR THE ELECTRONIC PIANO THE ELECTRONIC ORGAN ET-4230)....by L. MARGARET BOURKE-WHITE (Industrial Photographer) DID YOU KNOW by W. COMBINED RADIO PICKUP AND PUBLIC ADDRESS P. 1302 1304 1408 by Loren by J. by Loy Jones F. 1238 1240 1242 1309 1310 1019 1022 1026 1030 1033 by Loren 2000 KVA HIGH -PRESSURE CAPACITOR by V. E. Trouant WTAG INSTALLATION AT NEW LOCATION TYPE 50-A INDUCTOR MICROPHONE by L. J. Anderson FATHER, SON HEAR EACH OTHER ON BYRD PROGRAM (reciprocal broadcasts) THE SHOW MUST GO ON by Louise Landis NEW BROADCAST ORGAN AT WBEN by Oscar McClellan MORE RCA TRANSMITTERS IN THE FOREIGN FIELD by Fred Muller 1234 1237 PROGRAMS FROM SOUTH POLE by Howard Allan Chinn GRAND RAPIDS POLICE RADIO INSTALLATION by A. A. Kirchner POLICE RADIO NEWS SOLUTION OF VACUUM TUBE PROBLEMS BY THE ISOCLINE METHOD by I. G. Maloff NEW ART IN RADIO -An Outline of John Vassos DID YOU KNOW by W. S. Fitzpatrick THE ADMIRAL BYRD BROADCAST PICKUP by D. B. Templeton THE IMPORTANCE OF THE FIELD STRENGTH SURVEY by Wm. L. Foss SOMETHING NEW IN VERTICAL RADIATORS 1012 1014 ACQUAINTED BROADCASTING PERSONALITIES NEMO SPEAKING 100 -WATT BROADCAST TRANSMITTER (Type CATHODE -RAY NOTES INSTALLATIONS 1228 WEEKLY 1011 Author Subject A NEW HIGH- FIDELITY 5 -KW TRANSMITTER (Type 5-C KW Broadcast Transmitter) NEW LAPEL VELOCITY MICROPHONE (Type 30-A Lapel Microphone) TUBE CONSIDERATION IN CLASS B AMPLIFICATION. WTAR GOES NBC WINNING ORCHESTRAS 13,000 FEET ABOVE THE SEA THE WONDERS OF WIRELESS ABINGTON AND HAVERFORD 937 937 938 939 939 940 INDEX NUMBERING (ISSUES 10 THROUGH 66) First two digits indicate "Broadcast News" volume or issue number. Next two digits indicate the pages on which articles begin. 1506 1510 BROADCASTING CARACAS....by Edgar J. Anzola (in interview by editor) OF BROADCAST ANTENNAS by H. E. Gihring and Dr. G. H. Brown RADIO RIDES THE ZEPHYR THE RCA RADIO TUBE THAT FELL OUT OF THE STRATOSPHERE AND STILL WORKS (8 -w xtmr) THE TYPE OP -4 PORTABLE BROADCAST SPEECH INPUT EQUIPMENT by A. N. Curtiss DETROIT ORCHESTRA HALL by Howard Allan Chinn LET'S GET ACQUAINTED WTAR GOES HIGH FIDELITY DID YOU KNOW RECENT POLICE RADIO INSTALLATIONS - by J. L. Grether by W. S. Fitzpatrick Norfolk, Suffolk, Danville, Virginia; Roselle, N. J. HOW ECHOES ARE PRODUCED (artificial sound reflection) "ACORN" TUBE FOR RADIO EXPERIMENTERS WFBC GETS A NEW 1 -D TRANSMITTER FROM MICROPHONE TO LOUDSPEAKER A PLEA FOR BETTER STATION MANAGEMENT BRITISH TV COMMISSION VISITS CAMDEN, N. J. by Ben Adler by J. E. Young SHORT-WAVE HIGH FIDELITY PIONEER by S. E. Warner INTERESTING VOICE-GRAPHS CBS BROADCAST FROM S. S. REX by A. B. Chamberlain LIGHTNING PROTECTION FOR THE GIANT WLW TOWER by Joseph A. Chambers THE SPECIFIC TRANSMITTER PERFORMANCE REQUIRED FOR HIGH FIDELITY by Loren F. Jonas KOA GOES TO 50 KW by Raymond F. Guy NBC BROADCAST SOUND EFFECTS DID YOU KNOW by W. S. Fitzpatrick BRILLIANT IDEA BOOSTS POPULARITY OF WPEN BROADCAST STATION MAINTENANCE (2nd in series) by J. E. Young REMOTE STAR BROADCASTS FOR CBS by Henry Grossman OLD FRIENDS ADOPT NEW NAMES (RCA Manufocturing Co.) BROADCAST PERSONALITIES WHIO GOES ON THE AIR FIRE IMPERILS WMCA A SEA -GOING BROADCAST STATION ( "Seth Parker" installation) NEW RCA EQUIPMENT INSTALLED IN WCAU AUDITORIUM STUDIO by Kenneth W. Slowman HUM COMPENSATOR FOR BROADCAST STATIONS by Loy E. Barton NEAR AND FAR NBC SYNDICATED PROGRAM SERVICE- Transcription Activities Increasing POLICE RADIO INSTALLATIONS -W5XB DIRECT READING AND AVERAGING OF SIGNAL INTENSITIES RCA CATHODE RAY OSCILLOGRAPH COMPLETE FIELD INTENSITY SURVEY OF ALL NBC NETWORK 16 www.americanradiohistory.com by John P. Taylor by J. P. Allen by Raymond F. Guy BROADCAST NEWS MASTER TABLE OF CONTENTS -(Cont'd) (A) KEY TO INDEX NUMBERING (ISSUES 10 THROUGH 66) First two digits indicate "Broadcast News" volume or issue number. (B) Next two digits indicate the pages on which articles begin. Index Index No. 1514 1516 1518 1520 1522 1524 1526 1530 1534 Author Subject LET'S GET ACQUAINTED DID YOU KNOW by W. S. Fitzpatrick ELABORATE CEREMONIES MARK INAUGURATION OF WHIO BY THE MIAMI VALLEY BROADCASTING CORP. RADIO CENTRE, PHILADELPHIA GOES FLUORESCENT (Devised by Frank Hartman) BROADCASTING GRAND OPERA BROADCAST STATION MAINTENANCE by A. R. Hopkins GENERAL CONSIDERATIONS OF TOWER ANTENNAS FOR BROADCAST USE by Dr. G. H. Brown and H. E. Gihring MOBILE POLICE RADIO EQUIPMENT.. by P. A. Anderson and W. L. Lyndon TERRA -WAVE CRASHES THROUGH IN DANVILLE, ILLINOIS 1602 1605 NEW STUDIOS FOR WIP by Edward R. Johnston, Tech. Sup. -WIP DAVID SARNOFF'S STATEMENT ON TV CREATES STIR IN BROADCASTING INDUSTRY 1606 1607 1608 NBC BROADCASTS FROM THE NORMANDIE GEORGE CLARK VIEWS NORMANDIE'S ARRIVAL DELUXE TRANSCRIPTION TURNTABLE EQUIPMENT Type 70 -A Transcription Equipment VICTOR BOOK OF THE SYMPHONY (book written by Charles O'Connell) by W. S. Fitzpatrick DID YOU KNOW LET'S GET ACQUAINTED- BROADCASTING PERSONALITIES RECORDED PROGRAMS TREASURE HOUSE OF "THESAURUS " FAST TELETYPE NEWS SERVICE FEATURED ON PROGRAMS OF PHILADELPHIA STATION (WFIL) RCA ISSUES PARTS REFERENCE BOOK THE WCAU PHOTONA by John G. Leitch by S. Gubin BROADCAST STATION MAINTENANCE Adjusting the Class B Linear R. F. Stage by Loy E. Barton MODULATION SYSTEMS FOR TRANSMITTERS VERSATILE ENGINEERS RIG POLICE RADIO ANTENNA GENERAL CONSIDERATIONS OF TOWER ANTENNAS by Dr. G. H. Brown and H. E. Gihring FOR BROADCAST USE LATEST IN AVIATION RADIO EQUIPMENT- AVT -3A 1611 1612 1614 1616 1618 1620 1621 1623 1624 1627 1628 1637 1702 1704 1706 1707 1708 -A "CITY VOICES" AN UNUSUAL PROGRAM by Joseph D'Agostino MICROPHONE PROGRESS by W. S. Fitzpatrick DID YOU KNOW KVSO -"THE VOICE OF SOUTHERN OKLAHOMA" LET'S GET ACQUAINTED 1710 IMPEDANCE-MATCHING ATTENUATION 1712 1713 1714-1 1714-2 1715 NEW 1716 1718 1719 1802 1803 1804 1805 1806 1808 1809 1810 1814 1818 1823 1824 1825 1826 1834 1902 1904 1906 1908 1910 1911 1912 1914 HOME FOR KSD NETWORKS._. by J. P. Epperson by Robert L. Coe WIOD "THE GOOD WILL STATION OF THE CARIBBEAN EMPIRE" NEW VERTICAL RADIATOR AT WDOD WBEN PUTS CURVES ON AIR WBT ADDS VERTICAL RADIATOR TO by William A. Schudt, Jr. RCA TRANSMITTER POINTED FACTS ABOUT TRANSCRIPTION NEEDLES GENERAL CONSIDERATIONS OF TOWER ANTENNAS by Dr. G. H. Brown and H. E. Gihring FOR BROADCAST USE ASIDES AT THE NAB CONVENTION (Photo Page) HAVANA GREETS INTERNATIONAL RADIO CLUB by Maynard Marquardt THE VOICE OF LABOR ON THE AIR by Chester M. Sinnott A DISCUSSION OF THE DYNAMIC AMPLIFIER by Jerry Stone PERSONAL APPEAL IS TOPS AT SKYTOP by the Editor THERE'S GOLD IN THE AIR by Loy E. Barton SOME FURTHER THOUGHTS ON MODULATION AN IDEA ON THE AIR THE TRANSMISSION OF 9 CM WAVES....by Irving Wolff and E. G. Linder GENERAL CONSIDERATIONS OF by Dr. G. H. Brown and H. E. Gihring TOWER ANTENNAS by Frederick Wheeler HIGH FIDELITY FOR WREN by John Vassos MODERN DESIGN AVIATION HEADQUARTERS AT RADIO HEADQUARTERS BUSINESS IS GOOD AT WEMP by H. E. Gihring A FIELD INTENSITY SLIDE RULE FIELD INTENSITY AND SIGNAL RECORDING EQUIPMENT WHAT THE EUROPEANS ARE DOING THE ELECTRON IMAGE TUBE CBS EXPANDS, MODERNIZES THE AUDIO FREQUENCY DISCRIMINATOR KFBK, 5000 -WATTER MEASURING EAR SENSITIVITY NBC'S NEW HOLLYWOOD STUDIOS A SIMPLE METHOD OF ADJUSTING TOP LOADED AND SECTIONALIZED ANTENNAS by L. M. Clement by Dr. V. K. Zworykin by A. B. Chamberlain by M. A. Mclennan by Norman Webster No. 1916 1918 1922 1923 1931 1933 1934 2002 2005 2006 2009 2010 2012 2014 2016 2017 2018 2020 2021 2022 2032 2034 2035 2101 2102 2103 2104 2105 2106 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 Author Subject MODERN TRANSMITTER HOUSE DESIGN BEAUTY AND UTILITY COMBINED IN NEW STUDIOS W8XH, NEW HIGH FREQUENCY STATION A NEW MODULATION MONITOR ULTRA VIOLET LIGHT RECORDING NEW RCA PRODUCTS A DIGEST FOR THE RADIO READER TENTATIVE PROGRAM, FCC MEMBERS PROMINENT STATION PERSONALITIES 4 MICROPHONES -TYPE 44 -B, TYPE 50-A, TYPE 77 -A, TYPE 74-A NEW SPEECH INPUT EQUIPMENT 100W BROADCAST TRANSMITTER-TYPE 100 -E TYPE 100 -F BROADCAST TRANSMITTER TYPE ET- 4250 -100 /250W BROADCAST TRANSMITTER TYPE -D KW BROADCAST TRANSMITTER TYPE 5 -C 5 KW BROADCAST TRANSMITTER TYPE 40-D PROGRAM AMPLIFIER TYPE 41 -C PRE- AMPLIFIER TYPE 58-A TRI -AMPLIFIER TYPE 64 -A MONITORING SPEAKER NEW MODULATION MONITORS -TYPE 66 -A (large) and 66 -B (fast action) A NEW TUBE -TYPE 892 1 1 PORTABLE AMPLIFIER -TYPE 62 -A HIGH QUALITY STUDIO MONITORING AMPLIFIER-TYPE 94 -C ENGINEERING DEVELOPMENTS AT CBS by A. B. Chamberlain, C. E., CBS WITH THE ENGINEERS AT NBC by O. B. Hanson, C. E., NBC COMBINED MIXER AND SWITCHING PANEL -TYPE 46 -B AND GENERAL PURPOSE METER PANEL--TYPE 15 -C A TREATISE ON PIEZO- ELECTRIC QUARTZ CRYSTALS A TECHNICAL CLOSEUP OF WGN AN ENGINEER REPORTS SOME THOUGHTS ON STATION MANAGEMENT NEW COMMUNICATION SERVICE POSSESSES VAST COMMERCIAL POSSIBILITIES 2216 2218-1 2218-2 Taylor CBS REPRESENTATIVES WORLD CONGRESS OF BROADCASTERS MEETS IN PARIS WELL KNOWN LEADERS IN THE BROADCASTING INDUSTRY FROM THE BOARD OF DIRECTORS -NAB LEADING STATIONS WELL REPRESENTED 2202 by O. B. Hanson P. NBC REPRESENTATIVES ENGINEERS AND MANAGERS ATTENDING PROMINENT IN BROADCASTING AND RECORDING ATTACHMENT -TYPE 72 -A ENGINEERING PRODUCTS DIVISION IN THE FIELD WITH RCA PRINCIPAL PRODUCTS by Dr. G. H. Brown by J. Hopkins NAB CONVENTION RCA LINE AMPLIFIER-TYPE 55 -A 2212 2214 R. NAB OFFICIALS 2132 2133.1 2133-2 2134 2135 2136 2208 2210 by A. CRIME CONTROL WITH RADIO by David Sarnoff UP GOES POWER AT WFBC A STUDY OF NOISE CHARACTERISTICS by Vernon D. Landon NEW TRANSMITTER PLACED IN SERVICE BY WRAW CARE OF WATER COOLED TUBES by Ben Adler SOUTHWEST HEARS NEW WKY by Earl C. Hull NBC SOUND EFFECTS TECHNIQUE "HAM" OPERATORS PROVE THEIR WORTH IN FLOOD AREAS VIEWS OF THE NEW RCA DISPLAY ROOM Photograph by N. Newell, RCA Studios BUENOS AIRES NOW HEAR 'ROUND THE WORLD.... by R. V. Beshgatoor UNUSUAL STUDIOS FOR WMEX MILESTONES IN VACUUM TUBE PROGRESS by Joseph D'Agostino RECORDED SOUND EFFECT EQUIPMENT ALSO MAKES NOTABLE PROGRESS by R. H. Heacock A REVIEW OF BROADCAST ENGINEERING by J. P. Taylor NEW RCA PRODUCTS NOTES ABOUT OUR CONTRIBUTORS 2131 2204 2206 by John Vassos by Carl Meyers Diehl Hopkins by John N. Dyer by Frank S. Lane by W. by A. F. R. MICROPHONES AND MICROPHONES A NOTE ON THE PLACEMENT OF THE COIL IN A SECTIONALIZED ANTENNA by Dr. G. H. Brown WBT DEDICATES NEW STUDIOS POPULAR FORT WORTH STATION INCREASES POWER. by Eibert Haling by John Vassos AN ARTIST LOOKS AT DETAILS 17 www.americanradiohistory.com BROADCAST NEWS MASTER TABLE OF CONTENTS -(Cont'd) (A) KEY TO INDEX NUMBERING (ISSUES 10 THROUGH 66) First two digits indicate "Broadcast News" volume or issue number. (B) Next two digits indicate the pages on which articles begin. Index Index No. 2222 2224 2227 2230 2232 2302 2304 2305 2306 2310 2312 2316 2318 2320 Subject Author MAKING RADIO WAVES BEHAVE by WORLD CONGRESS OF BROADCASTERS A REVIEW OF BROADCAST ENGINEERING NOTES ABOUT OUR CONTRIBUTORS FOURTH ESTATE VIEWS TELEVISION._. _.. _._. WTRC 2412 2415 2416 2417 2418 2420 2425 2426 2428 2431 2434 2502 2515 2516 2517 2518 2519 2520 2522 2523 2602 2604 2607 2608 2609 2610 2802 2805 2806 2808 MODERN DESIGN-SIMPLICITY P. by David Sarnoff _ HEARST EXPANDS COAST STATIONS by LOGARITHMIC RECORDING OF FIELD INTENSITIES MODEL HOME FOR WORCESTER STATION NEW EQUIPMENT SOLVES PROBLEM FOR SMALLER STATIONS by James Galloway Frederick Ragsdale by John P. Taylor 2902 2904 LISTENERS LETTERS FROM LISTENERS TUBES 2907 2908 2911 2915 2916 2918 2921 2924 2928 2929 2932 3002 3003 3006 3007 3008 3010 3012 STATION BUILDINGS SPEAKING OF PICTURES IN THE FUTURE EQUIPMENT 3015 3016 3018 3021 THE HUMAN SIDE OF MARCONI IMPROVED SERVICE FOR CBS FOREIGN 3024 3027 3035 LISTENERS CONVENIENCE by John GOING PLACES IN DIXIE.. MISTAKES ABOUT MARCONI FACTOR _. SPACE BECOMES A FURTHER NOTES ON EXTERNAL CROSS MODULATION 2822 2832 2833 P. BUILDING A TRANSMITTER MAP OF INSTALLATIONS PRESS 2812 2814 2817 2818 2819 2820 Taylor by John ................... STREAMLINED 2811 2824 2826 by W. L. Lyndon DIRECTIONAL ANTENNAS by Dr. G. H. Brown REAL DRAMA ON THE AIR FLOODS MAKE WORK FOR NBC STAFF STEADY PROGRESS FOR WRAK by Louis N. Persio TWIN BUFFALO STATIONS MODERNIZE by Ralph J. Kingsley and P. E. Fischler FEATURES BRING NEW TRANSMITTER TO THE FRONT by C. M. Lewis ELECTRON PATHS MADE VISIBLE....by Dr. V. K. Zworykin and E. A. Massa UNIQUE FEATURES AT SEATTLE by Francis J. Brott BUILDINGS FOR MEDIUM POWERED TRANSMITTERS by T. A. Smith SIZE ISN'T EVERYTHING A REVIEW OF BROADCAST ENGINEERING by John P. Taylor 2616 2710 2712 2716 2718 _. WAVES AREN'T ALWAYS IN THE AIR LIGHTNING IS A MENACE.... A NEW LIMITING AMPLIFIER 2702 2704 2706 2708 Taylor by J. INCREASES COVERAGE WRGA INSTALLS NEW ANTENNA A REVIEW OF BROADCAST ENGINEERING 2612 2614 2618 2620 2622 2630 2634 DIRECTIONAL ANTENNAS A REVIEW OF BROADCAST ENGINEERING WHBL IMPROVES FACILITIES RCA PRESENTS TELEVISION TO BROADCASTERS GRAPHIC RECORDING OF FIELD INTENSITIES by John P. Taylor POWER GOES UP AT WDBJ A TREATISE ON PIEZO- ELECTRIC QUARTZ CRYSTALS RAPID GROWTH FOR WHIO by Palmer A. Greer and Charles E. Gay HOOSIERS LISTEN IN ON NEW WSBT A TURNSTILE ANTENNA FOR USE AT HIGH FREQUENCIES by Dr. G. H. Brown 2329 2402 2404 2406 2408 2410 Author Subject 2720 2723 MEETS IN PARIS PROBABLE PERCENTAGE MODULATION AT VARIOUS AUDIO FREQUENCIES 2334 No. C. Rundquist by Dr. G. H. Brown by J. P. Taylor NEW ANTENNA FOR WIZ 2326 2331 E. by .. B. W. Robins and J. by Lynn Brodlon WAGA AND A -DA 5000 WATTS FOR WRC 1 by Raymond F. Guy A RADIO FREQUENCY PHASE METER WITH MANY USES by Dr. G. H. Brown and Gilbert Swift KELO EXPANDS FACILITIES COLUMBUS STATION JOINS 5 -D TREND by Lester H. Notxger TRANSMISSION LINES by R. D. Duncan, Jr. SANTA BARBARA STATION COMPLETELY RCA A GLIMPSE OF STATION PERSONALITIES LOOKING IN ON THE STATIONS A CATHODE RAY TUBE HIGH SPEED RESPONSE INDICATOR AND RECORDER... by R. A. Hackley WLAW FORGES AHEAD by Irving E. Rodgers IT'S A 5 -D AT BIRMINGHAM SIMPLIFIED SOLUTION FOR ANTENNA IMPEDANCE MATCHING NETWORKS by A. Vollenweider AN ULTRA DIRECTIONAL MICROPHONE by Dr. H. F. Olson DIRECTIONAL ANTENNAS by Dr. G. H. Brown THE PRINTING PRESS GETS WINGS_.. MECHANICAL DESIGN OF OPEN WIRE TRANSMISSION LINES NEW STUDIOS FOR WOAI MODERN DESIGN -SIMPLICITY "BETTER THAN RATINGS" -RADIO STATION KFAM NEW STUDIOS IN WASHINGTON SOMETHING NEW IN SPEECH INPUT EQUIPMENT by H. C. Vance by H. M. Kearney by Lynn Brodton by C. M. Lewis ONE OF AMERICA'S MOST MODERN RADIO STATIONS by James L. Middlebrooks and Royal V. Howard HERE AND THERE IN THE RADIO WORLD SIMPLIFIED NETWORK SYNTHESIS by Edmund A. Laport DIRECTIONAL ANTENNAS Dr. G. H. Brown NOTES ON THE USE OF OSCILLOGRAPHS by B. W. Robins WCOU ENLARGES AREA by Leslie R. Hall RCA FACSIMILE FOR SCHOOLS THE UNI -DIRECTIONAL MICROPHONE CENTRAL OREGON'S -KBND by Ellsworth C. Dent by Dr. H. F. Olson _ MORE POWER TO WHBF LACQUER DISC RECORDING AND REPRODUCING by H. J. Hasbrouck and R. F. Brady INTERNATIONAL EXPOSITION TOMORROW'S TRANSMITTER TODAY. by J. E. Eiselein WMBI DEDICATES NEW STUDIOS DIRECTIONAL ANTENNAS by Dr. G. H. Brown MODERN IS THE WORD FOR WMCA WDAN- COMMUNITY STATION SIMPLIFIED NETWORK SYNTHESIS.. by Edmund A. Laport LOOKING IN ON WCCO WHLS -THE BLUE WATER STATION Vassos by J. L. Talley by G. H. Clark by C. M. Lewis by J. E. Young M. Brumbaugh by Dudley E. Foster by Karl B. Hoffman DIRECTIONAL ANTENNAS by Dr. G. H. Brown WIDER COVERAGE FOR WFBM by M. R. Williams COLUMBIA'S TELEVISION TRANSMITTER NEARS COMPLETION A REVIEW OF BROADCAST ENGINEERING by J. P. Taylor BUFFALO STATION INCREASES POWER MODERN IN EVERY DETAIL NEW HIGH POWERED SOUND PROJECTORS by Mox L. Graham A MODERN COMMUNITY STATION by Allan O. Brophy COMBINATION HORN AND DIRECT RADIATOR by H. F. Olson and R. A. Hackley LOUDSPEAKER. RAPID GROWTH FOR IOWA STATION WJDX INSTALLS FIRST AIR -COOLED TRANSMITTER.... by Wiley P. Harris AN ULTRA -SENSITIVE D -C METER by John M. Brumbaugh RECEPTION BEGINS IN THE ANTENNA by C. W. Horn 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 EARLY TRANSMITTER INSTALLATIONS LOOKING AT EARLY RECEIVERS EARLY RECEIVERS WERE CRUDE BUT AWE EARLY RADIO INTERESTED MILLIONS STUDIOS OF ANOTHER DAY DESIGNS HAVE BEEN REVOLUTIONIZED INSPIRING MODERN STATIONS OF TODAY NEW WORLDS FOR EVERYONE TWO DECADES LATER TELEVISION IS HERE TELEVISION HISTORY IN THE MAKING TELEVISION RECEIVERS ARE HERE FACSIMILE- JOURNALISM ON THE AIR THE NEWSPAPER OF TOMORROW SAFETY IS SERVED BY RADIO RADIO ENTERS LIMITLESS FIELDS RADIO AIDS INDUSTRY AT BOTH FAIRS -IT'S RCA Also included in this issue on back of front cover are excerpts from o letter written in 1916 by David Sarnoff "I have in mind a plan of development which would make radio a 'household utility' in the some sense as the piano or phonograph... 18 www.americanradiohistory.com . . BROADCAST NEWS MASTER TABLE OF CONTENTS- (Cont'd) (A) KEY TO INDEX NUMBERING (ISSUES 10 THROUGH 66) First two digits indicate "Broadcast News" volume or issue number. (B) Next two digits indicate the pages on which articles begin. Index Index 3202 3203 3206 3208 3211 3214 3216 3217 3222 3224 3228 3232 3236 Author Subject No. WCKY -FIFTY GRAND IN WATTS.. FROM THE TOP OF THE WORLD (Photos-Pages 4 -5) Photos by Hylen Photo Shop NEW EQUIPMENT TO MEASURE INTENSITY OF RADIO NOISE THE NEW STANDARD VOLUME INDICATOR AND REFERENCE LEVEL_ NORTH OF THE BORDER (Photos -Pages 12 -13) FLEXIBLE AND COMPACT WAY DOWN YONDER IN NEW ORLEANS THE STANDARD VOLUME INDICATOR AND REFERENCE LEVEL 3310 3312 3314 3316 3317 3320 3323 3326 3327 3331 3332 3336 3402 3403 3404 3408 3409 3410 3412 3414 3415 3416 3417 3419 3420 3421 3422 3502 3504 3506 3508 3510 3512 3514 3518 3520 3522 3525 3526 3534 3536 3602 3604 3606 3607 3608 by R. M. Morris by Edmund A. [apart ELECTRON MICROSCOPE THE 3304 3308 by Charles M. Burrill __._.._._.._ _..........by L. J. Flodman NEW COMMUNICATIONS RECEIVER by Edward Braddock by F. A. Dieringer IT'S MODERN -IT'S WFMJ.... (Photos -Pages 18.19) PARALLEL MIXER CIRCUIT CALCULATIONS by C. W. Slaybaugh by J. C. Walter CALCULATIONS OF T.I.F. FOR TRANSMITTER LOADS WHBC AMONG THE LEADERS DOING A MAN -SIZED JOB IN MANSFIELD FROM THE ARCTIC TO THE TROPICS 3áO2 3306 by C. H. Topmiller by Stanton D. Bennett by J. D. Bloom by R. M. Morris MEASUREMENTS OF FREQUENCY MODULATED FIELD INTENSITIES by B. W. Robins IT'S A 5 -DX FOR WOI by Professor W. 1. Griffith RCA TELEVISION FIELD PICKUP EQUIPMENT by Henry E. Rheo NEW 1000 WATTERS FOR THE NORTHERN CANADIAN by Wm. K. Marks MINING REGIONS FLASH -ARC CURRENTS IN TRANSMITTER TUBES by J. C. Walter A STREAMLINED KILOWATT FOR WCAR by Wiley D. Wenger by J. M. Brumbaugh NEW BROADCAST FREQUENCY MONITOR by Edward Braddock NEW COMMUNICATIONS RECEIVER IMPROVED INSTANTANEOUS RECORDING ATTACHMENT by C. N. Reifsteck RCA SPECIAL UNITS REQUIRE SEPARATE PLANT FEED THE LINE WITH QUALITY CALCULATIONS OF T. I. F. FOR TRANSMITTER LOADS....by J. C. Walter NEW RCA 64 -B SPEAKER CONVENTION CAMERA CONTEST VIEWS OF A FEW WELL-KNOWN WESTERN INSTALLATIONS A DIRECTORY OF COAST STATIONS FOR NAB VACATIONERS NEW RCA EQUIPMENT FOR THE EPICURE AND EPICURIOUS SAN FRANCISCO -WHERE THE EAST, THE WEST, AND THE NAB MEET NEW RCA EQUIPMENT A GUIDE FOR VISITORS TO TREASURE ISLAND A TOUR OF SAN FRANCISCO A DRIVE WHICH INCLUDES THE LEADING POINTS OF INTEREST IN SAN FRANCISCO SOME OUTSTANDING COAST INSTALLATIONS RCA AT THE GOLDEN GATE EXPOSITION NEW RCA EQUIPMENT SUGGESTIONS FOR COUPLING OF R -F TO MEASURING EQUIPMENT NEW STUDIOS FOR WIRE LATERAL DISC RECORDING by AT KYCA IT'S RCA WBOC, SALISBURY, MD. -VOICE OF THE EASTERN SHORE WWNC -ONE OF NORTH CAROLINA'S PROGRESSIVE STATIONS CHARACTERISTICS OF UNBALANCED OVERHEAD TRANSMISSION LINES by Dr. G. H. Brown ANOTHER STOP ON OUR 250-K PARADE -WCBI, COLUMBUS, MISS. 3622 3623 A FINE TRANSMITTING PLANT AT WTAG 3626 5000 WATTS AT WFLA, TAMPA, FLORIDA STATION, HAS LATEST IN RCA EQUIPMENT TWO STATIONS ON PACIFIC TIME 3627 NOISE REDUCTION IN DISC RECORDING 3628 by R. A. Lynn 3630.1 KYUM- ATTENTION -GETTER IN THE SOUTHWEST 3630-2 DOWN GEORGIA WAY THERE'S WMGA IN MOULTRIE 3631-1 TWO VIEWS OF WMCA 3631.2 IT'S WLOK IN WESTERN OHIO 3703 3704 3706 3708 3710 3712 3714 3717 3718 3720 3721 3722 3732 3735 by S. V. Perry BALTIMORE PATTERNS TAILORED TO FIT SMARTNESS PLUS EFFICIENCY -WREC DOWN SOUTH IN SAVANNAH UP NORTH IN CANADA THE ELECTRON MICROSCOPE GOES INTO ACTION A TWO-FIFTY IN TEXAS A COMPACT SET -UP FOR KHAS WISH, INDIANAPOLIS ... MEDIEVAL TORTURE 1943 LET'S LOOK AT THE RECORD 3816 3820 3824 THE STORY OF RCA RESEARCH AT WAR THE 5 -E, AN ENGINEER'S TRANSMITTER TELEVISION REMOTE PICKUP EQUIPMENT.. THE 50 -SW, A NEW TRANSMITTER FOR - by Loren F. Jones by J. E. Eiselein by H. E. Rhea INTERNATIONAL BROADCASTING 3828 3832 3835 3838 3841 3844 3846 3849 3902 3923 by J. W. Sanborn 3936 3938 E. ... by Thomas F. Joyce by Stokes Gresham, Jr. RCA TESTING CHAMBERS 3812 Eiselein by J. DELUXE RECORDERS AT WFM1 WHAT YOU HEAR THE DEVELOPMENT OF THE TELEVISION MARKET IN THE POST -WAR PERIOD 3928 3932 3935 WCBM, INTERESTING NEW SCHOOL INSTALLATION_ by K. L. Dragoo HIGHER VOLTAGES FOR THE ELECTRON MICROSCOPE SUPER INSTALLATION FOR PENNSYLVANIA'S SUPER HIGHWAY KOB PICKS 50 -E by George S. Johnson KOB- PROGRESSIVE STATION OF THE GREAT SOUTHWEST IN EMBATTLED CHUNGKING RCA EQUIPMENT CARRIES ON HERE AND THERE AMONG THE STATIONS SPEECH INPUT SYSTEMS by C. M. Lewis and J. D. Colvin 3806 3810 3925 FINEST EQUIPMENT FEATURED AT WFBC REMOTE CONTROL IN ALASKA by Stanton D. Bennett PORTABLE PERFECTION IN RECORDING by W. L. Lyndon SHEER MAGIC IN AUTOMATIC RECORD CHANGER UP -TO -DATE 3802 Fredenhall, NBC Audio Facilities Group THE DECIBEL SCALE RCA's 250'S (K'S) GET AROUND "RADIO CARACAS"-ONE OF VENEZUELA'S Author IN MONTERREY IT'S RCA 3613.2 3614 3615 3616 3903 3906 3914 B. F. Subject No. 3613-1 3941 3944 O BRASIL FALA . . . BRAZIL SPEAKS FM NOISE LEVEL AND AM NOISE LEVEL WARTIME OPERATION OF THE .5-D AND 5 -DX TRANSMITTERS KMPC- STATION OF THE STARS by W. J. Reilly by .1. Keachie H. WYOMING! HIGHWAY PATROL RADIO . . by H. C. Hill GOOD TUBES FOR OLD "ATTENTION MEN! THIS IS THE CHAPLAIN SPEAKING . by F. S. LeRoy ABOUT OUR REPLACEMENT AND REPAIR PARTS SERVICE . PICTURES OF NEW INTERNATIONAL STUDIOS OF ASSOCIATED BROADCASTERS THE FM -10.A TRANSMITTER FOR 10 KW FM STATIONS ANTENNAS FOR FM STATIONS.. by John NBC'S EXPERIENCE WITH PORTABLE P. Taylor TELEVISION EQUIPMENT by Robert E. Shelby and Harold P. See KLRA'S 10 -E TRANSMITTER by Kermit F. Tracy FM AUDIO MEASUREMENTS WITH AN AM RECEIVER.... by R. J. Newman THE 2 -A STUDIO CONTROL CONSOLE by J. E. Colvin "DC" PICTURE TRANSMISSION by H. N. Kozanowski RCA ENGINEERING IN OTHER FIELDS: RF POWER AIDS PENICILLIN PRODUCTION THE NEW RCA 9C21 AND 9C22 TRIODES by H. C. Vance TELEVISION LINEARITY CHARACTERISTICS by C. D. Kenfner FROM JUNGLE DRUMS TO 50 KW by Belly Fellows by R. D. Duncan, Jr. COVERAGE CURVES FOR FM ANTENNAS ORTHACOUSTIC REPRODUCING FILTER -MI -4914 by Walter and Keachie SIX WIRE TRANSMISSION LINE A SEA -GOING INSTALLATION WSAM -"RCA ALL THE WAY" KDYL-A BUSY STATION IN THE BEEHIVE STATE by C. M. Lewis and J. D. Colvin SPEECH INPUT SYSTEMS J. C. J. H. 4002 POLYCYLINDRICAL DIFFUSERS IN ROOM ACOUSTIC DESIGN 4008 4011 4012 PERFORMANCE OF BROADCAST STUDIOS WITH CONVEX SURFACES OF PLYWOOD WHLD STUDIOS KARK STUDIOS 4013 A MODERN MUSIC RECORDING STUDIO by John E. Volkmann DESIGNED by C. P. Boner by M. Rettinger 19 BROADCAST NEWS MASTER TABLE OF CONTENTS -(Cont'd) KEY TO INDEX NUMBERING (A) First two digits indicate "Broadcast News" volume or issue number. Index No. 4019 4022 4026 4031 4038 4046 4048 4057 NBC STUDIOS 6A AND 6B NAVY SETS UP PEARL HARBOR AND GUAM BROADCASTING FACILITIES WFAA -KGKO STUDIOS by George M. Nixon by J. D. Colvin WFAA -KGKO STUDIO EQUIPMENT by John P. Taylor SELECTING A SITE FOR AN FM STATION TO THE CAPPER STATIONS' GIRL OPERATORS.. by Judy J. Alesi ORCHIDS WWV- BROADCASTING FREQUENCY STANDARDS by R. J. Newman WITH RCA TYPE ET -7285 TRANSMITTERS TELEVISION COVERAGE CURVES FOR by R. D. Duncan, Jr. TURNSTILE ANTENNAS 4118 WOOC 4139 4144 4145 4151 4156 Next two digits indicate t::e pages on which articles begin. . WOOW, INTERNATIONAL BROADCAST __.by R. N. DeHart STATIONS INSTALLED BY CBS AT WAYNE, N. J. HOW TO DETERMINE THE AREA AN FM STATION by John P. Taylor SHOULD SERVE........ HOW TO DETERMINE THE REQUIRED TRANSMITTER by John P. Taylor POWER OF AN FM STATION ASSOCIATED BROADCASTERS INSTALL 50 KW SHORTWAVE AND EQUIPMENT FOR NEW INTERNATIONAL STUDIOS....by Royal V. Howard BERT SILEN TELLS HOW IT FEELS TO BLOW UP by Judy J. Alesi AN RCA TRANSMITTER WJBO -WBRL, AM -FM STATIONS AT BATON ROUGE, LA. by L. A. Thomas "BUNCH OF WIRES" "SINGA PAMBA" by E. A. Henry PRACTICAL DESIGN OF VIDEO AMPLIFIERS . . . . No. 4444 4456 4460 RCA ENGINEERS TEST PROJECTION TELEVISION RECEIVER AUDIO FREQUENCY RESPONSE AND DISTORTION MEASURING by R. J. Newman TECHNIQUES FOR FM TRANSMITTING SYSTEMS 4132 (B) Index Author Subject 4102 4112 4126 (ISSUES 10 THROUGH 66) . 4463 4466 4508 4518 4522 4524 4536 4538 4542 4546 4554 4556 4604 4609 4612 4621 4622 4624 4628 Subject Aut:-.or PLUG-IN AMPLIFIERS. _.. THE BTF -10B TRANSMITTER THE BTF -50A TRANSMITTER by H. by J. E. by C. J. DETERMINING THE POPULATION SERVED BY AN FM STATION GROUNDED -GRID POWER AMPLIFIERS by E. E. Duszak Young A NEW 50 KW AM TRANSMITTER A NON -DIRECTIONAL ANTENNA FOR MOBILE FIELD STRENGTH MEASUREMENT IN THE FM BAND by W. Lyndon THE ATLANTIC CITY STORY by Judy J. Ales! L. Starner Spitzer by B. W. Robins WTCN PLANS TELEVISION.. by Clifford J. Rion TELEVISING A CONVENTION by John P. Taylor TELEVISING AN OPERATION TELEVISING THE BULLFIGHTS by Edward K. Price KSD -TV INAUGURATES COMMERCIAL VIDEO SERVICE IN ST. LOUIS KSD -TV -A POSTWAR TELEVISION STATION by Robert L. Coe MILWAUKEE JOURNAL PLANS INSTALLATION OF RCA TELEVISION TRANSMITTER by Beatrice Ann Gehrung IMAGE ORTHICON FIELD EQUIPMENT by John H. Roe NAB ENGINEERING _.._ CLINIC HOW NAB USES THE RCA IMAGE ORTHICON CAMERA by F. A. Wankel and WARNER BROTHERS AND RCA PLAN JOINT PROGRAM ON LARGE -SCREEN TELEVISION THE NEWS OF THE HOUR STATION -WMIN AT LAST FM QUALITY SPEAKER FREQUENCY RANGE PREFERENCE FOR SPEECH -AN E. C. Wilbur by Frank M. Devaney by G. E. Rand AND MUSIC 4206 4224 NEW FM TRANSMITTERS NOW IN PRODUCTION A NEW FM EXCITER UNIT OF GREATLY IMPROVED 4230 THE GROUNDED -GRID .... PERFORMANCE 4236 4240 4242 4245 4246 4248 4253 4254 4258 4261 4266 4271 4306 4312 4322 4324 4342 4348 4350 4354 4362 4369 4372 4406 4414 4420 4428 4436 4442 Newman 4633 4636 by N. J. Oman by C. J. Starner 4638 4644 by AMPLIFIER R. J. MULTI -UNIT CONSTRUCTION-A FEATURE by John L. Ciba OF NEW FM TRANSMITTERS RANGE PREDICTION CHART FOR FM STATIONS by F. C. Everett ANTENNA _... THE SUPER TURNSTILE by R. W. Masters WCAU PLANS NEW STUDIO BUILDING NEW RATIO DETECTOR SIMPLIFIES FM RECEIVER DESIGN by Stuart W. Seeley RCA'S NEW HIGH -SENSITIVITY CAMERA REVOLUTIONIZES TELEVISION PICKUP TECHNIQUE ARMY DEMONSTRATES TWO RCA RADIO RELAY SYSTEMS GIMBELS AND RCA TEST INTRA -STORE TELEVISION by Judy J. Alesi RCA MICRO -WAVE RELAY SYSTEM by H. F. Mickel ABC'S VANDERBILT STUDIOS by Ben Adler CANADA'S LOUDEST VOICE THE 77 -D POLYDIRECTIONAL MICROPHONE by J. B. Epperson THE RCA ANTENNALYZER by G. H. Brown and W. C. Morrison HOW A TELEVISION STATION CAN GROW IN EASY STEPS WMT INSTALLS RCA 5F AIRBORNE TELEVISION IS AN RCA DEVELOPMENT by Henry Rhea AN FM CALIBRATOR FOR DISC RECORDING HEADS by H. E. Roy; WMC INSTALLS RCA 10F FILAMENT SUPPLY IN THE BTA -50! TRANSMITTER. by T. J. Boerner HOW TO MAKE A FIELD SURVEY OF AN FM STATION_.. .. by G. W. Klingman FM FIELD SURVEY TECHNIQUES by P. B. Loeser THE TYPE 301 -B FIELD INTENSITY METER by K. B. Redding FM FIELD SURVEY METHODS AS OUTLINED IN THE FCC "STANDARDS" THE TK -30A CAMERA RCA WAR RESEARCH by Norman by Loren S. Bean F. Jones MICROWAVE EQUIPMENT FOR TELEVISION RELAY SERVICE by W. J. Poch RCA SALES ORGANIZATION THE "PYLON" ANTENNA ISOLATION METHODS FOR FM ANTENNAS MOUNTED ON AM TOWERS and J. P. Taylor by R. F. Holtz by R. F. Holtz 4649 4650 4652 4657 4708 4713 4714 4722 4726 4732 4736 4738 4742 4746 4748 4752 4758 4762 4764 4769 4804 4816 4818 4820 4828 4832 4836 4838 4841 4842 4846 4856 4858 _..... ... by Harry F. Olson RECORDING STUDIO 3A by G. M. Nixon KOOL IN ARIZONA WFIL'S TELEVISION PLANNING THE RCA TYPE T.1-50A TELEVISION MOBILE UNIT by W. J. Poch and H. C. Shepard TTR -1 AND TRR -1 TELEVISION RELAY LNITS TESTED OVER LONG DISTANCE TOP ENGINEERS ATTEND TELEVISION COURSE by E. B. May A HIGH SCHOOL GOES FM by John W. Stahl CAMERA PLACEMENT AND SWITCHING FOR BASEBALL TELECASTING by John P. Taylor LIGHTNING TESTS ON THE PYLON ANTENNA WSAV'S PYLON by T. 1. Eldridge, Jr. MEASURED CHARACTERISTICS OF THE PYLON ANTENNA.... by O. O. Fiet 300 KILOWATTS OF FM POWER TELEVISION PROGRESS by David Sarnoff RCA AT THE NAB EXHIBII LARGE -SCREEN TELEVISION AT NAB TELEVISION ENGINEERING CLINIC REPEATED by E. B. May WWL CELEBRATES 25TH ANNIVERSARY WMOX, MERIDIAN, MISSISSIPPI WAAT READIES TELE WBAL'S "NEW WORLD OF TOMORROW" STUDIOS.... by Harold C. Burke TECHNICAL FACILITIES FOR WBAL'S NEW STUDIOS by R. S. Duncan WBRE -FM, WILKES- BARRE, PA. by David Baltimore WSBA AND WSBA -FM, YORK, PA by W. G. Eberhart AMERICAN TELEVISION SHOWN IN THE VATICAN._. __..by E. K. Price THE TT -5A TELEVISION TRANSMITTER THE by C. D. Kentnor RCA 8D21 QUICK CHANGING OF 8D21 TUBE WNBW AND WRC -FM TRIPLEXED ANTENNA AT WNBW /WRC -FM WOPI'S MILE HIGH FM INSTALLATION KGKL, SAN ANGELO, TEXAS by E. H. Potter by R. F. Guy by L. E. Wolle WKY'S MOBILE STUDIO WACE AND WACE-FM WTMJ.TV ON THE AIR PLANNING THE TRANSMITTER BUILDING.. by John Vassos and KFBK'S FM AND STUDIO INSTALLATIONS WCVS AND WCVS -FM, SPRINGFIELD, ILLINOIS 20 www.americanradiohistory.com S. W. Pike BROADCAST NEWS MASTER TABLE OF CONTENTS- (Cont'd) KEY TO INDEX NUMBERING (ISSUES 10 THROUGH 66) First two digits indicate "Broadcast News" volume or issue number. (B) Next two digits indicate the pages on which (A) Index Index No. 4860 4862 Author Subject 4866 WKBH, LaCROSSE, WISCONSIN HOW TO CONVERT A STANDARD TELEVISION RECEIVER INTO A DIRECT -VIEWING VIDEO EXTENSION MONITOR.... by WBEN -TV NEARLY READY 4906 4908 MIDGET FIELD INTENSITY METER WJPG -FM -FIRST FM SERVICE IN 4912 4920 4924 4928 4933 4934 4942 4946 4950 4952 4968 5002 5008 5018 5028 5032 5036 5052 :058 5105 5106 5108 5122 5128 5132 5145 5151 5154 5758 5166 5172 5174 5206 5208 5212 5240 5244 5248 5252 5258 5Z07 5208 5318 5320 5326 5332 5336 5344 5346 articles begin. by R. E. E. K. Price . . 300 BROADCASTERS COMPLETE RCA TV ENGINEERS' COURSE FACILITIES HOUSING FOR TV by Rene Brugnoni and Ben Adler PLANS FOR CBS' GRAND CENTRAL TELEVISION by A. B. Chamberlain STUDIOS NAB BROADCAST ENGINEERING CONFERENCE _.. ._. _by J. P. Taylor TELEVISION IN THE SPOTLIGHT AT NAB HIGHLIGHTS OF THE "SUPER POWER" 8- SECTION PYLON....by O. O. Fiet _. by R. H. Frye WKJG -FM ERECTS HIGH POWER FM ANTENNA. PHILADELPHIA STORY SALUTE TO KOMO KOMO BUILDS A NEW PLANT PLANNING THE NEW KOMO STUDIOS by F. J. Brott and S. D. Bennett CONSTRUCTING THE NEW KOMO STUDIOS by S. D. Bennett HEATING AND VENTILATING THE NEW _.. _..__.. KOMO STUDIOS by J. K. Gannett EQUIPMENT FOR THE NEW KOMO STUDIOS by M. E. Gunn KOMO'S NEW 50,C0) WATT TRANSMITTER by F. J. Brott and C. E. Miller NEW LIGHTWEIGHT REMOTE AMPLIFIER by R. C. Abbett CONSULTANTS ATTEND SPECIAL CLINIC by Erwin B. May WFIL'S TV STUDIOS WEWS TV ANTENNA INSTALLATION by J. B. Epperson WPAY-FM SERVES WIDE AREA CUSTOM-BUILT DUAL- RECORDING CONSOLE._ by A. S. Kerker WSAV ENLARGES FM BROADCASTING FACILITIES SCALE MODELS MADE FROM PAPER CUTOUTS AID TV STATION PLANNING.. by Marvin L. Gaskill PRACTICAL EQUIPMENT LAYOUTS FOR TELEVIS:ON STATIONS SECOND ANNUAL FMA CONVENTION by R. S. Mannheimer WWNC ON -AIR WITH NEW 5 KW TRANSMITTER WJAC -FM INSTALLS RCA TRANSMITTER AMERICAN TV SHOWN IN SPAIN _ by Edw. K. Price PLANNING RADIO AND TELEVISION STUDIOS by George M. Nixon HOW TO SHOCK MOUNT 70 SERIES TURNTABLES..... by W. E. Stewart BTF -50A, 50 KW FM TRANSMITTER.... by C. J. Starner THE 50 KW FM POWER CUTBACK SWITCH by C. J. Starner WTMJ -FM WORLD'S FIRST "SUPER- POWER" M....by Phillip 8. Loeser WBRC-FM WORLD'S MOST POWERFU'FM STATION. by G. P. Hamann 8- SECTION PYLON MAKES 546 KW A REALITY ... ... AT WBRC -FM HOW TO MAKE FM MEASUREMENTS WGPA, 250 W AM WMPS . . . 5406 5414 5432 5437 5443 5452 5474 THE NEW 5478 5504 5508 5516 5520 5524 5528 5530 5538 5542 5550 5552 5563 5604 5608 5628 5640 5646 5654 5655 5656 5657 5660 5662 5664 5666 5668 5672 5708 5714 5724 5728 5732 5740 5745 5746 5748 5758 5762 5764 by O. O. Fief 5804 Talmage _..._ by Arthur McCracken 5807 5808 5810 by KW FM MEMPHIS' 10 KW AM 3 _. .. _. F. E. ABC PIONEERS WITH MET TV PHILOSOPHY OF OUR TELEVISION SYSTEM by J. H. Roe PORTABLE TAPE RECORDER by W. E. Stewart WENR -TV by E. C. Horstman and J. M. Valentine TELEVISION FILM RECORDING by R. V. Little, Jr. THE PHILOSOPHY OF OUR TV SYSTEM (Part II) by John H. Roe RCA COMPLETES WCAU -TV SIXTH TV CLINIC by John G. Leitch HOW TO GET THE BEST PICTURE OUT OF YOUR IMAGE ORTHICON CAMERA by H. Kozanowski THE "BERKSHIRE " -A RADIO -PHONOGRAPH BUILT TO TRANSMITTING EQUIPMENT STANDARDS by Marvin Hobbs OPTIMUM HIGH -FREQUENCY BIAS IN MAGNETIC RECORDING by G. L. Dimmick and S. W. Johnson TV AND FM SITE TESTING.. by E. S. Clammer and E. M. Brown RCA DISPLAYS COMPLETE LINE OF EQUIPMENT AT NAB CONVENTION . CROSSOVER FILTER FOR DISK RECORDING HEADS BROADCASTERS COMPLETE 7TH RCA TV CLINIC NEW CUSTOM MOBILE UNIT WMGM CUSTOM EQUIPMENT by H. E. Roys by E. L. Schacht by M. E. Gunn by Robert C. Deigert and David N. Yerkes A NEW 150 KW AM TRANSMITTER by T. J. Koerner WRAK -FM, WILLIAMSPORT, PA. OSCILLOSCOPES AND VACUUM TUBE VOLTMETERS by George E. Reding and Paul A. Greenmeyer THE PHILOSOPHY OF OUR TV SYSTEM (Part III) by John H. Roe TV BLUEPRINT SUPERGAIN TV ANTENNA DEVELOPED BASEBALL TELEVISION. WPIX BASEBALL THE "NEW LOOK" AT KTBS KTBS'S NEW TRANSMITTER BY RCA KAKE KOOS KSYC _.. KXLL KRDO PROOF -OF- PERFORMANCE - Author Subject IMPROVED LACQUER DISK RECORDING HEAD by H. E. Rays CMQ- HAVANA'S KEY STATION BROADCASTING STUDIO PICKUP TECHNIQUE _..._..... by H. M. Guerin Grimm NORTH EAST WISCONSIN AREA _. by Elmo W. Reed WSBA -FM GOES TO 10 KW by W. E. Tucker and F. E. Talmage KCMO- KANSAS CITY'S 50 KW UP THEY GO AT WATV, NEWARK by W. O. Hodlock and M. L. Gaskill THE TP -16A 16MM TELEVISION PROJECTOR. by R. V. Little, Jr. A 10- KILOVOLT TEST PROBE FOR TELEVISICN_ _... by J. M. Brumbaugh HOW TO USE THE TELEVISION STABILIZING AMPLIFIER_.. by John H. Roe WLOS MAKES ITS DEBUT IN THE WONDER -UL LAND OF THE SKY _.. by Palmer A. Greer TRAINING A TELEVISION STAFF -WOW, OMAHA by Joe Herold NOTE ON MEANS OF MEASUREMENT OF OUTPUT PLATE A.C. VOLTAGE OF A TELEVISION DEFLECTION CIRCUIT by J. M. Brumbaugh WGAR, CLEVELAND -KMPC, LOS ANGELES KRON -FM SERVICE OF THE SAN FRANCISCO _ by R. A. Isberg CHRONICLE . No. 5350 5354 5358 5366 5373 WHHM WSRS -- -- .. ... _... WISL WLAK WBCK WBAL-TV by John Taylor P. by W. M. Witty by Harold H. Newby .... by Roger L. Spaugh by Jack R. Wagner ... by Paf M. Goodover by Joseph Rohrer by William Marsh by Ben H. Whittaker by B. T. Marshall by William P. Lee by A. J. Geronis by William C. Bareham FIRST UHF TRANSMITTER SHIPPED WMAR -TV, BALTIMORE, MARYLAND VOICE OF AMERICA'S 150 KW TRANSMITTER. RADIO ISTANBUL COVERS NEAR EAST WITH 150 KW TRANSMITTER WTCN, MINNEAPOLIS KENI, ANCHORAGE, ALASKA HOW TO USE THE TM -5A MONITOR THE STRANGE CASE OF THE FIVE BASEBALLS WHIO -TV, DAYTON by C. G. Nopper by E. L. Schacht by Paul C. Brown by John M. Sherman by A. G. Hiebert by H. J. Markley THEATRE TELE WPTZ'S USE OF THE REFLECTAR AND ZOOMAR LENSES KSEI, POCATELLO, IDAHO by Henry H. Fletcher HOW TO USE STANDARD FILTERS WITH NEW FLAT MAGNETIC PICKUP THE BN -2A PROVIDES FLEXIBILITY NEW SUPER -POWER BEAM TRIODE THE GENLOCK FOR IMPROVED TV PROGRAMMING . by H. E. Roys by J. H. Roe 21 BROADCAST NEWS MASTER TABLE OF CONTENTS -(Cont'd) KEY TO (A) 5814 5818 5828 5836 5842 5846 INDEX NUMBERING (ISSUES 10 THROUGH 66) two digits indicate "Broadcast News" volume or issue number. 5904 5907 5916 5924 5932 5936 5946 5950 5960 5962 5963 5964 6004 6008 6018 6026 6028 6034 6036 6038 6042 6048 -1 6048-2 6049 6050 6052 6054 6056 6058 6060 6068 6078 BRAZIL'S LARGEST RADIO NETWORK INSTALLING RCA TV TRANSMITTER by L. J. Anderson and L. M. Wigington THE "BANTAM" MIKE -KB -2C by B. Wolfe and G. Lohman WAAM, BALTIMORE by C. A. Rosencrans DIRECTIONAL ANTENNA SYSTEMS RCA BROADCAST SALES REPRESENTATIVES TV REMOTE CONTROL SWITCHING._. by W. E. Tucker and C. by HOW TO ADJUST FREQUENCY RESPONSE IN VIDEO AMPLIFIERS FOR TV L. 6242 6250 6256 6266 J. Wolf by J. H. Roe HIGH -FIDELITY, NOISE CANCELLING by L. J. Anderson and L. M. Wigington MICROPHONE 1057 -FOOT FM -TV ANTENNA COMBINING TV TRANSMITTER CONTROL AND by W. L. Lyndon and W. T. Douglas, Jr. PROGRAM SWITCHING NEW "UNOBTRUSIVE" RIBBON -PRESSURE by H. F. Olson and John Preston MICROPHONE NAB ENGINEERING CONFERENCE RCA SHOWS NEW EQUIPMENT AT NAB CONVENTION KRMG, TULSA'S NEW "FIFTY "..... _by A. F. Wooster and K. W. McCrum KANSAS CITY'S WDAF -TV DEVELOPMENT OF MULTIPLE-STATION ANTENNA FOR EMPIRE STATE BUILDING NOW UNDER WAY WALL-TYPE HOUSING FOR LC -1A "OLSON" SPEAKER HOW TO SHOCK-MOUNT "70" SERIES TURNTABLE COMPOSITION OF THE VIDEO WAVEFORM by Robert M. Crotinger AS SEEN ON THE SCOPE 6352 6354 6357 6366 6374 NEW LIMITING AMPLIFIER, BA -6A_. by G. A. Singer by R. J. Newman ALL NEW 250 -WATT AM TRANSMITTER WDSU, AM -FM -TV by The WDSU Engineering Staff A VERSATILE VIDEO SPECIAL EFFECTS SYSTEM by E. M. Gore KRNT 709 -FOOT TV TOWER UNDER CONSTRUCTION THE REQUIREMENTS OF TELEVISION STATION DESIGN (Part III) .___........____....._.by Dr. Walter J. Duschinsky FACTORS AFFECTING PERFORMANCE OF DIRECTIONAL ANTENNAS by A. Earl Cullum, Jr. RCA BROADCAST SALES EXECUTIVES RCA BROADCAST FIELD SALES REPRESENTATIVES MORE BASEBALL TELEVISION by John P. Taylor A PROFESSIONAL TAPE RECORDER by W. E. Stewart TWO NEW STUDIO CONSOLETTES by David Bain 6406 6408 KGVO, MISSOULA, MONTANA NEW LIGHTWEIGHT PICKUP AND 6304 6308 6316 6330 6334 6336 KB -3A, by J. P. McGrenra by H. E. Roys by Glenn Flynn TV FIELD EQUIPMENT ACCESSORIES RECORDING AND FINE GROOVE TECHNIQUE WOW-TV, OMAHA, NEBRASKA HOW TO MODIFY RCA CAMERAS FOR SETTING CORRECT TARGET VOLTAGE. UHF SYMPOSIUM AT KC2XAK, BRIDGEPORT by J. H. Roe by WGAN ANNOUNCER-TURNTABLE SETUP EMPIRE STATE TELEVISION HOW TO PLOT TV STUDIO LIGHTING R. W. Hodgkins by W. C. Eddy and H. Duszak by Thomas E. Howard WPIXIock RADIOMIKE COVERS REMOTES FROM HELICOPTER UNIQUE TAPE RECORDER CONSOLE AT WEEI NEW AM MODULATION MONITOR, TYPE BW -66E by Daniel M. Reed KPRS, OLATHE, KANSAS by David G. Sinclair KVFD, FORT DODGE, IOWA by Neil Arveschoug and Jack Casey WDHN, NEW BRUNSWICK, N. J by Gerald R. Chinski KXYZ, HOUSTON, TEXAS by J. V. Sanderson WSGN, BIRMINGHAM, ALABAMA by P. G. Caldwell TELEVISING FOOTBALL FROM L. A. COLISEUM by H. M. Gurin and R. L. Zahour TV STUDIO ILLUMINATION by G. W. Tunnel! NEW PORTABLE TV FILM PROJECTOR WBSM, WBSM -FM FLYING SPOT CAMERA, TYPE TK -3A 6134 THE WKPT, WKPT -FM by Otto F. A. Arnold by C. R. Monro by Thomas Phillips AND ALIGNMENT PROCEDURES by F. E. Cone and N. P. Kellaway FOR VIDEO AMPLIFIERS REQUIREMENTS OF TELEVISION by Dr. Walter J. Duschinsky STATION DESIGN TEST 6343 6415 6418 6420 6428 6434 6442 6448 6451 6452 6455 6456 6466 6506 6508 6514 6528 6530 6534 6536 6548 6555 6558 6561 6606 6608 by R. J. Newman AM, FM and TV BROADCAST STATIONS NEW LINK FOR THE AMERICAS.... by Meade Brunet RCA TELEVISION by George M. Burbach KSD AND KSD -TV, ST. LOUIS 6616 6618 6624 6630 6636 by C. R. Yarger KSD'S AM FACILITIES by J. E. Risk KSD TELEVISION FACILITIES THE REQUIREMENTS OF TELEVISION STATION DESIGN by Dr. Walter J. Duschinsky (Part II) 6640 6648 6656 EMPIRE STATE TELEVISION 6146 WOR.TV STUDIOS 6204 FCC AUTHORIZES STUDIO- TRANSMITTER LINK FOR by Newland F. ... ............. by A. D. Dahl and Clarence L. Touw TONE ARM by L. J. Anderson and C. R. Johnson METHOD OF DETERMINING THE CAPABILITIES OF A PICKUP by H. E. Roys RADIO PIONEERS DINNER RCA'S LARGEST NARTB SHOW FEATURES NEW VHF TV EQUIPMENT by W. O. Hadlock THE REQUIREMENTS OF TELEVISION STATION DESIGN (Part IV) by Dr. Walter J. Duschinsky KGO -TV, SAN FRANCISCO by The KGO -TV Engineering Staff A SOLUTION TO THE MAGNETIC TAPE TIMING PROBLEM by D. R. Andrews PRECISION AM FREQUENCY MONITOR by R. S. McKinney HAM FORUM by M. L. Gaskill TELEVISION TRANSMITTER MONITORING by R. A. Boot and I. E. Goldstein HOW TO ADJUST LIMITING AMPLIFIERS by W. E. Stewart VIDEO RELAY SWITCHING LAYOUTS by C. R. Monro AN EDITING MACHINE FOR MAGNETIC TAPE Smith 6141 Author Subject EMPIRE STATE TOWER NEARS COMPLETION by Nevin L. Straub WJAC -TV, JOHNSTOWN, PENNA DESIGN OF MOBILE TWO -WAY RADIO COMMUNICATION EQUIPMENT AT 152 -174 MC by R. A. Beers, W. A. Harris, A. D. Zappacosta by W. L. Lyndon A FLEXIBLE TV AUDIO SYSTEM Munro R. HIGH GAIN AND DIRECTIONIL ANTENNAS 6108 6116 6122 6128 6208 6222 6224 6230 6236 Next two digits indicate the pages on which articles begin. No. Author Subject FOR TELEVISION BROADCASTING 5854 (B) Index Index No. 5812 First RECORDING by D. C. Yarnes A CARRIER -AUDIO ALARM CIRCUIT FOR MONITORING BROADCAST TRANSMITTERS by Stan Bennett A NEW AM -FM -TV CONSOLE.... .. by P. W. Wildow and G. A. Singer NEW "TV PEAK" IN SAN FRANCISCO by Al Isberg WNAG'S NEW "250," BTA -250M by Robert McRoney STANDARDIZING AND MEASURING VIDEO LEVELS IN A TV STATION by J. H. Roe RADIO AT INDIANA STATE TEACHERS by Dr. C. M. Morgan WTAR, AM -FM- TELEVISION by WTAR Engineering Staff A LABORATORY TELEVISION SYSTEM by R. L. Hucaby TELEVISION STUDIO ACOUSTICS by M. Rettinger KNBC'S NEW AM VERTICAL HAM FORUM by M. L. Gaskill BROADCAST AUDIO WIRING PRACTICE by W. E. Stewart THE RCA "BASIC BUY" EQUIPMENT LAYOUT by L. E. Anderson and W. O. Hadlock WFIL GOES "45" by Louis E. Littlejohn TELEVISION MICROPHONE TECHNIQUES by Whitney M. Boston KOTA AND KOZY, RAPID CITY, SOUTH DAKOTA by A. E. Griffiths NEW 3' /a -INCH UHF ULTRA LOW LOSS COAXIAL LINE by O. O. Fiet "EIGHTH" BROADCASTERS' TV TRAINING PROGRAM by E. C. Mason and W. R. Coulter U. S. ARMY SIGNAL CORPS NOW HAS "ELECTRONIC EYES" NEW 5 KW AM TRANSMITTER by M. H. Hutt HAM FORUM by M. L. Gaskill THE 22 www.americanradiohistory.com BROADCAST NEWS CROSS -REFERENCE INDEX (Volumes -AACOUSTICS (Studio) AM FM 5728, 5640, 5354, 5258, 4968, 4752, 4633, 4002, 4008, 4013, 4017, 4018, 4019, 4026, TV.. 6555, 5258, 5108, 5122, 4011, 4312, 3105 5008, 5018 AIR CONDITIONING and HEATING (Stations) .. 5128, 1048 AM /FM TV _. _.. 5748 AMATEUR RADIO STATIONS 5654, 5666, 3217, STATIONS (50kw and 150kw)....5946, 5724, 5728, 5105, 5108, 4920, 4952, 4752, 4118, 4139, 3828, 3211, 1410, 918, 802, 702 STATIONS (others) 2012 6455, 6304, 5807, 5151, 4444, 3409, 3331, 2614, 2523, 2120, 2126, 2131, 2006, 1908, 1312, 1207, 1004 6558, 4261, 4019, 3419 -3, 2918, 2604, 2416, 2427, 2128, 2129, 1906, 1912, 1618, 1510, 1522, 1404, 1405, 1410, 1428, 1116, 1118, 1008, 1046, 1049, 1051, 918, 933-2, 938, 724 2208, 1623, 1524, ... 5552, 5358, 3835, 3422, 3316, 3224, 2326, 1914, 1808, 1624, 1408, TECHNIQUES.. ANTENNAS (DIRECTIONAL ARRAYS) 5646, 4952, 3514, 3016, 2928, 2720, 2620, 2412, 406 ANTENNAS (NON- DIRECTIONAL) 2826, 2612, 2426, 2214, 2227, 1718, 1628, 1526, 1406, 1304, 3332, 6343, 5946, 2808, 2833, 1430, 1207, 1116, 404, 422 Proof of Performance 6558, 4442, 1914, 1814, 1033, 819 -1, 512, 526, 418 MONITORING 6506, 6448, 6049, 3421, 3320, 2124, 1923, 1038, 930, 324, 214 TEST AND MEASURING.... 5552, 4906, 4369, 3424, 3206, 2929, 2808, 2820, 2716, 2406, 2306, 1826, 1834, 1502, 1506, 1217, 1042, 824, 736, - 4048, 3824, 3510, 2604, 1922, SHORTWAVE 1402, 1310, 912, 516 STANDARD BROADCAST (250w- 1kw)._.... 6528, 6308, 3508, 3101, 3011, 2523, 2420, 2114, 1214, 902, 915, 304 STANDARD BROADCAST (over 1kw)._._._..6646, 6406, 6224, 5946, 5724, 5728, 5542, 5145, 4508, 4350, 3816, 3106, 2118, 1202, 1232, 1102 TRANSMISSION LINES..._... 3602, 3616, 2904, 2814, 826, 526, 404 TUBES. 5936, 5808, 3936, 3316, 2125, 2010, 814, 614, 206 Installation Practices EQUIPMENT. Layout and Planning 3602, ANTENNAS AND TRANSMISSION LINES. 3616, 3016, 2904, 2928, 2826, 2833, 2720, 2612, 2412, 1526, 1406, 404 GENERAL EQUIPMENT.. ..6506, 6508, 5258, 4846, 4633, 2428, 302 _ 4838 4906, 4820, 3206, 2406, 1834, 1502 SURVEYS AND METHODS__. 1138, 1030, 716, 606 2616, 1826, 1510, CHIA WOOW 4266 4118 ..4118 4144 3902 KZRH KWIX WIXBS (1) 1402 Stations -AM (Std. B'cst) 50w-500w WNAG (250) (250).. WBSM ..(250).. WKPT KVFD KAKE ...(250) ...(250) ..(250) ..(250)_ _ KOOS KSYC KXLL .. WHHM ..(250)_ ..(250).. WGPA WSAV WCVS ..(250).. . WBOC WCBI ... WMGA WMAN KBND WDAN KFAM WCOU KGLO WROW WRAK WEBR WSBT WTRC KFJZ WRAW _. (250). __(250)._ KYCA WJHP WCBM KROD KHAS WFMJ .........5656 .. _. WSRS WSOO _. ... ... (250)_ (250).. (250) .(250)_ ...(250).. ....(250) (250) (250) . (250) ..(250) (250) .(250). ...(250)_ ....(250). (250).. (250). (250) (100) (250) ..(100).. ...(250)_ (250).. (500). .(250). (250).. (100) 6528 6108 6122 ....6052 .._..5654 5655 .................5657 (250) WSPB KFPW . ... .....(250) KRDO KROC WEMP KVSO WTAR __.(250) ._. .... 5658 5660 5662 .5344 .5206 4858 .4746 ...3613 ..3614 .3622 ....3630 3508 -2 .3508 -1 ..3509 -2 3509 -1 ...3512 ..3526 3534 3217 .3232 3006 ...3021 2911 .2932 ..2710 ...2608 _.2417 ...2418 2318 2329 2218 2009 (100) (100) 2031 1809 ... -1825 825 1 (250)_.. (100)_... (500). (100) .. .(500)... 150). . WTAG WBRE ... WGAM WGNY WWSW .... WSUN WFLA WORC - .... -1007 830 _834 536 .406 406 408 _. ... Stations-AM (Std. B'cst) KPRS 1707 1318, 1209 1233 ... (100) (250).. (250). (100). _... kw and 21/2kw 1 (1) WISL WLAK WBCK WACE WSBA .. KFAR .. (1)(1).. ... ..... (1) (1). WTAG (1) ...(1) (1). WCAR WHBF KSOO (212) ...2811 2811 (21/2)(1) (1) (1) (1) CKCK WROK WTAG WFBC (1).... KTBS (1) (1) (1) WWNC WEEV 4841 4764 3704, 3303 .... 3623 _.... 3627 .._. ....3314 .. 3317 3007 ... 2805 . (1) (1) WAGA .6050 5664 5666 5668 - (I)_. KRSC CJKL _ .. (1) (1) WLAW (50) (50) (50) WOOC WHOM KELO Stations -AM (Short Wave) WMOX ANTENNAS AND TRANSMISSION LINES 3602, 3616, 2904, 2612, 2214, 1526, 1406, 1304, 512 6506, 6508, 4758, 3018, CONTROL EQUIPMENT 2404 TRANSMITTING EQUIPMENT (250w -1 kw) 6528, 4838, 3526, 3314, 3317, 3203, 3217, 2702, 2710, 2428, 2318, 1318 TRANSMITTING EQUIPMENT (5kw-10kw- 25kw)__ 6648, 6406, 6222, 6224, 5740, 5646, 5244, 4836, 4860, 4636, 4145, 3502, 3518, 3522, 3310, 2806, 2812, 2712, 2604, 2418, 610, 502 TRANSMITTING EQUIPMENT (50kw and over) 5946, 5724, 5728, 5354, 5108, 4920, 4952, 4752, 4633, 4118, 4139, 3828, 3211, 2918, 2216, 1410, 918, 802, 702 UNITS Operating Practices STATION MAINTENANCE 1420, 1330, 916, 202 AM Equipment MOBILE 5354, 3018, 3027, 2404, Networks AMPLIFIERS (Audio) TRANSMITTING (250w- 1kw)__6528, 6308, 6050, 6052, 5655, 5656, 5657, 5658, 5660, 5664, 5668, 5670, 3502, 3526, 3317, 3203, 2318, 1318 STATIONS (5kw, 10kw and 25kw)......6648, 6406, 6222, 6224, 6056, 6058, 5740, 5646, 5346, 5244, 4636, 4145, 3522, 3310, 2604, 502 6656, 6561, 6451, 3323, 3336 -2, 3216, 2016 108 Through 66) 1 2822 2702 2706 2408 _1328,832 819 - 423 212 _. Stations -AM (Std. B'cst) 5kw and 10kw KOTA WTAR KGVO (5) .. (5) WSGN (5) (5) KENI (5)... KSEI (5).._. WMPS _. _ .. . _. .. .... (10). WWNC (5) WLOS (5)_. .(5)._. KGKL WKBH WMT WMC WJBO KLRA .._. . (5).... KSD KXYZ 6624 .6536 6406 ....6222 6056 ....6058 5740 5764 5346 5244 _._...__. -.(5) -4942 (5) (5)_.. (5)_. (5) (10) (5) .. (5) .. WISH KDYL WFLA WMCA WIRE CBM WOI WRC ._ .. .. .. ... ._ 4836 4860 4322 4348 4145 3923 ___..3806 3607, 509 (5)3626 (5) .3631, 3018, 1427 (5) 3502 (5)... 3522 (5) 3310 5)... 2806 (5)... 2812 (5 ).... 2824 (5) 2712, 2629 (5) 2618 (5) 2618 (5) 2622 (5).._ 2629 (5)_. .2418, 1714, 1240, 524 (5)... 2310 '5) .2316, 1518, 1427 (5).. 3703, 2005 (5)... 1910 .. (5)... .-_._. _ _1803 ._ ( WBNS . WBRC _ . WJDX WGR WKBW WFBM WIP .... WBEN WDBJ WHIO WFBC KFBK WCFL WREN .. (5). 1818 23 A-E BROADCAST NEWS CROSS- REFERENCE INDEX- (Cont'd) Stations-AM (Std. B'cst) 50kw and over KNBC KRMG KCMO KMPC (50) 6558 5946 (50) (50)... 4920 4952, 3830, 411 (50) (50) 4952 WGAR 4742, 610 WWL (50) WBAL 4752, 4758 (50) WCAU (50) 4245, 1621, 1429, 1237, 1161, 1162, 702, 710, 722, 521, 402 4266 CHTA (50) 3717 KOB .._... _ .. ...........(50) 3304 WWL ._. .....(50) 3202 WCKY (50) 3211 CBA (50) 3211 CBK (50) 1410 KOA ..(50) 1002, 820 WLW (500) 802 WOC (50) 802 WHO (50) 520 WTIC (50) . . Stations-AM (Std. B'cst) unclassified WFIL WDFU WGAN WEEI WMGM WKY .. WMIN KZRH 6616 6316 6034 6048 5646, 5640 5530 4838 4622 4144 4011 WHLD KARK WFAA KCKN WIBW WSAM WWNC KVEC WLOK KFI KOMO-K)R KNX KARM KSFO WHBC WMBI WCCO WHLS WOAI KSFO WOSU 4012 4026, 4031 4046 4046 3606 3615 3629 3631 3403 3403, 2426, 1159 3403 3419 3419 3228 3015 3027 3035 2907 2918 2921 WGIL 2921 KTMS 2817 2819 2819 2819 2519 2519 2519 2519 2519 2519 2519 2402 2404 2415, 1157, 939, 835, 602 WMPS KVI KPFA WFAA WEST W KY KRBC KTOK KARK KTSM WGRC KEHE WSM 2431 2331 2331 KPLT WSYR WRGA WGN WDOD WBT WJz WKY ._ WMEX WDAS 2204, 1918 2208, 1714 2216, 1715, 502 2227 2012 2020 1805 KSD WIOD WIP WFK WPEN WRAX WSYR 24 1520, 1712 1713 1602 1618 1418 1520 909 WLS 609 614 614 412 412 412 413 413 413 213 KFSD WENR WOAI WFAA WJDX WSUN WFLA WQBC KFGQ AVIATION RADIO 3115, 2921 -3, 1824, 1637, 847 -BBROADCAST ENGINEERING A REVIEW OF (Reading References) 2434, 2334, 2230, 2032, 2723, 2634, 1934 CAMERA LENSES (TV) 5762, 5608, 5628 ANTENNAS AM DIRECTIONAL 6343, 5946, 5646, 4952, 3514, 3016, 2928, 2808, 2833, 2720, 2620, 2412, 406 AM NON- DIRECTIONAL 6558, 4442, 2826, 2612, 2426, 2214, 2227, 1914, 1814, 1718, 1628, 1526, 1406, 1304, 1033, 819 -1, 512, 526, 418 FM PYLON 5908, 5332, 5036, 4708, 4713, 4714, 4722 FM TURNSTILE 4828, 4442, 4242, 3906, 2320 INSTALLATION PRACTICES AM ANTENNAS 3602, 3616, 2904, 2612, 2214, 1526, 1406, 1304, 512 6630, 6514, 6334, 6036, 5828, TV ANTENNAS 4924, 4748 LAYOUT AND PLANNING -AM ANTENNAS....3602, 3616, 3016, 2904, 2928, 2826, 2833, 2720, 2612, 2412, 1526, 1406, 404 TELEVISION ANTENNAS.... 6334, 6242, 6028, 6036, 5908, 5960, 5846, 5604, 5508, 5166, 4828, 4242 TEST AND MEASURING (ANTENNA) 5508, 4306 - COMBINATION AM -FM -TV LAYOUT AND PLANNING 6058, 5732, 5764, 5662, 5052, 4942, 4820, 4828, INSTALLATIONS....6514, 6536, 5732, 5206, 5052, 4820, INSTALLATION PRACTICES 5764, 5344, 5206, 5052, 4858, 4764 OPERATING PRACTICES 6536, 6316, 5344, 5346, 4858, 4764 6316, 6052, 4858, 4764 6316, 5908, 4942, 4820, 6052, 5206, 6058, 5732, 4828, 6316 COMMUNICATIONS Emergency FIRE AND POLICE.... 3841, 3115, 2002, 1627, 1530, 1534, 1436, 1324, 1230, 1142, 1143, 1145, 1011, 1012, 934, 937, 838, 841, 842, 844, 848, 720, 721, 628, 629, 528, 529, 416, 314, 210, 211, 110 HIGHWAY AND OTHER 3714, 3115, 819 R.C.A. 1049, 1026, 532, 222 ARMY, U. Two Way Mobile Radio AUDIO Equipment CONTROL EQUIPMENT; CONSOLETTES S. 6604, 4414, 4253, 4018, 4056, 3806 6256, 4838 AM AMPLIFIERS....6455, 6304, 5807, 5151, 4444, 3409, 3331, 2614, 2523, 2120, 2126, 2131, 2006, 1908, 1312, 1207, 1004 CONTROL, CONSOLETTES 6606, 6506, 6374, 6266, 5936, 4451, 3214, 2915, 2916, 2610, 2523, 2410, 2204, 2216, 2113, 2130, 2022, 1226, 836 CUSTOM EQUIPMENT 5530, 5132, 5174, 4031, 3928, 3703, 3722, 3608, 3106, 2216 MICROPHONES 6618, 6048, 5904, 5924, 5936, 5814, 4271, 3414, 3003, 2832, 2523, 2212, 2112, 2034, 1704, 1204, 1234, 940, 730, 506, 6506, 6508, 4758, 3018, 2404 AUDIO 6606, 6506, 6374, 6266, 5936, 4451, 3214, 2915, 2916, 2610, 2523, 2410, 2204, 2216, 2113, 2130, 2022, 1226, 836 CONVENTIONS; CLINICS 6418, 6420, 5932, 5713 -2, 5032, 4732, 4609, 4524, 3402, 3412, 3415, 3416, 3417, 2101 OTHERS 6636, 6028, 5524, 5443, 5002, 4726, 4738, 4604, 4650, 2707, 2717, 2302, 2305, 2224, 925 NARTB 320, 104 RECORDING CUSTOM EQUIPMENT 1908, 1217, 626 TRANSCRIPTION 6616, 6408, 6034, 5963, 5804, 5520, 5307, 3536, 3008, 1608, 818, 624 CRYSTALS 6442, 6466, 6366, 6008, 6048, 5936, 5406, 5350, 3706, 3732, 3409, 3414, 3326, 3008, 2133, 1930 TEST AND MEASURING....6415, 6442, 4628, 4342, 2312, 2202 -D- CUSTOM Layout and Planning EQUIPMENT AND SYSTEMS 6266, 5530, 4444, 4451, 3024, 2924, 1906, 1602, 318 TECHNIQUES 6618, 6606, 6514, 6374, 3722, 3608, 3222, 1314, 1118, 1702, 1434, 1314, 1326, 820, 831, 837, 511 2014, 2022, 6008, 6034, 2520 (INTERESTING FACTS) 1706, 1612, 1516, 1416, 1322, 1224, 1152, 1154, 1022, 910, 822, 735, 615 DIRECTIONAL ANTENNAS AM 6343, 5946, 5646, 4952, 3514, 3016, 2928, 2808, 2833, 2720, 2620, 2412, 406 DIRECTORIES COAST STATIONS STATE AND MUNICIPAL POLICE 1606, 1221, 1522, 1414, 1423, 1238, 1118, 1051, Operating Practices TECHNIQUES 6618, 6455, 6466, 6266, 6008, 5804, 5307, 3628, 3536, 3208, 3008, 1704, 1716, 1326, 1329, 1226, 730, 320, 322 5504, 5520, 4342, 3735, 3504, 3506, 3306, 1710 THEORY Surveys and Statistics 4628, 3506, 1911 DID YOU KNOW? 1154, Networks 5240, 5154, 3118, 3010, 2106, 1109, AUDIO.. 5530, 5132, 5174, 4031, 3928, 3703, 3722, 3608, 3106, 2216 INSTALLATION PRACTICES 6606, 6034, 6048, 5530, 5307, 3518 Installation Practices 6606, 6034, 6048, 5530, 5307, 3518 STANDARD 6618, 6514, 6048, 5963, 4444, 4451, 3536, 3420, 1906, 1918, 1602, 1314, 1118, 1154 THEORY 3722, 3608 5516, 5028, 3408, 3410, STATIONS 3404 316 -EEQUIPMENT AM - ANTENNAS DIRECTIONAL ARRAYS 6343, 5946, 5646, 4952, 3514, 3016, 2928, 2808, 2833, 2720, 2620, 2412, 406 NON -DIRECTIONAL 6558, 4442, 2826, 2612, 2426, 2214, 2227, 1914, 1814, 1718, 1628, 1526, 1406, 1304, 1033, 819 -1, 512, 526, 418 BROADCAST NEWS CROSS- REFERENCE INDEX -(Cont'd) TRANSMISSION LINES 3602, 3616, 2814, 826, 526, 404 MONITORING 6506, 6448, 6049, 3421, 2124, 1923, 1038, 930, 324, 214 TEST AND MEASURING._. 5552, 4906, 4369, 3206, 2929, 2808, 2820, 2716, 2406, 1826, 1834, 1502, 1506, 1217, 1042, 736, 108 - TRANSMITTING SHORT WAVE 2904, 3320, 3424, 2306, 824, STANDARD BROADCAST (1 kw and under) 6528, 6308, 3508, 3101, 3011, 2523, 2420, 2114, 1214, 902, 915 6649, STANDARD BROADCAST (over 1kw) 6406, 6224, 5946, 5724, 5728, 5542, 5145, 4508, 4350, 3816, 3106, 2118, 1202, 1232, 1102 TUBES 5936, 5808, 3936, 3316, 2125, 2010, 814, 614, 206 Antennas Studio- Transmitter Link (MICROWAVE)._ ._.6204, 6018, 5828, 5058, 4736, 4639, 4420 Test and Measuring 5552, 4906, 4369, 3424, 3206, 2929, 2808, 2820, 2716, 2406, 2306, 1826, 1834, 1502, 1506, 1217, 1042, 824, 736, 108 ANTENNA 5508, 4306 AUDIO 6415, 6442, 4628, 4342, 1908, 1217, 626 FM 5508, 5552, 4708, 4518, 4352, 4354, 4369, 4112, 3925, 3832, 3421, 3424 6530, 6128, 5964, 5508, 5552, 4933, 4823, 3308 TV Transmission Lines AM._. TV _. ..3602, 3616, 2904, 2814, 826, 526, 404 _. __ 6630 _...._. Transmitting ....6343, 5946, 5646, 4952, AM DIRECTIONAL 3514, 3016, 2928, 2808, 2833, 2720, 2620, 2412, 406 AM NON -DIRECTIONAL 6558, 4442, 2826, 2612, 2426, 2214, 2227, 1914, 1814, 1718, 1628, 1526, 1406, 1304, 1033, 819-1, 512, 526, 418 FM PYLON 5908, 5332, 5036, 4708, 4713, 4714, 4722 FM TURNSTILE 4828, 4442, 4242, 3906, 2320 TV 6334, 6242, 6028, 6036, 5908, 5706, 5846, 5604, 5508, 5166, 4828, 4242 Audio 6455, 6304, 5807, 5151, 4444, 3409, 3331, 2614, 2523, 2120, 2126, 2131, 2006, 1908, 1312, 1207, 1004 CONTROL EQUIPMENT; CONSOLETTES; SWITCH ERS 6606, 6506, 6374, 6266, 5936, 4451, 3214, 2915, 2916, 2610, 2523, 2410, 2204, 2216, 2113, 2130, 2022, 1226, 836 CUSTOM 5530, 5132, 5174, 4031, 3928, 3703, 3722, 3608, 3106, 2216 MICROPHONES 6618, 6048, 5904, 5924, 5936, 5814, 4271, 3414, 3003, 2832, 2523, 2212, 2112, 2034, 1704, 1204, 1234, 940, 730, 506, 320, 104 RECORDING.... 6442, 6466, 6366, 6008, 6049, 5936, 5406, 5350, 3706, 3732, 3409, 3414, 3326, 3008, 2133, 1930 SPEAKERS 5962, 4624, 3414, 3336, 2708, 2123 TRANSCRIPTION 6616, 6408, 6034, 5963, 5804, 5520, 5307, 3536, 3008, 1608, 818, 624 AM- SHORTWAVE Lighting (STUDIO)....__ 6038, 6068, 5936, 5452, 5158, 4546 3117, 2802, 2704, 2210, 1018 3712, 3525, 3302 FACSIMILE... 3113, 3002, 2902, 2908 RF HEATING 3935 RESEARCH 3812, 3116, 2425, 1904, 1138 ALL OTHERS 3327, 3104, 3108, 3109, 2908, 2607, 2206, 2218 -2, 1916, 1806, 1823, 1605, 1607, 1611, 1616, 1424-1, 1110, 1134, 1160, 846, 743 -1, 623, 424, 219 ELECTRON MICROSCOPE Mobile TWO WAY RADIO... TRANSMITTING 5528, 6256, 4838 4838, 3704, 1051, 933, 938, 540 VIDEO 6640, 6004, 6018, 6042, 6069, 4644, 4556, 4406, 3903, 3820, 3312 5728, 5542, 5145, 4508, 4350, 3816, 3106, 2118, 1202, 1232, 1102 FM 5308, 5318, 5320, 5326, 4722, 4456, 4460, 4206, 4224, 4230, 4236, 3421 MOBILE 5528, 4838, 3704, 1051, 933, 938, 540 TVUHF VHF 5708 6420, 6028, 5916, 4804, 3914, 3110 FM 5936, 5808, 3936, 3316, 2125, 2010, 814, 614. 206 4466, 4230 TV 6506, 6448, 6049, 3421, 3320, 2124, 1923, 1038, 930, 324, 214 ..6452, 4862 Proof of Performance AM_... FM 4816 4248, 1904, 806 TV TV (IMAGE) UNCLASSIFIED 3844, 2518, 1310, 906, 744, 521, 306 Two Way Radio 1140, 1014, HIGHWAY -F- 4906, 4820, 3206, 2406, 1834, 1502 4318, 4362, 3944, 3925, 3308 Stations (FM) -3kw KOZY KVFD WSGN WPGA WPAY WKJG WJPG WLOS KRON WRC (3) (3) (3) (3) (3) (3) (3) (3) (3) (3) (3) (3) (3) (3) WOPI WACE WCVS WSBA 5036, 4708, 47 13, 4714, 4722 .._ 4828, 4442, 4242, 6624 6052 6058 5344 5172 5052 4908 4942 4968 4820 4832 4841 4858 ....4764 Stations (FM) -5kw and 10kw WBSM WKPT . __(10) _........__..... WSAV WSBA KOOL (10) (5) (10) (5)_. 6108 6122 5206, 4713 4912, 4764 4636 (50) (50 5320, 4554 Stations (FM) -50kw WTAR WTMJ 6536 Unclassified 6316 5326, 5332 4838 Test and Measuring 5508, 5552, 4708, 4518, 4352, 4354, 4369, 4112, 3925, 3832, 3421, 3424 Transmitting Equipment 5308, 5318, 5320, 5326, 4722, 4456, 4460, 4206, 4224, 4230, 4236, 3421 Tubes -GGOVERNMENT S 6640, 4414, 4253, 4018, 4056, 3806 NAVY, U. S 4414, 4324, 4017, 4022, 3806, 3846, 614, 409 ARMY, U. -H4536 Antennas PYLON.... .5908, 5332, 4145 3710 HOSPITAL TELEVISION FM 3 906, 2320 Installation Practices 6508, 5550, 5318, 5320, 5326, 5248, 5172, 5036, 5052, 4908, 4912, 4924, 4968, 4832, 4838, 4714, 4633, 4145, 3710 Layout and Planning 6508, 6052, 6054, 6058, 5908, 5550, 5318, 5320, 5326, 5248, 5258, 5172, 4908, 4912, 4924, 4968, 4832, 4833, 4838, 4846, 4652, 4145 5552, 5318, 5358 Proof of Performance EQUIPMENT _.. _..... _. KALW 6054 5764 5662 5550 5248 4856 4762 4466, 4230 3714, 3115, 819 6256, 4838 TWO WAY MOBILE 4518, 4362, 3925, 3944, 3308 AND METHODS .5336, 4463, 4354, 4362, 4372, 4240, 4112, 4126, 4132, 4038, 3944, 3832 SURVEYS .. _. - EMERGENCY COMMUNICATIONS FIRE AND POLICE........ 3841, 3115, 2002, 1627, 1530, 1534, 1436, 1324, 1230, 1142, 1143, 1145, 1011, 1012, 934, 937, 838, 841, 842, 844, 848, 720, 721, 628, 629, 528, 529, 416, 314, 210, 211, 110 TURNSTILE... _._ (1) (1) (1) (1) ..(1) (1) WKY Tubes (Transmitting) kw (253w). WRAK WJAC WBRC 1327 AM KSEZ WSRS KFBK WBRE WBRL 1 (1) (1) WDSU Tubes (Receiving) Operating Practices Monitoring AM 2604, - Miscellaneous COMMERCIAL 4048, 3824, 3510, 1922, 1402, 1310, 912, 516 AM- STANDARD BROADCAST 1KW AND UNDER 6528, 6308, 3508, 3101, 3011, 2523, 2420, 2114, 1214, 902, 915 OVER 1KW 6646, 6406, 6224, 5946, 5724, AMPLIFIERS TV WDHN 6048 4048, 3824, 3510, 2604, 1922, 1402, 1310, 912, 516 Stations (FM) -250w to Radiomike AM E-1 -IINSTALLATIONS Combination (AM- FM -TV) 6514, 6536, 6316, 6052, 6058, 5732, 5206, 5052, 4820, 4858, 4764 Practices (AM) 250W-1KW 6528, 4838, 3526, 3314, 3317, 3203, 3217, 2702, 2710, 2428, 1318 5KW- 10KW -25KW 6648, 6406, 6222, 6224, 5740, 5646, 5244, 4836, 4860, 4636, 4145, 3502, 3522, 3310, 2806, 2812, 2712, 2604, 2418, 610, 502 50KW AND OVER....5946, 5724, 5728, 5354, 5108, 4920, 4952, 4752, 4633, 4118, 4139, 3828, 3211, 2918, 2216, 1410, 918, 802, 702 UNCLASSIFIED 3518, 3027, 2012 CONTROL EQUIPMENT 6506, 6508, 4758, 3018, 2404 ANTENNAS AND TRANSMISSION LINES 3616, 3602, 2904, 2612, 2214, 1526, 1406, 1304, 512 25 I-R BROADCAST NEWS CROSS- REFERENCE INDEX -(Cont'd) Practices (Audio) TV 6606, 6034, 6048, 5530, 5307, 3518 STANDARD....6618, 6514, 5963, 4444, 4451, 3536, 3420, 1906, 1918, 1602, 1314, 1118, 1154 3722, 3608 THEORY CUSTOM Practices (FM) 6508, 5530, 5318, 5320, 5326, 5248, 5172, 5036, 5052, 4908, 4912, 4924, 4968, 4832, 4838, 4856, 4714, 4633, 4145, 3710 Practices (TV) ANTENNAS 4924, 4748 6630, 6514, 6334, 6036, 5828, INTERESTING FACTS AND FEATURES 1706, 1612, 1516, 1416, DID YOU KNOW? 1322, 1224, 1152, 1154, 1022, 910, 822, 735, 615 848, 619, 525, 410 WHAT IS IT OLD TIMER? MISCELLANEOUS 3327, 3104, 3108, 3109, 2908, 2607, 2206, 2218 -2, 1916, 1806, 1823, 1605, 1607, 1611, 1616, 1424-1, 1110, 1134, 1160, 846, 743 -1, 623, 424, 219 INTERNATIONAL Broadcasting 5812, 3613 -1, 3510, 1802, 1302, 912, 743.2, 510 50KW 4139, 4151, 3941, 3828, 2018, 1242, 620, UNDER 50KW 411 ..5928, 4118, 204 OVER 50KW_.. 6428, 5538, 5058 1430, TECHNIQUES 6618, 6455, 6466, 6266, 6008, 5804, 5307, 3628, 3536, 3208, 3008, 1704, 1716, 1326, 1329, 1226, 730, 322, 320 THEORY 5504, 5520, 4342, 3735, 3504, 3506, 3306, 1710 Combination AM -FM -TV 6316 .5762, 5608, 5628 TV CAMERA AM 3602, 3616, 2904, 2814, 826, 526, 404 _.._.. 6630 TV -MMAINTENANCE (Station) 2208, TV FM 5552, 5318, 5358 LINES (Transmission) AM 1623, 1524, 1420, 1330, 916, 202 5854 MARINE RADIO TV MAINTENANCE 5552, 4906, 4369, 3424, 3206, 2929, 2808, 2820, 2716, 2406, 2306, 1834, 1826, 1502, 1506, 1217, 1042, 824, 736, 108 ANTENNA 5508, 4306 AUDIO .6415, 6442, 4628, 4342, 1908, 1217, 626 FM 5508, 5552, 4708, 4518, 4352, 4354, 4369, 4112, 3952, 3832, 3421, 3424 FREQUENCY MEASURING SERVICE 1158 TV 6530, 6128, 5964, 5508, 5552, 4933, 4820, 3308 1704, 1204, 1234, 940, 730, 506, 320, 104 Others MICROWAVE STL MISCELLANEOUS 3602, 3616, 3016, 2904, 2928, ANTENNAS 2826, 2833, 2720, 2612, 2412, 1526, 1406, 404 4838 6308, 6050, 250W-1KW 6528, 5655, 5656, 5657, 5658, 5660, 5668, 5670, 3502, 3526, 3317, 2318, 1318 6648, 6406, 5KW- 10KW -25KW 6056, 6058, 5740, 5646, 5346, 3522, 3310, 2604, 502 4145, 5946, 5724, 50KW AND OVER 5108, 4920, 4952, 4752, 4118, 3211, 1410, 918, 802, 702 6052, 5654, 5664, 5666, 3203, 3217, 6222, 6224, 5244, 4636, AM TRANSMITTING 5528, 4838, 3704, 1051, 938, 540 TWO WAY RADIO 6256, VIDEO 6640, 6004, 6018, 6042, 6069, 4556, 4406, 3903, 3820, 3312 3849, 1048 PERSONALITIES 6352, 6354, 5836, 5713 -1, 5606, 5607, 5446, 5247, 4919, 4620, 4545, 4428, 4353, 4138, 3721, 3230, 3234, 3036, 2937, 2818, 2823, 2715, 2602, 2608, 2633, 2516, 2436, 2325, 2331, 2232, 2102, 2103, 2104, 2105, 2108, 2109, 2110, 2111, 2134, 2135, 2035, 1708, 1724, 1614, 1514, 1424-2, 1433, 1316, 1331, 1210, 1228, 1146, 1149, 1150, 1036, 926, 933, 937, 827, 828, 841, 719, 726, 727, 616, 631, 518, 407, 414, 311, 312, 313, 323, 208, 106, 107 6506, 6448, 5354, 3018, 3027, 2404, 2012 EQUIPMENT AND SYSTEMS 6266, 5530, 4444, 4451, 3024, 2924, 1906, 1602, 318 6618, TECHNIQUES 1118, 1154, 6536, 6316, 6052, 6058, 5732, 5344, 5346, 5206, 5052, 4942, 4858, 4764 FM 6508, 6052, 6054, 6058, 5908, 5550, 5318, 5320, 5326, 5248, 5258, 5172, 4908, 4912, 4924, 4968, 4832, 4833, 4838, 4846, 4652, 933, AND METHODS 1138, 1030, 716, 606 AM 1834, 2616, 1826, 1510, EQUIPMENT 4518, 4362, 3925, 3944, 3308 5336, 4463, 4354, 4362, 4372, 4240, 4112, 4126, 4132, 4038, 3944, 3832 TV 4254, 4057, 3802 PYLON ANTENNAS 5908, 5332, 5036, 4708, 4713, 4714, 4722 6049, 3421, 3320, 2124, 1923, 6558, 4261, 4019, 3419 -3, 2918, 2604, 2416, 2427, 2128, 2129, 1906, 1912, 1618, 1510, 1118, 3206, 2406, FM 4644, -N1522, 1008, 1404, 1405, 1046, 1049, 1410, 1428, 1116, 1051, 918, 933 -2, 938, 724 AUDIO 2014, 2022, 1702, 1606, 1522, 1414, 1423, 1434, 1314, 1326, 1221, 1051, 820, 831, 837, 511 TV 5764, 5662, 4820, 4828, 4906, 4820, 4838 NETWORKS 6008, 6034, 2520 Combination AM -FM -TV EQUIPMENT 1502 4838 1038, 930, 324, 214 6606, 6514, 6374, 3722, 3608, 3222, 1314, PROOF OF PERFORMANCE AM MONITORING (AM) Audio 5552, 5563, 5437, SURVEYS AND METHODS MOBILE 5728, 5105, 4139, 3828, 6330, 5745, 4934, 4538, PARTS (Replacement) SURVEYS 3327, 3104, 3108, 3109, 2908, 2607, 2206, 2218 -2, 1916, 1806, 1823, 1605, 1607, 1611, 1616, 1424-1, 1110, 1134, 1160, 846, 743 -1, 623, 424, 219 AM STATION INSTALLATIONS 6204, 6018, 5828, 5058, 4736, 4639, 4420 LAYOUT AND PLANNING MOBILE UNITS -TV 6530, 6452, 5916, 5810, 5366, 4933, 4657, 4536, -P- AM 6618, 6048, 5904, 5924, 5936, 5814, 4271, 3414, 3003, 2832, 2523, 2212, 2112, 2034, -L- 5854 TECHNIQUE 6608, 6618, 6357, 6128, 6042, 6060, 5762, 5608, 5628, 5474, 4946, 4950, 4842, 4612, 4542, 3312 THEORY 6026, 5964, 5746, 5373, 4156, 3932, 3938 3604, 3115, 2415, 1405 MEASURING AND TESTING 6208, 5252, 4769 5354, 4144, 3720, 3236, 3010, 1902, 618 1207, 1116, 404, 422 Audio MICROPHONES Television 4145 6508, 6018, 5414, 4638, LENSES 6608, 6508, 6230, 6146, 5916, EQUIPMENT 5950, 5818, 5748, 5714, 5672, 5414, 5452, 5158, 4866, 4748, 4638, 4546 6618, 5916, 5058 TECHNIQUES UNCLASSIFIED 5552, 5358, 3835, 3422, 3316, 3332, 3224, 2326, 1914, 1808, 1624, 1408, TECHNIQUES BUILDINGS AND EQUIPMENT._.6608, 6618, 6434, 6456, 6222, 6230, 6116, 6146, 6028, 5950, 5818, 5714, 5748, 5672, 5452, 5206, 5212, 5158, 5018, 4748, 4546 SYSTEMS- STATION DESIGN 6630, 6514, 6336, 6236, 6134, 5908, 5828, 5508, 5563, 5437, 5258, 5008, 4924, 4312 TECHNIQUES. 6038, 6060, 5916, 5608, 1238, 1118, 6434, 6146, 6060, 6068, 5708, 5366, 5258, 5058, 5018, 4820, 4726, 4612, 3914, 3928, 2630 -OOperating Practices AM MAINTENANCE .2208, 1623, 1524, 1420, 1330, 916, 202 26 www.americanradiohistory.com -RRCA COMMUNICATIONS.... ........1026, 1049, 532, 222 FREQUENCY MEASURING SERVICE 1158 REPLACEMENT PARTS 3849, 1048 RADIO AMATEUR.... 6656, 6561, 6451, 3323, 3336 -2, 3216, 2016 AVIATION MARINE 3115, 2921 -3, 1824, 1637, 847 3604, 3115, 2415, 1405 TWO WAY MOBILE 6256, 4838 RADIOMIKE 6048 RECEIVER (AM-FM-TV) 5478, 4862, 4246, 4102, 3802, 3708, 3323, 3216, 3102, 3103, 3110, 3111, 3112, 2718, 2034, 1804, 1309, 629, 540 RECEIVING TUBES 1327 R-Z BROADCAST NEWS CROSS-REFERENCE INDEX -(Cont'd) Lighting RECORDING 6442, 6466, 6366, 6008, 6048, 5936, 5406, 5350, 3706, 3732, 3409, 3414, 3326, 3008, 2133, 1930 RESEARCH AND THEORY 3812, 3116, 2425, 1904, 1138 -S- TEST Layout and Planning BUILDING 6434, 6028, 5452, 4546 AND EQUIPMENT 6608, 6618, 6508, 6456, 6222, 6230, 6116, 6146, 6018, 5950, 5818, 5714, 5748, 5672, 5414, 5206, 5212, 5158, 5018, 4748, 4638, SYSTEMS AND DESIGNS 6630, 6514, 6428, 6336, 6236, 6134, 5908, 5828, 5842, 5508, 5538, 5563, 5437, 5258, 5008, 4924, 4312 STATION HEATING AND AIR CONDITIONING 5128, AM / FM 1048 5748 TV ....6618, 6008, 6034, 2520 TECHNIQUES 5762, 5608, 5628 AM 6528, 4838, 3526, 3314, 3317. 3203, 3217, 2702, 2710, 2428, 1318 6648, 6406, 6222, 6224, 5KW- 10KW -25KW 5740, 5646, 5244, 4836, 4860, 4636, 4145, 3502, 3522, 3310, 2806, 2812, 2712, 2604, 2418, 610, 502 5946, 5724, 5728, 5354, 50KW AND OVER 5108, 4920, 4952, 4752, 4633, 4118, 4139, 3828, 3211, 2918, 2216, 1410, 918, 802, 702 3518, 3027, UNCLASSIFIED 2012 FM 6508, 5550, 5318, 5320, 5326, 5248, 5172, 5036, 5052, 4908, 4912, 4924, 4968, 4832, 4838, 4856, 4714, 4633, 4145, 3710 TV 6608, 6508, 6230, 6146, 5916, 5950, 5818, 5714, 5748, 5672, 5414, 5452, 5158, 4866, 4748, 4638, 4546 STATION MAINTENANCE 2208, 1623, 1524, 1420, 1330, 916, 202 5854 AM TV 5728, 5640, 5354, 5258, 5108, 5122, 4968, 4752, 4633, 4002, 4008, 4011, 4012, 4013, 4017, 4018, 4019, 4026, 3105, 1918, AM /FM 1602, 612, 521 -1 6555, 5258, 5008, 5018 TV SURVEYS (and Methods) 2616, 1826, 1510, 1138, 1030, 716, 606 AM 4628, 3506, 1911 5336, 4463, 4354, 4362, 4372, 4240, 4112, 4126, 4132, 4038, 3944, 3832 6434, 6146, 6060, 6068, 5708, 5366, 5258, 5018, 5058, 4820, 4726, 4612, 3914, 3928, 2630 TECHNIQUES 6608, 6357, 6128, 6042, 5762, 5608, 5628, 4946, 4950, 4852, 4542, 3312 TV 1118, 1154, 318 6630, 6514, 6428, 6336, 6236, 6134, 5908, 5822, 5842, 5508, 5538, 5563, 5437, 5258, 5008, 4924, 4312 -T- 6530, 5916, 5366, 4657, 6334, 6242, 6028, 6036, 5908, 5960, 5846, 5604, 5508, 5166, 4828, 4242 Film Recording Radiomike Stations (5kw) 6048 (5) 6536 6316 (5) ....6222, 6230, 4542, 4546 (5) 6250 (5) 6018 (5) 5950 (5) 5818 (5) 5714 (5) 5732 (5) 5748 (5) 5672 (5) 5414 (5) 5452 (5) 4924 (5) 4820 (5) 4842, 4554 (5) 4866 (5) 4748 (5) 4522 (5). KSD WJAC WDAF WAAM WMAR WTCN WHIO WBAL WENR WCAU WATV .. KRNT WOR WPIX W PTZ ACOUSTICS 5748 5158, 4866, 4748, 4638, 4546 6618, 5916, 5058 1327 Transmitting 5936, 5808, 3936, 3316, 2125, 2010, 814, AM. 614, 206 4466, 4230 FM TVIMAGE 4248, 1904, 806 4816 UNCLASSIFIED 3844, 2518, 1310, 1140, 1014, 906, 744, 521, 306 OTHERS TWO WAY RADIO 6256, 4838 UHF -TV TRANSMISSION LINE TRANSMITTING U. 6630 5708 ARMY S. 6640, 4414, 4253, 4018, 4056, 3806 NAVY U. S. VHF -TV TRANSMITTING 3110 6420, 6028, 5916, 4804, 3914, (MOBILE) 6640, 6004, 6018, 6042, 6069, 4644, 4556, 4406, 3903, 3820, 3312 STUDIO 6608, 6420, 6434, 6456, 6330, 6116, 6004, 6026, 6042, 5916, 5929, 5936, 5810, 5842, 5745, 5762, 5432, 4928, 4934 FIELD Transmitting Equipment EQUIPMENT 6608, 6508, 6230, 6146, 5916, 5950, 5818, 5714, 5748, 5672, 5414, 5452, Receiving VIDEO 5758, 4736, 4621 ANTENNAS.... 6630, 6514, 6334, 6036, 5828, 4924, 4748 TUBES 6555, 5258, 5008, 5018 Theater Installation Practices VHF 4414, 4324, 4017, 4022, 3806, 3846, 614, 409 Studio 6208, 5252, 4769 5708 6420, 6028, 5916, 4804, 3914, 3110 UHF MOBILE COMMUNICATIONS 6514 6434 6334 6146 6042, 5628 5762 5562 5158, 4638 5166 KRON KGO 6204, 6018, 5828, 5058, 4736, 4639, 4420 International TV Systems, Techniques 4536 5326, 4722, 4456, 4460, 4236, 3421 5528, 4838, 3704, 1051, 933, 938, 540 4254, 4057, 3802 Studio -Transmitter Link Hospital 5308, 5318, 5320, 4206, 4224, 4230, Mobile Proof of Performance AIR CONDITIONING AND HEATING. 5432 6452, 5810, 4933, 4536, FM WFIL WEWS Antennas TECHNIQUES.. 6618, 6060, 5474, 4612, WGN TELEVISION 6330, 5745, 4934, 4538, 2523, 2420, 2114, 1214, 902, 915 OVER 1KW 6648, 6406, 6224, 5946, 5724, 5728, 5542, 5145, 4508, 4350, 3816, 3106, 2118, 1202, 1232, 1102 6026, 5964, 5746, 5552, 5563, 5437, 5373, 4156, 3932, 3938 WTMJ WBEN WAAT WTCN 1602, 1314, 5854 SHORTWAVE 4048, 3824, 3510, 2604, 1922, 1402, 1310, 912, 516 STANDARD BROADCAST 250W- 1KW.... 6528, 6308, 3508, 3101, 3011, THEORY WNBW AUDIO 6606, 6514, 6374, 6266, 5530, 4444, 4451, 3722, 3608, 3222, 3024, 2924, 1906, AM - MAINTENANCE FM AND DESIGN 6630 TRANSMITTING EQUIPMENT Operating Practices WTAR WDSU 5520, 5307, TV Networks AUDIO SYSTEMS 6616, 6408, 6034, 5963, 5804, 3536, 3008, 1608, 818, 624 AM__..........3602, 3616, 2904, 2814, 826, 526, 404 6452, 4862 WOW STUDIO ACOUSTICS TRANSCRIPTION TRANSMISSION LINES Monitoring 250W -1KW 5552, 4906, 4369, 3424, 3206, 2929, 2808, 2820, 2716, 2406, 2306, 1826, 1834, 1502, 1506, 1217, 1042, 824, 736, 108 ANTENNA 5508, 4306 AUDIO.. 6415, 6442, 4682, 4342, 1908, 1217, 626 FM. 5508, 5552, 4708, 4518, 4352, 4354, 4369, 4112, 3925, 3832, 3421, 3424 TV 6530, 6128, 5964, 5508, 5552, 4933, 4820, 3308 Lenses (Camera) STATION INSTALLATIONS AND MEASURING AM 6038, 6068, 5936, 5452, 5158, 4546 UHF ....5708 VHF 6420, 6028, 5916, 4804, 3914, 3110 -W- Tubes IMAGE TRANSMITTING _ .4248, 1904, 806 ....4816 WHAT IS IT (FEATURE) OLD TIMER? ........848, 619, 525, 410 27 BROADCAST IN AUDIO W. E. STEWART, Mgr. Audio Engineering Section The latest RCA Mi crophone to be announced is the BK -1A Pressure type, successor to the 88.A. 1 952 The indicating the period at which an item first appeared. There are several phases to trends that can be considered. audio equipment required to set up satisfactory studio installation comprises an important part of the Broadcast Station's investment. Thus, its purchase and installation is generally treated with serious study; and once installed, it must serve for a long time. To discern trends we must go back over 20 to 25 years of Broadcast history, since most of the installations of 10 to 15 years ago are still in use. a The BK-4A Starmaker Microphone, a Ribbon- Pressure type suited for 1959 Television use. Suppose we start with styling. Most of the early control room equipment was black as was the power plant equipment and the automobile of 25 years ago. The first attempts to liven the appearance of this equipment consisted of adding chrome plate. Whole chassis and various louvres were plated to give them a flashier appearance. The accompanying group of pictures have been chosen to illustrate typical construction as nearly as possible, with some The Pressure Microphone (suc1938 cessor88 -A to the 50 -A) has been widely used for announce and newscasting. 193c The Type 77 -A Universal (Rib bon) Microphone, forerunner the present -day "77 -D ". 28 www.americanradiohistory.com of 1933 The Model 50 -A Pressure type, first in the line of induction microphones. 1948 The KB -2C "Bantam" Veloc. ity Microphone, designed 1944 for studio or remote use. The popular 77 -D Ribbon type which may be used as a "bi- directional ", "non" directional", or "uni- directional" microphone. About this time the use of color became common and various manufacturers stand- 1900 The 77-C, Universal (Ribbon type) 7UV Microphone. a predecessor of the famous 77-D. makes it easier for the station to change for TV; and the new RCA consolette are the color to its choosing. examples of this trend. ardized on certain colors to make their equipment distinctive. This made the sta- Now that TV is with us, the control A well planned control room can be a room must be darkened. Dull surfaces. real show place for visitors, and the smooth tions more color conscious (or perhaps the lighted meters and dials, and better vision lines of today can give an impression of stations led the manufacturer, I don't know over the control desk are some of the most efficiency even better than the gadgety who was first) recent changes in this line. racks of , and they occasionally de- manded color schemes of their own. As color came in chrome went out so far as the control room is concerned, and outside surfaces were made plainer. This 1932 15 years ago. Color has been put to work in several In the studio, microphones have had recent cases to indicate related switching and mixing functions. The CBS Audio quite a different history. This item is before the producer and subject to his demands. It remained large and gaudy until Console for TV; the NBC Audio Console The 44 -BX Velocity Microphone has become the standard broadcasting where the highest quality reproduction is desired. of of An early model Ribbon Microphone 1930 (Velocity type). Note attached preamplifier and use of electromagnetic field. 1928 early Condenser type Microphone with pre-amplifier attached. An TV came along. Now, it must suddenly become unobtrusive. It must have its glitter removed, lest it become a beam in the TV camera's eye. Smaller microphones, and microphones with dull finishes are now available for this application. For AM, the smaller microphones are finding use in interview work, but the old standards are not changing rapidly in the studio. Again in the control room, the reduction in size of units, compactness of control consoles, and technical improvement in put 6 in 84/4 inches. The new CBC Master installations. 25 to 50 circuit switching is still required in some cases. A control system Control System in Montreal has a City, Italy, last smaller amplifier and so does the new RCA was installed in Vatican consolette. summer that accommodates ten men at the Master control systems are becoming larger. More and more stations have come the realization that central control desk, each man handling the program in a different language. well planned While the systems are becoming large, Master Control system can reduce the cost and more input and output channels are to a and improve the performance of their op- required, stress on planning with skillful eration at the same time. As the oppor- application of these trends which have im- tunity ripens, various stations are rebuild- proved efficiency and flexibility has kept ing their systems. the size of the control room and central switching has kept up with the growth of The Voice of America installation in operating desks to a minimum of expan- Amplifiers are getting smaller. New York City, built during the last war, sion. Note the increased amount of equip- the new CBC switching system at ment within reach of the operator in recent systems. Where a preamplifier formerly 3% to 1948 5 required inches of rack space, you can now and Montreal are outstanding examples of large Modern Broadcast Studio Control Console and companion audio equipment rack of the BR-84 series. Note matched appearance and styling of rack and console. 30 www.americanradiohistory.com control desks. 1940 Audio equipment rack of the RCA Type "9 AX"' series. Note trend toward streamlining. equipment rack Audio showing use of chrome plate, different amplifiers, and "square-type" meter. 1936 Early audio rack which employs round meters and some components still mounted on the front 1934 Early version which shows the use of tubes and components mounted on the front panels. 1932 panels. Some form of preset system is usually necessary. This is usually planned to conform to the division of labor as found in the particular union contracts, to use men's time more efficiently, to make the switching as mistake proof as possible, and to assign definite responsibility. If an oper- ator knows that he is responsible for a certain operation and that errors in its execution can be traced to him, he is less likely to make an error. Error prone operators can be quickly pinned down and moved to other jobs. Recent Master Control plans show definite improvement along these lines. Another early audio equipment rack in 1932 which tubes, components are mounted directly on panels. Note the greater number of controls and adjustments required. www.americanradiohistory.com A deluxe, custom -built Master Control Console installed at Radio Station WMGM. It .7YU handles ten studio inputs and feeds six channels simultaneously, or individually by preset relay system. Note how the twelve audio equipment racks are installed "in- line" at either side of the operator's position for convenience and accessibility. 1948 TV has made new problems in MC switching and interesting results are be- Trends in Audio would not be complete without some mention of recording. many records as ever and fine groove recording is gaining slowly. ginning to emerge from the struggle with this operation. In nearly every case, ways The most important item has been the are being sought to make a single control sudden addition of magnetic tape record- improvement in acetate recording but perform both the audio and video switch- ing. Its use is still on the increase. New still somewhat experimental. ing. To do this and still keep flexibility as applications are still being found for this to source, previewing and other functions excellent programming tool. under control presents many new engineering problems. Several approaches to this problem are in use or being planned and will no doubt be the subject of future Audio Engineering articles. Hot stylus recording has offered some In summary: is Overall trends indicate larger installations, circuit -wise; smaller The advent of tape seems to have slowed components to give more compact installa- disc recording somewhat, but it is still a tions; and centralization of control. With respect to style we have the additional use of color, and simpler appearance. big business. Discs still have many advan- tages. The disc jockey programs use as 32 www.americanradiohistory.com Master Control Console installed at Radio Sta- 1940 tion WLS. In this ar rangement controls, meters and switches are convenient to operator by a "U" type turret arrangement. Audio racks are installed nearby at the rear of console. t_--+- _- _s_._ _T_ ___. .-- .. Master Control Console and 1938 associated audio equipment racks installed at Radio Station WFBR. This shows the trend toward bringing controls, meters and switches into convenient operating range. ++r111e % á Early WGN Master 1935 Control Console. Note that fewer controls and switches are convenient to the operator's position. . 1. External Edge-Light Pro Ìector Assembly shown in oper. ating position on the under side of the Tx -20A Film Camera. FIG. - IMPROVED TELEVISION PICTURE PERFORMANCE Step -by -Step Description on How to Modify RCA Film Camera Equipment by H. N. KOZANOWSKI TV TERMINAL Developments in the art of television broadcasting during the past few years have shown very forcibly that programming is depending more and more heavily on film material either as a basic source of programs or for continuity in live broadcasts as well as for the usual advertising sources. It has also been recognized that the quality of film transmission as compared to live talent material leaves, in many cases, much to be desired. An ideal situation would be one in which the home viewer would not be aware whether the source of broadcast material were live talent or film recording. With the now wide -spread and continuing increase of kine -photography this criterion of performance becomes more and more vital to the success of any long -range op34 EQUIPMENT ENGINEERING eration. For this reason, we have studied possible methods of improving motion picture reproduction in television broadcasting and have arrived at a very encouraging conclusion. The iconoscope film chain, when suitably operated and improved according to our recent findings, can produce pictures which closely approach studio quality. We shall discuss the basic philosophy of operation of the iconoscope film chain, paying specific attention to the factors which at present limit performance, pointing out their relative importance, and then outlining in greater detail the changes which can be made in existing equipment to bring the standard of performance up to the quality which has been produced in the laboratory. Work during the last year on developmental iconoscope film chains has resulted in the crystallization of specific improvements which contribute to bet- ter overall film reproduction. Demonstrations to critical viewers over a long period have indicated that these improvements are significant. We have prepared this discussion and information in order that stations which wish to introduce these improvements will have sufficient detailed data to do this themselves without waiting approximately six months, the estimated time in which RCA can furnish the required modification items. For purposes of logical presentation, we can list the areas of improvement and then discuss each item in detail. 1. Video Amplifier Mosaic Illumination 3. High Peaking and Microphonics 4. Amplifier Over -load 5. Black Level Control 2. Amplifier The predominant source of noise in an iconoscope chain is not the iconoscope itself but the first -stage amplifier. Extensive study of this problem has resulted in the development of a cascode preamplifier using the Western Electric 417A triode for the input, feeding an RCA 6J6 as the output tube. This preamplifier unit, shown in Fig. 2, physically replaces the conventional triode -connected RCA 6AK5 stage used in existing equipment. Since the transconductance of the 417A tube is approximately 25,000, the improvement in equivalent noise resistance over the RCA 6AK5 is 5 to 1 giving an equivalent reduction in noise voltage which is the square -root of this number of 2.24 to 1. This means that 1. Video for the same voltage amplification the signal -to-noise ratio of the chain increases by at least a factor 2. This is certainly of primary importance. In addition, the use of the cascode amplifier makes the Miller effect relatively small as compared to that which exists in the conventional triode preamplifier. The overall voltage gain of the WE417A, RCA 6J6 cascode amplifier with a 1000 ohm load resistance is 24 as compared to approximately 8 for the original RCA 6AK5 stage. The 417A -6J6 cascode amplifier is particularly subject to parasitic self-oscillation in the region of 80 to 240 Mcs. These have been suppressed by the use of small resistors in the first and second grid circuits and in the output -plate coupling condenser lead. By -pass condensers of very low inductance have also been provided in the filament circuits to provide stability against parasitic oscillations and pickup from filament supply. We have found it essential to operate the heaters of the cascode amplifier from D.C. in order to eliminate completely the familiar sharp 60 -cycle "glitches" which exist on practically all 60-cycle power lines. The matter of heater power supply will be discussed in detail later. It has been found that the use of the RCA 6J6 in the second stage of the cascode amplifier entails practically no sacrifice in performance and at the same time allows the tube to be operated within heater -to- cathode voltage rating. Since the tube is already used in the output stage of the camera, its application in the cascode amplifier represents a definite advantage from the standpoint of reduction in the tube cost and stock maintenance. 2. Mosaic Illumination A. EDGE LIGHTING This problem is one of the most subtle problems connected with the correct operation of an iconoscope chain. It is perhaps interesting to outline the function of an edge light in this manner: Any iconoscope which has "normal" sensitivity resolution and storage will have a rather restricted range of beam current (0.1 to 0.2 micro amps.) within which satisfactory operation can be obtained. This is determined fundamentally by the effectiveness of edge lighting in providing sufficient photo -emission from the mosaic frame to suppress edge and bottom flare associated with a given beam current. Restating the situation: It is important to operate with a maximum beam current within the above limits which can be used with the available edge lighting to produce a substantially flat and "flare-free field when the active portion of the mosaic is in complete darkness. This edge -lighting requirement may vary between iconoscopes. The reason for choosing an unilluminated mosaic as a reference lies in the fact that flare is particularly prominent and annoying in fades to black and in low -key scenes. If the field can be made flat and black by the control of edge -light intensity and by introduction of electrical shading signals, all other modes of operation at higher light levels on the mosaic are non-critical of adjustment. It is important to point out that when correct and adequate edge-lighting is used, the flare is no longer dependent on the picture content of the active portion of the mosaic and therefore edge-lighting is introduced as a fixed adjustment during the initial setup of the iconoscope and need not be changed during actual use. B. EFFECTS OF STRAY LIGHT ON STORAGE A factor which cannot be ignored is the effectiveness of edge- lighting in the illumination of the edges of the mosaic, also called the frame or mask, without at the same time throwing an appreciable amount of useless stray light on the active mosaic area. This useless light produces two effects which are inter -related. We are here concerned primarily with motion picture operation with light -pulse exposure occurring during vertical blanking time. In this case, all available picture information is on the mosaic as a stored charge image and should ideally persist at full amplitude from top to bottom of the vertical scan. Stray light from any source, either edge lighting, back lighting, or accidental ambient room light, falling on the mosaic will tend to wipe out the charge image, giving a poor storage characteristic, and will produce a signal of progressively decreasing amplitude from top to bottom of the picture. This can, of course, be electrically shaded to have a flat axis but will show progressive slumping of detail contrast from top to bottom of the picture. Evidence from pulsed -light single-frame operation of stationary film indicates that, in the absence of edge, back, and stray light, the average iconoscope storage characteristic is excellent, but deteriorates rapidly with an increase in the intensity of stray light falling on the working surface of the mosaic. The mechanism of the effect of stray light on the mosaic can be outlined by the following argument. Assume that the light application pulse is rectangular and lasts for 5% of the total field scanning time and that the light input-mosaic potential relationship is substantially linear. Then the average value of lighting is 1 /20th of the rectangular light pulse peak. Now let us further assume that the stray light is uniformly distributed over the mosaic. What must be its maximum permissible value in order to have a tolerable small effect on storage? If the light range of film material is 40 to 1, a typical value for motion picture film, the black gamma step would be represented by 0.5 foot -candles on the mosaic and the white level step by 20 -foot candles. Now if there is an area at the bottom of the mosaic which is black 0.5 foot-candles, as a result of the light application pulse, an increment of a 0.5 foot -candles due to stray light will raise the effective potential of this area to that corresponding to one -foot candle; whereas the highlight potential has at the time been raised to 20.5 foot -candles equivalent, decreasing the effective charge image contrast ratio from 40 to 1 to 20.5 to 2. Thus a stray -light level of 2.5% of the average projector light intensity is sufficient to knock down the contrast ratio in the image by 2 to 1 at the bottom of the raster. Tests have been made of this reasoning by the use of a calibrated grey -scale wedge at the top and bottom of the picture under pulse-light or motion picture operating conditions. Using an external projector to produce uniform stray light and adjusting the stray light to equal the average projector illumination, it is very easy to bracket the limits for permissible stray light. Using neutral density filters having 1, 2, and 5% transmission, one can demonstrate that 5% produces intolerable wash -out of storage, 2% is quite noticeable, while 1% represents an adequately low and readily attainable value. It should be pointed out that the effect of stray light is cumulative, having very little influence immediately after the 35 www.americanradiohistory.com RCA-6J6 W.E.417-A FIG. 2. Low -Noise Cas- code Preamplifier shown as it appears from the front. light pulse and having greater and greater effect towards the bottom of the scan. The present edge-lighting produced by the line source filament and the opaque slotted mask results in rather poorly defined edgelighting and a rather large amount of scattered light on the active mosaic area when compared with the same "effective" edge lighting intensity from an external edgelight projector. This is due to a great extent to the necessity for firing the edgelighting image through the lower glass seal region of the iconoscope front face plate. This region may be inhomogeneous, striated, and quite variable from tube to tube. "Effective" edge lighting intensity is that which will suppress the edge and bottom flare in the iconoscope output signal with no light on the mosaic at the maximum operable beam current without causing the storage characteristic to deteriorate markedly. Various possibilities for edge lighting were investigated. An external projector edge -light mounted below the camera has been developed which has excellent performance and which does not hamper the chain operationally. This is shown in Fig. 1 and will be described in detail later. As a result of our tests, it is our opinion that many iconoscopes criticized for poor storage actually have adequate storage but may work under severe handicaps as a result of limitations in the edge- lighting or back -lighting sources. C. INFRA -RED FILTERS The use of infra-red and heat absorbing filters in the projector light path and in edge lighting sources has been investigated by several independent groups. It has been found that a polished plate of Corning #9788 filter glass* approximately Smin in thickness or equivalent does an excellent job in attenuating the high-energy infrared and red components of the incandescent source to which the iconoscope is normally quite sensitive and thereby gives improved detail contrast and apparent gain in resolution. The improved contrast with the use of a red cut -off filter for technicolor movies is truly startling, the contrast range going from very small values with no filter to completely acceptable values with the filter. A probable explanation of the observed effect is that when the lens is focused for a visible light image, the infra -red image is out of focus or diffuse, but still responsible for a large proportion of the mosaic photo emission. Removal of this component by the filter leaves only the sharp image information which results in gain of both resolution and contrast ratios. In the case of color film, the transmission of infra-red components between various color dyes in the various sections of the picture is substantially the same, producing practically no differential contrast. With removal of the infra-red, the dye absorption of visible light previously masked by the over -riding infra -red transmission is again normal and gives the observed increase in contrast. D. BIAS OR BACK -LIGHTING AND AUTOMATIC BLACK LEVEL CONTROL The main function of variable intensity bias lighting is the illumination of the photosensitive walls of the iconoscope in * Corning Catalogue #9788 ground to Transmission Curve 4 -97, approximately 5mm. thick. Can be obtained from : Esposito and Stuhier Optical Co., 911 Willow Avenue, Hoboken, N. J. 36 www.americanradiohistory.com order to furnish an easily adjustable source of low velocity electrons which act to stabilize the D.C. photoemission of the mosaic, the "floating" mosaic frame, and to actually increase the signal output of the iconoscope itself. It was pointed out by Schade in an unpublished memorandum in 1942 that with correct adjustment of edge and back-lighting intensity, taking precautions to keep stray light from the useful picture area of the mosaic, the iconoscope is capable of true D.C. operation. The iconoscope under these conditions generates a constant "peak white" signal in its output load resistor which is determined by wall and edge illumination and is generated during the horizontal and vertical blanking intervals when pulses are applied to the control grid of the iconoscope to cut off the beam current. This peak white signal is substantially independent of the illumination of the mosaic itself and once adjusted remains fixed for a given value of beam current. By adding to this peak white signal a constant "black pulse" or blanking wave, the resultant output wave behaves normally and, using circuits essentially identical to those in the image orthicon field and studio chains, gives a close approximation to true d -c presentation. Thus, an unilluminated mosaic will give zero pedestal height and a "fully" illuminated mosaic will give maximum pedestal height. With a slide, the action is fully automatic and produces a video signal in which elemental signal amplitude is directly related to the elemental mosaic illumination. Under pulsed -light motion picture operation conditions, the black level setting addition is a fairly good approximation to the ideal, even when the iconoscope is used as a full storage device, ONE -SIDE FROSTED BACK LIGHT FILTER FILTER MASK BACK-OFLENS IRIS LENS BARREL LOCK FIG. where the picture is pulsed on the mosaic during the vertical retrace interval. We believe that this "d -c" mode of iconoscope camera operation is one which has great operational importance since, with the other improvements, it makes it unnecessary for the operator to manipulate any pedestal height controls for artificial black level setting. In addition; with controllable but fixed edge- and -back -lighting, any motion picture having tolerable transmission characteristics can be shown over the chain without touching any controls. This appears to us a major step forward from the present mode of operation where shading and pedestal contror variation during a program has become a fine art requiring a well -developed sense of anticipation or reflex action, or has been ignored altogether. The primary function of the back lighting in our mode of operation is that of effectively cancelling the application pulse signal in the video amplifier which is developed during vertical retrace time which has no direct functional part in operation but is the cause of serious amplifier overload. It is quite normal for this video pulse signal during retrace time to be 5 to 15 times as large as the useful video signal during the scan cycle. It is essential in setting up a chain to use the minimum amount of edge- and -back lighting to achieve flare suppression and application -pulse cancellation for smallest signal deterioration due to stray -light effects over the active mosaic surface. Tests have shown that the present backlight source operated from D.C. and using an infra -red filter with additional diffusion is adequate for our purpose. Fig. 3 shows the back -light diffusing filter, projector lens barrel lock to provide additional rigidity in the assembly, special edge-lighting mask slide, iris, and edge -light lens filter. EDGE LIGHT EDGE LIGHT 3. Details of Edge and Back -Light Elements. 3. High Peaking and Microphonics Detailed study of the high peaking problem as it applies to iconoscope input circuit compensation has shown that our present high impedance R -C plate compensating circuit can be replaced by a two stage R -C low impedance cathode peaking arrangment with substantial improvements both from the standpoint of compensation and freedom from microphonics. Calculations have shown that the frequency characteristic of the iconoscope output resistor shunted by the stray capacity can be compensated completely by a two -stage cathode high peaker arrangement having two timeconstants which are substantially independent of each other in adjustment. The short time-constant peaking circuit affects only the high -end of the passband and the long time- constant peaking circuit affects only the low -end (45 kc). These two circuits can be adjusted exactly for no high frequency overshoot or low frequency trailing by a technique which is almost intuitive and very easy to acquire. The physical arrangements are shown in Fig. 4. It is important to point out that some very low frequency trailing may probably be present in the picture which is not affected by either of the cathode peaker controls. This is due to inadequate phase and frequency fidelity in the video amplifier low-frequency coupling circuits and can be practically eliminated by the use of a suitable low boost circuit in the camera preamplifier as will be described later in detail. In order to suppress residual streaking in the film with a wide range of picture content the low frequency amplitude and phase characteristics of all video pre- amplifiers should be good to 300 cycles or even lower instead of to half -line frequency as had previously been assumed. A very important improvement which results directly from the change in high peaking arrangement is that of eliminating of microphonics. The present high -peaker is driven from two video amplifiers in series, having a total gain of 50, through the R -C -R divider having a low frequency attenuation of the order of 200 to 1. This means that with a 10 millivolt signal at low frequencies from the iconoscope 2.5 millivolts appear at the high peaker grid. Laboratory tests indicate that with tubes of the 6AK5 variety the equivalent sine wave voltage for an "average" microphonic tube is at least of this order of magnitude. Thus with a "microphonic" excitation of this reference amplitude the signal-tomicrophone ratio is unity. With the cathode high peaker which has been developed the previous sampling network is no longer necessary and the low frequency input signal rises to 0.5 volts giving signal -tomicrophonic ratio for the same microphonic excitation, of 200 to 1. The new arrangement allows us to use 6AK5's throughout and has shown that the microphonics problem due to the high -peaker has been eliminated. On occasions we have definitely traced an appreciable portion of amplifier shot noise to the presently used high peaker. Since low frequency video input voltage to the high peaker grid is 1/4th of that existing at the iconoscope, sufficient amplification must be provided to bring this up to standard level, the tube behaving as another first stage and contributing shot noise. 4. Amplifier Over -Load With the 417A -6J6 cascode input stage and two -stage cathode high peaking compensation we get considerable increase in system gain. This excess gain has been ab37 JONES PLUG FOR BEAM CURRENT -METERCIRCUIT FIG. 4. sorbed in additional cathode degeneration, in order to obtain greater signal latitude for the video and application pulse signals and to minimize the problem of amplifier overload. It is important to point out that adjustments of bias lighting and edgelighting will decrease, cancel, or reverse the polarity of the useless high amplitude video signal generated during the vertical blanking interval. Therefore, in actual operation, it is desirable to adjust back -lighting so as to just cancel the application-pulse signal, providing a condition of greatest freedom from amplifier setup and overload. of Deflection Non -Linearity and Yoke Distortion The effectiveness of appropriate edge lighting on suppression or cancellation of flare is based on uniform or constant scanning velocity at the mosaic during horizontal and vertical sweep time. This requires careful adjustment of horizontal and vertical mosaic sweep linearity. Any serious non -linearities may produce false flare signals which cannot be controlled by the action of edge light but which will disEffects 38 Location of Compensation Controls. appear when the sweep is adjusted to be linear. Excessive geometric distortion or bowing in the deflection yoke particularly at the bottom will make it difficult to suppress bottom flares completely over the whole mosaic width at the same time. In this case, it may be necessary to replace the yoke. Gamma Characteristics During the past year, there has been a great deal of discussion resulting in conflicting recommendations for modifying the transfer characteristic of the iconoscope film chain. Tests made on a wide variety of motion picture film subjects and accurately calibrated grey-scale step film, have shown that at least a range of 50 to 1 can be transmitted by the iconoscope and a conventional kinescope so that the gradation between adjacent steps can be definitely recognized. This indicates that, with a kinescope gradient of 2.5, the iconoscope transfer gradient is substantially less than unity, approaching square root, in its upper light range. Attempts at white expansion with fixed peak kinescope bright- ness result in a final display with compressed blacks. Our demonstrations have indicated that by using a linear amplifier transfer characteristic, with the iconoscope as the gradient- determining element in the system, a grey -scale range of at least 50 to 1 can be used. It is possible that with some films and kine-recordings which crush whites, white- expansion may be useful. However, we believe that this does not hold true in general for normal, typical motion picture film. Concepts Involved in the Overall Operation of an Iconoscope Film Chain In order to clarify the procedures involved in operating an iconoscope chain so as to obtain the best possible picture we can tabulate the variables involved as: 1. Film characteristics 2. Projector lamp 3. Beam current intensity 4. Video gain 5. 6. Edge and back lighting Shading signal -_- V16-6AK5 R20-8200 V15-6AK5 R15-8200 PIC. AMP. C9 O S 11CO" 1I s -_1 n 47 G 1 Iá I - .os ---'¡-- ó F. CIS -4C C14 I +I 79 6 Cu I PICTURE POLARITI 47 I 1 A 1 o l-1 ó13 ol 11 __l2_1 3 G 14 a e I ;.j7,1;-11 A 1 O O CIOAI I-I ó 80T H C65 COMP. T IIDób63,4 C12 1 4 3 o Vn -6J6 PIC. OU TPU AMP. m 7 R18 oo T8 1 J c- 1 80T I ni R25-IOK PIC. 220 .ST MMF O CI, qp a 'YING TK-20A CI3A PICTURE GAIN 5 FIG. 9A. Schematic of new Jones Power Plugs circuit. This entire section would be heavy if shown in a general schematic. NT JONES PARTS FOR FILM CAMERA MODIFICATION Qty. 2 2 2 1 1 1 2 1 3 1 3 1 1 I 1 1 1 2 1 4 1 1 1 1 1 I 1 1 2 Symbol No. R201, R202 R125, R126 R207, R209 R208 R210 R206 R203, R205 R204 R117, R120, R121 R130 R68, R119, R134 R116 R118 R129 R124 R115 RI23 R122, R127 R133 C60, C61, C58. C59 C62 C64 C65 C67 C66 L2 S201 X20 X12, X201 12 1 1 I 2 1 1 1 L 2 J3 P2 P3 V201, V12 V20 V14 M1 S-406 SB Description 50,000 Ohm Potentiometers, 2 W. Linear 2000 Ohm Potentiometers, 2 W. Linear Resistors, 1 Meg., I W., ±10 %a Resistor, 300 Ohm, 1 W., ±5% Resistor, 1000 Ohm, 1 W., ±5% Resistor, 2.7 Meg., 1 W., ±5% Resistors, 100,000 Ohm, 1 W., -±-10% Resistor, 47,000 Ohm, 1 W., ±10% Resistors, 100 Ohm, W., ±10% Resistor, 39 Ohm, W., ±10% Resistors, 100,000 Ohm, W., ±10% Resistor, 120,000 Ohm, % W., ±10% Resistor, 1000 Ohm, 2 W., --10% Resistor, 1200 Ohm, 2 W., ±10% Resistor, 15,000 Ohm, 10 W. Resistor, 1.0 Meg., W., -1.-10% Resistor, 1500 Ohm, 1 W., -±-10% Resistors, 330 Ohm, W., ±10% Resistor, 1.0 Meg., 1 W., ±5% Capacitors, .01 MFD, 600 W. V. D.C. (Ceramic) Capacitor, 225 MF, 15 V. (Electrolytic) Capacitor, 2200 MMF, 500 V. (Mica) Capacitor, 220 MMF, 500 V. (Mica) Capacitor, 80 -10 MFD, 400 V. (Electrolytic) Capacitor, .47 MFD, 200 V. Peaking Coil; approximately 10 Micro H., wound on slug tuned coil form, 2 pies, 18 turns each, 1/16" wide, spaced 1/16 ", #30 S.C.E. wire Switch, 3 Position, 4 Pole-Oak Type #49530K1 Tube Socket, 9 Pin with Lug Strap and Shield Base Tube Sockets, 7 Pin Connector (Jones Catalog #P- 406SB) Connector (Jones Catalog #S- 406SB) Plug (Jones Catalog #P- 406CCE) Iza 0"120 J2 // / / / D'8U J3 II U -0 ' I2-" JONES P-406 SB R133 /e Plug (Jones Catalog #S- 406CCE) Tubes, 6J6 Tube, WE -417A Tube, 6AK5 Meter -100 Microamps Power Supply (Stancor Model #752) Kodaslide Type lA Projector Filter Glass (See Fig. 3) LI9100 I. MEG (Iw±S; C661 \ Q' .47 1 U7 GND. CO -AX. AT THIS lJ END ONLY I TO V19 dl www.americanradiohistory.com circuit values and wiring details of the cascode amplifier. The photograph of Fig. 8 shows the installation of the cascode amplifier in the iconoscope compartment. It is important to adhere to a single path grounding system in order to minimize the possibility of spurious feedback from later stages. The plate current of this cascode amplifier in normal operation is approximately 24 m.a. and can be checked by measuring the voltage drop across the plate filter resistor R -129 in the above schematic. It should be noted that the plate and screen supply filters which formerly provided voltages for the normal first and second video stages now supply only the second stage alone and must be revised accordingly. High Peaker Circuits The photograph of Fig. 4 shows the location of the two compensation potentiometers in the cathode circuits of the two video stages, V14 and V15. The appropriate R -C time constant values are given in the schematic of Fig. 9, which outlines all of the changes required in the video amplifier to obtain the new improved form of operation. The potentiometer marked "A" and located on the video amplifier shelf is used to control low- frequency compensation for the iconoscope input circuit characteristic. The control marked "B" governs the response at the upper end of the frequency characteristic. These are mutually independent and can be set using a standard test pattern as the basis for alignment. It is easily possible to set the high frequency control for good resolution with no white overshoot and the low frequency control for no low -frequency trailing or black or white smear. It may be found that after adjustment of these two controls there will still be present some residual very low frequency streaking which is not affected RCA HEATER SUPPLY 12 PEAK COIL CATHODE BY-PASS C. INPUT BY -PASS OUTPUT CONDENSERS FIG. 5. Side View of Cascade Preamplifier showing details of by -pass condensers and connections. by the controls previously mentioned. This is due to inadequate phase and frequency fidelity at extremely low frequencies and can be corrected almost completely by the use of a plate-booster filter CIA, and C,B, and R123 (1500 ohms) shown in Fig. 9. Heater Supply Fig. 10 shows a dimensioned photograph of the rear of the camera giving details of the Jones Plug at the left which has been added to provide an easy means for connecting to an external d -c, 6.3 volt dry rectifier filtered power supply which we have located in the base of the camera. It D -C necessary for making the unit. BY-PASS C's RCA 6J6 9-20MICROHENRY W.E.417-A Ta, FIG. 6. Wiring View of Cascode Preamplifier, showing wiring structure OUTPUT 6J6 W,E.417A INPUT CATHODE BY PASS is necessary to reconnect all camera heater circuit leads to provide for 6.3 volt d -c operation instead of the balanced 12.6 volt circuits previously used. These changes are indicated in the schematic of Fig. 9. It has been found that the use of D.C. in the first two tubes of the cascode amplifier is essential in order to eliminate the effect of "glitch" disturbances introduced by the usual A-C heater supplies. It is just as convenient to provide for complete d -c heater operation in the camera unit using the Stancor Model 752 power supply shown in the photograph of Fig. 11 to furnish the 9 ampere, 6.3 volt D -C heater power. Suitable Jones connectors are provided for easy interconnection of the d -c filament supply and camera unit. Beam Current Metering The plug at the right of the camera (Fig. 10) provides connections for the iconoscope beam current metering circuit located on the camera control console. The iconoscope beam current normally operates within the range of 0.1 to 0.2 microamperes. The center conductor of the coaxial metering line is attached to the collector terminal of the iconoscope, and terminates at the camera Jones plug in a 1 megohm resistor and suitable bypass as shown in Fig. 4. The voltage drop across this resistor, which is directly proportional to iconoscope beam current, is applied through an interconnecting cable to a D -C Average photographic film has a typical density range D = 0.2 to D = 1.8, or a range of 40 to I, in release prints where density D is defined as log 1/T and T is the transmission in per cent. With D = 0.2 or a transmission of 62% the minimum open -gate illumination from the projector should be 32- foot -candles to obtain a 20foot- candle highlight illumination on the mosaic. For these conditions the low -light mosaic illumination will be 1.6% of 32foot- candles or 0.5 foot -candles. Increased illumination in the projector above this level does not produce radical changes in the appearance of the picture because of the wide latitude of the iconoscope characteristic. However, decrease of illumination may cause the picture to deteriorate. primarily because of lower output signal and hence poorer signal -to-noise ratio, and accentuation of residual flare and local defects which would ordinarily be unnoticed with normal illumination. For this reason we have found that stopping down the projector lens to obtain greater sharpness or depth of focus of the projected image produces poorer overall performance. Since the standard f:2.6 Kollmorgen Projector Lens has a television resolution of at least 1200 television lines at the magnification used, it alone does not represent a limitation in 16mm film reproduction. All cases investigated, in which significant improvement in resolution was noted on stopping down the lens, were traced to clamping strain distortion of the front surface multiplexer mirrors, or were due to insufficient care in aligning the iconoscope itself to coincide with the focal plane of the projection system. When these difficulties were eliminated there was no noticeable difference in resolution between wide-open and stopped -down lens operation. Providing depth of focus by stopping down the lens to take care of system errors is a rather uneconomical method of operating the iconoscope chain. The adjustable iris in the present lens furnishes a convenient means of checking these factors and of decreasing light output for special films in which this may be advantageous. In order to obtain maximum light output, it is important to make sure that the condenser lens system and the reflector in the projection lamp path are clean and that the projector lamp is operated close to rated voltage since a 5% decrease in lamp terminal voltage produces a 16% decrease in the light output. It is apparent that the success of a motion picture film chain depends directly on the quality of the film itself. In general, the resolution and gray scale of commercial 35mm film releases are excellent. whereas 16mm film has appreciably poorer resolution and more variable range characteristics. It is beyond the scope of this discussion to analyze the factors involved in poorer film quality, but it is only fair to point out that poor film does not make good television pictures. Side-by -side comparisons of 16mm and 35mm motion picture film material using a well-adjusted iconoscope film chain are very striking; the 35mm film giving quality very close to that obtained in a studio shot, while 16mm film is decidedly softer and lacks snap. In such a comparison the only variables in an in stantaneous mechanical switching or dousing operation are the two film sources and projectors, the iconoscope chain adjustment remaining untouched. One must be quite sure that in the process of evaluating film chain performance the quality of the film used is adequate. Otherwise, this evaluation becomes a comparison of relative film performance, which in 16mm film is a bottleneck limiting performance at much lower levels than the capabilities of the iconoscope chain itself allow. Even the currently available 16mm television test film prints used for checking television performance leave a great deal to be desired particularly in the resolution and detail contrast in the various resolution frames of the film. One can verify this easily by examining such frame sections under a microscope, using a magnification of 30 to 50 times. The same criticism holds true for available 2 x 2 television test slides, except that, in addition. the performance of the still projector lens often limits resolution seriously. We have found that a simple circular front -of -lens stop Yi to 5/ inch in diameter produces a decided improvement in picture appearance and still provides sufficient light for good operation. This test is very easy to try and provides a method for producing an optical image on the mosaic which approaches the quality required to obtain meaningful information on system performance. Beam Current Edge and Back Lighting As previously mentioned, with adequate provisions for edge lighting and back lighting, the iconoscope should be operated with the maximum permissible beam current which can be accommodated to produce a flare -free field. This beam current will be between 0.1 and 0.2 microamperes. The video gain is then adjusted with normal illumination on the mosaic to provide an output signal of 1 volt peak -to -peak across the 70 ohm output line. It has been found that with a continuous indication of beam current, one can duplicate accurately the results with a given chain from day to day. In the absence of beam current metering facilities the operator is governed entirely by intuition and he is likely to set up for smaller than normal beam current, making up for decreased iconoscope signal output by increasing video amplifier gain at the expense of poor signal-to -noise ratio or will select a beam current which is higher than normal and will sacrifice overall performance from the standpoint of excess flare. The addition of a beam current metering circuit makes it possible to provide straightforward means of setting up and maintaining a high standard of operating quality. Edge lighting and back lighting should be used to provide satisfactory cancellation of flare, cancellation of light application video pulse and to improve signal output. It is again important to point out that these factors should be handled with some discretion in order to minimize stray light and to preserve good storage characteristics with acceptable gray -scale rendition. In principle, it is possible to manipulate edge- lighting intensity and distribution and back lighting amplitude so as to produce an output signal from the chain which requires no addition of electrical shading signals. However, the problem is made much simpler if edge -lighting is used primarily to control the abrupt flare components at the sides and bottom of the picture and electrical shading is introduced horizontally and vertically in the familiar available sawtooth and parabolic waveforms to produce flat output and flat shading. Our experience has shown that with preliminary setup of edge lighting, back lighting and electrical shading using an unilluminated mosaic as the most difficult condition, it is thereafter unnecessary to touch either the edge lighting, back lighting or the electrical shading signal controls during the reproduction of film. DETAILS OF IMPROVEMENTS IN THE TK -20A FILM CAMERA EQUIPMENT Video Amplifier The cascode video amplifier consisting of a Western Electric 417A and an RCA 6J6 tube has been designed to replace the present 6AK5 single stage triode preamplifier located in the iconoscope compartment. The chassis- mounting features are identical with the previous design. The photograph of Fig. 5 shows a side view of the cascode preamplifier chassis and Fig. 6 shows a rear view including the important features of parasitic suppression resistors. heater by -pass condensers, and general wiring arrangement, including d -c filament supply leads. The schematic of Fig. 7 gives (Continued on page 42) 39 AMPLIFIER CASCODE j C63 V13- 6AK5 PIC. AMP. V 12 6J6 R 7-8200 V14 - 6AK5 1M/ PIC. AMP. PIC. AMP. 80T 16 a * o o m_ 3 C58 .011, Of .01 m PREAMP CHASSIS 100 K I R119 11wwwr R I29-2W zoo -=L TO v19 ICONOSCOPE SIGNAL PLATE FIG. 9. General Schematic of Compensation Control Changes in the Film Camera Circuit. New parts or changes are indicated in heavy lines. INFORMATION FOR MOD!' COMPLETE FILM CAMERA TABLE MODIFICATIONS: For those who have no spare cameras, the modifications have been divided up and listed below in steps. The camera may be used after each change has been accomplished: OF MODIFICATIONS The potentiometer in place of R122 is adjusted so that with a normal picture input to iconoscope .5 volts peak-topeak is obtained at the 51 ohm camera output. Later, when the preamplifier is installed R122, 330 ohms, is installed in this position. 1. EQUIPMEI 3A. Metering Panel: Assemble the metering circuit according to schematic, Fig. 13. A cable containing one coax as well as three individual conductors must be provided between the camera and camera control, where the metering panel may be mounted. Cathode Type High Peaking: Remove the following components from the camera: R9, C4, R10, R11, C6, R6, and R23. Disconnect C5A. At V14, install R125, 2000 ohm pot. and C64, 2200 mmfd cap. At VIS, install R126, 2000 ohm pot. and C65, 220 mmfd. cap. Change V14 to Type 6AK5. At V16, install R127, 330 ohm resistor. At V13, install temporary pot., 500 ohms, in place of R122. At V13, connect C7 to T6, pin 4. 2. Jones Plugs: Cut holes in rear of camera and mount 6 pin Jones plugs as shown in Fig. 10. These plugs are the H. B. Jones type, 400 series. Power Supply and Iconoscope Metering Provision: Remove the heater circuits from Plug J I and ground and connect to the Jones plug J2, as shown in Fig. 9. 3. D.C. Connect D.C. supply to camera through plug J2. Remove the collector wire from the iconoscope, V19, to ground and connect iconoscope through a suitable length of RG -59/U to J3 as shown in Fig. 9. At J3, connect R133, 1 megohm, and C66, .47 mfd., as well as heater and plate voltages as shown in the same figure. The iconoscope camera will operate satisfactorily with or without a connection to the metering circuit. Schematic of V19 1850A Iconoscope and new installation of RG 59/U Ground Coax. FIG. 9B. 40 www.americanradiohistory.com 4. Edge Light: Remove original edge light assembly and control. Cut clearance holes in bottom of camera. Mount previously made projector support and mirror assembly on camera. It will be necessary to provide a Variac or a high wattage variable resistor to control the intensity of the edge light. 5. Preamplifier Stage: Assembly preamplifier as shown in Fig. 7. Remove temporary potentiometer in V13 cathode. Remove R2, R17 at V17, and original preamplifier. Disconnect C2A, C2B, and CIA. Connect R124, 15,000, R123, 1500 ohms ; C67, 90 mfd. mounted in place of C6; CIA and B, .5- .Smfd.; R121, 100 ohms; C2, 90 mfd.; R129, 1200 ohms; and R134, 100,000 at V17. Install preamplifier. Connect output to C63. Connect B+ to preamplifier at C2. Connect heater coax center to V13. pin 4 and shield to ground lug at V13. Connect input to iconoscope. GASCODE PREAMPLIFIER OUTPUT TO C63 ? 1000 367 ó N V12 6J6 R 118 L2 6 PIC AMP. FIG. 7. Circuit diagram of the new Cascode R117 Preamplifier. 100 R120 C60 I00 C58 01 C62 .01 PRE-AMP CHASSIS RI 9 100 K 225 V V V -(_1.'113, PIN 4 R29 +280 1200 -2W C? 90 IA FD bridge -type amplifier, meter, and controls located in a separate panel, as shown in Fig. 13. Since the metering circuit is cornpletely self- contained, it can be located where operational control is most convenient. This D-C bridge amplifier is shown schematically in the drawing of Fig. 13. The 100 microampere D -C meter for beam current indication is calibrated for sensitivity by variation of the series meter resistor, and the bridge is balanced by the zero -adjusting potentiometer to give zero meter reading. The three -way switch allows the operator to select zero, calibrate, and operate positions with a minimum of effort. The calibration voltage is obtained from regulated B- supply using a resistordivider to provide one -tenth volt D -C, corresponding to 0.1 microampere beam current, and applied for bridge calibration to the opposite grid of the 6J6 dual-triode bridge amplifier. It is easy to adjust for a full scale sensitivity of 100 or 200 milli microamperes merely by changing the sensitivity control. This metering circuit has been in daily use for several months and shows very little tendency towards drift after the initial warm -up period. The approximations introduced in calibration and design were made on the basis that it is more important to provide a stable simple indicator of beam current rather than a precise measuring means since the original selection of an appropriate b °am current is made on the basis of freedom from picture flare. It is then only necessary to maintain this current during operation without any direct regard for its absolute value. The photograph of Fig. 4 indicates the arrangement of coaxial conductor, Jones plug and the location of pilot voltage resistor and filter condenser. Plate and heater supply voltages are furnished to the remote ti.GNDATVI3 INPUT V V19 SIGNAL PLATE amplifier and meter circuit from the Jones plug as indicated in the same photograph. It is desirable to preserve a one-point ground at the camera Jones plug, leaving the circuit at the camera control floating in order to avoid disturbing effects of interchassis differences of potential. New Edge-Light Arrangement The photograph of Fig. 2 shows the edge -light arrangement which has finally been developed for use with the iconoscope chain. This is basically an Eastman 1A projector using a special metal -insert key- stoned edge -lighting slide, an infra -red cutoff filter and a back -of -lens iris. The projector is installed below the camera in the normal operating position. In order to change iconoscopes or to service the equipment, it is merely necessary to push the projector forward on the guide-rails by means of the supporting bracket, giving ample clearance for opening the swinging door to the rear compartment, as shown in the photograph of Fig. 14. The diagram of Fig. 17 gives the layout of projector, bracket, guide rails, reflecting mirror and the dimensions of the special preamplifier FIG. 8. The Cas code Preamplifier is shown installed in position inside the TK -20A Film Camera. 43 www.americanradiohistory.com chassis and edge -lighting slide. It is preferable to use D -C on the edge -light to eliminate the possibility of introducing a light hum component in the video output. In the edge-light layout drawing are given the exact dimensions of the clearances required in the various chassis locations for mirror and adjustable edge light bracket and the dimensions of the slide mask. Back Light Tests have shown that the present backlighting system operated from D -C is adequate for the purpose. It is desirable to add an infra-red cut -off filter and a diffusing screen. Black -Level Control While automatic black-level set in a developmental camera control amplifier has been in satisfactory operation for some time, it should be pointed out that this feature is not absolutely essential at the present time to improve camera performance in all other details. We believe it advisable to postpone the actual conversion of the camera control to a later date, at which time we expect to have complete simplified information which will require the minimum number of changes. These are not extensive and consist basically in providing a convenient adjustable source of pre -blanking, d -c clipper -level control, and a physical rearrangement of the FIG. 10. clamper so that it is d-c coupled to the grid of the clipper stage. Suggestions on Conversion In our investigation of the problems of conversion, particularly with stations which have one, or a limited number of cameras which cannot be taken out of service for an extended period, it is safer to plan on this conversion in several stages which will allow for interim operation of the camera chain and which will finally result in complete introduction of all of the new features without taking the camera out of service except during the usual maintenance and overhauling intervals. For this possibility, we suggest that the work be divided as follows: 1. The high peaker circuit can easily be revised by addition of the two potentiometers and the appropriate condensers to give immediate improvement in microphonics and high peaking characteristics. It will at the same time be necessary to introduce variable degeneration (approximately 80 ohms) in the cathode circuit of video amplifier V13 Fig. 4, so that when these changes are introduced the excess gain can be absorbed in this degeneration to provide normal signal output levels. 2. Holes can be cut and Jones plugs installed for the D -C heater supply and Location of the new !ones Power Plugs. FIG. 11. D.C. Power Supply Unit suit. able for use in the modification procedure. for the iconoscope beam current metering circuit. 3. The metering circuit can be installed and calibrated. 4. The edge lighting hole in the bottom of the iconoscope camera can be cut, the 5. mirror and support installed, and the Eastman lA Projector with special bracket and slide can be adjusted for improved edge lighting. The cascode preamplifier previously described in detail can be installed and appropriate peaking and degeneration gain settings can be frozen to provide for normal systems operation. By proceeding in the manner outlined, it will be possible to modify the chain a section at a time without at any point being caught in the position of having the iconoscope equipment unavailable for film use. In HEATER SUPPLY For convenience in carrying out the camera changes, the following table of component additions, removals or change of values has been prepared. In all cases. the part numbers are those used in the schematics of Instruction Books for the TK -20A Film Camera Chain. New part numbers are assigned to added components. When the changes have been completed, that the improved performance in picture quality, signal -to-noise ratio, and simplicity of operation, with the assurance of continuously controlled high standards of picture excellence, will more than repay the required modification efforts. we feel We take this opportunity to express our appreciation to Mr. Vernon J. Duke of the NBC Television Engineering Staff, working under the direction of Mr. George M. Nixon, in charge of NBC Development Engineering. He first recognized many of 44 FIG. 12. Circuit R202 Diagram of Beam Current Metering Panel. 50 K FILM CAMERA Rí01 50K 8209 lees a MI I OPERATE CAL 4 SZOI OPERATE CALIBRATE BEAM CURRENT A I MEG ZERO ADJUST .7 OPERATE FIG. 13. R207 Beam Current Metering Control Panel. R208 300 DO NOT GROUND TO CHASSIS - 9 ZERO ZERO -39-K---C J9-R---f'- -- PARTS LIST Qty. Symbol No. 5 Cl, C4, CS, C6, C12 1 C3 1 2 RI, R8 1 R2, R3, R4, RS R6 R7 R9 R10, R11 R12 1 L1 4 the limitations in iconoscope camera performance, and first demonstrated the improvements possible in commercial equipment by careful attention to many details which had hitherto been neglected. We wish also to thank Mr. Otto Schade for his fundamental studies on the iconoscope, which evaluated many of the factors which we have introduced in commercial equipment. Dr. Janes and Mr. Marschka of RCA, Lancaster have cooperated completely in discussion and analysis of iconoscope problems and in furnishing special and standard tubes for test. Mr. E. M. Gore of our Advance Development Group, and Mr. R. J. Marian of Product Design, deserve special commendation for their many contributions during the initial and final phases of this study. C7 I 1 I 2 2 V1, V2 1 V3 2 1 X1, X2 X3 for ALTERNATE PREAMPLIFIER Description Capacitors, .01 mfd. 600 V.D.C. (Ceramic) Capacitor, 2000 mfd. 6 WVDC, non -inductive, Electrolytic, (Aerovox Type E3A208) Capacitor, .1 mfd., 400 V. Resistor 100,000 Ohm, W., ±10% Resistors 100 Ohm, W., ±10% Resistor, 15 Ohm, W., ±10% Resistor, 12 Ohm, W. Resistor, 1 Meg., W., ± 10% Resistors, 1800 Ohm, 2 W., ±10% Resistor, 470 Ohm, 2 W., x-10% Peaking Coil: approx. 10 micro. H. wound on slug -tuned coil form, 2 pies, 18 turns each, 1/16" wide, spaced 1/16", #30 S.C.E. wire Tubes, 6BQ7 Tube, 6AG7 Tube Socket, 9 pin (no shield) Tube Socket, Octal (Amphenol type S) // / // ; (The above symbols refer to Figure 1 yt 15 only.) Refer to Figure 9. Change value of C64 to: C64 Capacitor, 3900 mmfd. (mica) ALTERNATE MODIFICATION During the preparation of this article, development and study of Film Camera Modifications have continued. As a result. we have found that substantially the same improvement in video amplifier signal -tonoise ratio can be realized by the use of two RCA -6BQ7 double triodes driving an RCA 6AG7, triode connected, in exactly the same cascode arrangement as was described for the Western Electric 417 -A, RCA 6J6 tube complement. As these tubes are much more readily available and lower in cost than the W.E. -417A, we feel that they can be used to advantage in the camera modifications we have outlined. A detailed schematic, parts list, general remarks, and chassis details for the 6BQ7 -6AG7 cascode amplifier are shown in Figs. 15 and 16. FIG. 14. External Edge -Light Projector Assembly is shown pushed forward to the farthest point in the track so that easy access makes possible work inside the film camera. 45 www.americanradiohistory.com CASCODE PREAMPLIFIER OUTPUT TO C63 6AGT PIC AMP PIG. AMP 6 2 LI 9 -15 INPUT V 19 SIGNAL PLATE Cj CI .Nh C6 Cl2 C5 20oq 01 .01 .01 T01 T2_1 PRE AMPLIFIER CHASSIS V13-P11.4 4 GND.AT V1j +280 V. CZ 90 M FDI. FIG. 15. RIZ 410-21V Circuit diagram of alternate Cascode Preamplifier. NOTE: The case of the Stancor pack should be connected to the negative output terminal. However, with the alternate modification the heater drain is increased and a heavier supply is recommended. This d -c supply which has a continuous current rating of 20 amperes at 6 volts is the Electro Model "B" manufactured by Electro Products Labs., Inc., 4501 Ravenswood Ave., Chicago 40, III. V3, 6AG7 should be mounted so that pins plane. (See RCA Tube Manual.) 2 and are in a vertical 7 FIG. 16. Preamplifier Chassis. GRIND3Ze APPROX TO BLEND WITH ADJOINING .257 WA. 3-HOLES SURFACES 7 .199 DIA. HOLE 167 toot .0935 0937 .750 DIA. 2 -HOLES 147 DIA. 4 -HOLES 16 XiX34R-3- SLOTS- 120 °APART CA 3-DIA HOLE s L2 61 V3- 6AG7 VI-6BQ7 1.172 DIA.HOLE 45!_ V2 -6007 q *á - 2- CHAMFERS MATERIAL- 'NC +"STEEL 1-...\ 4 t 46 www.americanradiohistory.com CS :.\ wowç;'vñ1°w .-i :r, FIG. 17. Assembled scale draw. ings- continued on next page. 47 www.americanradiohistory.com 7 .17!-DIA. SHOLlS 4 EOUAL SPACES @iT _-.. -+-- 4 EQUAL SPACES Viz 6- - OMATERIAL --THICK ALUMINUM 173-DIA. S- HOLES ® .147 -DIA. 2 -NOMES 2 -i TR. ALUMINUM MATERIAL AR ALL INSIDE BENDS - HOLES 3 THICK ALUMINUM I 1111 4-40 TAPI 4 DEEP 2 MOLES N N 4w OMATERIAL - ¡THICK ALUMINUM CLI FRONT SURFACE MIRROR -6 -THICK PREAMPLIFIER CHASSIS 125 DIA. - 6/44"STEEL IT2 32 3 DIA. -L i 3-TABS 12O°*36O° o C) IRIS STOP (2 STANDARD 2s2 SLIDE MASKED AS SHOWN OVERLAP 45.APPROX. FIG. 17. The assembled scale drawings shown on these two pages give the detailed dimensions of the various parts. By following the construction directions given for each part, the engineer should have no difficulty in converting the TK-20A Film Camera for improved results. 48 M APPROX. -56 TAP. *DEEP B OATeRIAL y MATERIAL-.01S TM. PHOSPHOR BRONZE SPRING TEMPER MATERIAL-.020 THK. PHOSPHOR BRONZE SPRING TEMPER TELEVISION ON THE WING ... The first attempt to receive television aboard a transpacific Hawaii -bound airline met with great success on United Air Lines' Flight 49, outbound from San Francisco. The joint experiment, conducted by technicians of United and KRON -TV of San Francisco, was the first of its kind on the West Coast. The photo (at right) shows intent passenger interest as Phyllis Chase, United Air Lines stewardess adjusts the three -yearold RCA Victor television receiver (10 -inch screen), which was used in the test. Richard Grace, United radio engineer who monitored reception of a KRON -TV newscast, reported that the program came in clear while the Mainliner Stratocruiser prepared for take -off. During take-off the image grew fuzzy, but sharpened as the plane gained altitude. VERSATILE ANTENNA TEST The Broadcast Design Group of the RCA Engineering Products Department is the proud possessor of a new and easy method for testing broadcast antennas. It consists of a 100 -foot circular concrete apron which resembles a huge sundial. upon which are Reception at 20.000 feet was perfect for 250 miles west of San Francisco. Beyond that point the signal grew progressively weaker and finally faded out 306 miles from the West Coast. APPARATUS mounted five wooden dollies that support the steel frame. The center dolly revolves through a 360- degree arc around a vertical shaft in the center of the apron, while the steel frame holding the antennas being tested is built in sections that can be used to extend it up to 140 feet in length. This $25,000 test installation, located at Medford, New Jersey, eliminates the need for erecting antennas in the normal vertical position. This system permits movement of antenna elements in a horizontal position, the only reliable means of establishing the gain characteristics of broadcast antennas. The antennas are connected by cables to electrical test equipment in a nearby building. A signal generator is located at a distant point, and the antenna is rotated on its horizontal axis while data is recorded by means of a selsyn drive. irr Such facilities enable the engineers to continue their measurements with the highest degree of accuracy with a minimum of lost time for construction changes in the units under test. It's the answer to a test engineer's dream. 49 www.americanradiohistory.com CARPENTER PLASTER DRAPERY PROPERTY TURNTABLE SET PLATFORM STUDIO EFFECTS METAL PAINT ELECTRIC MINIATURE -(DOOR REH EARSAL "ASSEMBLY -LINE TV STUDIOS" In the field of motion picture production it has at various times been suggested to construct all necessary sets outside of the sound stages, and to convey them to a certain stage when needed there. After the use of the set, it was to be removed and another set was to take its place. By this method of production fewer sound stages would be required, while the sets could be constructed near the machines frequently required for this purpose, such as joiners, band -saws, plaster mixers, etc. One such system is known in the motion picture field as the "Pelton System" after F. E. Pelton;' another is referred to as the "Kasold System";2 a third as the "Berkely System" .3 At least a half dozen patents have been issued decsribing various means and methods of prefabricating sets and then conveying them in some manner to the locale of production, as may be noted in the references given at the end of this paper.4 Indeed, the problems involved are often well stated in the patents, as in British Patent No. 439,969, to quote: 50 By M. RETTINGER stages into stationary theatre spaces of different sizes for filming the different scenes. RCA Victor Division Radio Corporation of America Hollywood, California "According to the invention, a filmtaking installation is proposed, wherein the filming apparatus together with at least a part of the lighting equipment constitute an independent unit, and a number of successive rooms, cubicles or the like accommodating the built -up sets or scenery for "At the present time, the cost of production of motion pictures (silent or with sound) is materially increased by the time and labour involved (apart from that occupied by the actual scene -shooting) in erecting and dismantling the sets in the studios and in assembling and dismounting the lighting installation required for each scene, and also by the players' fees which have to be paid during this time and from which no immediate benefit is derived. "It has already been proposed to overcome part of the above disadvantages by employing movable stages having sets already prepared thereon and inserting such sets constitute another unit, the said units being movable relatively to one another, for example on rails, in such manner that any desired combination of the filming and lighting unit with a set may be selected therefrom." While such "systems" generally lay claims to motion picture production, they. can with equal benefits be applied to television work. Indeed, the construction of pre- fabricated sets which can be wheeled on and off a sound stage when needed appears even more desirable in the case of television work than for motion picture production. First, most motion picture stu- C o Ó Floor plan layout of a TV studio constructed on 20' x 40' platforms. Platforms are supported by wheels which move on rails. Platform floors and shop floors are at same elevation. FIG. 1. "streamlined" dios are located in suburbs where ground is not very expensive, while television studios, like radio stations, tend to occupy metropolitan areas where ground can be had only at a premium. Secondly, television production is more nearly a round -theclock activity which employs various programs and directors, while a motion picture is most always made by one director, cameraman, and cast, who require rest periods. Thirdly, motion picture scenes are of relatively short duration, and hence may be rehearsed in the sound ,tage after the set has been built. Television scenes are frequently rather lengthy, however, and are preferably rehearsed at some place outside the sound proof and voluminous sound stage. Indeed, under the present method of television production the set may be photographed, that is, used in actual production, for some 20 minutes, while it may be employed for several hours during rehearsing. These difficulties are not unknown to the television industry, and have recently been noted by various authors, as for instance Morton H. Read and Eugene N. Bunting, who write:5 "Set design in a small studio can be something of a problem, especially if it is necessary to have several sets ready at the same time. When budgets are low and space is limited, casts cannot be kept on subsistence while sets are changed and the studio is rearranged. This is especially true when a series of television commercials involves (as they often do) a kitchen, dining room, living room, hallway with front door, etc. If the studio can be completely set up in advance with all top lighting in place, it is possible to do a vast amount of work in a minimum of time." The problem becomes even more complicated when it is realized how many different material -processing and fabricating shops and subdepartments go into a large television set. A cursory summary includes the following factors: carpentering, drapery, property, paint, scenic, lumbermill, foundry, cabinet, hardware, mechanical, greenery, miniature and special effects. For this reason, as well as those mentioned above, it appears desirable to construct a set off -stage, to use it for rehearsing at a convenient location, and then to wheel it onto the sound stage where a low noise level is assured, where high platforms provide adequate lighting facilities, and where room is available for the operation of microphone booms. In the design of television studios employing an assembly -line type of production method, a U- shaped set construction area has to be provided containing various shops-painting, plastering, metal work, etc. When the set has been constructed it is conveyed in some manner-either by the rehearsal room wheels, or elevator or stage. Several rehearsals can well take place simultaneously in that enclosure, with the lighting adjusted and noted in a book. At the program hour, the set is conveyed to the sound stage where the actual recording and televising takes place. At the end of the program the set is removed and another set is wheeled in. It should be noted that this method of production is possible also when the sound stage is of the type which accommodates an audience. Indeed, if such is used for the presentation of a theatrical feature with several acts, hardly any other method appears practical if the sets are to be "real ". -to Fig. 1 shows the layout of a "streamlined" television studio. The set is constructed on 20 -foot by 40-foot platforms in a locale containing the various shops required to fabricate sets. Thus, in the car- penter shop the essential "flats" are constructed, which may be made of press wood, compositionboard, plywood, fiberboard, etc. In the plastering shop are built all necessary "casts ", and plaster forms made by sprayingthe material on with special spray guns. The platforms are supported by wheels which roll on rails set at such a height that the platform floors have the same elevation as the floors of the shops. After the set has been constructed it is rolled into the rehearsal studio, the "apron" floor of which is again at the same elevation as the platform on which the set is built. It should be realized that, at present, in a rehearsal studio intended for rehearsing as well as set construction, rehearsing is constantly interrupted by men hauling set props, carrying ladders, hammering, sawing, and perhaps even operating machinery. To facilitate lighting operations, the rehearsal studio, like the sound stage, may be equipped with grids which can be raised and lowered. These may be suspended from the roof trusses, with all cables located overhead, instead of lying across the studio floor as at present. Sound proof doors obviously are required between the shops and the rehearsal studio as well as between the rehearsal studio and the sound stage. They must be large enough to allow the sets to pass as a whole. At program time, the set is wheeled onto the auditorium stage, if the studio has an audience, or into the sound stage if no such audience is present. The stage may be equipped with a number of "catwalks" for lights which can be raised and lowered to accommodate sets of various heights. Two turntables in the sound stage assure a practically continuous flow of sets into and out of the enclosure. They are made of steel and electrically operated. The stage contains, of course, the usual video monitoring rooms, and may incorporate an orchestra pit. References Pelton, F. E., "The Pelton System," a privately published and mimeographed folder dated May 1, 1947. 2 Kasold, E. B., U. S. Patent No. 2,290,242. s Berkely, B., U. S. Patent No. 1,979,363. 4 U. S. Patent No. 479,001 Issued to J. H. Gutierrez. U. S. Patent No. 748,116 Issued to O. Stoll. U. S. Patent No. 1,045,398 Issued to C. L. Hagen. British Patent No. 439,969 Issued to Normaton Filmgesellschaft. o Read, Morton H., and Bunting. Eugene N., "Practical Operation of a Small Motion Picture Studio," SMPTE Journal, July, 1951, Vol. 57. No. 1, Page 24. 1 51 WÑt' F Broadcasting M EXCL. VE LY By QUINTEN G. CUMERALTO Chief Engineer, WRZE -FM BUILDING HALL i FIRE DOWN AP EI-/ - ELFTYPE DOWN 1 FUSE Box CLOSET SOUND CLOSET LOCK DOWN WOMEN 1. Floor plan show ing the WRZE arrangement of studio, offices and studio control room. FIG. ÿ BACI( GENERAL OFFICE I. NAGER FFICE Or- ,-,A C: MEN J A STUDIO "A' Yó STUDIO L-JI CONTROL MEE MIM REC located in York, Pennsylvania, is an "FM only" station with coverage that takes in a large portion of southeastern Pennsylvania, and northeastern Maryland. and to move solid rock in order to make room for the building and tower. This task being completed, the remaining construction both at the transmitter and at the studio went along smoothly. The construction permit for WRZE was granted on August 17, 1947, for eventual operation on channel 253 with an ERP of 8 KW. Clearing of the land for the transmitter location was begun shortly thereafter. This proved to be somewhat of a job, as it was necessary to construct a road for some distance through the woods Since the remodeling of the building for our studio location had to be completed first, installation of the audio equipment began during May of 1948. Soon after, the transmitter building and tower was completed, and a crew proceeded with the installation of the transmitting equipment. Even though we had no communication , UTTIN EQUI P. O , MOBILE REC. T E Cou sel. - ELI -I equipment between studio and transmitter during this phase of the work, very little trouble was encountered. The only real difficulty occurred while attempting to orientate our STL antennas without communications. However, we managed to get enough signal to the transmitter, to operate the receiver, and when our communications equipment arrived shortly thereafter, we were able to touch up the rough spots. WRZE went on the air with program on September 6, 1948, and we have encountered very little trouble since that time. The only exception has been power failure several times. However, this will be taken care of when the 31.25 KVA stand -by unit, now located at the main transmitter, is installed. Studios As our main studios are quite small, it is necessary to take advantage of all possible space, and this is done in the following manner: The Main studio is equipped with two mikes with facilities for a third mike if necessary. Our control room is ideally suited for combination work and has facilities for two mikes and three turntables. In addition, as the floor plans show. Quinten G. Cumeralto, Chief Engineer, shown at the controls of the 3-KW FM Trans. FIG. 2. miner, RCA Type BTF.3B. it is possible to use the manager's office for an announce booth, should the occasion arise. The studio has the ordinary run of equipment which includes the RCA 76B Con solette, Two Turntables, Two Portable Cutting Tables with associated amplifier and an audio rack with VU meters, amplifiers, etc. In addition, the communication equipment consisting of the RCA CT1A transmitter and the CRIA receiver is mounted on shelves in the control room as is the remote receiver which is part of the RCA Model BTM -1B remote equipment. Of course, our STL transmitter is also located at the studios with the low power section in the control room and the IPA tripler and the PA doubler section in a small closet adjacent to the control room. The STL antenna and the remote receiving antenna, of the ground plane variety manufactured by RCA, are located on a thirty foot tower on top of the studio building, with the Communications antenna mounted at roof level. The transmitting portion of the BTM 1B remote equipment is mounted in a Willys Jeep at the present time. However, we hope to improve these facilities in the near future since the frequency allocations for this type of service have been completed. Our audio equipment for remote use consists of the OP -6 and -7 as well as a three channel amplifier and a tape recorder. Transmitter The transmitter location is some fifteen miles southeast of York. As this is one of the highest points in York County, 705 feet above average, this location was chosen even though it is somewhat inconvenient with respect to mileage. Our transmitter building is a two story structure with all radio equipment on the second FiG. 3. Transmitter house. FM antenna and relay tacilities are located about fifteen miles southeast of York. floor and the heating plant and storage space on the first. The original plans called for a one story structure with basement, however, it was found to be impractical to excavate for the basement, and this accounts for the two story building. The second floor of the building is quite elaborate as it contains a complete studio control room, office, shop and bath room with shower. The studio- control room is of the "room within a room" type of construction and is quite effective in eliminating the blower noise from the transmitter. We are presently using the RCA BTF -3B operating with a power output of 2.1 KW feeding the RCA 3 Bay Super Turnstile Antenna with a gain of four, giving WRZE an ERP of 8 KW. The audio equipment, all located in the studio -control room, consists of a standard console, two turntables and the audio rack with the RCA 86 -A limiter, VU meter Panel, and Monitor amplifier which feeds the hall speaker from any portion of the audio line chosen with the selector switch on the VU meter Panel. In addition, the modulation monitor and an FM receiver for re- broadcast purposes are also located in the rack. Adjacent to the audio rack is the STL receiver on the right and the Monitor speaker on the lef t with the control box for the communications equipment, which is also the CT lA transmitter and the CR lA receiver; with the antenna located atop the transmitter building as is the FM receiving antenna. All wiring in the building is run in conduit with each joint welded and the conduit bonded every foot of the way to a system of ground wires which are terminated to a buried ground system located behind the building. As it was felt that this would not be adequate, due to the poor conductivity of the soil, the ground system is also connected to the copper water pipe which runs some 800 feet under ground to a 200 -foot well. Each of the tower legs is also connected to this ground system. STOI1.36e 00 Ilan CONTROL. STUDIO SHOP SW Fuá! asea Ig CON 50..77 F s BTr-3B i The Super Turnstile is mounted on a 40 -foot supporting structure complete with stairs to the top, which enable the engineering staff to do all maintenance on the antenna and associated lighting. Also included is a 110 volt AC receptacle at the base of the Turnstile, and it has proven a very handy accessory. As seen by the accompanying photo, our STL receiving antenna is mounted on one corner of the supporting tower. --rOFFICE FIG. 4. Floor plan of the WRZE transmitter building showing location of the FM transmitter and control equipment. 53 ENLARGING TELEVIEWING AUDIENCE THE By E. T. JONES Engineering Products Advertising RCA's interest in its customers and products extends far beyond the actual design and sale of the equipment. No constructive phase of the business is overlooked. As a concrete example, take the case of the Television Broadcaster. In certain locations a good portion of his potential audience has been unable to view the programs because: (a) apartment house management refused to permit tenants to erect a multitude of television antennas on the roofs of their buildings. Bedside television receivers to brighten the road to convalescence is lust one of the many conveniences made available by the management of Hahnemann Hospital. (b) in some communities individual rooftop antennas were shielded from TV signals by mountains which surrounded the city or town. To overcome the above mentioned difficulties, RCA engineers developed and perfected special Television Receiving Antenna and Distribution equipment . RCA Antenaplex® System. . APARTMENT -HOTEL- HOSPITAL . SYSTEM With a single array of antennas on the roof, this system is capable of distributing New York City's famous Waldorf-Astoria Hotel serves its guests with clear, sharp television pictures. Seven television channels are fed to 2.500 receivers by means of RCA Antenaplex system. signals equivalent in quality and quantity to those provided by individual antennas to as many as 350 TV receivers located in as many apartments or rooms. Rooftops no longer need be disfigured by an unsightly and hazardous clutter of antennas. A modern installation of this kind, employing only one array of antennas, prevents damage to the roof and lessens the hazard of personal injury -with resultant law suits-through the collapse of individual rooftop antennas. The Twin Oaks Apartment House of Kansas City. Missouri--designed for gracious living-provides tele- vision reception to more than 600 apartments through the expedient of RCA Television Antenaplex System. The RCA Television Antenaplex array looms above the 20 -story hospital. The hospital is the first in the world to provide patients and staff with this multiple- outlet RCA master tele. vision Antenaplex system. Hahnemann Hospital of Philadelphia. the first hospital in the world to install an RCA Television Antenaplex system. provides clear and uniform television reception for patients and staff members in virtually any part of the 20 -story building. The system is especially free from interference presented by diathermy, X -ray, and other hospital equipment. Television at the patient's bedside affords many hours of fine entertainment by bringing to him the world's greatest entertainers. He can derive a variety of enter- Frank E. Douglas. jr.. Business Manager of Hahnemann Medical College and Hospital, is shown with RCA Anten plex amplifier and distribution equipment. Excellent reception throughout the entire hospital area is assured. tainment from Drama, Comedy, Sports and Religious programs which are broadcast from nationwide networks. The hospitalized patient is truly a receptive audience. HOW THE WALDORF INSTALLATION OPERATES It is capable of receiving, through the seven antennas mounted on five masts on the roof, every channel presently locally receivable or programmed for the future, whether in color or in black and white. A special pre -amplifier located in the Tower feeds ten individual risers, one for each 4 Typical of the units installed at the Waldorf- Astoria Hotel, this 7- Channel Antenaplex Amplifier intensifies the re ceived signals and assures excellent reception in every apartment. . Wall outlets provide the final link of the distribution system. The television receiver is ready for operation as soon as the cord is plugged in. www.americanradiohistory.com channel with three spares running from the 45th to the 6th floor. These risers assure full strength signals at every floor level of the house. To cover the needs of the East and West Towers, the Lower Tower and the various guest and public rooms in the main body, individual amplifiers serving upwards to 250 outlets each, are tapped off the system at the 45th, 18th and the 6th floor. Each amplifier represents a typical antenaplex master antenna system, distributing signals through a single coaxial cable approximating the size of a The shielding effect of Sharps Mountain on the homes in the city of Pottsville is clearly illustrated. This 80 -foot tower reaches out over the top of Sharps Mountain, itself 1.390 feet above sea level, to pick up the throe Philadelphia television stations and distribute their programs to the residents of Pottsville. pencil to the individual set outlet in each room. This unique system gives the Waldorf a capacity for operating over 2500 television receivers simultaneously. Moreover, all television receivers throughout the house give clear sharp pictures on every channel. As far as television is concerned This special RCA Community Television Antenaplex Amplifier greatly intensifies the signals picked up on top of Sharps Mountain- assuring excellent reception in Pottsville homes. the Waldorf can truly be said to be "ghostfree". All equipment is RCA throughout, built to the highest standards of quality. These features, outstanding as they are, are only a partial measure of the system's value, for in tackling the problem of the Waldorf's public rooms, Master Video and 56 www.americanradiohistory.com RCA Service engineers developed the special "Master Video control panel" for the public room system which is installed in the Radio Room. This panel enables the Waldorf to completely control the signals to all public rooms from the small parlors and meeting rooms on the fourth floor, to the Grand Ballroom. By means of this control panel, the hotel can give its clientele any desired capacity, from one to 200 receivers operating simultaneously in any public room. Thus the hotel is able to offer to manufacturers, distributors and dealers a proven means of demonstrating their sets or their products through television. Waldorf, like many buildings in the area is still faced with the DC problem in portions of the house. Master Video's modifications incorporating the hotel's radio system in TV receivers, provide the hotel's guests with the finest combination system yet evolved. At the same time, by utilizing the spare risers from the roof level to the control panel, the hotel can take off the air direct radio relay signals beamed exclusively to the Waldorf and transmit that signal to any given public room; or the hotel can transmit a closed circuit sales meeting or similar telecast to one or more of the public rooms. All this can be done without disturbance to the Waldorf's guests or normal television reception in other parts of the hotel. Any number of public rooms can be linked for such closed circuit meetings. Or, if the hotel desires, it can transmit its own telecasts to its patrons and guests without resort to outside facilities. example, was installed by Master Video in the Peacock Lounge for the World Series, naturally contributing towards an increase in restaurant and beverage business. The results were substantial both in revenue and in guest satisfaction. RCA Victor set equipment was carefully tailorded to the hotel's needs. Seventeen inch consolette-type receivers have been expressly modified, both to incorporate the hotel's radio system and to permit the hotel to cover the needs of those portions of the house still not equipped with the master system and alternating current; for the A special 6' x 9' projection unit, for RCA COMMUNITY ANTENAPLEX SYSTEM Even entire communities, previously shielded by mountains, have been added to the televiewing audience through the application of the RCA Community Antenaplex System. Clear programs may be obtained from stations up to 100 miles or more depending on the strength of the signals. Providing television signal reception and distribution service for an entire community, the system consists of a master antenna assembly, mounted on a tall mast on the highest nearby elevation; a network of coaxial cable, strung over utility poles from the antenna site through the areas to be served; amplifiers mounted on poles at fixed intervals to boost the strength of the In addition to the main amplifier, line amplifiers like those below are in- serted wherever needed to maintain a definite value of signal strength. signals; and lead -off lines terminating in wall or baseboard outlets in the homes of set -owners subscribing for the service. On the antenna mast are three separate elements, each tuned for a channel on which programs are available. The system eliminates the television "blind spots" represented by mountain ringed communities, as well as those on flat terrain where the nearest broadcast stations are too remote to permit reception with individual roof -top antennas. At Pottsville, Pennsylvania, a mountainringed community, an RCA installation of this kind is bringing high -quality television reception to more than 400 families whose receivers are connected to the corn munity antenna system. Programs are received from three stations in Philadelphia, more than 75 miles away. Before the community antenna system was installed, television reception in Pottsville homes was extremely poor, even with elaborate roof -top installations costing in excess of $500 and very often more than the cost of the television receivers. The new system makes use of roof -top antennas unnecessary. Local operating companies, such as the Trans -Video Corporation at Pottsville, Pa., offer the service for a fixed installation fee, plus a monthly service charge. From these distribution boxes, individual homes are fed strong signals which provide high -quality pictures and sound. 57 www.americanradiohistory.com Student announcer gets acquainted with the RCA 77 -D Microphone. The "Studio Schoolhouse," jointly sponsored by RCA Victor and Station WFIL is a busy student activity. 9 7atee FOR BROADCASTING By GEORGE KOEHLER Promotion Director Philadelphia Inquirer Stations, WFIL -WFIL -TV and E. C. MASON Associate Editor -BROADCAST NEWS Radio Station WFIL has helped Temple University establish a radio department to provide a practical laboratory for teaching the finest techniques of broadcasting. Temple's Department of Radio Speech and Theatre operates a campus Radio Station-WRTI. Advice and assistance in the functioning of WRTI is provided by members of the WFIL Stations' Staffs. The University's Philadelphia Collegiate Network consists of four stations linked together by telephone lines to provide afternoon and evening listening. Temple's WRTI is the Network's key switching center with programs provided by WXPN -the University of Pennsylvania, WPWT -the Philadelphia Wireless Technical Institute and WRTI. The Intercollegiate Network is an agency of good will and a community service. WRTI frequently contributes recordings of important campus speeches and other events for broadcast over Philadelphia's WFIL. Students trained on WRTI appear five times each week in WFIL's Studio Schoolhouse programs, designed for inschool listening. Other students assist in television productions over WFIL -TV. Located in the basement of Thomas Hall, Park Avenue and Norris Street and directed by Professor John B. Roberts, WRTI is a completely independent operating unit . four studios, four control rooms, reception rooms and lavatories. WRTI, a small but efficient radio station, operates on a frequency of 640 kilocycles. Costing more than $40,000, it was constructed in 1947 with the aid of a grant from Philadelphia's radio station WFIL. Completely RCA-equipped (as WFIL), WRTI uses everything in microphones from the RCA 44 -BX down to the Bantam KB -2C's. Also RCA 70 -D Turntables and RCA type 76-C consolletes. The OP6 and Transmission eminates from two 10watt transmitters operating simultaneously through the University's electrical system, covering a 4- square -block area. Radiation the OP7 RCA Remote Amplifier and Mixer is used for remote broadcasts. is never beyond 200 feet from the power lines. Although registered with the FCC, is not licensed because signal radiation is confined to such a small area. However, there is strict adherence to FCC regulations at all times. WRTI 58 www.americanradiohistory.com . . In the hands of the ingenious and alert student broadcasters, this remote equipment has been a versatile instrument, bringing to the listening audience the voices of such distinguished personalities as President Harry S. Truman, Senator Francis J. Myers, Carl Sandburg, Arthur Garfield Hays, Adolph Berle, Thurman Arnold and Dr. Ralph Bunche. In the field of enter- tainment, Virginia Mayo, Joe Walcott, Duke Ellington and others. WRTI broad casts more remotes (other than sports) than any other Philadelphia or surrounding area stations. Thirty-five percent of WRTI's programs are "live" programs-more than any other Philadelphia professional station. Over 200 students take part in some phase of its activity. WRTI MEANS BUSINESS! WRTI sells time and is a complete replica of the most efficient commercial station with regard to programming. Audience analysis, scheduling and logging of programs and maximum utilization of available talent follows the pattern of the most highly organized broadcast service. In radio, the signing of an advertising contract is an important event. WRTI offers the advertiser a highly select radio audience. A positive friendly relationship has been constantly maintained with the local . During the football season, WRTI's flag waves from the press box in the stadium, where WRTI sports men cover the game. Basketball, baseball, track, and all physical training meets are handled by the roving special -events staff. TEMPLE'S TECHNICAL INSTITUTE To provide the Radio and Television Industry with technical men, the Temple University Technical Institute offers courses designed to meet the needs of a highly specialized field. The work is intensive in nature and the lectures are supplemented by thorough and practical laboratory experiments. Competent instructors are from radio and television industries in the area -field, test, and telecasting engineers. Thus, Temple gives a completely rounded group of courses in all phases of radio, electronics and television. WRTI'S PURPOSE WRTI has been dedicated as a means of improving present radio standards. Since WFIL helped launch WRTI as a means of providing a reservoir of trained per- Technical Men of the Future. sonnel. it is natural that many graduates have become a part of WFIL's organization. But others have become affiliated with WCAU, WDEL, WORK, WCOJ, as well as TV stations. Many other stations have been availing themselves of students graduating with a B.A. degree in radio. stations. RCA Professional Broadcast Audio Equipment creates the "authentic atmosphere" at WRTI-prepares the student Broadcaster adequately for his future. HANDLED WITH CARE! Discussion type programs that most stations would not tackle are handled at WRTI Minority Group Problems .. . Republican to Democrat Progressive to Socialist all receive full and fair treatment! ... ... ... WELL- BALANCED DIET WRTI listeners have enjoyed programs ranging from newscasts received in a teletype- equipped news room, to classical music and dramatic shows. The music library is large and constantly growing. In the dramatic line, "stay -at -home theatre goers" hear weekly presentations by the Temple Theatre Guild. Many of these half -hour shows are written by WRTI staffers. All this means hours of rehearsal time for actors, announcers, musicians, and sound -effects men. WRTI has grown from a sparsely- staffed, "trial and error" operation to a well -organized, smoothly functioning team. The "Ninth" Television Training THE c( t'" BROADCASTERS' TV TRAINING PROGRAM V,', November 26, 1951 the "Ninth" Broadcasters' Television Training Session was presented by RCA Engineering Products Department in the Exhibition Room in Camden, New Jersey. More than 60 Broadcasters attended the week -long session bringing the number of Broadcasters attending all sessions since their inauguration to the grand total of 500. hearty welcome was extended by W. W. Watts and T. A. Smith with genA A group of Program- Tuesday Morning Class. announcements and introductions made by E. T. Griffith. The topics discussed at the Monday session were: "What It Takes to Make a TV Station "-by E. C. Tracy; "Introduction to TV Studio Equipment" H. Duszak; "Television Theory" H. Roe and A. H. Lind; "TV Camera Equipment" A. Reisz; "Flying Spot Equipment " -W. E. Tucker "Synchronizing Generator "-R. J. Smith.. 'TV Switching " -L. E. Anderson. eral -J. - - ; Broadcasters inspect a four -section version of ACA's new Antenna- one of the many Items of Interest displayed. TFU -24B UHF The Exhibition Room was divided into three sections: a lecture room, a display area and a luncheon section. An intermission at each morning and afternoon session-with refreshments-provided relaxation and an opportunity to "get acquainted". During the recess much interest was shown in a four -section version of RCA's new TFU-24B UHF Antenna. A showcase displayed a model studio layout of RCA's "Basic Buy" TV Studio Package-fully described in BROADCAST NEWS No. 66, and soon to be released as a 12page brochure. Many familiar pieces of equipment and many items entirely new to the Broadcasters were shown. Luncheon was served each day at 12:30 and high -fidelity music was provided by the RCA RT-11A Professional Tape Recorder and LC -1A Loudspeaker. TUESDAY'S PROGRAM The Tuesday program included talks on "Film Projectors" - --by A. E. Jackson; "Video Amplifiers " -R. J. Hucaby; "Video Monitors "-N. P. Kellaway; "Genlock and Special Effects " -E. M. Gore; "Mi. crowave Relay "-C. A. Rosencrans; "TV Mobile and Supplementary Equipment" L. E. Anderson; "TV Pick -Up Tubes" R. Johnson (RCA Tube Dept.); "TV - -- 60 www.americanradiohistory.com REGISTRANTS AT THE 9TH TELEVISION TRAINING PROGRAM WALTER KALB H. ALLEN ... WDET -FM THEODORE ANDRAS GEORGE ANDREWSKV .... WBRE WJDA JAMES ASCHER MAJOR JOHN BAURIEDEL ALLEN BELL EDGAR T. BELL ROBERT WELM -WCLI KTOK M. BOOTH WPTZ WNOE WXEL .. WTAG KWBU WMAR WWNY WIBW WFAA GEORGE BORDEN RAY BOYD HAROLD BRINKMAN ELLIOT A. BROWNING NESTOR CUESTA W. DARLING MAYNARD DAVIS LEWIS DICKENS FLEETS WILLIAM ELLIS CRC J. GILMOUR ... WJLS A. J. GINKEL A. GOODMAN WMAR KTOK A. HILL WBRY FRANK HAIES J. HAROLD HAUGHAWOUT KTAR GEORGE HIXENBAUGH ..WMT KARL B. HOFFMAN ... WGR WIBW ARTHUR HOLBROOK .. WFBM HAROLD HOLLAND ....... . WMAR W. HOOPER ARTHUR HOPWOOD PAUL HUHNDORFF .... WPTZ .. KPRC ALEXANDRIA, I.A. DETROIT, MICH. WILKES-BARRE, PA. QUINCY, MASS. JOLIET, ILL. ELMIRA, N. Y. OKLAHOMA CITY, OKLA. WASHINGTON, D. C. PHILADELPHIA, PA. NEW ORLEANS, LA. CLEVELAND, OHIO WORCESTER, MASS. CORPUS CHRISTI, TEX. BALTIMORE, MD. WATERTOWN, N. Y. TOPEKA, KANSAS DALLAS, TEX. `\WILLIAM HUNT NORAN E. KERSTA C. LAU WMAR D. LEIBENSPERGER WILLIAM G. MATTA MONTREAL, QUEBEC BECKLEY, W. VA. BALTIMORE, AL SMITH MD. Studio Lighting " -H. M. Gurin (NBC); H. Roe; "Installation, "TV Systems " Tune -Up and Maintenance "-T. Griffin (RCA Service Co.) -J. . WEDNESDAY'S SESSION On Wednesday morning a laboratory visit was conducted under the direction of W. J. Poch to acquaint the Broadcaster with new developments in video equipment. After having lunch and returning to the lecture room, discussions covering "Introduction to Audio Equipment "-by D. Bain; "Audio Systems for TV "-W. E. Stewart; "Custom Audio for TV " -M. Gunn; and "Microphones and Microphone Techniques " -by G. Graham (NBC) were presented. WHIZ _ CRC WARD MILLER J. H. MITCHELL CARLTON NOPPER N. J. PAPPAS BEN PARRISH CHESTER RECTOR F. REMLEY JOSEPH H. ROHRER JOHN ROTH CHARLES SAKOSKI R. F. SANTO JOSEPH H. SAXON ERWIN SCHONEY OKLAHOMA CITY, OKLA. WATERBURY, CONN. PHOENIX, ARIZ. CEDAR RAPIDS, IOWA BUFFALO, N. Y. TOPEKA, KANS. INDIANAPOLIS, IND. BALTIMORE, MD. PHILADELPHIA, PA. HOUSTON, TEX. . J. H. JONES WHP .. WLOA WHLD WFLA . WMAR CBC KHMD WIOU W. WEAVER L. A. WILKINSON W. A. WILSON ROBERT J. WILSON CHARLES WIRTENAN G. WOODEN tenna " -W. Darling; "TV Antenna Components"-L. J. Wolf ; "TV Super -Turnstile Antennas " --H. Wescott. Thursday evening provided a little diversion -with Cocktails and a Banquet. Truly a cordial evening! FRIDAY'S SESSION Friday's session included such topics as: "VHF Custom Antennas " -by L. J. Wolf; . RRADDOCK, PA. NIAGARA FALLS, N. Y. TAMPA, FLA. BALTIMORE, MD. MONTREAL, QUEBEC CBC MONTREAL, KCOM WMAR WFPG GEORGE TOWNSEND CITY MD. HARRISBURG, PA. WPTZ WBRE WTOK WGBP BLAIR THRON OHIO QUEBEC HANNIBAL, MO. KGKOMO, IND. ANN ARBOR, MICH. COLORADO SPRINGS, COLO. PHILADELPHIA, PA. WILKES- BARRE, PA. KRDO H. SNYDER ZANESVILLE, MONTREAL, NEW YORK BALTIMORE, WSPR WNOW WTOP KBOR WHLD ., WIBM WMAR QUEBEC MERIDIAN, MISS. EVANSVILLE, IND. SIOUX CITY, IOWA BALTIMORE, MD. ATLANTIC CITY, N. J. SPRINGFIELD, MASS. YORK, PA. WASHINGTON, D. C. BROWNVILLE, TEX. NIAGARA FALLS, N. Y. JACKSON, MICH. BALTIMORE, MD. "UHF Antenna Systems Equipment " -O. -D. Balmer; "TV O. Fiet; "TV Towers " Markets " Halpin; "Monitor and Test -D. Equipment " -W. T. Douglas. Since 1947, RCA has played host to over 500 enthusiastic Broadcasters at nine Television Training sessions. The "Tenth" Training Program will be held February 25, 1952. Discussing the RCA "Basic Buy" and 20 KW Conversion Equipment display are (I. to r.): Paul Huhndorff, KPRC. Houston, Texas: Harold Brinkman, WXEL, Cleveland, Ohio: Nestor Cuesta, KWBU, Corpus Christi, Texas: James Barclay, RCA. THURSDAY'S PROGRAM Thursday's schedule included "Introduction to Transmitters " -by R. J. Newman; "Principles of TV Transmitter Design" Gluyas; "TT- 2AL /2AH, 2 K\\ TV Transmitter " -W. T. Douglas; "TT10AL/10AH, 10 KW TV Transmitter " R. Meisenheimer; "TT- 25AL /20AH, 25 Talmage; and 20 KW TV Amplifiers" "TTU -1B, TTU -10A, 1 KW and 10 KW P. Tissot; "GenUHF Transmitters " eral Principles and Theory of TV An- -T. - -F. -T. 61 RAM FORUM -41W A DEPARTMENT FOR THE BROADCAST RADIO AMATEUR - LIVING ROOM STYLE! HAM SHACK Those who have been in the Broadcast Business for at least 10 years won't have to guess what was used to make this attractive ham console.* Construction of this neat, convenient desk for receiver, VFO, freq. meter, speech amplifier and monitor scope, with all power supplies, was the ingenious work of Fred de Jaager, W2CGJ, Chief Engineer of Empire Broadcasting This should give Corporation, N. somebody i- d -e -a -s ! Y.... ... Fred's transmitter, shown beside the console, is a 750 -watt job, 100% TVI- proofed, with push -pull 100TH's in the final. This transmitter made DXCC in 1949, operates on 3.5, 7, 14 and 28 mc. Beams for 10 and 20, mounted atop a 50 -foot pole several feet behind the house, are fed with one piece of co -ax. A relay at the top of the pole selects either beam. Co-ax and all control wires between the house and pole are underground. W2CGJ made this attractive ham desk (above) from an RCA Broadcast Type 80 -B Console Desk. Below, Allen Jones, W1NW of WHDH is shown operating W1TOP, Tri Tower Radio Club Headquarters Station. W1TOP GOES AFTER W -A -C 75 FONE Philip K. Baldwin, WIZW, Chief Engineer of WHDH and WHDH -FM, Boston, reports excellent results with W1TOP, 200 watt headquarters station of the Tri Tower Radio Club. In only a few months operation, they have worked all districts several times and dx including two ZL contacts all on 75 -meter phone! Club membership is limited to employees of WHDH and WHDH -FM, Boston. - W1TOP is installed in the WHDH transmitter building at Needham, Mass., twelve miles southwest of Boston. One corner of the workshop bench (see photo at left) is utilized for the club's installation. The transmitter uses a pair of 812's in the final modulated by Class B 811's, and a surplus * RCA Type 80 -B Console Desk. Address correspondence to: HAM FORUM Marvin L. Gaskill (W2BCV) Associate Editor, Broadcast News RCA, Camden, New Jersey 62 www.americanradiohistory.com aircraft transmitter ECO. Two receivers, an SX -28 and NC100 are used with a switching arrangement for selection of either to feed the speaker. Groundplane Vertical Antenna The W1TOP antenna is a groundplane vertical radiator 61 feet long. The radiator, constructed of aluminum tubing, is supported by a 30 -foot pole and wire guys. Four horizontal radials spaced at 90- degree intervals terminate in a copper ring at the base of the radiator about 16 feet above ground. The antenna is fed at this point with RG8U cable. Operation is presently confined to 75 -meter phone. Let's hear from some W6's and K6's. All districts have been heard from but the sixth. Shame! 73, W2BCV ... - NAA 1914 How Many Do You Know? John Stenger, Jr., W3ZS of WBAX, Wilkes Barre, Pa., submits this picture of the 1914 crew at famous NAA. Are any of the sigs familiar to you? Inset shows John at his ham station, SNR, in 1912. inHe was 5G in 1908, 8ZS in 1915 terrupted his ham career during World War I when he joined the Navy. ... Effective 1/4 wave vertical Below, 1914 NAA personnel of U. S. Naval Station, Arlington, Va. Top row, left to right: J. E. O'Neil, Chief Machinist: Simonton, Civil Clerk; W. A. Eaton, Chief Elect.: Penland, Chief Elect.: George Clark, Radio Inspector; Wood, Chief Yeoman; J. W. Scanlon, Chief Elect., Radio, In Charge; Lt. Cmdr. S. W. Bryant, Asst. Supt. Naval Radio of W1TOP is shown in above photo behind WHDH station wagon. Service: J. H. Knapp, Asst. Paymaster. Middle row, left to right: Pritchett: Palmer: (the mascot. "Static "): Bain; Burge: Carbin: Hunter; Pitts, all Operators; and Hildum, Yeoman. Bottom row, left to right: Burke, Operator; Kweeder, Yeoman; Ferree and Wilken, Operators; M. E. Eason. Chief Elect. FIG. 2. External view of the low bond amplifier for channels 2 to 6. TT- 25AL/20AH CONVERSION EQUIPMENTS HOW TO CONVERT AN OPERATING 5 -KW TV STATION ON VHF TO 200 KW (ERP) The TT -25AL and the TT-20AH conversion equipments are high power amplifiers for use with 5 kilowatt television transmitters. The TT -25AL operates on channels 2 through 6 and will provide up to 25 KW peak visual power and 12.5 KW aural power. The TT -20AH operates on channels 7 through 13 and will supply up to 20 KW peak visual power and 10 KW aural power. These equipments are designed primarily to operate with the RCA TT -5A television transmitter but can also be furnished for use with any other 5 KW television transmitter meeting the FCC and RTMA specifications. In the light of the effective radiated power increases which the FCC has granted recently to operating TV stations in the VHF band, the RCA Transmitter Power Conversion Equipment has assumed new importance to the industry. For the TV station on- the-air which began life on a small scale, the opportunity to raise its effective radiated power is afforded through a conversion job, rather than a complete, new installation. by F. E. TALMAGE BROADCAST TRANSMITTER ENGINEERING Using the TT- 25AL /20AH Conversion Units with a 5 -KW Transmitter as a driver, it is possible for a station to multiply its transmitter power 4 or .5 times, depending upon whether the channel in use is low band or high band. Thus, a transmitter with a 20 -KW output, used in conjunction with a 6 -bay antenna and an average length of line would give an effective radiated power of at least 100 KW. With a 12 -bay antenna, the ERP would become at least 200 KW. The advantages of higher power are obvious. The station gets increased coverage with its signal, plus better signal to noise ratio in the picture. More effective use of indoor antennas is possible in the reception area, and there is less receiver oscillation interference. Fig. 1 is a block diagram of the TT-25AL /TT -20AH equipment. The internal circuits of the 5 KW driver are not 64 www.americanradiohistory.com changed. The video and audio signals are fed to the driver and the modulation occurs in this unit. The RF output from the visual driver is fed to a class "B" linear amplifier. The aural amplifier is similar to the visual amplifier except that it may be operated class "C" since the sound carrier is frequency modulated. Construction The power and control equipment for the amplifiers are housed in four cabinets which match the cabinet of the RCA TT-5A. These cabinets may be placed either in line with the TT-SA or at right angles. Several suggested floor plans are shown on the preceding pages. Since the two power supply cabinets do not contain any operating controls or meters, they can be mounted either with the other cabinets or in the rear as shown in the second floor plan. The RF circuits are housed in two cylindrical cabinets illustrated in Fig. 2. The units for the visual and for the aural amplifier are mechanically almost identical. TO ANT. DIPLE)kER I I SIDE BAND I FILIE R I MONITOR MONITOR UNIT 2-RCA GALS I -RCA 2021 2 UNIT RCA6AL5 I- RCA 2021 SOUND R C A AMPLIFIER 5 -RCA SOUND IN H.V. POWER SUP PLY 6 -RC A 673 I -TT5A BIAS SUPPLY -RCA SR4GY LINEAR AMPLIFIER 7 -RCA 5762 Equipment as used with TT -5A Television Transmitter. 4 PICTURE IN BIAS SUPPLY I -RCA 5R4GY 7-RCA 6AS7G I-RCA 65H7 -RCA I -RCA I The lower rectangular section of the amplifier unit houses the blower, filament transformers, meters and tuning controls while the upper cylindrical section contains the tubes and RF circuits. Air for cooling the tubes is drawn in through two filters on the sides of the bottom section and is expelled out the top of the unit. Access to the tubes is obtained through four hinged doors near the top of the unit. All other parts are easily accessible for servicing by removing the top dust cover, the side plates or the filters. The refiectometer and monitor circuits are contained in a separate unit which may be inserted in any convenient place in the output line. FIG. 1. Block diagram of the TT -25AL / TT -20AH Conversion PICTURE TELEVISION TRANSMITTER 5762 H.V. POWER SUP PLY 6-RCA 673 003 0A3 Circuit Description The visual RF amplifiers for both the low -band and the high -band equipments each employ seven RCA -5762 air cooled tubes operating in parallel in a grounded grid circuit. The tubes are placed in a circle as shown in Fig. 3. The aural amplifier also contains seven RCA-5762 tubes in an almost identical circuit, however, the filaments of two of the seven tubes may be turned off if desired, leaving only five operating tubes. The general appearance of the low and high band units are similar but the internal circuits necessarily differ in several important respects. Both the low and the high band units will be described separately below in more detail. Low-band Amplifier: The operation of the low -band unit can best be understood by referring both to the simplified equivalent circuit Fig. 5 and the cut -away view of the amplifier shown in Fig. 4. The plate tank circuit is tuned by (L -10). As can be seen in the cut -away view, this inductance is a co -axial tank formed by the outer shell, and an inner cylinder, and varied by a shorting bar located below the tubes. The shorting bar is motor driven and controlled from the front panel. The output transmission line is brought up through the center of the tank and coupled to the plate circuit through a variable capacitor (C -40). This capacitor is also motor driven and controlled from the front panel. What is equivalent to a second tuned circuit is formed by inserting a shunt capacitor (C -10) in the output transmission line apFIG. 3. Closeup showing the cluster of seven air -cooled 5762 triodes used in the 20 kw amplifier equipment. proximately one quarter wave from C -40. This secondary circuit is tuned by sliding capacitor (C-10) along the line. The inductance L-30 shown in the equivalent circuit is actually the first quarter wave of the output transmission line. By a suitable selection of the value of capacitor (C-10) and proper adjustment of the coupling capacitor (C-40) a broadband flat- topped circuit can be obtained as illustrated in Fig. 6. The optimum circuit has been found to be 8% to 10 megacycles wide between half power points and almost fiat over the six megacycle channel. The input or cathode circuit is also essentially a co -axial tank circuit tuned by a shorting bar shown near the center of Fig. 4 just above the tube level. In the equivalent circuit this is shown as a variable inductance (L-40). Because of the high input capacity of seven tubes in parallel this tank is actually much less than a quarter of a wavelength long. A large part of the inductance is formed in the tube and by the tube leads. The input line is fed through the center of the cathode tank and is connected in series with the input circuit at a low impedance point. In order to match this impedance to the 72 ohm line from the driver two quarter -wave transformer sections T9 and T10 are employed. In the cut -away view these are shown built into the 3%" input line by using the proper size center conductors for the quarter -wave sections. To allow for variation in tube input capacity and for variation in feed- through power, a means for making some adjustment to the input coupling must be provided. In the low band amplifier this is ac65 Range (20 to 200 kw). For a new station desiring to start with power, the 20 -kw Type TT -20B Transmitter will provide the full used in connection with an RCA 12- section Super Turnstile Antenna. the TT -20B Transmitter is located "In-line" with associated power the rear. Some Broadcasters may prefer a block "U" arrangement. 20 -KW. VHF ERP the maximum 200 kw when In this layout equipment at PLANS FLOOR 20-KW CONVERSION ERP Range (20 to 200 kw). For stations already on the air with 5 -kw transmitters, the 20 -kw VHF con version equipment shown here provides the means for increasing power without disturbing existing facilities. With suitable RCA antennas, ERP's of up to 200 kw may be obtained. AND STATION Floor plan of TT -25AL TT -20AH with power supply and power control racks located at the ends of the transmitter. Shaded portions of the diagram are TT -SA units. j//i/%' / i 010.0tER t AURAL PA BLOWER TANK +NiNN VESTIGIAL BAND FILTER SIDE 24VISUAL PA. BLOWER & TANK SAmemIXMAII î TER A COOLER 2,3650H101.1 200 VISUAL CONTROL AND OISTRIBUTIO AURAL POWER SUPPLY & FILTER VISUAL POWER SUPPLY FILTER t VISUAL \N 25- WATER COOLER MAY BE INSTALLED AT ANY CONVENIENT PLACE NEAR THE TRANSMITTER NOTE #2 PLATE TRANSFORMERS SHOULD BE LOCATED NEAR THE POWER SUPPLIES TO AVOID LONG RUNS OF HIGH VOLTAGE WIRING. NOTE MONITORING EQUIP RACKS 43, ALL DIMENSIONS ARE MINIMUM www.americanradiohistory.com PLATE TRANSFORMER LAYOUTS FOR / / / /!/ // / / / // / // // / /// 4 / 24 %/ +T I AURAL /imo VISUAL PA PA BLOWER &TARR BLOWER &TANK O AURAL VISUAL POWER POWER QRREAER L. 12Tb:tet SUPPLY SUPPLY AND AND FILTER FILTER 84-NIGH 64 NIGN 1.-36 WATER COOLER VESTIGIAL 4-24" SIDE BAND 2íA361 FILTER 34:421.4CMN SO NIGN 3B 1 --4 iI`C>,y, AURAL PLATE TRANSFORMER 2iE2 VISUAL PLATE JAL AURAL TRANSFORMER 2iÁ42 CONTRD Floor plan of TT -25AL/ with power TT -20AH, AND AND DISTRIB DI STRIE supply and power control racks located behind the transmitter. Shaded portions of the diagram are TT -5A units. Y 25' 200- NOTE WATER COOLER MAY BE INSTALLED AT ANY CONVENIENT PLACE NEAR THE TRANSMITTER. NOTE MONITORING CONTROL RACKS 20A 441 B4 -NIGH ,I 42 PLATE TRANSFORMER SHOULD BE LOCATED NEAR THE POWER SUPPLIES. TO AVOID LONG RUNS OF HIGH VOLTAGE WIRING NOTE *3 ALL DIMENSIONS 25/20 ARE MINIMUM CONVERSIONS KW TRANSMITTER %//// /r/////////iii/JI// ////// /a(// /i//iii/////////// /. /////// t / / VISUAL PA BLOWER d TANN AURAL PA (BLOWER & TANK 24 AURAL VI UAL PLATE TRANS- PLATE 2í-r TRANS- FORMER FORMER 24142 24"x 42 R'FsAER (IWATER (COOLER t36Á 50 NIGH 24ya . EF -R L- Floor plan showing the straight line arrangement of TT- 25AL /TT -20AH. The shaded portions of the diagram are TT-5A units. FILTER 24'42..44.4I AND STRIE Ar,I DIS- ,e,/\'.\e/.,ÌNA í zs:-.14-2s- 3/ VISUAL VISUAL POWER CCNTgpI SUPPLY POWER SUPPLY AND FILTER 2t VESTIGIAL.2Ó SIDE BAND ÌU 0 1 f N AND FILTER \7\,V/V 25' 200' 25-. 1.-3' 69. NOTE PI WATER COOLER MAY BE INSTALLED AT ANY CONVENIENT PLACE NEAR THE TRANSMITTER NOTE .2 PLATE TRANSFORMER SHOULD BE LOCATED NEAR THE POWER SUPPLIES TO AVOID LONG RUNS OF HIGH VOLTAGE WIRING NOTE .3 ALL DIMENSIONS ARE .1 RACKS 1 MINIMUM MONITORING EQUIP complished by adding in shunt capacitors C- 101 -107. As can be seen in Fig. 4 these capacitors take the form of seven co -axial capacitors. To vary the capacity a mycalex cylinder which has a dielectric constant of approximately 6 is inserted between the center and outer tubes. These seven mycalex cylinders are mechanically ganged together and driven by a tuning motor. Since the tube leads form a portion -C of the tank inductance these capacitors are not actually in parallel with the tube input but are part way down the tank circuit where it has been found that they serve as a coupling adjustment and have little effect on the resonant frequency of the circuit. High Band Amplifier: A cut-away view of the high band amplifier is shown in Fig. 8 and the simplified equivalent circuit is shown in Fig. 9. The general appearance of this unit is similar to the low band unit. but the circuit actually differs in several important details. Because the operating frequency is much higher, it would be impractical to use a simple quarter wave concentric line tank similar to that used in the low band amplifier since there would be little or no tank circuit left outside of the tubes themselves. To overcome this, two T9 -INPUT TRANSFORMER T 10 -INPUT TRANSFORMER L40 C101 - INPUT TUNING -C107 INPUT COUPLING FIG. 4. Cut- away view showing circuits R C 40 - OUTPUT COUPLING L 10 -F of TT -25AL Amplifier. the - PLATE TUNING L30 - OUTPUT TANK C10- OUTPUT TUNING 58 POSITION OF HANDLE AND OUTER CONDUCTOR FOR MAXIMUM Ee 7-RCA 5752 TUlES FIG. 5. Simplified equivalent circuit of the TT -25AL (low band amplifier). co -axial tank circuits are employed. One of these tanks is inside the other as shown in Fig. 8. These function as inductances in parallel and thus raise the effective resonant frequency. In the equivalent circuit these inductances are (L -10) and (L -20). The output is coupled to the inner of these plate tank circuits across a shunt inductance L-60. To preserve the circuit symmetry this inductance is actually made up of seven small adjustable shorted transmission lines connected in parallel and located on a circle just inside the inner plate tank. Like the low band unit, the secondary or output circuit is formed by inserting a shunt capacitor C -10 in the output transmission line and is tuned by sliding this capacitor along the line. Because the two circuits are coupled at a low impedance point this capacitor is located approxiwave length along the line. This mately secondary circuit, coupled to the plate circuit by means of a mutual reactance L -60, forms the necessary elements of an overcoupled broadband circuit whose response is equivalent to that shown in Fig. 6 for channel 6. F:G. 7. Cross -section view of variable Z. transformer used bi TT-20AH. provide for an input coupling adjustment one of the transformers (T-9) is constructed so as to have a variable characteristic impedance as the outer shell is rotated through 90 °. A cross sectional view of this transformer is shown in Fig. 7 (above). Power and Control Equipment: The control equipment is of conventional design. An instantaneous trip relay is connected in the cathode return circuit of each of the seven power amplifier tubes. In addition, a total d -c current relay is provided and a-c relays are inserted in the primary leads of the high voltage plate transformer. The overload system has an automatic reset feature. After an overload occurs the plate / The cathode circuit, like the plate circuit, cannot be made a conventional quarter -wave tank because the first low impedance point will occur on the tube straps. To compensate for this extra inductance of the straps, the seven co -axial capacitors C- 101 -107 are connected in series with the tube leads instead of in shunt as was the case in the low band amplifier. These capacitors are variable and when mechanically ganged together serve as the input tuning control. This cathode circuit is matched to the 72 ohm input by two quarter -wave transformer sections in series. To -C voltage will be removed momentarily then automatically returned twice. If the overload persists for the third time the plate voltage will remain off. All circuits such as the filament bus, the blower and the bias supply are protected by breakers with built -in overload trip coils. The control equipment for the aural transmitter is identical to that for the visual transmitter and the two are arranged so that the two carriers may be turned on and off independently. Except for the bias supply and slight differences in the high voltage filter, the power equipment for the aural and visual equipments are identical. The high voltage rectifiers for each employs six RCA -673 I.--- CHANNEL WIDTH- --Ad 20 I PICTURE CARRIER - - ML RESPONSE I i )0 60 FIG. 6. Curve showing typ- ical response output circuit, of TT -25AL 6. N\ 60 channel to >o 0 76 SO 82 84 ee es so 92 PREO. MC 69 mercury vapor rectifier tubes in a three phase full wave circuit with a balance coil. The bias supply for the visual amplifier is well regulated, its output voltage remaining constant for large changes in grid current. The bias for the aural amplifier is essentially obtained from grid leaks with just enough fixed bias to protect the tubes when there is no drive. Installation The layouts shown in the floor plans on the pages preceding this article are only three of many possible arrangements. In all three views the amplifiers are shown in the rear of the driver. Actually they can be located at the ends or at right angles to the TT-5A. This feature should be of particular interest to those stations which already have their 5 KW driver and are limited in available space to add an amplifier. The important thing to keep in mind is that the length of transmission line between the driver and the amplifier should be kept as short as possible. Distances between the output of the driver and the center line of the amplifier of 15 feet or less should be satisfactory. If the distance is much greater than this it will be difficult to obtain the required bandwidth. To understand why the line cannot be too long it should be remembered that the amplifier input circuit is essentially a single tuned circuit and can terminate the line exactly at only one frequency. To provide for a line of indefinite length, it would have to have a standing wave ratio of better than 1.1 to 1 over the six megacycle channel. This would mean that the bandwidth of the terminating cir- T9 - INPUT TRANSFORMER (VARIABLE) T IO INPUT TRANSFORMER CI01 -C107 INPUT TUNING FIG. 8. Cut- showing R -F away view circuits of the TT.20AH high.band amplifier. LIO - PLATE TUNING L20 -PLATE TUNING (OUTER) (INNER) L60 OUTPUT COUPLING 70 L30 -OUTPUT TANK CIO-OUTPUT TUNING 7-RCA5762 TUBES l.i1 p A INPUT TRANSrORNCR RCA TTSA TT25AL ANPLIPIER CHANNEL NO.AfINCHESI FIG. 9. Equivalent circuit of the for channels 7 to TT -20AH ['CINCHES) ¡WAVELENGTH 2 121 3 10I 5 9314 175 77 64 5 141 45 741- 6 125 29 698 25 IO31%- Amplifier 13. Table and sketches showing length of line between driver and 25 kw amplifier and several ways of running the line to obtain the correct length. FIG. 10. cuit be 60 megacycles between half power points. On channel 2 this is equivalent to having a Q of 1 which is obviously an impractical condition. It is necessary, therefore, that the input circuit of the amplifier must be a part of the driver output circuit. On the low channels it is not only important that the length of line be kept short but the effective length of line should be in approximate multiples of % wavelength. Fig. 10 gives a table of the recommended length of line for the low band channels. This line does not necessarily have to be straight but can have a right angle bend or a 180° fold as shown in the two bottom views in Fig. 10. Performance A summary of the performance specifications is shown on the next page. When the TT -25AL or the TT -20AH amplifier is used with the TT -5A the overall performance will meet all the RTMA and FCC requirements. The overall linearity curve is shown in Fig. 12 and the linearity curve for the input signal is shown in Fig. 13. From these two curves we have plotted the linearity of the amplifier alone. This is shown in Fig. 14. It will be noted that the amplifier introduces almost negligible amplitude distortion except in the sync region where it can be easily compensated for by the sync stretcher in the TT -5A. 175A T T2 S AL Overall frequency response of the Driver. Measurements were made on channel FIG. 11. 7 TT25AL Transmitter including the TT -5A with the side band response analyzer. TT -25AL 2 TS FtG. 12. Overall linearity curve of the TT-20AH including the TT-SA driver. A typical overall frequency response curve without a sideband filter as viewed on the sideband response analyzer is shown in Fig. 11. Note that the response at 4 mc. is considerably better than the 4 db limit proposed by the RTMA standard. Performance Specifications* Type of Emission: Aural Visual A3 A5 Frequency Range: TT -25AL TT -20AH Channels Channels Power Output: TT -25AL Aural 2 -6 7 -13 Visual FIG. 13. Linearity curve of the TT-5A driver made under the same conditions as those of Fig. 12. ***2 db at 0.5 2 db at 1.25 2 db at 2.0 2 db at 3.0 3 db at 4.0 Power Line Requirements: Voltage Phase mc mc mc mc Ambient Temperature: +10° +45° Minimum Maximum 208/230 3 Frequency 60 cycles Instantaneous Regulation +3% Slow Time Drift +5% Power Consumption (approx.) 60 kw (with black picture) (Conversion Equipment only) Power Factor (approx.) 0 90 Exhaust air recommended for cooling, aural and visual amplifiers only, each 2000 cf m.t * The overall performance of a TV Transmitter using a TT-25AL or TT -20AH Ampli- fier is necessarily dependent upon and governed by the performance of those portions of the transmitter preceding the amplifier. ** For pre-emphasized response, the preemphasis filter (MI- 4926 -A) may be inserted in the 600 ohm audio input at the most effective point. * ** Maximum variation with respect to the idealized rectified vestigial sideband response. These are overall limits when the amplifier is used with the TT -5A Television Transmitter. t Air ducts from the top of each amplifier are recommended. The above figure is based on a duct with approximately four square feet cross section. Operation without ducts requires considerably more air movement. SYNC PEAR 22RW PEAR OUTPUT 100 kw from sideband filter i Aural Visual BLACK LEVEL 75 TT-20AH 10 kw FIG. 14. Linearity curve of th e amplifier only. The curve was plotted by comparing Figs. 12 and 13. 20 kw from sideband filter ós0 é 25 R -f Output Impedance 51.5 ohms WRITE LEVEL Frequency Response: Aural 25 100 50 O75 INPUT VOLTAGE/ * *Uniform -!-1 db LINEARITY CURVE TT20AM AMPLIFIER ONLY 30 to 15000 cy. 72 www.americanradiohistory.com C mc 12.5 kw Visual....25 C Field Engineering Service to Broadcasters... AM, FM, TV /IIJTTIJuhLy Ulf 444 PAGES RCA Service Company engineers are experienced in all the latest techniques and are equipped with the most modern specialized measuring equipment. The RCA Service Company has been working hand in hand with the nation's broadcasters for over 25 years. OUR SERVICE TO BROADCASTERS . . . Installation supervision and measure. merits of transmitting, studio and FM . . . AM, accessory equipment or TV. Instruction and tr g of station op- erating personnel. Measurement and curves on FM and TV antennas and accessory equipment, including transmission lines, matching networks, diplexers. Prompt help in emergencies. Technical advice, service, and assistance on special problems. Performance measurements and adjustments for station compliance with FCC regulations. For further information call or write Communications Service Section, RCA Service Company, Inc., Camden, N. J. (For .serr ire outside the l'. S. A.. consult your Authorized RC.4 Distributor) NOW- restore the original quality of your RCA micro- phones, transcription pick -ups and test and measuring equipment under the new Factory- Reconditioning Plan. For complete details, write: Return Apparatus Control, Building 11-1, Camden, N. J. OF TV TECHNICAL DATA . Al1TIIORITATIVE An up -to -date reference for the television station engineer or planner. Provides complete coverage on television equipment, its operation and maintenance. Contains complete descriptions, schematics, floor layouts, and illustrations that add clarity to the topics covered. Extensive, new material on UHF! Used as a basis for successful RCA Television Broadcast train- ing sessions, this reference has Typical of . . COMPLETE earned the approval and acceptance of many Broadcasters. It's a "must" for any TV library, and will enable you to effect appreciable savings by knowing how to properly plan, what equipment to buy and how to get the most out of your equipment. with payment of eight dollars direct to E. T. Griffith, RCA Engineering Products Commercial Service, Building 15 -6, Camden, New Jersey. Your RCA Training Manual will be promptly mailed to you. Send orders the wealth of engineering information on television which the RCA Manual contains, is the spread il- lustrated Floor here. plans, schematics, circuit diagrams, and theoretical illustrations are included. RCA Service Company, Inc. A Subsidiary of the Radio Corporation of America CAMDEN, NEW JERSEY 73 RECTIFIER TABE Projection from high- uoltage ouerloads resulting from grounding stick shorts By MAL MOBLEY, JR. Field Supervisor Radio Station KMPC Los Angeles, California Summary A simple means of protecting rectifier tubes against excessive overloads resulting from grounding stick shorts has been devised, insuring against premature arc back and subsequent program interruptions. The KMPC transmitter plant utilizes both RCA 10E and 50F transmitters. These transmitters are equipped with the usual safety devices such as door interlocks, high -voltage grounding relay, and grounding sticks in the power amplifier, modulator and high -voltage rectifier bays. As an added safety precaution, grounding sticks have been added to all other units where high voltage is present, such as in the 50F exciter bay and in the transformer vault. The use of grounding sticks upon entering high- voltage bays are important to the safety of the operating personnel, but on occasion have proved detrimental both to the operation and to the longevity of the high -voltage rectifier tubes. For example, during testing or work on the transmitter following a carrier failure, occasionally a grounding stick is left shorted across the high voltage. Consequently, on application of plate voltage, a direct short to ground places an excessive overload on the mercury vapor rectifier tubes, thereby reducing their expected tube life and possibly resulting in an additional delay in restoring the program. Mercury -vapor rectifier tubes, such as 857B's, will withstand a considerable overload under normal operating conditions, however, as the tube ages, its ability to withstand overloads lessens, and arc backs become more prevalent. 74 Experience with 857B rectifier tubes used in KMPC's 50F transmitter over five years of operation has indicated that premature arc backs and tube failures can be indirectly attributed to excessive overloads caused by grounding stick shorts. In an effort to increase rectifier tube life, but maintaining rigid safety precautions set forth in KMPC's operation, thought was given toward a means of providing rectifier tube protection and main- taining the usefulness and protection of the grounding sticks. This problem was resolved by devising a series of grounding stick switches in such a manner that, if any grounding stick is left off its hook, a micro switch in series with the door interlock circuit will be actuated, preventing application of plate voltage, thereby offering protection to the rectifier tubes. KMPC Engineer, Tom Crosnoe is shown at BTA -50F High.Voltage rectifier bay demonstrating a lever actuated micro switch which provides protection against accidental grounding switch shorts. CAV TION! USE GROUNDING STICK The grounding -stick switches were assembled from surplus aircraft parts consisting of normally open micro switches, lever -type actuators, aluminum junction boxes, lead hookup wire and some ingenuity. The lever -type actuators were modified, installing hooks for hanging the grounding sticks which have sufficient weight to actuate the switches. The switches were wired into the transmitter door interlock circuit, as this was both convenient and effective, since the door interlock switches in the 50F transmitter are in series with interlock relay 6E7, which is in the control circuit, preventing application of plate voltage unless all door and grounding stick switches are closed. Transmitter and console interlock-indicator lights are also actuated, giving a visual indication of whether the interlock circuit is completed. The photo shows a grounding -stick interlock-switch installation as installed in the high -voltage rectifier bay of KMPC's S0F transmitter. This is a typical installation of those made in other units of 50F and 10E transmitters. In conclusion, it is felt that the addition of this protective circuit will increase rectifier tube life, with added assurance against arc backs and resulting program interruptions. TH HT 1S YOUR forced -air cooled tube ... still a favorite a gleam cooled tubes were just minBack when forced-air of 5 gallons of water in our eye, it took upwardsof this class. Today, i's done tube in mainute to cool a power greater convenience entirely with air. Benefits: tenance and operation. le of RCA's is only one example Forced -air cooling the best in modern you bring to efforts for your on RCA quality tubes tube design. Insist station operations. I tubes can supply Your RCA Tube Distributor time. Call himl minimum in station for your FIGHT INFANTIL[ MtALY91t NI NATIONAL FDUNDATNIN OR INMNTIIt PARALYSIS FRANKLIN D. RDOftYtLT, FtRM\ RADIO CORPORATION ELECTRON TUBES of AMERICA HARRISON, N. J. 75 www.americanradiohistory.com Good-bye'. 11 .s0.1: OVE Annoying "Roll- over "-starts up in TV sets when you mix remotes with locals Good -bye "Roll-over "! The RCA TV RCA's TV Genlock TG -45 ends picture slipping when you "lap dissolve" and "superimpose." Now you can lock two entirely different programs together -remote or local -and hold pictures steady right through switching! No manual adjustments of phasing to fiddle with. No extra equipment needed at remote pick -up points. Here's how the GENLOCK works. Located in your main studio, this simple unit compares the signal of your remote sync generator with the signal of your local sync generator. The difference in the phasing of the pulses produces an "error" signal which locks your local generator as a "slave" to your remote generator as a master. This enables you to treat remote signals as local signals -and switch back and forth without picture "roll- over," no matter where your program originates! The RCA GENLOCK is simple in design, completely automatic in operation-"locks-in" much faster than you can switch. It fits any standard 19-inch TV rack. Give your programming a lift. Switch as you please between programs for variety and for special effects. It's easy with a GENLOCK. For more information call your RCA TV equipment representative. Or write Dept. 19AE, RCA Engineering Products, Camden, N. J. . Z tightly locks your local and remote sync generators together -instantaneously and automatically. GENLOCK This is the simple, automatic system that electrically locks two separate television pick-up systems together. RCA GENLOCK, Type TG -45. TELEVISION BROADCAST EQUIPMENT RA®/® CORPORATION of AMERICA ENGINEERING PRODUCTS DEPARTMENT, CAMDEN,N.J. In Canada: RCA VICTOR Company Limited, Montreal www.americanradiohistory.com 1-"P VI" ot levision St ns in Latin Ame 'ca, RCA Equippe jeft New Transmitters add millions to audience of TV- the New Teacher ONE YEAR AGO there were five television transmitters supplied by RCA in operation, or on order, in Latin America. Today nine are completed or planned for early inauguration, all RCA equipped. These are: three in Mexico; three in Cuba; two in Brazil; one in the Dominican Republic. RCA is First in Television in the U.S.A.... and in all the Americas. RCA welcomes creative video talent around the world ... as Television the New Teacher helps to advance educational programs of nations both old and new. Your RCA Distributor will be glad to keep you fully informed on RCA television, or write the RCA International Division. First in Radio - RCA I First in Sound Television receivers embody the experience of over 2,000,000 instruments in use in the U.S.A., Canada, and Latin America. RCA - World Leader in Television NATIONAL DIVISION RADIO CORPORATION of AMER/CA RCA BUILDING 30 ROCKEFELLER PLAZA, NEW YORK, N.Y. U.S.A. 77 a rF:, AIqF ppOhTS X. ,NSFORMERS Ts IOX, NOTE._ ALL WEIGHTS ARE APPROX. 500 www.americanradiohistory.com LBS THE drawings spread across these pages are layouts Typical 2 -kw TV station layout for VHF (ERP range, 2 to 20 kw) A low -cost arrangement for getting up to 20 kw ERP with an RCA high -gain antenna. The installation includes: an RCA 2 -kw transmitter, control console, trans- mitter monitoring equip- ment, audio equipment, sync generator, video equipment, and power supplies. of typical TV transmitter rooms using RCA equipment. They are prepared expressly for TV station planners in accordance with the best engineering practice known today. Each plan represents the basic or minimum TV transmitter room equipment needed to get "on the air" for a specific power. Each indicates the approximate space needed for the equipment including approximate weights of individual units. Each provides wide flexibility for equipment rearrangements to meet the special or future requirements of individual stations. "Ready -to-use" plans like these are just one of RCA's many television services now available to you through your RCA Sales Representative. For a complete engineering analysis of your station requirement;, call this expert. He can show you exactly what you will need to get "on the air" for a minimum investment. - Effective radiated power ENGINEERING PRODUCTS DEPARTMENT CAMDEN, N.J. Radio beams Radio beams never ice. The invisible beam of the RCA Microwave system can provide reliable communication channels through ice storms, lightning, wind, sleet and even amid falling trees. Repeater stations, usually built on hilltops, spanning distances up to thirty -five miles, provide signal paths over mountains, rivers, swamps and rolling countryside. Each station picks up microwaves from its neighbor and focuses them like a searchlight at the next station. RCA Microwave systems eliminate pole lines, simplify right -of-way problems, eliminate line maintenance expense and cost ice! locations which are inaccessible for periods of several months. Are you missing a bet on RCA Microwave? It is being used by power and light companies, telegraph companies, highway commissions, game commissions, pipeline companies and many others. RCA Microwave is quick and easy to install. If you need reliable communications that can span long distances over any terrain and through all kinds of weather, let an RCA engineer survey your situation. Find out how RCA Microwave can Designed for unattended operation, help solve your communication problem. Investigate today. RCA Microwave can be installed at You'll find RCA Service Ens' leers with U. S. Air, Land and Sea Forces. less per mile than any other type of system with comparable communication facilities. RCA Microwave with its "multiplexing" system can do many other things than provide two-way voice communication. RCA Microwave can provide for remote control of switchgear, telemeter ing (transmitting pictures of voltage, current, power and pressure meter readings), teleprinter, facsimile and many other services. RADIO CORP RAT/ON of AMER /CA ENGINEERING PRODUCTS DEPARTMENT, CAMDEN, N.J. It plays -45's, 331/3 fine- grooves', 33'/3 standards', 78 standards' l.t.o The All -New RCA Pick -up and Tone Arm installed on a 70 -D turntable. t `1 r PICK-UP... one arm, all speeds! RCA's All -New Tone Arm -with magnetic lateral plug -in heads -fits all standard turntables. Only two heads are needed for all speeds. ... This versatile pick -up and tone arm combination installed on your turntable ... can play every record and transcription in your library. Just plug in the head for the right record groove -and spin the platter. It's as easy as that. Designed for studio- quality at all standard speeds, this unique system has outstanding features over previous types. For instance, plug -in magnetic heads need no adjustments for stylus pressure. Vsibility of the stylus (from the top of the head) permir accurate groove-spotting. AUDIO E Anti-friction pivots and low inertia provide easy tracking on eccentric and warped records. Lower weight assures better record service -longer stylus life. Tracking error of the arm is less than 4 degrees. Arm assembly MI -11885 is complete with tone arm, mounting plate, hardware, and the filter modification kit MI -11874 (for 70-series turntables). You use plug -in head MI -t 1874 -4 with the -mil stylus for fine -groove records. You use plug-in head MI- 11874 -5 with the 21/2-mil stylus for standard transcriptions and 78 rpm records. Order from your RCA Broadcast Sales Engineer, or direct from Dept. O -7, RCA Engineering Products, 1 Camden, New Jersey. )AD CAST EQUIPMENT RADA.. CORPORATION of AMER/CA ENGINEERING PRODUCTS DEPARTMENT, CAMDEN, N.J. In Canada: RC A VICTOR Company Limited, Montreal 2.1623. www.americanradiohistory.com --111ENIK11 BRQADVIST NEWS ISItijilDVIST NEWS BMWS? 111110.446MMIIILMP±iilla NEWS IIMIDANST NEWS BIRWIDVIST NEWS BRO4INIST NEWS k/fr a e RCA an." umpaor, t s 111.11111111111111111 N SWAMI IKAVMs. kt I tar lorep.n411, (*v.,. llterge Ce.inak, km. Corisol. I , 14/ .1.. -411111111111L - BRowsT NEWS ISITADIAST NEWS BROADVIST NEWS lawfavisr NEWS BROIDVIST NEUS Nmcior, t\ ICA kin* (oo.d.t. Altalor laa -31110=IMINA RIZOKIST NEWS RI Aare.. Caomponlwa... Camilos .1 SC as , REWS BROADCAST REWS BROADCAST RE1115 BROADCAST BRUADOST NEWS BRU It LW Uri .. o Ito PRono CJITT iTup BRaill1Ç Blom Has BROADCAST 11E115 EIRNOCAST flET5 I -- ST 11EILIS 5 BROADCAST fl 6