A Review of Philco's Television Progress
Written by E. N. Alexander
Program Manager, Philco Radio & Television Corporation
(This article was written in the first half of 1941)
(W3XE operated from Philadelphia and is now known as KYW-TV)
Shortly after the false boom in mechanical television in 1926 and early 1927, the Philco Corporation decided to investigate this new communication medium. To pursue this investigation, Philco built and staffed the necessary experimental laboratories, studio, and transmitting facilities to receive from the Federal Communications Commission in January 1932, an experimental television broadcasting license and call letters W3XE. This was one of the first electronic television systems in the United States on the air and so licensed.
Philco's television broadcast experience might well be considered a record since, from 1932 to date (1941), it has operated W3XE and its associated relay transmitter W3XP, a total of almost 6,000 hours.
In its authorization of commercial television, the Federal Communications Commission has prescribed a minimum 15 hour broadcast week. Our log of almost 6,000 hours on the air, on that basis, would total over seven years of continuous operation.
Naturally, only a small portion of these transmissions were of entertainment programs, since the period of 1932 to 1939 was dedicated to research, experimentation and development to and in determining acceptable television standards. Since the readers...are drawn from all branches of the radio industry, perhaps some of the outstanding developments and contributions to the art of television resulting from this program of research would be of interest.
DC Transmission - Seven years ago, we developed the transmission of DC components in television pictures. This development enables the transmitting operator to have complete control over the range of tones in the reproduced picture. This conception has subsequently been adopted by the BBC in England and the American television stations.
High Fidelity Picture Transmission - We have endeavored constantly to obtain the highest order of fidelity in television. As a part of this program, we sponsored the 6-mc channel in an effort to achieve more than the 343 lines then generally believed acceptable. Philco was the first to transmit a 441-line picture. This was done in a television demonstration at the Franklin Institute, Philadelphia, in January 1937. This, however, did not satisfy our engineers. They have constantly experimented to achieve greater picture fidelity and are now pleased with the decision of the industry to employ better than 500 lines as the television standard for the United States of America. On May 3, 1941, the Federal Communications Commission of the United States approved 525 lines as standard. W3XE has been broadcasting experimentally on 525 lines since September 16, 1940.
Sesqui-Sideband Transmission - In addition to demonstrating the superiority of increased line structure for higher picture fidelity, we further advocated for the same purpose sesqui-sideband transmissions. As early as 1936, Philco initiated experimentation on sesqui-sideband filters. During 1938, we designed, built, and installed the first sesqui-sideband television picture filter and were first on the air with a successful sesqui-sideband program transmission. This development has made it possible to achieve higher picture fidelity within the allocated channels.
Ion Spot Trap - A few years ago, the most objectionable ion spot, the dark spot which appeared on picture tubes after short periods of use, had almost become an accepted limitation of these tubes. To remove this defect, our engineers developed a unique type of construction for the electron gun and tube. That annoying ion spot is now a thing of the past.
Flat-Faced Tubes - Another accepted limitation of the television picture was its so-called "onion" or bulbous shape. It was thought necessary to make the viewing surface of the tube convex so as to withstand the external pressure over the large evacuated volume. This shape, however, resulted in optical distortion of the picture as well as acting as a convex mirror to pick up extraneous light reflections from every direction in the room, regardless of the position of the viewer. Our research engineers believed that these disadvantages would be objectionable to the viewers. As a result, they developed the Philco flat-faced safety tube which, by virtue of its perfectly flat glass viewing surface, 5/8 inches thick, not only eliminated the optical limitations of its predecessor but, in addition, it has been found to be a tube of unusually safe construction.
Black and White Pictures - During 1935, green colored television pictures were generally considered satisfactory. Our engineers were of the opinion that black and white contrast was a primary requisite of the viewing public, and in February, 1935 they developed and demonstrated black and white television pictures of such outstanding merit that now most television pictures approach this black and white contrast.
Rectangular Tubes - Philco has originated and built rectangular-shaped cathode-ray picture tubes which accommodate a considerably larger-sized picture than the circular type, since they have less evacuated volume and are, therefore, less hazardous.
Television Transition Effects - To secure wipes, fades, dissolved, roll cuts, and other transitions commonly associated with motion picture production technique, our engineers invented new and improved mixing amplifiers for multiple television camera operation. These amplifiers permit the director of a television program to use the same transition effects that the movies have found so desirable to maintain continuity and to enhance interest. Application of this invention will aid materially in lending a smooth, "professional" appearance to television productions.
240-Mc. Transmission - In order to relay television programs from remote points to the main television transmitter for rebroadcast, we have successfully conducted a series of both test and program transmission on 250 mc. These tests, of course, cover transmitting and receiving circuits, apparatus and technique, and have emphasized the importance of these high frequency channels in future television work.
Frequency Modulated Sound - The Federal Communications Commission in their report of May 3, 1941, requires that the sound accompanying television broadcasts be transmitted by frequency modulation. Five years ago, our engineers developed an FM circuit which is now used not only in our television sound transmissions, but also in our FM radio receivers, with exceptionally good results.
Cable Transmissions - In conjunction with the remote program originations, we have conducted extensive research into the problem of transmitting video frequencies with fidelity by wire. Some of this work has been done in conjunction with the Bell Telephone Laboratories, and many experimental program transmissions have been made over a matched telephone-pair wire-link of considerable length. Further, Philco research laboratories have developed special balancing amplifiers to permit the use of long lengths of ordinary cable for the transmission of these frequencies on temporary installations.
The results of these studies will be most appreciated with the advent of numerous remote transmissions when television reaches a commercial basis.
Push Button Tuning - We have used push buttons for convenient, accurate tuning for the selection of television sound and picture channels since early 1938.
Built-in Antennas - As in standard broadcast receivers, Philco was early to develop and demonstrate a practical built-in antenna system for television receivers. The advantages of such a system are:
1 - The material reduction of diathermy, automobile and other forms of man made inference with a resulting improvement in the signal-noise ratio, by simply rotating the antenna control at the receiver and making use of its directional properties.
2 - The elimination of costly and unsightly outside television antenna structures in most cases where the receiver is located in a primary service area.
3 - A television receiver incorporating this plug-in-and operate feature is as moveable for cleaning or room rearrangement as a comparable radio model.
Natural Color Television - Considerable space has been given in the newspapers recently to the possibility of natural color television. We produced experimental color television more than three years ago. Many additional problems remain to be solved, but the solution of the problems is looked for in the years to come.
Synchronizing - Electrical and Mechanical Synchronizing Generator. in the belief that television pictures are no better than the synchronizing which holds them in position, during 1934 we instituted a comprehensive program to stabilize and improve synchronizing circuits. One of the first milestones of progress was the electro-mechanical synchronizing generator. At that time, the most reliable method known for generating synchronizing impulses was the mechanical disc synchronizing generator. We realized that in a system such as this minute inaccuracies were unavoidable. To remove these inaccuracies and improve the resultant synchronization our research engineers invented a combined electro-mechanical synchronizing generator. This electro-mechanical synchronizing generator has proved to be the logical step to all electronic synchronizing now accepted generally by the television industry.
Quenched Synchronizing - The next step in this program was the invention of the quenches synchronizing circuits. These circuits made the synchronizing oscillators insensitive to extraneous or static pulses except at the time synchronizing pulse was expected. This resulted in the most stable synchronizing pulse then conceived.
Noise Discriminating circuits - Noise discriminating circuits are noise gates, as applied to the synchronizing pulses, were then produced. The increase in effectiveness in the synchronizing pulses resulting from the use of these circuits has been generally realized as shown by the use of these circuits today.
Automatic Synchronizing Control - Realizing that synchronizing oscillator systems are cumbersome, costly, and difficult to generate manually, and that a minimum number of controls would be welcomed by the public, pioneering was done in the field of automatic synchronizing control. Field tests of this system have proven most satisfactory.
Narrow Vertical Synchronizing Pulse - Another type of synchronizing improvement developed by Philco was the narrow, vertical pulse which, because of the definite distinction made between the horizontal and vertical pulses, made these pulses more readily distinguishable at the receiver.
Alternate-Carrier Synchronizing - these synchronizing studies led to the development of alternate-carrier synchronizing. This system uses synchronizing pulses on an alternate transmitter carrier higher in frequency than the picture carrier. This alternate carrier is only present for the duration of the synchronizing pulse, and replaces the picture carrier which is present at all other times. Actual field test measurements of this system show a five times increase in synchronizing signal from the same transmitter power. This development, we believe, will extend appreciably the effective service area of any television station, enabling trouble-free reception in areas where the picture was formerly destroyed by static form such everyday devices as vacuum cleaners, kitchen mixers, electric razors, doorbells, and automobiles. We are, therefore, proposing that this synchronizing method be adopted by the industry as standard.
Broadcasts - In October 1939, Philco decided that a necessary adjunct to their program of technical research in television was the production of a regular schedule of television program broadcasts, and continuous broadcast program research. The objectives of this plan of program research were as follows:
1 - To make immediate use of our existing television studio and motion picture facilities to determine the adaptability of this equipment to a commercial television broadcast service.
2 - To alter, adapt, and build such new equipment as would be found necessary to carry on the above program.
3 - Coincidentally, to conduct a program of research to determine types of broadcast program material, video effects and production techniques most suitable and acceptable for this new medium.
Since this program was inaugurated, a total of 488 program hours have been televised - starting on the basis of two program hours per week, gradually increasing the total number of hours per week to five until, from March 15, 1940 to date (1941), Philco has maintained ten hours of programs each week the transmitter was available.
This total of 488 hours was made up of these main classifications of program material:
Studio Programs - Under this classification, Philco has produced practically every known type of program adaptable to the television studio including:
Variety: running the gamut of night club, vaudeville, and musical comedy acts.
Drama: with such well-known stage successes as "Family Portrait," "Fresh Fields," and "Kind Lady," as well as a host of material including one-act plays, serials, and original scripts adapted to television.
Women's Programs: including Beauty Contests, Fashion shows, Beauty Culture and Make Up and Interior Decoration.
News Programs: with world-famed war correspondent and Philco News Commentator, Frazier Hunt.
Educational Programs: such as scientific demonstrations, Hobby Shows, Arts and Crafts, and programs of historical interest.
Plus: Music Programs, Operas in Miniature, Political, Children's Programs and programs of religious interest.
Motion Pictures: include the televising to date of 1,578,150 feet of film, including both feature pictures and short subjects.
Remote Television Broadcasts - Our remote television broadcasting activities date back to the televising of the Republican National Convention, June 24 to June 28, 1940. At that time, Philco engineers installed on ultra-high frequency relay transmitter, W3XP, atop Convention Hall, in Philadelphia (where the convention was held).
This transmitter has proved to be the keystone of subsequent remote activities. Video signals, from several points of origination, have been piped to this relay transmitter, radiated to the main transmitter and thence rebroadcast. The highlights of these programs follow:
Football Telecasts - During the Fall of 1940, we undertook the project of televising for the first time in history, a complete schedule of major college football games. This effort took place at historic Franklin Field of the University of Pennsylvania, from October 5 to November 23, 1940. The schedule of home games was unusually heavy, due to the University of Pennsylvania Bicentennial Celebration, which was running currently. The schedule of the total of the seven games is as follows:October 5 - Penn vs. Maryland
October 12 - Penn vs. Yale
October 19 - Penn vs. Princeton
November 2 - Penn vs. Navy
November 9 - Penn vs. Harvard
November 16 - Penn vs. Army
November 23 - Penn vs. Cornell
Concurrent with the technical discoveries and developments made possible by the experimental broadcast of these games, and program staff conducted extensive research to develop a commercially desirable program technique. The research naturally included the attack of such fundamental problems as camera placement, angles, and lens complements. In addition, we sought the solutions to the problems of developing an absorbing program continuity, the relief of the many slow and inactive visual portions of the game, circumvented in radio by "color" commentating, and the conception of a production technique to enable the welding of the many elements into a complete, unified, entertainment program.
To fulfill the above, many production devices were originated, including a pre-game visual analysis and comparisons of teams, a camera-announcer "color" technique, a unique and all-inclusive television scoreboard and gridiron chart for recapitulation of the plays, as well as a complete, graphic, check chart to make all necessary information available to the television announcer at a glance.
In order to produce maximum enjoyment of these programs, 3 television cameras were used, 2 for the variety of shots originating at Franklin Field, and the balance at the Philco Live and Projection Studios for the origination of the various devices and effects discussed.
Remote Arena Broadcasts - At the close of the 1940 football season, we installed in the Philadelphia Arena (46th & Market), the necessary platforms, cameras and associated television equipment to televise from this source the variety of events it afforded. During the period December 21 to the present (1941), we originated from the Arena an impressive number of sporting events, including tennis, ice hockey, wrestling and boxing. In addition, such outstanding entertainment highlights as "The Ice Carnival" and "The Ice Follies of 1941" were televised.
Mummers' Parade - For years, the world-renowned Philadelphia Mummers' Parade has been a "must" on the entertainment menu of hundreds of thousands on the Eastern seaboard. Heretofore, it was traditional to literally freeze while witnessing this event. This was, of course, before the advent of Philco television. On January 1, 1941, for the first time in history, Philco televised in its entirety this northern counterpart of the New Orleans Mardi Gras. Those fortunate Philadelphians who possessed television receivers relaxed in the comfort of their own homes while the magic of the television camera gave them, in effect, grandstand seats as the parade, complete with shooters, comics, fancy capes and costumes and string bands, was brought direct to the screens of their television receivers.
We also originated many other remote television broadcasts, including such noteworthy events as the Philadelphia Sportsmen's Show and the University of Pennsylvania's 47th Annual Relay Carnival.
Other Pertinent Facts - Philco equipment at present includes a total of 8 television camera and associated equipment used as follows:
3 Studio cameras
2 Movie cameras
3 Remote cameras
Six of these cameras are of the Iconoscope type. Two of the three used on portable work are Orthicons.
Our television facilities include a fully equipped television studio with associated control room, engineering laboratories, special effects and sound effects laboratory, scene shop, offices, dressing rooms, and viewing rooms, and one truck and one station wagon. In other words, it is a complete plant.
The television research, engineering and program staff's total more than 50 people with an unusual complement of talents, from script writer to glass blower, from program director to research engineer.
W3XE's sound and picture transmitters now serve a radius of approximately 25 miles from the transmitting town, 230 feet high. Reception has been reported as far as 40 miles in unusual instances. In the near future, Philco plans to increase this power in order to supply a much greater service area.
Our television experience dates back to the inception of electronic television. Our progress has been steady and its accomplishments numerous, and now with the advent of commercial television, we are ready to take our place as a pioneer and leader in this new industry as we have in many other fields of endeavor.
From the official archives of the Broadcast Pioneers of Philadelphia
Article originally donated by Norm Gagnon and the GGN information Systems Website
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