1942: Television

Effect of War.

In 1942, television as a public service made few advances. Shortages of trained men and materials forced the industry to mark time, pending the end of the war. So urgent were the needs of the war economy, in fact, that the FCC permitted a reduction in the service rendered by commercial television stations from 15 to 4 hrs. per week. The effect of this order was to release transmitter operators and engineers for war duties, and to conserve the life of transmitting equipment particularly high-power transmitting tubes, which were virtually unobtainable except for war purposes. The transmitting tube situation was felt also in conventional sound broadcasting. In this field, the FCC ordered a 25 per cent reduction in transmitter power and permitted a considerable increase in harmonic distortion, in the interest of extending the life of transmitting tubes.

The reduction in the required number of hours was met by retrenchment of the part of the television broadcasters. One station in New York, WNBT, restricted its output to air-raid warden instruction courses and films. Another in New York, W2XVW, broadcast on Sunday only, but offered a consistently entertaining variety program, making use of many performers formerly seen on other stations. In Philadelphia, WPTZ broadcast local football games. In general, each station met the minimum requirements as best it could, but the program fare was not calculated to rivet the attention of the viewing audience. The size of the audience remained static, since no television receivers were produced in 1942, and very few sold from dealers stocks.

Behind the scenes, in contrast, there was a high degree of activity. Hints began to appear in the press of the important role now being played by television circuits, equipment and techniques in the prosecution of the war effort. Virtually all men trained in the design and use of television gear had been absorbed by the armed forces and their contributory civilian laboratories. National advertising campaigns appeared, glorifying the term 'electronics' and promising great things to come, chief among them a national television service.

Post-War Development.

The attention of all, industry and public alike, was thus directed to the future. That television would receive a concerted impetus at the end of the war was certain. The only question was the form the service would take. Here opinion seemed agreed that the service would resume as it left off, provided that the war ended in 1943 or 1944. If the fighting continued for a much longer period, it seemed likely that the present television service would come to a complete stop, and that technical developments for the war would so advance the art, that an entirely new service would be possible and economically justified. Such an eventuality might mean the scrapping of the present standards of transmission (formulated by the National Television System Committee in 1941 and adopted by the FCC just before our entry in the war).

There were doubts, however, that the standards could undergo any basic modification, in view of certain technical facts. Improvement of the television service, that is, improvement of the basic pictorial detail of the image, is possible only if a larger portion of the ether spectrum is utilized by each broadcast station. If the available ether space is limited, the future of the art thus resolves itself into a contest of quality vs. quantity. A few broadcast stations may serve a restricted audience with pictures of high quality. Or a large number of stations may serve a larger audience (with the benefits inherent in competition) with pictures of proportionately lower quality. The compromise adopted in the present FCC standards is a picture of approximately the quality of 16-mm. home motion pictures, available on 18 channels which may be duplicated at intervals of approximately 200 miles. In the crowded East this situation restricts the program choice in a given large city to 3 or 4 stations, less in smaller cities. Thus television service is severely restricted compared with sound broadcasting in which 10 to 15 program choices are available in comparable large cities.

If the detailed quality of television pictures is to be improved (and this is the principal justification for a change in standards) fewer stations can be accommodated, unless more ether space can be found. It seems very unlikely that a reduction in the number of stations is justified, since the quality of the pictures is already capable of an acceptable home service. But if more ether space can be found, and made available for television, then improvement is possible and justified.

The extension of the ether spectrum into the higher frequencies just above the present limit of the television channels has been vastly accelerated by the war. Generation of high power on such high frequencies, once difficult, is now more readily accomplished. Simple antenna structures for transmitting and reception have been developed. The sensitivity and ease of tuning of receiving equipment has been improved. So far as apparatus is concerned, the stage is set. But as waves of higher and higher frequency are employed, their suitability for broadcast service becomes less. Particularly in large built-up cities, the higher frequencies (even frequencies now assigned for television service) are intercepted and reflected by tall buildings to such an extent that truly broadcast coverage of the community is difficult if not impossible. In small communities, built on level ground with low buildings, not constructed of steel, the higher frequencies can be used, but in the centers of large population their utility is doubtful. Engineering surveys of the coverage possibilities of the newly available high frequencies must be conducted before the issue is finally decided. See also RADIO AND ELECTRONICS.

1941: Television

In 1941 television took a stride forward when the Federal Communications Commission approved standards for commercial broadcasting and for the first time permitted television stations to operate on a commercial basis. Television was thus put on an even footing, so far as government sanction goes, with standard broadcasting. This long-awaited event followed many months of work on the part of the National Television System Committee, a group of 168 specialists formed in 1940 to investigate the questions of standardization for a commercial television service. On March 20, 1941, this group appeared before the FCC and recommended the adoption of 22 specific standards, on which substantially complete agreement had been reached. On May 3, 1941, the FCC announced the approval of these standards and issued an order permitting the operation of television stations, under these standards, on and after July 1, 1941, on a full commercial footing.

Coincident with this order, the Commission issued rules governing the operation of commercial television stations which set the pattern under which the new art is expected to progress. Each commercial station must maintain a program service 15 hours per week, including at least two hours between 2 and 11 p.m. each day except Sunday, and one hour five days a week between 7:30 and 10:30 p.m. The commercial licenses are issued for a period of one year, but no individual or organization is permitted to own or control more than three stations. This latter ruling arose from the limited facilities available in the ether. A television station occupies an enormous path in the ether spectrum, fully 600 times as wide as that required for a standard sound broadcast station. Despite this fact, room was found for 18 commercial television channels, in the ultra-short-wave region between 50 megacycles and 294 megacycles (wavelengths of 6 and 2 meters, respectively). Since the range over which a station can create interference with other stations is limited to about 100 miles under normal conditions, these 18 channels may be reassigned for simultaneous use at intervals across the country. Hence hundreds of television stations can be accommodated, but the number in any one city is necessarily limited.

Under the new FCC rules the commercial stations were permitted to engage in experimental activities, provided that suitable identification of the experimental nature of the program is made. In fact, the Commission definitely requires each station to submit reports on tests on two important phases of the art: color television and the synchronization of the received image with the image in the studio.

In addition to this list of commercial stations, the Commission had licensed, as of Oct. 1, 1941, 43 experimental television stations, several of which were operating with occasional programs for the public.

N. T. S. C. Standards.

The standards officially adopted for the use of commercial television stations, drawn up by the National Television System Committee, differ from the standards previously in general use in two noteworthy particulars. According to the new standards, the television pictures are composed of 525 horizontal lines, each of which is composed of the variations in light and shade which constitute the picture content. The 525-line figure represents an increase from the previous value of 411 lines used by the majority of experimental stations. The increase in the number of lines permits a proportional increase in the amount of pictorial detail which can be accommodated in the vertical dimension of the picture. But the total amount of pictorial detail in the picture, measured horizontally as well as vertically, is fixed by the width of the ether channel assigned to the station. Since this channel width remains unchanged (at a width of 6 megacycles) in the new standards, the total pictorial detail is unchanged, and the increase in the detail vertically is accompanied by a decrease in the detail horizontally. The net result, however, is a better balance of the detail in the two dimensions, so that the overall effect is noticeably better. The increase in the number of lines also makes the line structure less visible to the viewing audience.

The second change of importance in the new standards is the use of frequency modulation for the sound program which accompanies the picture. Frequency modulation (see RADIO) is a system of sound broadcasting on the ultra-short waves which has proved capable of transmitting sound with greater freedom from distortion and interference than is possible with the conventional amplitude modulation system used in standard broadcasting. The frequency modulation specifications adopted for the television sound are the same as those used for commercial f-m broadcasting. Hence the same circuits which receive the sound in a television receiver may also be used, merely by providing an additional tuning range, for the reception of f-m sound broadcasting. Thus economy is achieved in the production of combined television-fm receivers, which, it is believed, will be the type most widely used by the public.

Other differences appear in the new standards, for the most part deeply rooted in the technical operation of the system. One potential improvement is the achievement of much more stable reception of pictures at a distance from the transmitter, when the received signal is weak. The synchronization of the received picture is often disturbed by interference from electrical appliances and passing automobile ignition systems, in such outlying locations. The use of frequency modulation to improve the synchronization was under active investigation during the year. The use of the f-m signal does not require radical changes in existing receivers, and in fact many receivers will operate with it without any changes whatsoever.

The limiting distance of television transmissions, while subject to some improvement by the system just mentioned, is still limited by the fact that the television signals are intercepted by the horizon. The signals bend slightly around the curvature of the earth, but their strength is rapidly diminished in the process. The reliable range of television stations is thus about 30 miles, for a low-powered transmitter with a transmitting aerial of moderate height, to about 60 miles for a powerful station with its aerial located on a skyscraper or mountain top. With exceptionally good receiving conditions, reception up to 100 miles is possible, but beyond this the pictures can be viewed only under exceptional conditions of the atmosphere.

Programs.

Two stations in New York and one in Philadelphia have maintained extensive program schedules throughout the latter part of the year. The most comprehensive and varied program fare was offered by station WNBT, operated in New York by the National Broadcasting Company. This station broadcast a number of sponsored programs, including regular time signals (a clock face displayed between programs), daily weather reports in cartoon form, fashion shows sponsored by department stores, and a regular program of professional wrestling, sponsored once a week by a hat-manufacturer. The size of the audience remained small, roughly 6,000 receivers, and the potential audience even for a program of major importance was probably not larger than 30,000 persons.

Among the notable telecasts were several showing refugee children telephoning to their parents in England. These programs were broadcast over the national networks and were accorded a high degree of interest even when reproduced by sound alone. With the aid of the television camera, which recorded the facial expressions of the children, the emotional appeal was greatly enhanced.

Sports continued to occupy a basic place in the schedule. During the summer regular broadcasts of the professional baseball games between the pennant-winning Brooklyn Dodgers and other teams in the National League were broadcast from Ebbets Field. All of the collegiate football games played at Baker Field, the home field of Columbia University, likewise went before the cameras, and professional football was available nearly every Sunday during the Fall. Horse racing from Belmont Park and Jamaica, intercollegiate basketball and professional hockey from Madison Square Garden, water meets at the New York Aquacade, the Eastern Clay Court Tennis Championships, the Soap Box Derby at Riverdale, were typical events.

Interest in the War in Europe and the Pacific was reflected by a regular weekly feature 'The Face of the War,' in which Sam Cuff brought noted correspondents into the studio, and with the aid of maps and charts, outlined the events of the preceding week.

Station WCBW, the Columbia Broadcasting System station in New York presented an extensive schedule of programs. Question bees, country dances, analyses of sports, stories such as 'Around the World in Eighty Days' dramatized serially for children, and variety shows featuring well-known vaudeville artists, were among the programs offered by this station.

The programs also contained occasional motion picture films. Many of these, particularly travelogues, were highly interesting, especially when the traveler who made the films was present in the studio to offer accompanying comments on the film. But 'feature' films of the entertainment variety were generally of poor grade, showing that the film producers in Hollywood and the television broadcasters had not yet worked out a cooperative understanding.

Receivers.

No new receivers were offered to the public during 1941, due to the effect of the War. Essential materials, particularly aluminum, and component parts, including cathode-ray tubes, were unavailable due to priority ratings. The majority of the technical personnel in television, outside the broadcasting stations, was transferred to defense activity during the year, so man-power to design and produce new receivers was not available. A small production of existing types of receivers was kept up by a few manufacturers, and receivers in the hands of the public were rapidly converted so as to receive pictures in accordance with the new transmission standards. This situation so limited the supply of television receivers that the audience remained practically static.

Technical Advances.

The principal technical advances of the year were those relating to the establishment of the new transmission standards. Since the lack of materials and manpower in the manufacturing companies prevented the design of new types of receivers, technical research was retarded in this field. The technical staffs of the broadcasting companies were, however, busy refining and improving the quality of the transmitted pictures.

One such improvement was the adaptation of the 'lap-dissolve' technique widely used in motion pictures. This consists of fading one picture into another, between scenes, so that both scenes appear simultaneously during the transition. In television the dissolve is accomplished by combining the television signals from two synchronized cameras, the signal being reduced in one camera by a control similar to the volume control in sound broadcasting, while the signal from the other camera was increased. The same method is used to display two images simultaneously when the occasion warrants. Thus, on the evening of the municipal election in New York, bulletins in the form of charts showing the voting returns were superimposed on the screen, during the broadcast of wrestling matches.

The experiments with color television were continued by several of the commercial broadcasting stations, including WNBT and WCBW in New York. The early transmissions announced in 1940 were limited to film subject matter, such as motion pictures and slides, but the technique was extended in 1940 to permit full-color transmission of studio scenes and outdoor pick-ups. The principal limitation in the use of color was a lack of detail in the pictures received, resulting from the fact that three separate images in the three primary colors must be sent in rapid succession, in the place of one black and white picture. The difficulties of maintaining correct color balance throughout the range from shadows to highlights were also evident, and the problem providing a simple and inexpensive receiver had not been solved.

Perhaps the most noteworthy technical contribution of the television art to the country's welfare was the accumulated experience of its engineers and technicians, who were turned over almost without exception to special problems in the defense organizations of the radio manufacturing industry. See also RADIO: Television.

1940: Television

Television in 1940 experienced a slackening of commercial activity, due largely to uncertainty regarding the adoption of standards of transmission, but from the standpoint of the programs broadcast and the technical advances announced during the year, the art made definite forward strides. Full coverage of the political campaign, including telecasts of the two major nominating conventions, rallies, and a vote-by-vote tally of the election returns, were available to owners of television receivers in the New York metropolitan area. Demonstrations of television transmissions in full color, on an experimental basis, were made to the press and to the Institute of Radio Engineers. The prospect of a national television network was heightened by the announcement of a perfected radio-relay technique and by demonstrations of improved transmission over coaxial cable. Small, light-weight television transmitting equipment capable of being carried in several suitcases was announced and demonstrated televising New York City from an airplane. A number of notable 'firsts' were made in television programs, including the televising of The Ringling Brothers' Circus from Madison Square Garden, and the addition of professional soccer, ice hockey, and collegiate basketball to the list of sports previously telecast. In the field of science, the partial eclipse of the sun provided opportunity for a noteworthy broadcast on April 7, 1940.

Television Standards.

The major event affecting the commercial status of television was the decision of the Federal Communications Commission to withhold the issuance of commercial licenses to television broadcast stations which would have permitted the payment of fees by the sponsors of commercial programs. This action was taken early in the year, following previous announcements that full commercialization would be permitted before the end of 1940. The reason given by the Commission was that commercial activity in the sale of television receivers, which indicated a sale of perhaps 25,000 receivers within a year if it had continued, was in effect setting up standards of transmission to which the Government had not given approval, and that future developments might make desirable a change in these standards which would conceivably render obsolete all receivers then in the hands of the public. Two major hearings on this subject were held by the Commission in Washington, in which expert testimony was heard from engineers representing commercial and technical organizations. The consensus of these experts was that sufficient flexibility could be incorporated in receiver design to obviate early obsolescence, but not all agreed that such flexibility would serve a useful purpose, even if its cost were low.

The net effect of this action and the publicity which accompanied it in the newspapers was to bring television receiver sales virtually to a halt, and to cause the broadcasters, in the absence of any promise of financial return, to review their budgets for television programs. Considerable disapproval of the Commission's action was evident in the press, in answer to which the Commissioners promised to seek an answer to the problem, in consultation with the television industry at the earliest possible occasion. This promise was fulfilled by the formation, in August, of a large committee of engineering experts, the National Television System Committee, appointed by the Radio Manufacturers Association with the advice and consent of the Federal Communications Commission.

Television System Committee.

The National Television System Committee, with its subcommittees, consists of 168 members and alternates. Functioning as an independent body, this Committee has been active in devising a set of television transmission standards which are to be recommended for official adoption by the FCC. Nine subcommittees or 'panels' have prepared reports on different aspects of the problem, together with specific recommendations concerning the manner in which television transmission shall be carried out. The Committee and the Chairmen of its panels were scheduled to meet on January 27, 1941, with the Federal Communications Commission to report their findings to that date. Thereafter, the action taken by the FCC will determine the immediate commercial plans of the industry. If the recommended standards receive governmental approval, it is expected that the manufacturers of television receivers and the television broadcasters will resume their plans for commercial expansion. If, however, the Commission's action is negative, it seems likely that several years of further non-commercial technical work may intervene before the public is actively invited to participate in the service.

Broadcasting Stations.

Another action taken by the Federal Communications Commission which affected television broadcasting to a minor extent was the shifting of station allocations in the ether. One of the ether channels formerly assigned to television (that between 44 and 50 megacycles) was removed from the television category and assigned to the frequency-modulation broadcast service. Another channel, from 60 to 66 megacycles, was transferred from the government service to television, thereby restoring the total extent of the ether devoted to television to its former level. Many stations which had operated on the older channel, notably the NBC transmitter in New York, were forced to go off the air for extended periods in order to shift wavelength in accordance with this change. No scheduled broadcasts were available in New York during the months of August and September on this account. The program service rendered by NBC in New York in the latter part of the year was on a reduced schedule, in part because the transmitter was often in use for tests conducted by the National Television System and partly due to uncertainty regarding the future of the service.

Despite the lessened commercial activity, a large number of experimental authorizations were issued by the Commission to applicant companies. The applications filed with the Commission by these organizations indicated a total expenditure of approximately $8,000,000, to be spent on research in programs methods and technical experimentation. The list of experimental stations now embraces many of the larger cities, as follows: New York City, 6 stations; Philadelphia, 3; Boston, 1; Chicago, 3; Los Angeles, 7; San Francisco, 2; Washington, D. C., 2; Schenectady, 1; Camden, N. J., 1; Iowa City, 1; Kansas City, 1; Manhattan, Kan., 1; West Lafayette, Ind., 1; Milwaukee, 1; Cincinnati, 1.

The stations active in providing program service during the year included W2XBS, the NBC station in New York: W3XE, the Philco station in Philadelphia; W2XB, the General Electric station near Albany, New York, and W6XAO, the Don Lee station in Los Angeles. The DuMont station W2XVT was transferred from Passaic, New Jersey, to a skyscraper in New York City, and was in operation with low power but had no scheduled programs.

Commercial receivers were available for sale during the year at prices approximately two-thirds those set early in 1939, but few new models were offered. The most popular model sold at slightly under $400. At the end of the year the total distribution of television receivers over the country was estimated to number no more than 5,000, of which from 3,000 to 4,000 were in the New York area.

Television Programs.

Programs originating in the NBC studios in New York were transmitted to the metropolitan audience via W2XBS. Many of these programs were relayed to the New York capital district around Albany by W2XB. In the dramatic field, among the plays originated by NBC at the beginning of the year were Ethan Frome, The Gorilla, June Moon, Charlotte Corday, The Perfect Alibi, When We Are Married, Dangerous Corner, Julius Caesar (in modern dress), and The Passing of the Third Floor Back. Among the notable sporting events were the finals of the Golden Gloves Boxing Tournament, from Madison Square Garden; track meets held by the A.A.U., the I.C. 4A, and the Finnish Relief Fund; professional ice hockey games, likewise from Madison Square Garden; the opening baseball game between the Brooklyn Dodgers and the New York Giants from Ebbets Field; several collegiate baseball games; four professional football games during November, and intercollegiate basketball from Madison Square Garden. Religious services and a view of the Fashion Parade on Easter Day were relayed from New York by the Albany station to a snow-bound party in the Adirondacks, some 240 miles away from New York.

In the political arena, the most significant technical accomplishment was the televising of the Republican National Convention in Philadelphia and its transmission over coaxial telephone cable from Philadelphia to New York where it was presented to the New York audience by W2XBS. This was the first intercity hook-up by wire facilities and its quality, both technically and as program fare, was universally praised. The Democratic Convention in Chicago could not be brought directly to the New York audience because the necessary coaxial or radio-relay connections do not exist between these cities. However, motion pictures taken at the Convention were flown to New York and put on the air the following day. The final campaign rallies of both parties were transmitted successfully from Madison Square Garden. On election day one of the longest continuous telecasts on record, nearly seven hours, was devoted to bringing the returns, views of maps, etc., to the audience, interspersed with commentary from leading observers. During quiet spells, the camera was focused on the tape of an automatic newsprinter operated from the news service lines, so the television audience received the news, visually, at the earliest possible moment.

Technical Developments.

From the consumer's standpoint, the outstanding announcements of technical advances were those dealing with the size and brightness of the reproduced pictures. Conventional picture tubes capable of reproducing an image about 12 by 16 inches in size were announced. Projected pictures about 4.5 by 6 feet in size, and of great brilliance were demonstrated and their utility for use in theaters was discussed. Projected pictures for home reception were also under active development, and plans for announcing a home receiver capable of producing projected pictures about 15 by 20 inches in size were under way. (See also PHOTOGRAPHY.)

From the long-range point of view, perhaps the most significant technical accomplishment was the demonstration of television transmission in full color by engineers of the Columbia Broadcasting System. Color television experiments date back as far as 1927, but the results obtained by the CBS system greatly surpass previous efforts. When first demonstrated the CBS color television system was limited to subject matter picked up from colored motion picture film or from transparent colored lantern slides, but successful televising of live subjects has since been announced.

The color aspect of the transmission is introduced by employing two rotating discs composed of transparent filter segments in the three color ranges, red, green and blue. One of these discs is set up directly in front of the television camera in the studio. As the disc rotates, pictures of different hue are transmitted, one picture containing all the red light, the next all the green light, and the next in blue light. These three pictures are transmitted in rapid succession, each picture consuming about one half the time generally used in sending a conventional black-and-white picture. At the receiver a similar disc is rotated in front on the receiving tube screen, synchronously with the motion of the disc at the transmitter. The white light from the screen, passing to the eye through the filter segments, assumes the color of the filter, which corresponds to the color of the image being transmitted at that instant. Thus the eye sees three different colored pictures in rapid succession, through successive segments of the revolving filter disc, the first containing all the red light in the scene, the second all the green light, and the third all the blue. The succession of pictures occurs rapidly enough (in about 1/40th second) so that the three color impressions persist together in the mind of the observer and the colors of the original subject are thereby reproduced. The necessity of sending the pictures at a rate approximately twice as rapidly as in black-and-white transmission requires a proportionate reduction in the pictorial detail transmitted in the scene, but this degradation is largely made up by the presence of color in the reproduced pictures.

The question of the commercial introduction of color television transmission is closely bound up with the question of television standards, since the CBS method of color transmission cannot be adapted readily to the transmission standards currently employed for black-and-white pictures. Color television transmissions using but two colors, similar in appearance to the early technicolor movies, have been demonstrated recently by engineers of the General Electric Company, using the black-and-white transmission standards without change. The question of color transmission is being considered by the National Television System Committee, which will make recommendations concerning it to the Federal Communications Commission early in 1941. See also RADIO: Television.

1939: Television

The year 1939 marked the beginning of television program service for the public in the United States. For several years prior to this experimental transmissions had been made, particularly in Los Angeles and New York. But television receivers were not available to the public, and no coordinated effort was made to bring television out of the laboratory and into the home.

The signal for the inauguration of the service was the opening of the New York World's Fair, on April 30, 1939. President Roosevelt's opening address was televised by the cameras of the National Broadcasting Company directly from the Fair Grounds; the images were relayed to the television transmitter in the Empire State Building, New York, and thence radiated to the several hundred receivers which by that time had been installed in homes in the metropolitan area. Coincidently, four manufacturers announced lines of home television receivers in retail stores, prices were established, and a regular schedule of programs was announced. The new infant prodigy of the radio had taken its first step.

Stations.

Several months later station W6XAO, the television transmitter of the Don Lee Broadcasting System in Los Angeles, was modified to conform with the transmission standards for which the commercial receivers were designed; and receivers were made available to the people of Los Angeles. The regular program schedule, which had been maintained theretofore on an experimental basis, was continued and expanded.

At the end of 1939 these two stations were the only ones offering regular programs to the public on an announced schedule. The station of the Columbia Broadcasting System in New York, W2XAB, began experimental transmissions in November 1939, preparatory to going on the air with regular programs early in 1940. An occasional program schedule was maintained by the Philco transmitter W3XE in Philadelphia. The General Electric station, W2XB in the Helderberg Mountains near Albany, New York, went on the air in December, and announced that regular programs would begin in January 1940, and that the programs of the New York station would be picked up and relayed to the tri-city area of Albany, Troy and Schenectady. Transmissions were made, on low power, by the station of the DuMont Laboratories, W2XVT, in Passaic, N. J. Stations were under construction or operating occasionally in Chicago, Milwaukee, San Francisco, Boston, Kansas City, Bridgeport, Conn., Iowa City, Iowa, and Camden, N. J. But the sale of television receivers was restricted principally to the metropolitan areas surrounding New York and Los Angeles, inasmuch as stations in these cities were offering regularly scheduled programs.

Receivers.

At the beginning of the service, the radio industry was very optimistic about the immediate commercial success of the venture. Some early predictions looked to the sale of as many as 20,000 television sets in New York City in the first year of the service. In the first nine months, to the end of 1939, these predictions proved far in excess of the fact. Actually, the most reliable estimates place the total number of television receivers sold to the public at slightly over 1,000, most of these in the New York area. The industry at first was very much disappointed in this showing, but reasons were quickly found to explain it and to point the way to greater sales in the future. The principal bars to wide acceptance of television receivers have been the high prices, the fact that there is but one reachable source of programs, and the feeling on the part of the public that reduced prices and technical improvements would come in the near future. In support of that feeling was the fact that the Federal Communications Commission refused to accept or to reject the transmission standards proposed by the Radio Manufacturers Association, on which the television transmissions and receiver designs have been based. Lacking such government approval, there has been the chance that the standards might be revised, and the equipment already sold might thereby become obsolete or at least reduced in efficiency. Experience with the standards has shown them to be suitable as a basis for transmission, however, and there seems little likelihood of their being changed in any way which would affect equipment already in the hands of the public.

Reduction in prices, on the other hand, seems much more likely. At the beginning the prices ranged from about $200 for a simple television attachment to be used in conjunction with a standard radio receiver and producing a picture about 4 x 5 in. in size, to about $600 for an elaborate console model including television sight and sound equipment and a standard all-wave radio, the picture size being about 8 x 10 in. Several firms announced near the end of 1939 limited price reductions of about 33 per cent and it seemed probable that such a scaling down of prices would become general for 1940. By the end of 1939, approximately 20 manufacturers announced their intention of soon making television receivers available and about 10 of these had definite plans for commercialization early in 1940.

Programs.

The programs offered by the National Broadcasting Company over station W2XBS in New York included a wide variety of information and entertainment. The program schedule was increased from approximately 2 hours per week when the service started to from 11-14 hours per week at the end of 1939.

The NBC programs included plays enacted by Broadway casts. Outstanding among these were Jane Eyre, Treasure Island, The Milky Way, Dulcy, The Dover Road, Three Men on a Horse, Another Language, Stage Door and Little Women. A great variety of films, short subjects and features, were also presented. Among the educational features were several meetings of the Explorer's Club, casual gatherings of outstanding personalities in the world of exploration who discussed their exploits and showed films taken on their travels. Among those present were Sir Hubert Wilkins, Phil Plant, Col. C. W. Furlong, Capt. Bob Bartlett and Capt. John Craig, the undersea explorer. Saturday afternoons were devoted to the series 'Wings of a Nation,' giving information on all phases of aviation and air travel. Spelling bees were held frequently, proving that the eye provides half the fun in such mental tests.

The mobile transmitting equipment of W2XBS, consisting of two trucks of apparatus including camera equipment and a relay transmitter, was active in bringing to the air all manner of sporting events and occasions of public interest. Many telecasts from the World's Fair were presented during the 1939 season. The first 'television ball' held at the Waldorf-Astoria for the benefit of the Goddard Neighborhood Center was telecast, as was the occasion of the opening of Gone with the Wind at the Capital Theater in New York. The cameras picked up almost every sport on the calendar, such as collegiate and professional baseball and football, bicycle racing, professional wrestling and boxing, track and field events, skating, and jujitsu.

Transmission Technique.

The achievement of true television, that is, the instantaneous transmission of half-tone images in motion over the air, dates back to 1925. Since that time, steady progress has been made in refining the clarity of the images, as well as in increasing their size and removing the flicker and unsteadiness which characterized early attempts. Today, the modern electron television system stands as one of the greatest achievements in electrical communication, if not the greatest.

Some idea of the television system's capabilities may be gained from the following brief description of the technique involved: Pictorial reproductions consist ordinarily of half-tone dots, such as are familiar in the printing of pictures by half-tone engravings. A picture suitable for portraying the usual range of subject matter must contain several hundred thousand such dots. In television images the picture or scene to be televised is divided arbitrarily into about 200,000 dots, which are arranged in about 400 parallel horizontal rows. The television camera explores each of these rows from left to right, one after the other, in much the same manner as the eye reads a page of printed matter. The camera, in thus exploring the picture for the information it contains, converts each little half-tone value of light or shade into a corresponding electrical impulse, and as the picture is 'scanned' row by row, a succession of such electrical impulses is produced. These impulses are imposed on the radio carrier wave and intercepted by the receiver, which converts the succession of impulses to corresponding values of light and shade which are assembled, row by row, before the eye on the viewing screen.

The eye would see each half-tone dot separately if it were not for the great speed at which they are reproduced and assembled before the eye. In fact, all of the 200,000 dots in the picture are reproduced within 1/30th of a second, and as a result the eye appears to see them all at once, because of the persistence of vision. Each picture reproduced in 1/30th second is immediately followed by the transmission of another picture in the same manner, each picture differing slightly from the picture preceding and following it, in the same manner as motion pictures are reproduced. Thus 30 complete pictures, each containing 200,000 dots, are sent in each second: and any motion which occurs within that time is divided into 30 small motions which appear to blend smoothly one into the next, as viewed by the eye. The detail and the motion of the scene are thus reproduced artificially.

Since 30 pictures, each containing 200,000 half-tone dots, are sent in each second, the television system must be capable of transmitting no fewer than 6 million items of information per second. This extraordinary rate of transmission has imposed severe engineering requirements on the system. One result is the necessity of using very short waves (from 4-7 meters in length) for transmission. Another is the necessity of using a very wide 'path' in the ether, about 600 times as wide as is required by an ordinary radio sound broadcasting station. This fact limits the number of television stations which can be accommodated simultaneously on the ether within a given transmission area. At present 7 frequency assignments are available for television stations in the currently useful portion of the ether spectrum. Room for more stations will be found, and in fact has already been reserved for television purposes; but for the present no more than two or three stations can be assigned in any one city. Fortunately the problem of interference between stations is not so serious on the ultra-short waves as on the conventional broadcast wave-lengths, so that the frequency assignments may be duplicated many times across the country if not in any particular city.

National Network.

The use of television in theaters was demonstrated in New York during the summer of 1939. The equipment required is elaborate and expensive compared with the cost of a receiver for the home, but it is capable of bringing telecasts to large gatherings in a manner comparable to that of the motion picture. No commercialization of this service is in immediate prospect, but eventually it may well be an auxiliary service by which local theaters may bring to their audiences events of national importance as they happen. At present, one obstacle to a national network of stations is the impracticability of sending television programs over conventional telephone wires; but eventually special wire circuits and radio-relay circuits, now being developed will in all likelihood, link stations in a national television network comparable to the present networks of the sound broadcasting system. See also PHOTOGRAPHY; RADIO.

1938: Television

Descriptive Definition.

Television is that physical process whereby a specially constructed transmitter may have optical images and scenes thrown upon it and transformed into electrical impulses for transmission by wire or by radio. At a distant point these electrical impulses are taken by a receiver and retransformed into a faithful reproduction of the original images and scenes, and made visible to an observer. If sound effects also are transmitted, the more realistic becomes the whole process for the observer.

The modern telephone is an analogous procedure. The telephone is a device whereby a specially constructed transmitter may have audible sounds thrown upon it and transformed into electrical impulses for transmission by wire or by radio. At a distant point these electrical impulses are taken by a receiving device (receiver) and retransformed into a faithful reproduction of the original sounds and made audible to a listener. If visual effects could be added to the telephone's transmission of sound, the whole process would be more realistic.

Legacies of Science.

In order that the transmitter and the receiver for illuminated scenes may be better understood, it will be necessary to describe several discoveries and inventions whereby such transmissions are made possible.

It has been known for some time that when light falls upon layers of certain different kinds of metals, an electrical potential difference is set up between these layers of metal which varies with the quantity of light falling upon the bounding surfaces of the metals. Such a device is known as a photoelectric cell. This furnishes the basic principle for the transformation of the light reflected from objects and scenes into electrical impulses. By a process known as scanning, an object — for example, the face of an individual — has a pencil of light rapidly swept over its surface so that in a minute interval of time every little section of the surface has been touched in regular order by the delicate wand of light. Each successive area as illuminated reflects its light onto a photoelectric cell. Inasmuch as some sections of the surface will reflect less than others, there follows in rapid succession, as the scene is scanned, a series of electrical impulses from the photoelectric cell which are directly proportional to the quantity of light reflected from the section illuminated. These electrical impulses, into which light from the various areas of the illuminated object has been transformed, may now be sent into a radio amplifier and these stepped-up electrical impulses transmitted by wire or by radio as are other radio signals.

The Process.

At the receiving end, these electrical impulses must be transformed back into visible light. There are various forms of receivers for such electrical impulses, but the simplest to understand is the one based on the neon lamp. This form of light source consists of a glass tube from which all gas has been exhausted except a minute amount of neon gas. Into the ends of such a glass tube have been sealed metal wire leads. When a small potential difference is applied to the terminals of such a tube, a conduction of electrical charges occurs, and the neon gas emits its characteristic light, the amount of which will depend upon the potential difference applied to the terminals of the tube. Hence, if the varying electrical impulses which have been transmitted by wire or by radio from the transmitting set are applied to the neon tube, its illumination will fluctuate in just the same way as did the light falling originally on the transmitter. By this means a series of varying light and dark spots could be transmitted by electrical impulses and at the receiving set retransformed into a faithful reproduction of the original dark and light areas which were scanned in the transmitter.

But how can one receive a scene or the image of a complete object which has a large area of surface? To do this, the light of varying quantity which is reproduced at the receiving end must be fashioned into a pencil or wand of light similar to the one with which the original object was scanned. These two wands of light must now be synchronized so that they will move together in direction at all times and not get out of step with each other. If the sending pencil moves rapidly, so must the receiving pencil. Consequently, as the receiving pencil of light moves synchronously in speed and direction with the original scanning beam of light, this wand or brush of light at the receiving end will paint on a screen a series of light and dark spots which correspond precisely with the quantity of light reflected from the series of light and dark spots originally illuminated on the objects at the sending station.

The receiving pencil of light paints its successive spots so rapidly that, by the persistence of vision which belongs to one's eyes, we seem to see the whole image or scene at once, and yet its various parts have been laid down in an extremely rapid sequence.

Mechanics of Television.

These pencils of light are formed by drilling in a circular disk a spiral of holes which are separated by equal angles between the various radio vectors which connect the center of the disk and the holes. A broad beam of light falls on the upper part of the disk as it rotates. Each hole, as it moves in front of a definite opening, which serves as a frame to the picture and is situated between the disk and the source of illumination, will allow a pencil of light to pass through and is then swept across the object or scene in a horizontal direction, making a narrow, illuminated band across the object or scene. The next hole, being nearer the center of the disk, will, as it moves across the object, illuminate the same with a band which lies just below the one made by the preceding hole. Thus, for succeeding holes, the same thing will occur until every minute section of the entire surface of the object has been momentarily illuminated in rapid succession, one after the other.

At the receiving end is another disk exactly like the one just described, which is used in scanning the object at the transmitting station. Both are run on synchronous motors, so that the two disks are exactly in step. The light coming from the neon lamp goes through the holes in the disk as a pencil of light; and so, as each hole passes across the opening in the 'framing' of the picture, the pencil peculiar to each hole draws its own band of light across a screen in which each band corresponds precisely with the bands of illumination thrown on the object at the transmitting station. Due to persistence of vision, one sees the whole as a faithful reproduction of what was illuminated at the transmitter.

Other Systems.

Various systems have been devised besides the one just described. Instead of a pencil of light, one system employs a pencil of cathode rays as a sweep system, and the cathode particles excite a fluorescent screen to give the image of the distant illuminated object. Details will vary, but in most of these systems the scanning process seems to be a necessary one.

The year 1938 will stand out as a landmark in the history of the development of television because in that year it was decided actually to put television receiving sets on the market and in this way gradually to iron out some of the imperfections which still remain in the mechanisms for the electrical transmission of images of illuminated objects.