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SEEN BEHIND THE SCENES OF TELEVISION AT NBC-In the four main phases of television shown here you see: (a) The studio in the RCA Building where actors and technicians work under studio lights (b) The master control room where engineers and directors monitor the sight and sound pickups, whence the electronic impulses speed by cable to the Empire State transmitter (c) Antenna atop the Empire State Building which broadcasts television programs over a 50-mile radius (d) Combination receiver which reproduces sight and sound transmitted by video and audio carrier waves.
TELEVISION. . . THEN-AND NOW An Adventure in Science Television began in the minds of men centuries before it became practical. The longing to see afar, to penetrate fog and night, earth and substance with our sense of sight is a primitive instinct. But the specific inventions and discoveries that relate directly to television go back only to the year 1817 when Baron Jons Jacob Berzelius, a Swedish pharmacist, discovered a strange element which he named selenium. A scientific oddity of that day, relatively little was heard of it until 56 years later, in 1873, when May, a telegrapher working at the Valentia TransAtlantic Cable Station, in Southwestern Ireland, observed that a resistor made of selenium transmitted current better when the sun shone upon it. Other experimenters corroborated the fact that light causes selenium to transmit electricity better than when it is immersed in darkness.This discovery foreshadowed the modern photoelectric cell, a device designed to convert light variations into equivalent electrical impulses; this photo-cell principle is the crux of RCA's all-electronic system of television.Although we ordinarily think of television as a 20th century development, its basic principles were known and demonstrated in the 1880's! Silhouettes and crude outlines were televised, transmitted over wires for short distances, and finally reproduced. Of course, the images did not compare with the 441-line standard of today. For several decades thereafter, television was rather dormant. People generally regarded it as an interesting laboratory oddity, but doubted whether it could ever be perfected. One factor which seriously hindered early progress was the lack of a satisfactory medium for transmitting a program from the camera to the receiver. But in the period of the World War, 1914-1918, radio developed a new stride. Spurred by necessity, engineers greatly improved transmitting and receiving equipment and studied the peculiar nature of radio waves. Within a few brief years, radio entered the home, and the old crystal sets gave way to modern vacuum tube receivers. In the pioneer days of sound broadcasting, it was discovered that crude action pictures could be sent through the air on radio waves. At once, sensing the practical potentialities, experimenters attacked the television problem anew. NBC's parent company, the Radio Corporation of America, was among the first to enter this field. A photoelectric cell made possible the first practical tests in television. The simplest of these tests (Upper) Television image picture as it appears on the home receiver in 441 lines. (Lower) Natural photograph of the young woman appearing on the screen above. employed a single photo-cell unit. The experimenters soon progressed to a unit containing eight photoelectric cells. The television subject stood before this battery of eagle eyes while a scanning machine swept a brilliant point of light across his face in a series of parallel lines. In far less time than it takes to tell, the light was reflected from the subject's face to the photo-cells, which converted it into pulsating electric currents. Conducted to a transmitter station, the weak currents were amplified, superimposed upon a radio carrier wave and broadcast -all similar to the procedure in sound broadcasting. The receiving equipment used in those early tests was rather crude. With the aid of a neon tube and a scanning disc, a radio signal was converted into visible light, thus reproducing the original studio action in a series of horizontal lines. The televiewers observed the program through a magnifying glass. Scanning is the crux of television, and as important to the modern electronic system as it was to the early mechanical system. The original mechanical scanning projector used by Dr. E. F. Alexanderson, of the General Electric Company, Schenectady, about 1930, may now be seen in NBC's Radio City studios. The experimenter dimmed (Upper) lconoscope, or "electric eye", of the television camera. The image is focused on a photo-sensitive mosaic inside the large end of the tube. (Lower) The inescope, corresponding to the "loud speaker of an ordinary mdio receiver, transforms electrical impulses into visible images. The large end of the tube is the fluorescent glass screen. the overhead light and turned on a "scanner" which projected a tiny spot of light upon a screen about 10 feet away. As the scanning disc rotated on its axis you saw the spot traveling from left to right in a series of parallel arc lines. These lines - actually composed of spots - were reflected back to the electric eyes, which created what engineers call the "television signal," subsequently amplified and broadcast. Until a few years ago, the scanning function in the camera and receiver was accomplished mechanically. Then Dr. Vladimir Zworykin, now a scientist of the Radio Corporation of America, perfected his system of electronic scanning, which revolutionized television and ushered in the present era. The Iconoscope, the television camera's eagle eye, corresponds to the microphone in sound broadcasting. It is a vacuum tube with a light-sensitive plate behind the camera lens. This mosaic plate consists of about 400,000 microscopic photo-electric cells. The camera lens focuses a given scene upon it, and an electron gun beam scans the scene as a searchlight would scan it, moving from left to right and top to bottom, covering the 4 to S-inch plate in about one-thirtieth of a second. The weak television "signal" thus created is subsequently amplified and broadcast on a radio carrier wave. The image-reproducing tube of the receiver consists of two main parts, an electron gun and a fluorescent glass screen. After a suitable antenna intercepts the television
'The television director has stopped a rehearsal to give a few pointers to his cast. "signal," it speeds to the electron gun which scans the fluorescent screen in horizontal lines, and the picture reappears before your eyes, a faithful reproduction of what originally appeared on the Iconoscope plate. The electronic system of television appears effectively to solve the problem of seeing at a distance. Progress in the past five years has been unprecedented, and it was climaxed in 1936 by the inauguration of an experimental program service from NBC studios in Radio City. In the months to come, NBC contemplates carrying this work to a stage of development that will warrant a daily program service. A television receiver bears strong resemblance to the ordinary home radio console, but it really consists of two receivers inside one cabinet - one receiver capable of reproducing the sound, and the other capable of reproducing the pictures. The heart of the instrument is the Kinescope, the large end of which comprises a glass screen on which pictures appear. The image is reflected onto a mirror under the lid because it is impracticable to build a receiver with a direct-view screen. Electrons move at such an inconceivable velocity that in describing the complex synchronization of the television system, we may think of seconds as weeks because so many fractional divisions are necessary. The camera electrons and the home receiver electrons move in a sort of "lockstep," and if one group lags behind the other by as much as onemillionth of a second, the finished picture may look fuzzy or distorted. In a typical television studio, incandescent lights illuminate a scene and the camera focuses on that scene from behind the lights. A microphone attached to a "boom" is suspended above the camera's field of vision. In ordinary practice the light is diffused evenly throughout the studio. Spotlights may be used to emphasize certain parts of a scene or close-ups of actors. The purpose of an aluminum wall surface is to help the eyes make a normal adjustment when they turn suddenly from a bright scene to an unlighted surface.Heads-Hearts-Hands The men whose heads, hearts, and hands strive to build an American Television industry may be grouped into three departments based on their respective functions, to wit: 1. PROGRAMMING 2. ENGINEERING 3. ECONOMICS PROGRAMMING Under artificial sun, the program staff creates the form and substance of television entertainment. All the color and pageantry of modern life, from a football game to the inauguration of a President, from a telescopic view of the moon to a microscopic view of microbes, will eventually appear upon the televiSIon screen. Nourished by hard toil, a new stagecraft evolves into an art based upon pre-existing arts, but differing from them all in presenting a wondrous imagery that conserves time and compresses space within the orbits of your eyes. Had he lived to witness television, Shakespeare might have said, "All the universe is a stage . . ." From the bowels of the earth and the depths of the sea to the far, far dominions of cosmic space there exist no boundaries for human sight. Television program men hope to bring this universe of life and substance, of fate and circumstance, before your eyes. What things to see! What riddles to solve! But before they embark upon such quests, they must familiarize themselves with numberless details about this difficult technique of broadcasting animated pictures. Right now they work with simple program material - one-act plays, travelogues, newsreels, vaudeville, demonstrations of science, etc. But each day they extend their horizons and draw plans to embrace new activities. The chief aims of programming at present are to discover or create material suited to television, and to learn the best ways of presenting this material before a television audience. Thus they come face to face with the grim realities of producing programs that are entertaining and stimulating, but also different from the usual fare of sound radio, the stage, and the movies. To find the right solutions they need time. As with the theatre and the movies, most programs begin with a writer whose job is to conceive plays and special features, invent plots, draw characters, plan action, or write dialoguc. His is the creative force, the chief inspiration and mainspring of human action. Upon completion, the writer's script goes to the production director who confers with his colleagues on the problem of translating the cold words on paper into living human activity. On the basis of their discussions, assignments are made. A director is named to supervise production. His responsibility extends to a .thousand and one details, but he must not overlook that all his activity is a means to an endto provide provocative entertainment or graphic information for the televiewer. In the case of a studio production, the director hands a copy of the script to the scenic artist who conceives a logical setting for the action. He sketches a studio scene in rough outline and, following approval by the director, executes his designs. Artists arrive for conferences, auditions, and tryouts. Exercising his judgment of their qualifications and of the specific requirements, the director chooses a cast. If special sight or sound effects are necessary, they are either built to order, or selected from a warehouse collection. Costumes and props may have to be rented. Rehearsals begin on schedule, and after a preliminary reading of lines, the three partners of technical production are called in. They are the camera operator, the sound boom engineer, and the lighting expert. At present NBC employs several studio cameras, each "shooting" the action from a different angle. Camera operators are skilled in the "framing" of pictures and quick to respond to a director's orders. The light technician is more than an ordinary stage electrician, for he must not only understand the color values in corresponding shades of gray, but he must also know how to "paint" a picture in lights and shadows. The man at the "boom" is charged with picking up both voices and incidental sound effects in a program. He must, of course, keep his microphone clear of the cameras' field of vision and at the same time he must keep it near the actors.He moves his microphone backward and forward by means of a crank, and swings it from side to side on a swivel.
ENGINEERING Television engineering embraces a wide assortment of outdoor and indoor activities. The program personnel is responsible for creating a picture that can be televised. The engineering personnel is responsible for converting that picture into a suitable "signal" ; also for transmitting that signal to a transmitter, and finally launching the signal on a carrier wave that radiates into space. To control the intricate machinery that makes sight broadcasting possible, it is necessary to place engineers at strategic points along the route of a television signal between the camera and transmitter. In the master control-room overlooking the studio, members of a "jury" manipulate ingenious devices which enable them to control the quality of the sight and sound transmitted by the system. Side by side sit the video control engineer, sound control engineer, and the engineer responsible for switching from one camera to another. After a television program is "monitored," it goes from the RCA building via coaxial cable or "link" radio transmitter to the Empire State building where sight and sound transmitters are located on the 85th floor. Here the sight "signal" is amplified and conditioned for broadcasting on a carrier wave to televiewers in the New York metropolitan area.Besides these indoor activities, a squad of engineers is at present ex Inside the television studio control room. From this position, the sight and sound engineers and the production director "monitor" a program as it goes on the air. Television receiver in a home setting. The image is reflected from the Kinescope On a mirror under the lid. Actual scene from "Nine Loves of Emily", a one-act play, as it was enacted before the electronic cameras at NBC's television studio. perimenting with a Telemobile Unit - a complete sight and sound broadcasting station on wheels for outdoor program pickups. Supporting all this activity is a group of research men assigned to a wide assortment of technical problems that bear directly on television progress. The immediate promise of television broadcasting is for metropolitan communities, because it is both uneconomical and impracticable at present to make sight broadcasting as general as sound broadcasting. Hence, the possibility of a television network as extensive as present-day sound networks is remote. The comparatively small coverage of a television transmitter and the high cost of transmitting programs from city to city preclude any mushroom growth for coast-to-coast networks. Regional networks, uniting a group of favorably-located cities, appear more feasible and may materialize within several years. The practical difficulties confronting television may be judged from the fact that it would require 100 transmitters to cover five per cent of the country. It seems, therefore, that for many years the less populous areas of the United States must depend solely upon sound broadcasts for radio entertainment. Much remains to be done and no one can predict when the goal of television will be reached, but all the experience gained from operating the system on an experimental basis rather definitely points the way toward a high-definition daily broadcast service.ECONOMICS Television broadcasting has never earned for itself one cent of revenue, either in this country or abroad, but those who have faith in the medium hope that a way may be found to balance the industry's broadcasting economics. No one expects that television will yield at profit for years to come from commercial broadcasting. It is a gradual development requiring wide support from other industries before it can stand on its own feet.Preliminary to balancing television's economics, it is necessary to carryon surveys alluding to population distribution, geographical markets, network areas, local coverage, etc., involving the preparation of maps, charts, and tables of figures. Special interviewers, statisticians, and mathematicians handle this work. Their aim is to establish an economic stability that will pave the way for a daily broadcasting service with programs of artistic merit.The first telemobile unit in America, built by the RCA laboratories for the use of NBC. NBC's telemobile unit camera operator places a "sombrero" over the eagle eye of his camera as he "shoots" toward the sun.
THE QUESTION IS: The ten questions listed here are asked most frequently by visitors to NBC's Radio City studios. Question 1: When will the first scheduled television
broadcasting service begin in N ew York? Question 2: How much will a television receiver cost? Question 3: How far can television programs be broadcast? Question 4: Do you have television in colors? Question 5: What kind of makeup do you use in television? Question 6: What will be television's effect on motion
pictures? Question 7: Is England ahead of the United States in
television development? Question 8: Why are such bright lights necessary? Question 9: Will television ruin the legitimate theater? Question 10: Who invented television? Inside the telemobile unit, the engineer in charge manipulates the controls.
SIGNIFICANT DATES FROM THE DIARY OF TELEVISION 1676 - Olaus Roemer discovered that light travels at finite velocity. 1817 - Berzelius discovered selenium. 1830 - Joseph N. Niepce and Louis Daguerre produced the first practical system of photography. 1845 - Faraday found that a ray of light polarized in a certain plane can be diverted by action of a magnet. 1857 - Geissler produced the first glass vacuum tube. 1873 - Light-sensitive properties of selenium discovered by a telegraph operator named May, indicating that light values could be converted into equivalent electrical values. 1878 - Sir William Crooks invented the Crooks tube, and demonstrated cathode rays. 1883 - Edison discovered the "Edison effect," occurring in an incandescent lamp. An electric current was made to pass through space from a burning filament to an adjacent metallic plate.1884 - Paul Nipkow patented the television scanning disc. 1888 - Photoelectric cells were built. 1890 - C. Francis Jenkins began experimenting with apparatus that could be used with the Nipkow scanning disc. 1895 - Louste, inventor, demonstrated sound movies. 1906 - Lee de Forest invented the three-element vacuum tube with a filament, plate, and grid. 1925 - C. F. Jenkins in Washington, D. c., demonstrated apparatus which showed far-off, moving objects, or "shadowgraphs." 1926 - J. L. Baird, in England, demonstrated television transmission by wireless and wire by sending half-tone moving pictures from point to point. 1928 - First television drama, "The Queen's Messenger," broadcast from WGY's studios, Schenectady. 1929 - Vladimir Zworykin, of RCA, demonstrated a non-mechanical receiver using a special cathode ray tube called "Kinescope." 1930 - First showing of television in a theatre. The program was broadcast from the General Electric Laboratories to Proctor's Theatre, Schenectady. 1933 - After 10 years of work Zworykin announced success of his "Iconoscope," the modern television camera tube. 1934 - New television camera tube demonstrated by P. T. Farnsworth, in Philadelphia. 1935 - New type of wire line, the coaxial cable, capable of transmitting television signals, announced by Bell Telephone Laboratories. 1936 - July 7th, RCA held a demonstration of the modern 441line television all-electronic system before radio manufacturers. 1938 - September 15th, NBC conducted first television sidewalk interviews with passers-by in the Rockefeller Plaza, New York City. Transmission picked up by NBCRCA mobile television unit, relayed to Empire State Building and then broadcast to the metropolitan area.
THE NBC TELEVISION TOUR A more complete demonstration of the tele-picture art and science is afforded by the Television Tour at NBC's Headquarters, Radio City, New York. These paid tours are conducted by competent guides at ten-minute intervals between 9 A.M. and 11 P.M. daily.
A television broadcast of 1939 automobile models featured the opening of the New York Automobile Show. Television image picture of auto company officials and One of the models paraded before the television camera.
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Magazine advert for NBC 10 year anniversary. |
