What's on the air (Mar-June 1931)

©C1B 112430 *«**' WHAT'S ON THE AlR VOLUME II. THE MAGAZINE FOR THE RADIO LISTENER MAY, 1931 No. 7 jeleofslon (eeps (Wind fibe vomer Stj Don Dagfe TELEVISION has lurked "just around the corner" for many years, but in spite of the pessimistic reports early in the year, this spring has seen television peeping around that corner. Television has made a good start, and, if this writer is not very much off his reportorial course, you, the radio listener, will become a "looker-in" before next Christmas. Sight and sound transmissions have been on the air nearly a year. Chicago has contributed tremendously in this phase, while New York has just recently begun such broadcasting with the inauguration of the WGBS-Jenkins station at Fifth Avenue and Fifty-second Street. The Columbia Broadcasting System should be on the air with an experimental television transmitter by the time this story has been printed. The National Broadcasting Company has been operating experimental television station W3XBS atop the New Amsterdam Theater building for several months. Their sole transmissions, however, have been views of cards and of Felix, a wooden cat. Boston experimental stations created a stir in that city some time ago when television images were picked up in a local store and shown to the general public. Hundreds of interested visitors lined up for hours to glimpse the one-inch square images which were reflected from a television receiver. A news story widely published by newspapers throughout the country recently told of television images being reproduced by M. A. Sanabria, a Chicago engineer, on a ten-foot screen. Investigation proved that this was actually being accomplished, although the equipment utilized was in an experimental stage and highly expensive. It was designed, the inventor hastened to explain, for use in theaters and large auditoriums. Triple scanning, neon arc lamps and electrical retouching have also been introduced by Sanabria. Another company, known as Radio Pictures, has been transmitting images for many months in the A television receiver which presents pictures tight inches tquare (R. /.. Rcplogle, assistant to president nj Jenkin Deforest Co.). New York area. In Washington, D. C, Jenkins has long been transmitting half-tones, motion pictures and silhouettes from W3XK. Images from this station have been on the air since 1925. The Baird Television Corporation of Great Britain has established offices in New York. Although the Baird interests have no transmitter in operation here, they are London's leading television experimenters and broadcasters, where they have contributed nobly to the science with many developments. Baird and Jenkins claim to be the pioneers of the industry, although the General Electric Company and the American Telephone and Telegraph Company have both been engaged in laboratory experimentation for years — perhaps before either of the two inventors who brought their researches before the public at earlier dates. General Electric, it is said, was the first to broadcast an actual play by television. Three television cameras, or projectors, were utilized for this unusual transmission which took place between 1925 and 1927. Line-wire television demonstrations are being shown regularly by the A. T. & T. in their New York laboratories. Their results are striking, to say the least. Clear and sharp are the pictures as one sees them in the strange little telephone-television booths especially constructed for the demonstration. Parts for construction of television receivers arc readily obtainable in most of the large cities. Completed receivers are making their appearance on the markets, although they are rather expensive for the average radio listener. Small television units may be purchased for $100, which, when operated in conjunction with proper semi-short-wave receiving equipment, will give clear pictures about one inch square. It might be said here that the televisor unit is attached to Television Eyes in the NBC Experimental Studios the receiver in the same manner as the conventional loud speaker. Television receivers must utilize resistance coupled amplifiers, with power tubes. They must tune broadly and have a range of between 100 and 200 meters. The one main requisite of television reception is to obtain loud signals. The louder you hear television signals, the clearer and brighter will be your images, since the neon tube in the televisor depends on this superimposed current from the amplifiers of your receiver for its brilliance and resultant pictures. The receiver must, in the case of television reception, tune broadly. If it tunes sharply, you will obtain distorted images. A televisor consists of a synchronous motor, which must run at the same speed and phase as the transmitting motor. This motor turns over a scanning disk, which contains forty-five or fortyeight or sixty holes carefully spaced. These holes must correspond with the holes in the transmitting scanning-disk. They form the lines of your picture. Thus it is said that you receive forty-eightline pictures or sixty-line pictures. Television has been somewhat simplified in this respect in the East, since an agreement reached last month will make it necessary for all television transmitters to utilize the sixty-line transmitting disks. Behind your disk there is the neon tube, on whose plate the images appear to form while they are being scanned. Then through a magnifyingglass you peer through the disk at the plate and the images become visible. The commonly used scanning-disk is gradually being replaced in laboratories by the drum scanner-disc, which, through the added use of powerful magnifying-glasscs, will give sharp and clear images eight inches square. This equipment is intended for home use. Of course, much larger images can be obtained where money is not an important factor in purchasing equipment. (To be con tin lied next issue.) \ situ I*!,, home television set over which Doi othy SchuJt, wife oj CBS "Going to Press" man, is viewing motion pictures from Boston in her New York home.