Radio age research, manufacturing, communications, broadcasting, television (1941)

casliii}! Company and the Don Lee OriJ^anization in California. It was put into service in the hitter part of 1939. After sufficient field experience had been obtained, certain limita- tions were found. In particular, in televising: football games, which are an extremely popular source of programs, it was discovered that when the late afternoon shadows fell on the field, the sensitivity of the cameras was not sufficient to produce a good quality picture. The next step in the program, there- fore, was to adapt the newly devel- oped orthicon to a field camera. . . . This tube is approximately ten times as sensitive as the iconoscope and greatly extended the scope of (ielil operations. Requires Small Staff 111 UtlO anil Utll, (irthiccin typi- field ei|iiipment was developed anil constructed for such organizations as the Bell Telephone Laboratories, Columbia Broadcasting Sy.stem, National Broadcasting Company, and Don Lee. It proved to be very satisfactory and enjoyed a variety of uses. For example, all of the pick-ups from Madison Square Garden are made with this type of apparatus. It is easily .set up and is so designed as to permit opera- tion by a small staff of technicians. In actual use, the camera control and master control units are grouped with the synchronizing generator at some central control location. It is possible at this loca- tion to preview the picture from each of the cameras before switch- ing to the relay transmitter through the master control unit. The cameras are, of course, located on the field of action and can be spaced as much as 500 feet from the central control location. The relay transmitter and receiv- er supplied with this apparatus were designed for operation in the 300 megacycle band. They employ directive antenna systems and sat- isfactory line of sight transmission over ranges up to ten miles has been obtained. In the cameras, provision was in- corporated for using a variety of lens types. During an actual pick- up, it is usual practice to provide one of the cameras with a long focal length lens to permit close-ups [22 RADIO AGE] while the oilier camera is used with a short, or medium, focal length lens in order to cover a wide portion of the field of action. Panning and lilting heads, of course, are stand- ard e(|uii)nK'nt. ^■iew finders arc provided in the cameras so that the cameramen not only can follow the action in the field but also can por- form optical focusing. The camera control units contain the deflection generators and ampli- fiers for the cameras and the w^ide band high fidelity video amplifier. .A 7-inch monitor is included in each camera control unit as is also a 3- inch oscilloscope to permit accurate adjustment of the signal level. Signals from the various camera control units are connected to the input of the master control. In this miit. synchronizing signal is mixed with video signal and switches are jjrovided for switching I lie output of any one of the cam- eras to the outgoing cable. The 7- inch monitor is connected to the outgoing cable and a 5-inch oscillo- scope is incorporated to maintain signal level ad.justments. The out- going cable, of course, feeds the re- lay transmitter. The synchronizing generator con- sists of two units—one being the master pulse generator, and the other containing the shaping cir- cuits where the synchronizing pulses, blanking pulses, and deflec- tion pulses are formed. The receiver, like the rest of the apiiaratus, has wide band amjilifiers so that no loss of definition results. A\C circuits are i)rovided to mini- mize the effects of signal fiuctua- tion. Generally, the receiver is lo- cated in either the main studio or the main station transmitter room. A photograjih of this jirewar ap- liaiatus is shown. Improvements Planned When we are again in a position to start the manufacture of televi- sion station equipment, there are a number of additional improvements that may be incori)orateil. For example, it may be possil)lt' to build our new equiiiment ai'oiind a more sensitive pick-up tube. It would be possible with this equip- ment to televise nearly any scene that can be clearly observed by the human eye. It is likelv that the relay trans- mitter and receiver will operate on higher frequencies and con.sequent- J ly, for the same range of satisfac- " tory transmission, will be consider- ably smaller and lighter in weight. This will be made possiltle through the use of extremely directional an- tenna systems. It is also expected that the de- sign of the apparatus will be of such form as to permit a more rapid set-up on the field of action. A sta- tion wagon or truck can be utilized and the interior arranged so that the control units can be mounted on an operating desk and remain in l)lace during those pick-ui)s where it is possible to drive the station wagon or truck near to the scene to be televised. This would make necessary the removal of only the cameras from the truck and will materially reduce the set-up time, ri'ovisions could be made for the easy removal of the control and J other units so that, when it is not \ possible to get the truck close to the scene of action, the entire set could be removed in a very short time and iilaced in oiieration on the field. Better Programs Possible With this type of equiiiment, the scope of field pick-ups will be great- ly extended. Events that previously could not be televised because of equipment limitations, such as low sensitivity, could then l)e success- fully utilized. It would, for exam- ple, be possible to use the apparatus in a department store for demon- strating products via television to the public or to customers in other parts of the store. This could be done without resorting to the ex- pensive and powerful lights that are now required for adequate il- lumination. Basketball games, hockey, and I>rize fights could be satisfactorily televised without supplementing the existing lighting systems. Night l)aseball and football could be used successfully for the first time as television program material. Many other new sources of material would be uncovered. Such equipment will do much to accelerate the progress of televi- sion. It will make possible far bet- ter programs at lower costs, and thus will encourage public accept- ance of the new service. i