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

and thousands of new receivers for these channels are reaching Amer- ican homes daily. If and when additional channels in the higher frequency band are opened to television, their function will be to supplement, not to replace, the channels already in use. Instru- ments now in service will continue to serve, and new instruments also will come into American homes in much the same way that a new streamlined automobile takes to the road alongside cars that are 10, 20 and even 25 years old—and all con- tinue to give service to the public. The Radio Corporation of Amer- ica has done more to investigate the ultra-high frequencies (UHF) than any other manufacturer or broadcaster. Its experiments go back many years, and have been on a virtually continuous basis ever since. These experiments, described in articles widely read throughout the industry, have provided the main basis for the consideration of television in the UHF band at the hearings held by the FCC. With this background of experience, unique in the industry, RCA pre- sents the following facts regarding television today and its possible lines of development in the future: Original Channels Retained In 1945, the FCC established 13 channels for commercial television broadcasting between the frequen- cies of 44 and 216 megacycles. These channels have remained unchanged to the present day, with the excep- tion of Channel #1, from 44 to 50 megacycles, which was transferred to another service before it was put into commercial use. The only com- mercial television authorized by FCC is on the 12 channels from 2 to 13, inclusive. All RCA Victor television receivers and nearly all other television receivers have been engineered and manufactured to these standards, the only standards authorized by the FCC. These fre- quencies are referred to as VHF (very-high frequencies) in contrast to UHF (ultra-high frequencies). The continuance of channels 2 to 13 for television broadcasting is un- questioned. As previously men- tioned, FCC Chairman Wayne Coy has stated positively that this is so. It is well recognized in the in- dustry that a need does exist for additional channels to supplement the present ones, in order that all sections of the country may have full enjoyment of television service. The only space available for these additional channels is in the ultra- high frequencies. Therefore, it is assumed that the FCC will author- ize these frequencies for television use if and when experiments, in- cluding field tests, prove them prac- tical and reliable for regular serv- ice to the public. Where UHF Stands Today Although UHF has been studied intensively, and numerous tests have been conducted by RCA and others, much information necessary to its practical operation is still to be de- veloped. The situation as of last September was summarized in a re- port to the FCC by the Joint Tech- nical Advisory Committee of the Institute of Radio Engineers and the Radio Manufacturers Associa- tion, as follows: "JTAC finds that there is no commercial equipment for UHF television available at this time. It estimates that a period of not less than one year, possibly two or three years, will be required to develop and produce transmitter tubes suitable for short-range coverage, for the 475-890 mega- cycle band and UHF television receivers suitable for commercial production. The development of equipment, particularly receivers, must await the adoption of per- formance specifications, which in turn depend on the availability of further engineering informa- tion." It will be noted that this state- ment emphasizes the development period of UHF transmitter tubes — only one element of many involved in the establishment of a practical UHF television system. RCA began its more recent UHF tests from the Empire State Build- ing, New York, early in 1946. A second field test was conducted in the Washington, D.C. area during the Fall of 1948. During this test television programs were broadcast simultaneously on VHF and UHF to provide comparisons between these two frequency bands. Full technical reports covering the operation of the.se stations have been published. The information needed is still far from complete and RCA is now un- dertaking tile erection and opera- tion of another UHF television sta- tion in Bridgeport, Conn., with the objective of obtaining solutions to remaining problems. This station is expected to begin operating for tests late in 1949. It is impossible for anyone to predict with accuracy when UHF television will become a practical reality. The approval of FCC, the setting of standards, the designing of transmitters and receivers, all have to follow the solution of engi- neering problems. RCA Victor television receivers are designed and manufactured to provide the customer with the finest obtainable television at the lowest possible price. While keeping the customer's future needs constantly in mind, nothing has been added to increase the cost of his equipment today. If a manufacturer has par- tially provided for possible conver- sion to UHF in current receivers, the customer is paying for such pro- vision today for an arrangement which may prove inadequate to- morrow. Facts for the Customer The customer should be told these facts: (1) The additional cost to the buyer of equipment built by the manufacturer into re- ceivers today for possible use on UHF tomorrow. (2) The still/!/rf/tercosi of mak- ing this equipment usable when UHF comes. (3) Whether the UHF equipment built into the television re- ceiver today will be sufficient to receive on any UHF chan- nels which the FCC may allo- cate eventually. To determine the real cost to the consumer of converting his receiver to UHF, it will be necessary for him to add these first two factors together—that is, the initial extra cost of built-in UHF equipment and the future cost of adapting it to actual use. In the RCA Victor method previously referred to, the (Continued on page 27) [R.ADI O AGE 7]