The Possibilities of Reduced Television Bandwidth

A solution is sought to the following problem: Given a wide bandwidth of the order of 50 kc, devise standards such that the entertainment value shall be maximized. Four applications are considered: tape recording at a tape speed of 15 inches per second; telephone conversation accompaniment over high-quality telephone lines; long-distance wire-line transmission over high quality telephone lines; and short-wave transmission over a 120 kc channel. Bandwidth reduction is achieved through reduced resolution, reduced field frequency, increased interlacing ratio, the use of dot interlace, and the use of quantizating and coding. The scanning frequencies and synchronizing signal are derived for each case. In addition, for the short-wave system, a method of combating multipath transmission is suggested.