A New Modulation Concept in Channel Translating Equipment

Modern technology has made it possible to develop a new channel translating equipment capable of modulation directly into the 12-552-kHz frequency range. This range is chosen to include the basic 60-channel supergroup (312-552 kHz) together with supergroup 1 (60-300 kHz) and group A (12-60 kHz). The channel translating equipment is arranged to provide sideband orientation compatible with the North American and CCITT frequency plans. The inclusion of the basic 60-channel supergroup permits direct connection to standard supergroup translating equipment obviating the need for the traditional group bank. This equipment has been designed to anticipate the trend toward large channel cross sections where the need for the basic 12-channel group is diminishing. The channel translating equipment developed is described and its flexible application to both high- and low-density systems is illustrated.