Multiple carrier frequency generating system - for pre-modulators generates twelve carriers at four KHZ intervals from basic four KHZ

摘要

The multiple carrier frequency generating system, for pre-modulators, generates channel carriers of 112 to 156kHz at spacings of 4 kHz, and the premodulation frequency of 48 kHz all form a 4kHz fundamental by converting to pulses, filtering, multiplying and amplifying. The 12 and 28 kHz harmonics are produced and are converted into rectangular-wave pulses to give - along with the converted 4 kHz - three basic signals that can be multiplied by various integers to give the required total of 13 output signals. The advantage of the generating system is that the number of filters required is reduced.