A Single-Side-Band Receiver for Short-Wave Telephone Service

A new radiotelephone receiver has been developed for the reception of reduced-carrier single-side-band signals in the frequency range from 4 to 22 megacycles. This receiver employs triple detection in which the first beating oscillator is continuously variable and the second is fixed in frequency. The first oscillator is a very stable tuned-circuit type, the proper adjustment of which is maintained through the use of an improved type of synchronizing automatic-tuning-control system. The second oscillator is crystal controlled. Separation of the carrier and side band is accomplished in the receiver by means of band-pass crystal filters which provide extremely high selectivity. Unusually high stability and selectivity characterize the performance of the receiver.