Multiplex signal receiver

A multiplex signal receiver used for multiplex signal transmission systems which transmit two independent signals by amplitude modulation and angle modulation of a single carrier, said receiver comprising:

• a switching circuit;
• an angle demodulator for demodulating an angle modulated signal component of a signal received by said receiver;
• an envelope detector for demodulating an amplitude modulated signal component of said received signal;
• an intermediate frequency detector for detecting an intermediate frequency and for outputting a control signal for controlling said signal switching circuit;
• and
• a matrix circuit for modifying an output signal of said angle demodulator and an output signal of said envelope detector by addition and subtraction thereof so as to obtain two output signals for driving a two channel amplifier through said signal switching circuit;
• wherein said signal switching circuit is supplied with said two output signals of said matrix circuit and the output signal of said envelope detector and selects as its output signals either said two output signals of said matrix circuit or said output of said envelope detector according to said control signal;
• and wherein said selection of the output signals of said signal switching circuit is dependent upon the closeness of said intermediate frequency to a predetermined frequency, and wherein the frequency range of said intermediate frequency for selecting said two output signals of said matrix circuit as the output signals of said signal switching circuit is set according to the characteristics of an intermediate frequency filter included in said intermediate frequency detector.