Abstract: A multichannel signal transmitting and receiving apparatus comprises a single reference local oscillator, a phase locked loop including a phase comparator receiving as one input a signal resulting from a frequency division of the output of the local oscillator and a voltage controlled oscillator, a frequency divider for supplying the output of the voltage controlled oscillator as another input to the phase comparator, a circuit for heterodyning a signal received through an antenna with the oscillation outputs of the voltage controlled oscillator and the local oscillator and thereafter detecting the signal thus heterodyned thereby to obtain an audio signal, a frequency converter for obtaining a carrier wave for signal transmission from the oscillation outputs of the local oscillator and the voltage controlled oscillator, a circuit for modulating the carrier wave thus obtained with the audio signal and transmitting the modulated signal through the antenna, a circuit for controllably changing over the oscillatio