PURPOSE: To easily reproduce an IF signal without provision of a PLL circuit consisting of a frequency divider, a phase comparator and a reference signal oscillator for reproducing the IF signal by mixing an output of a voltage controlled oscillator and an output signal of an FM modulator so as to extract the IF signal.

CONSTITUTION: A control output signal of a phase comparator A4 required to make a frequency of a direct FM modulator 2 stable is branched to a VCO 8 to control the VCO 8, from which a local oscillation signal fL is obtained. Then the local oscillation signal fL and a transmission high frequency signal fo are mixed by a mixer 9 and a difference frequency is used for a reproduced IF signal. In this case, the relation of IF=fo-fL is established and a circuit with the same characteristic such as a temperature declination in the oscillating frequency or the like as that of the direct FM modulator 2 is employed for the VCO 8, then the IF reproduction signal frequency is kept substantially constant. Furthermore, the frequency deviation in the reference signal oscillator A5 is cancelled by the mixer 9. As a result, the IF reproduction is implemented by using the VCO 8 and the mixer 9 only and then the circuit is simplified.