PURPOSE: To eliminate a relative frequency variation of an input signal and also to make a titled circuit small-sized and light as a whole by mixing and generating an oscillating signal of one oscillator and oscillating signals of M pieces of oscillators, which use in common a receiving local oscillating signal.

CONSTITUTION: Local oscillating circuits of N sets of receiving devices in a radio repeating installation are constituted so that plural receiving waves f1∼ fN of different frequencies are converted to the same intermediate frequency fTF, each signal is switched and connected like time division, and thereafter, they are converted to different frequencies again and are transmitted. Subsequently, from an oscillating signal fL of one oscillator 10 used in common and at least another local oscillating signal, M pieces (M≤N) of oscillating signals whose frequencies are converted so as to be different from frequencies of plural receiving waves f1∼fN by the intermediate frequency fIF, respectively are used as local oscillating signals fL1∼fLN of each receiving device.