PURPOSE: To make to coincide a RF signal level by each channel and to highly improve the reliability of a signal processing equipment by comparing the RF signal level by channel, feeding back a correcting value of by the level difference and regulating an amplification gain.

CONSTITUTION: The peak value of the RF signal by channel inputted from each front end amplifiers 4', 5' is detected with a detector 15, and outputted via a LPF 16 as a reproduction RF signal level detecting signal of each channel. This detecting signal is fed to a detection comparing part 13, the size of the RF signal level of two channels is compared, and a switching control signal for a channel to be compensated is fed to a switching part 14. In the switching part 14, one of the output of convertors 11, 12 is fed back as a gain regulating signal of amplifiers 4', 5' and whereby the gain of the related amplifier is corrected.