Abstract: A multipath noise detecting circuit, which is not affected by ignition noise nor by the level of the antenna input voltage, includes a band pass filter having a mean frequency of 114 KH supplied with signals output from a FM demodulator, an AM detector for subjecting the signal input from said band pass filter to AM-detection, and a detector section for detecting as multipath noise the pulses included in the signal output from said AM-detector.

Abstract: A radio receiver has a first radio receiving part which receives the signal of the desired radio broadcasting station, a first receiving field intensity detector which detects the receiving field intensity of the desired signal received by the first radio receiving part, a second radio receiving part which receives an interference signal having the frequency adjacent to the desired signal frequency, a second receiving field intensity detector which detects the receiving field intensity of the interference signal received by the second radio receiver, a receiving frequency controller which generates a control signal for controlling the frequency of the desired signal received by the first radio receiving part in such a direction to become more remote from the disturbing signal frequency based on the receiving field intensities of the desired signal and disturbing signal detected by the first and second receiving field intensity detectors, and a local oscillation frequency controller which controls a local osci