Abstract: A radio receiver in which, even with large variability in the components, the receiving conditions can be set according to the antenna input level in a uniform way. A high frequency cutoff circuit 30 reduces high frequency components in a composite signal by a high frequency cutoff ratio depending on a voltage applied to an HCC pin 30a. A principal signal included in the composite signal is demodulated by a principal signal demodulator 32, and a subsidiary signal is demodulated by a subsidiary signal demodulator 34. In the subsidiary signal demodulator 34, based on a voltage applied to a SPC pin 34a, the subsidiary signal demodulation level is varied from 0 to 100% according to stereo separation characteristics, to control the stereo separation. A matrix circuit 36 regenerates left and right channel signals from the demodulated principal signal and subsidiary signal. A microprocessor 20 inputs a signal meter output voltage from an FM detector IC 12.

Abstract: In a tuner for converting antenna input signal into audio signals, tuner circuit components are mounted on a tuner circuit substrate. Of the tuner circuit components, FM wave front end circuit components constituting a high-frequency amplifying circuit, a mixing circuit and a local oscillating circuit are surrounded by a shield case. An antenna jack including an earth tube and a signal terminal insulated from the earth tube is mounted on the tuner circuit substrate. The signal terminal of the antenna jack is connected to an antenna input signal pattern of the tuner circuit substrate. The earth tube of the antenna jack is forced in and supported by a jack attachment plate that is an extension of the shield case.