A first PIN diode (DR1) is connected to the input side of a tuner (T) at the front end of an FM receiver, in an AC coupled fashion parallel to the tuner (T). A correction inductance (L₂) is connected parallel to the first PIN diode (DR1) in an AC coupled fashion. The tuner (T) is connected, at its output side, parallel to a series-connected circuit of a correction capacitor (C₆) and a second PIN diode (DR2). The anodes of the first and second PIN diodes (DR1,DR2) are supplied with an automatic gain control (AGC) voltage. When the AGC voltage varies, the resistances of the first and second PIN diodes (DR1,DR2) vary in a manner to adjust the degree to which the correction inductance (L₂) and the correction capacitor (C₆) affect the resonance in the tuner.
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