PURPOSE: To ensure an optimum working state of a high frequency amplifying transistor at each receiving band by setting the resistance value of a voltage supply resistance at different levels according to the receiving bands for an input tuning coil switching diode connected to a receiving band switching current terminal.

CONSTITUTION: A voltage supply resistance 33 of an input tuning coil switching diode 39 doubles as a voltage supply resistance to a gate terminal of a high frequency amplifying transistor TR35 when the voltage is applied to a BL terminal 16 in a VHF low channel. While a voltage supply resistance 38 of the diode 39 doubles as the voltage supply resistance to the gate terminal of the TR35 when the voltage is applied to a BH terminal 26 in a VHF high channel respectively. Then the voltage supplied to the gate terminal of the TR35 via the resistances 33 and 38 is set at different levels at each receiving band. Thus an optimum working state is secured for a high frequency amplifying TR at each receiving band.