PURPOSE: To adjust received frequency precisely with a simple constitution by providing the titled device with a circuit for outputting a signal having the frequency corresponding to receiving frequency lagged by the frequency of a normal intermediate frequency signal from the oscillation frequency of a local oscillating circuit.
CONSTITUTION: A required signal is applied to a control terminal 1 to actuate a motor control circuit 13, an intermediate frequency oscillator 15 and a mixing circuit 16 respectively. Consequently, the mixing circuit 16 mixes the output of the intermediate frequency oscillator 15 with the output of the local oscillating circuit 8 and outputs a high frequency signal having the frequency equal to the received frequency. Under said status, a switch 2 is turned off, said high frequency signal is applied to the receiver and an output obtained from an intermediate frequency amplifier circuit 9 and a wave detecting circuit 10 is applied to a level detecting circuit 12. In addition, a motor driving circuit 13 is controlled so that each output shows its peak value and the capacitance value of a variable capacitor 4 is adjusted by a motor 14 so that precise receiving frequency is obtained.
MIYANAGA KATSUHIKO
KUBOTA JIYUNICHI
