FM RADIO SET WITH WIRELESS MICROPHONE

PURPOSE:To decrease number of components, to simplify the adjustment and also to attain miniaturization by adopting the constitution that a tank circuit of a transmission circuit and an antenna tuning circuit of a receiver use in common a filter. CONSTITUTION:A high frequency signal picked up by a cord of a earphone 12 is inputted to the filter 4 via a jack. A switch 13 is thrown to the position R at reception, a diode 14 is conducted, a high frequency signal of an FM radio broadcast band appears at a terminal 1 of the filter 4 by the band pass characteristic of the filter 4 and is inputted to a point A. A reception circuit 9 receives the high frequency signal of the point A, outputs a demodulation signal B, which energizing the earphone 12 by using an amplifier 10. In throwing the switch 13 to the position T, a circuit comprising a transistor (TR) 16, a coil 17 and a variable capacitor 18 starts the oscillation of a transmission frequency, and the oscillated output is subject to cascade amplification by a TR20. The filter 4 acts like a load of the TR20 and also eliminates a harmonic component included in the amplified output, and the signal is transmitted from a terminal 3 via a jack 11 by using the cord of the earphone 12 as an antenna.