| 摘要 |
PURPOSE:To improve various characteristics such as S/N even at the reception of monaural broadcast, by detecting the presence of a pilot signal and interrupting a pilot cancellation signal with a switch means when no pilot signal exists. CONSTITUTION:A detecting circuit 11 detects the presence of the pilot signal and a switch circuit 12 is controlled so as to be opened and closed with the detected output in response to the presence of the pilot signal. A pilot cancellation signal from a waveform shaping circuit 8 is supplied to a pilot cancellation circuit 5 at the opened state so as to cancel the pilot signal in the receiving signal, and an output side of the waveform shaping circuit 8 is grounded at the closing state, and since the output from the waveform shaping circuit 8 is not supplied to the cancellation circuit 5, the noise component such as hum and self-running frequency signal of an oscillator 2d is eliminated, thereby improving the S/N. |
