| 摘要 |
PURPOSE:To obtain a sound signal free from buzz disturbance by reproducing a buzz disturbance component essentially included in the demodulated output of a sound subcarrier, and subtracting the reproduced component from the demodulated output. CONSTITUTION:The output from a sound detecting circuit 35 is inputted to a subtractor 12 and the output from a voltage control oscillator(VOC) 44 is led into the other input of the subtractor 12 through an FM demodulator 11. The output signal from a mixer 42 includes an FM component and the FM component is generated in the output signal from the VOC 44, so that its own buzz disturbance can be extracted by demodulating the FM component by the FM demodulator 11. On the other hand, a mixer 41 executes synchronizing detection on the basis of the output of the VCO 44 including the FM component, its output includes an FM variance and a buzz disturbance component is included also in the output of a sound detecting circuit 35. When the output of the FM demodulator 11 is subtracted from the sound demodulation output, a sound signal from which the buzz disturbance component is removed is outputted from the subtractor 12.
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