| 摘要 |
PURPOSE:To reduce the distortion and to improve the S/N ratio, by controlling the demodulation level of a subsignal and the frequency characteristics of a main signal of a stereo multiplex decoder with an output frequency component after decoding. CONSTITUTION:An FM intermediate signal from a terminal T1 is detected at an FM detector 1 and outputted from terminals T2, T3 as left and right signals at a stereo multiplex decoder 2. This output is applied to a peak detection diode 8 via an adding amplifier 3, netowrk 4, amlifier 5, and a filter 6 to perform the peak detection, and a DC component is obtained at a filter 9 and picked up at a control signal. The control signal is applied to a frequency characteristic controlling circuit 2C of the main signal of the decoder 2 via a line 11 and the frequency characteristics of the main signal and the demodulation level of the subsignal can be controlled. |
