| 摘要 |
PURPOSE:To suppress occurrence of the inversion phenomenon without deteriorating the S/N by making variable equalizer characteristics which are added to a regeneration FM video signal linearly or nonlinearly in accordance with a demodulation video signal. CONSTITUTION:An output regeneration FM video signal of a preamplifier 9 is supplied to a dynamic equalizer circuit 21 through a delay circuit 17, and it is supplied to an equalizer circuit 16 inside a regeneration video signal level detection circuit 15. The level detection circuit 15 is connected to the equalizer circuit 16, a limiter 18, an FM demodulation circuit 19 and a low-band filter 20 longitudinally. The demodulation video signal of the regeneration FM video signal is supplied to the dynamic equalizer circuit 21 as the level detection signal from the low-band filter 20. Although the equalizer circuit 16 is the conventional type, the circuit 21 is a circuit which makes variable the ratio of the level strength for low-band frequency components for high-band frequency components of the input regeneration FM video signal linearly or nonlinearly. |
