| 摘要 |
PURPOSE:To attain excellent equalization and to improve the grade of picture quality, by detecting various signal changes generated in a relay line propagating path so as to stabilize the level ratio of a video intermediate frequency signal versus sound intermediate frequency signal. CONSTITUTION:A distributor 54, filter circuit 57, sound intermediate frequency signal amplitude modulation component pickup circuit 58, synthesis circuit 56 and a phase shift circuit 55 form an amplitude modulation component suppressing circuit. When an input signal is normal, no output of a synthetic circuit 62 is supplied, the degree of quality of the input signal is kept and the operation is performed so as to attain the objective only when the input signal is failured for attaining the compensation. Thus, the reliability of characteristic of a main signal line is improved, and this suppression circuit means exerts no adverse effect. Since a video intermediate frequency signal and a sound intermediate frequency signal are not treated by separation as shown in Fig. 3, the circuit is operated with a good performance even with the increased band width relating to the sound signal. |
