| 摘要 |
PURPOSE:To stabilize the operation with a high S/N for a nonlinear compensating circuit, by eliminating the cross modulation component out of the multiplex signals by means of a signal obtained by multiplying the carrier component of high frequency signals forming the multiplex signals by a low frequency signal with a prescribed relation between the amplitude and the phase. CONSTITUTION:A multiplex signal shows a video FM signal with a fed 10 frequency, a sound FM signal with the amplitude respectively. Such multiplex signal is set at a prescribed level at a level control circuit 13 by a control signal supplied through an input terminal 12. The sound FM signals separated through a filter 14 are supplied to a multiplying circuit 17. At the same time, the carrier component of the video FM signal is separated from the multiplex signal through a filter 15. This carrier component receives a phase shift 16 of pi/2 radian of the carrier wave and is supplied to the circuit 17. Then the output signal of multiplication of the video FM carrier wave and the sound FM signal is supplied to an adder circuit 18. Thus the cross modulation in the multiplex signal supplied from an input terminal 10 is offset and delivered 11. |
