| 摘要 |
PURPOSE:To allow one modulator to modulate any of a scramble television signal and a non-scramble television signal. CONSTITUTION:An AGC clamp processing circuit 26 implements the processing to supply a scrambled television signal to a modulation circuit 12 modulating a television signal. A polarity inversion clamp processing circuit 22 implements the processing to supply a non-scramble television signal not scrambled to the modulation circuit 12. One of outputs of both the processing circuits 22, 26 is selected by a changeover switch 16 and fed to the modulation circuit 12. The selection is implemented by a control signal from a descrambler or a receiver supplying the scramble television signal and the non-scramble television signal. |
