| 摘要 |
PURPOSE:To prevent a configuration of a CATV center from becoming too complex, to avoid the quality of BS, CS signal from degrading and to let a company which broadcasts BS, CS manage subscribers to CATV when a satellite broadcast is transferred by CATV. CONSTITUTION:BS, CS signal is demodulated by a BS, CS tuner 2, and then that demodulated signal is modulated by a TV modulator 3. At the same time, a sound sub-carrier is taken out of the detected output of the tuner 2, and then its frequency is converted by a converter 4 into a dead channel of CATV, and then the outputs of both the converter and the TV modulator are forwarded to a transfer path 5 of CATV at once. Mean while, by a democlulator 7 in a subscriber's house, the signal on the transfer path 5 is demodulated so as to be inputted into a decoder 8, and the sound sub-carrier is permitted to be a bit stream signal by a receiver 9. By the bit stream signal, scrambling between a video signal and a sound signal is released at the decoder 8.
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