| 摘要 |
PURPOSE:To change a setting of a scramble channel freely by an indication from a center side by generating an interference wave time shared correspondingly to the respective channel in a distribution unit, and selecting an insertion or an exclusion of the interference wave by the control from the center side according to the condition of a channel registration with respect to respective terminals. CONSTITUTION:In a ditribution unit 11, a television signal from a branch line 10 is separated to a television signal and a data signal superimposed thereto in a signal separating unit 7. Then, the data signal is fed to a main control unit 1, based on the information, to an RF switch unit 4 corresponding respective terminals, control signals are fed in accordance with an audio and visual permission situation corresponding to respective channels. From the main control unit 1, a voltage signal time shared correspondingly to the respective channels is given to an interference wave generating unit 2. In this case, the interference wave generating unit 2 has a voltage control oscillator. A control voltage signal in which a voltage is changed stepwise correspondingly to the respective channels in the main control unit 1 is given to the interference wave generating unit 2. |
