| 摘要 |
PURPOSE:To enable to monitor the complicated and large scale CATV system, by synthesizing the monitor signal per amplifier group and retransmitting it to the monitor room. CONSTITUTION:The TV signal received is transmitted to the coaxial cables A, B, C via the monitor room 2 from the head end 1, and each cable is provided with the signal converters 3-6, amplifier groups 31-, 41-, 51-, 61-. Further, for example, each amplifier of the amplifier group linked to the converter 4 modulates the specific carrier with the signal in response to the operating condition and outputs the monitor signal. Then, the converter 4 receives the carrier of each amplifier to form the composite monitor signal and specific carrier assigned is modulated and outputted to the monitor room 2. The carrier of each amplifier and frequency of carrier of the converter 4 are selected to remarkably increase the number of sets of amplifiers to be monitored. Accordingly, complicated and large-scale system can be monitored. |
