摘要 |
In transmission of information over junction routes with exchanges, the feedback circuits that occur in hybrid sets are a major problem. High demands are made of them and the balancing networks. This invention eliminates these shortcomings in that quasi-4-wire circuits are formed by providing coded alternating currents of different frequencies and/or frequency positions for the two transmission directions and filters with high stop band attenuation for the opposite direction are provided when it is necessary to separate the two transmission directions.
|