CATV NETWORK WITH FILTERS

摘要

For use in a CATV network, an upstream filter circuit comprised of at least one bandpass filter for receiving an upstream signal, an electronic switch connected to the output of the at least one bandpass filter for applying a filtered upstream signal from the at least one bandpass filter to an upstream line, apparatus for detecting the energy level of the filtered upstream signal at a point between the at least one bandpass filter and the electronic switch, and apparatus for enabling the electronic switch to close in the event the energy level is above a predetermined threshold.