Bidirectional cable network with a mixing tap for suppressing undesirable noise in signals from a remote end of the network

摘要

Noise energy and other undesirable signals are suppressed in a return frequency band of a return path of a bidirection cable network. Data signals in a third frequency band and a prybar signal are transmitted on a user site to a mixing tap. The mixing tap contains a filter for eliminating signals in the return frequency band generated at the user site. The prybar signal is received by the mixing tap and activates a local oscillator. The third band signals and oscillation signals are applied to a mixer in the mixing tap and the third band signals are converted to return band signals. This mixing tap then applies the return band to the return path of the cable network.