CODEUR, DECODEUR AUDIO POUR SYSTEME DE TELEVISION SUR ANTENNE COLLECTIVE

摘要

In a Community Antenna Television (CATV) System, a system for hiding the audio portion of a television program from unauthorized television receivers connected to the CATV distribution system, is provided by converting the video carrier frequency to another frequency whereby intercarrier demodulation at a receiver, which is necessary to recover the audio program, cannot be accomplished. Provision is made at authorized receivers for restoring the video and audio carriers to their proper relative frequency locations.