Automatic cable attenuation compensation system

Claim 1

An automatic cable attenuation compensation system for use in compensating for cable attenuation losses in a signal transmitted in a cable, comprising: means for generating and adding at least one test signal to the signal being transmitted in the cable at one end of the cable; a fixed compensation part (FC-R/G/B) coupled to another end of the cable, said fixed compensation part having a plurality of fixed compensation sections thereby providing a stepwise adjustable attenuation compensation for substantially compensating cable attenuation over an entire predetermined range of compensation, said fixed compensation part further including a measuring and setting circuit for measuring the test signal and for activating selective ones of the plurality of fixed compensation sections until a level of said at least one test signal reaches a predetermined reference level, the stepwise adjustable attenuation compensation of the fixed compensation part being set after power-up; and an adaptive compensation part (VC-R/G/B) coupled to an output of said fixed compensation part, said adaptive compensation part including a means for measuring said test signal and for generating a control signal based on the level of said at least one test signal, and automatic gain control means coupled to said measuring means for providing a continuously active compensation, equivalent to one of said stepwise adjustable attenuation compensation of said fixed compensation part, for a further compensation of the cable attenuation based on said control signal.