A method and apparatus for automatic compensation of insertion loss in signals transmitted over conductors is presented. The present invention is particularly applicable to the transmission of signals over long lengths of CAT-5 or similar twisted-pair cables. A reference signal having a known form and strength (e.g. a pulse signal) is provided to each pair of conductors carrying a component of a signal from a transmitter to a receiver. The receiver includes adjustable gain amplifiers for each conductor pair over which a component of the signal is transmitted. The gains of the amplifiers are initially set at an initial level (e.g., their maximum gain) to allow detection of the reference signal. Once the reference signal is detected in a conductor pair, the amplifier gains are adjusted such that the level of the reference signal is restored approximately to its original form and strength.