Telephone carrier system repeater and power supply

A signal-amplifying telephone carrier repeater adapted to be connected to a two-conductor transmission line in a plural channel amplitude modulated telephone carrier system in which said transmission line has a preselected cable gauge and is connected to transmit a plurality of first frequency division multiplexed carrier signals in one direction from a signal source to the telephone carrier repeater and to transmit a plurality of second frequency division multiplexed carrier signals in the opposite direction from the telephone carrier repeater to a termination, said signal-amplifying telephone carrier repeater comprising first means responsive only to a first preselected one of said first carrier signals following its transmission over said line for producing a first d.c. control signal whose magnitude varies as a function of the level of just said first preselected one of said first carrier signals, second means responsive only to a second preselected one of said first carrier signals following its transmission over said line for producing a second d.c. control signal whose magnitude varies as a function of the level of just said second preselected one of said first carrier signals, said first and second preselected ones of the first carrier signals having different frequencies, and further means under the control of said d.c. control signals for automatically adjusting the level of each of said second carrier signals as a function of the cable gauge of said transmission line and the length of said transmission line between said source and said repeater to compensate for both the length and the cable gauge of said transmission line.