A power line carrier communication system for linking individual power customers with a central station includes the power distribution network between a distribution substation and the customer locations. Frequency translating and signal reconditioning repeaters are connected to intermediate locations of the network to relay carrier signals at different frequencies. Customers are also linked to individual repeaters so as to be grouped into separate communication zones. Each repeater includes separate repeater channels for duplex operation in which two receiving and two transmitting carrier signals have separate and non-interfering frequencies. The repeaters maintain the carrier signals at usable signal to noise ratios when transmitted through extended power line distances having various attenuation and loading characteristics.