A telephone station repeater is disclosed which will provide bidirectional gain in a long telephone loop at the customer's station. The repeater is powered from the central office battery over the loop and provides gain with very small power consumption and virtually no power consumption when not in use. The station repeater comprises a negative impedance amplifier including a shunt negative impedance, a series negative impedance and an autotransformer connected in a π configuration. The shunt converter is disconnected when the telephone set is on-hook. The autotransformer provides impedance matching to the telephone set.

Bitzer Dipl-Ing Wolfgang

Papers

Negative impedance converter