Bell Telephone Laboratories

Jeffrey H Derby

Tadikonda N Rao

Barry Sheldon Bosik

A bilateral transmission line repeater is disclosed in which opposite directions of transmission are separated into different frequency bands. The amplifiers for each direction of transmission include an automatic gain control circuit for controlling the gain of the amplifier. Gain control for the inward bound amplifier (toward a central location such as a telephone central office) is under the control of an automatic gain control signal derived from the outward bound signal as well as from the inward bound signal. Feedback around the gain control amplifier is accomplished using a current mirror circuit to avoid loading the amplifier output.

Repeater feedback circuit

A bilateral repeater for communication transmission lines is described in which the opposite directions of transmission are separated by frequency bands for amplification. The repeater is powered from a power conversion unit energized from the line potential. The repeater includes three-electrode gas tube breakdown devices connected across the repeater for each conductor of the transmission line. The third electrodes in the gas tubes are cross-connected together with no ground connection.

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New York, NY, United States of America

Jeffrey H Derby