Abstract: An attenuator introduces a known attenuation into telephone circuitry at connecting block terminals of incoming and outgoing, tip and ring lines when clipped thereto. The attenuator is particularly suited for attachment to an insulation displacement terminating block, known as a 66 type block, for telephone wire circuits or pairs. An attenuation network in the form of a balanced square pad is mounted on a substrate to form a printed circuit board and resistance assembly. Electrical contact means include four electrical contacts that have tail portions connected to the attenuation network and clip portions that grip the connecting block terminals of the incoming and outgoing, tip and ring lines. The printed circuit board and resistance assembly and the electrical contact means are received within a protective, insulating cover and retained therein by potting material. The attenuation rating or loss for the attenuator is marked on the top surface of the cover.

Abstract: A self-contained switchable, incremental attenuator device for interposing in a two line power circuit to attenuate the power level for proper power matching. The device includes a series of modulized, individually switchable attenuator circuits of differing attenuation values mounted upon a pluggable card for interfacing with input and output connectors of a circuit. The attenuation values of the sections are selected such that manipulating the switches will allow attenuation of the power level in the circuit by an integral multiple of a given base incremental value within a given range. The attenuator device is designed to mate with a mounting device for holding the attenuator in contact with the circuit connectors.

Abstract: A power amplifier for use in uni-directional telephone line signal amplification requirements on voice and data grade circuits includes a balanced input transformer and associated differential line transient protection circuit and line matching network, a balanced differential voltage feedback amplifier circuit with externally interchangeable, balanced, passive, terminated attenuators in the voltage feedback path for varying the amplification factor of the signal amplifying circuit, a balanced-to-unbalanced common mode rejection circuit, low and high cut frequency filters, and a balanced output transformer with associated output line matching and circuit protection components. The interchangeable attenuators are calibrated and marked in terms of overall power amplification resulting from their individual and specific use in the circuit.