AIRCRAFT COMMUNICATION HEADSET TESTER

摘要

A self-contained, hand-held device for testing an aircraft helmet communication system including a microphone and earphones in which a selection switch on the housing of the device is movable from an off position to a talk-through position at which the microphone is connected to both the earphones and a volume indicator on the housing and to a selftest position in which actuation of a pushbutton switch on the housing applies the output of an oscillator both to the volume indicator and a circuit having a voltage divider made up of a potentiometer and a fixed resistance to provide a self-test signal which energizes an illuminable element on the housing if the device is functioning properly and to an earphone impedance test position at which the output of the oscillator is applied to a circuit having a voltage divider made up of the potentiometer and the earphones to produce an earphone impedance-test signal which energizes the illuminable element if the earphone impedance is of the correct value. The potentiometer is adjustable from outside the housing.