Westinghouse Electric Corporation

United States of America as Represented by the Secretary of the Air Force

Daniel J Healey, Iii

Steven Morrison

Hyo K Hahn

The disclosed apparatus for determining the acceleration induced changes in the electrical characteristics of a quartz crystal includes all the apparatus necessary for subjecting the crystal to random acceleration forces and simultaneously determining the electrical characteristics of the crystal. More specifically a vibration generator is provided to subject the crystal under test to random vibrations of a predetermined acceleration. A low noise signal generator provides a signal at the resonant frequency of the crystal. The crystal couples the output of the low noise signal generator to a phase detector to determine the phase shift of the crystal. The output signal of the phase shift detector is analyzed to determine the acceleration versus electrical characteristics of the crystal under test.

Apparatus for determining frequency versus acceleration characteristics

An improved presettable integrator circuit is disposed in a fast frequency changing phase lock loop for presetting the voltage-controlled oscillator thereof as governed by a preset signal and a pulsed signal generated by a frequency controller. One input of the integrator circuit is coupled to the preset signal, another input is coupled to an integrator control signal, and the output is coupled to the voltage-controlled oscillator for use as a tuning signal thereof. A switch is included in the integrator circuit and is governed in a first state by the pulsed signal to cause the integrator circuit to respond rapidly to an applied preset signal to preset the output signal thereof. In a second state, the switch renders the integrator circuit responsive to an integrator control signal which is selected by a phase lock condition of the loop from either a reference signal or a filtered phase error signal, being coupled to the other input of the integrator circuit. Also disclosed are methods for calibrating the voltage-controlled oscillator of the phase lock loop using the improved presettable integrator circuit when the phase lock loop is selectively governed by one of either a first or second frequency reference source.

Presetting circuit for the voltage-controlled oscillator of a phase lock

An amplitude modulation detection apparatus utilizing a balanced diode rectifier circuit to detect amplitude modulation on HF and VHF amplitude modulated carrier frequencies at rates approaching to the carrier frequency without diagonal clipping. A temperature compensating forward biasing supply circuit is connected to the rectifier circuit to supply thereto a forward bias potential that varies with temperature and a trickle current that remains substantially independent of temperature variation.

Large dynamic range low distortion amplitude modulation detector

A phase locked oscillator provides an agile frequency signal source with low phase fluctuations for use in radar and communications systems wherein the phase fluctuations of a predetermined input signal are reduced by the phase locked oscillator by modulating the phase of a delayed feedback signal in response to the phase difference between the input signal and the output signal.

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Baltimore, MD, United States of America

Daniel J Healey, Iii