Abstract: A mechanical bandpass filter has a first resonator which is designed to resonate at a first frequency and a second resonator which is designed to resonate at a second frequency. The two resonators are electrically connected together and the input signal is applied to the first resonator and the filtered signal is removed from an electrical connection to the second resonator.

Abstract: A time compensated clock oscillator is disclosed that has a first low power oscillator that drives an output device such as a time-of-day clock, a second more precise oscillator whose output is compared to the output of the first oscillator, and develops a correction signal that is used to periodically correct the output device.

Abstract: The present invention uses two interconnected baluns with the balanced output of one feeding a balanced input of the other. When this filter is used in conjunction with a signal frequency converter, the balun pair not only provides extremely effective bandpass filtering so as to pass the RF frequencies and not the IF frequencies but, in addition, provides a condition which appears to the IF as a nearly open circuit and thus provides a large amount of reflection or return of the IF signals to the signal converter so that the overall signal converter operation is more efficient in combination with the present invention than with any comparable known prior art signal isolating device.

Abstract: A carrier signal modulated with digital data is transmitted through a medium polluted with harmonic signals by asymmetrically positioning the carrier signal frequency between two adjacent harmonics and employing a baud rate for the data so that the (sin x)/x spectral density nulls of the modulated carrier signal in the frequency domain coincide with the two adjacent harmonics, thus affording efficacious discrimination against the harmonics in the receiver detector which has a matching frequency response.

Abstract: A faceplate assembly is provided for use in printed circuit board assemblies comprising a printed circuit board with electrical contact surfaces, and a housing frame with slotted guide rails to receive the circuit board, and edge connector means fastened to the housing frame and displaced at the end of the guide rails. The faceplate assembly includes insertion, extraction and positive latching means molded as an integral part of the faceplate. The faceplate body extends substantially the entire length of the printed circuit board edge and is pivotally mounted to the printed circuit board near one corner thereof. The insertion/extraction means, located on the pivotal end of the faceplate body, is actuated by manual pivotal movement of the faceplate thereby causing the insertion/extraction means to coact with a housing frame U-channel to thus effect engagement or disengagement of the printed circuit board electrical contacts to or from the housing frame edge connector contacts.

Abstract: An oscillator is temperature compensated by adjusting a slave oscillator with an error signal, that is produced by using the temperature of a reference oscillator to determine the frequency error of the reference oscillator, and then adjusting the frequency of the slave oscillator until its frequency coincides with an ambient reference frequency.

Abstract: A digital bit error violation rate circuit monitors the bit error integrity of a data stream and generates an alarm if the bit error rate exceeds an established bit error integrity threshold.

Abstract: A multipath diversity spread spectrum communications receiver will enhance system performance over communication channels with distortion caused by multipath and fading effects. The multipath diversity receiver utilizes decision directed coherent integration with post detection correlation techniques for performance enhancement. The receiver also incorporates a fast attack, fast release automatic gain control to process noncontinuous wideband spread spectrum signals which are subject to fading and multipath effects.

Abstract: Circuitry is disclosed for detecting signal amplitudes of a signal which is phase indicative of a digital logic level and providing a feedback signal for use in amplitude adjusting the signal to have a substantially zero slope over the relevant frequency bandwidth. The compensation is obtained by applying a voltage to variable impedance pin diodes which form part of a reactive load circuit.

Abstract: An improvement is disclosed for a machine of the type having a main drive which may be activated to move a ram with a high force against a workpiece. The improvement is a safety device which includes an apparatus in addition to the main drive for moving the ram to a position near the workpiece with a low force capable of being stopped by contact with a part of the human body. Further apparatus is provided that allows the main drive to become activated only when the ram is within a preselected distance of the workpiece. As a result, the distance can be selected to be smaller than, say, a finger, so that the presence of a finger between the ram and a workpiece will prevent the ram from being driven at a high force.

Abstract: The specfication discloses a meteor burst communication system including at least two spaced apart master stations, in association with a plurality of groups of remote stations spaced at locations remote from the master stations, with each group being associated with one of the master stations. Each of the master stations includes a radio transmitter for transmitting probing digital radio signals having address portions which are directed from the master station for reflection from meteor trails to the remote stations associated with the master station. Circuitry is provided to vary the length of the address portions transmitted by the master station in dependence upon desired signal-to-noise and timing considerations. Each of the remote stations includes a radio receiver for receiving the reflected probing digital radio signals from the master stations. Each of the remote stations also includes at least one sensor of physical characteristics such as snow depth, rain fall or the like.

Abstract: The frequency response of the frequency sensitive amplitude equalization circuit disclosed herein can be adjusted by a single potentiometer to be either flat or give a positive or negative gain at a selected frequency.

Abstract: A voltage dividing and reference circuit for creating a pseudoground from a unipolar power supply such that when used in combination with a digital voltmeter circuit a bipolar input signal can be measured for both polarities with respect to ground.

Abstract: A method and apparatus is disclosed for protecting a circuit from excessive current flow by pulse width modulation of a current sense signal and interrupting the circuit when the width of the pulse is less than a reference period.

Abstract: Both wide-band and narrow-band noise suppression can be achieved by the disclosed signal normalizer in which the properties of hard limiting and adaptive control weights are fully utilized.

Abstract: Variable rate digital control of a frequency synthesizer is afforded by periodically generating a digital signal from among a plurality of such digital signals representative of various tuning rates, converting each digital signal to a digital control word through a rate decoding means in which each control word is associated with at least one of the digital signals, applying the control words to a digital counting means having a plurality of counting rates, with each rate being determined by a different one of the control words, and applying the digital count of the digital counting means to the frequency synthesizer to control its frequency.

Abstract: Disclosed is a method and apparatus for transceiving full duplex anti-jam radio signals in a burst of audio data on a carrier frequency that is pseudorandomly selected.

Abstract: A radio navigation antenna system suitable for use in an aircraft is disclosed. The fed element of the system is stationary, being at one end of a coaxial conductor which extends through a hollow shaft of a motor. Mounted around the hollow shaft is a ground plane disc capacitively coupled to the outer sleeve of the coaxial conductor, thereby avoiding the use of brushes in the system. A cylindrical dielectric antenna support is mounted on the ground plane disc around the fed element. A T-shaped reflector is formed by a conductive layer on the cylindrical surface of the antenna support.

Abstract: A balun is constructed by rolling a strip of flexible dielectric into a loop which has conductive strips on each face.

Abstract: A fiber optic cable is coupled with an electro-optic transducer through a ferrule which terminates the cable that is inserted in a passageway of a housing which is mounted on a planar surface so that the passageway is transverse thereto. A cover placed over the housing and latched thereto isolates the ferrule from dust and external light and insures its proper alignment with the electro-optic element, which is inserted in the passageway from the opposite end via an opening in the planar surface, by exerting a spring force on a flange of the ferrule which is a greater distance from the end of the ferrule than the distance between the passageway entrance to the ferrule and the electro-optic transducer when positioned in the passageway so that the fiber optic cable and transducer abut one another upon placement in the passageway to effect an efficacious coupling.