Abstract: A static protective housing includes a plastic housing having an outer wall and an interior. A metallic fastener extends into the housing from the outer wall. A static vault within the housing receives the metallic fastener for insulating the fastener from the housing interior. The static vault is provided with a well portion which receives the fastener and a cover which closes the well portion.

Abstract: In accordance with the present invention there is provided a bandpass T filter and power splitter for electromagnetic energy. It is composed of a plurality of resonant elements serially arranged to form a plurality of forward multi-pole bandpass filters. At least one resonant element is common to both signal paths. The common resonant element transfers energy from the common path to the independent signal paths to effect a power split. The two signal output paths are isolated from one another by a multi-pole bandpass filter. The resonant elements may be composed of either resonant waveguide cavities or dielectric resonators.

Abstract: An AFC circuit may include an oscillator having an output frequency responsive to a derived error signal, a mixer for mixing a received signal with the output of the oscillator to produce an intermediate frequency, and a signal recovery detector for recovering the information carried by the intermediate frequency. An integral loop filter and compensation circuit receives the recovered signal from the detector, provides a compensated recovery signal which is independent of the closed loop frequency response of the AFC circuit, and provides an error signal which controls the oscillator.

Abstract: A paging station remote control system encoder is described. The paging system encoder generates signals in accordance with a predetermined signalling scheme comprising a series of tones and timed pauses and generated in response to control signals supplied either manually or by a paging terminal. The paging system encoder provides control signals which instruct a paging transmitter station to key in the analog or binary modulation mode or to switch from one mode to another without first dekeying the paging transmitter.

Abstract: An improved electronic clip-on lead is disclosed. It is comprised of an elongated shaft suitable for electrical connection having a front spring finger extending from one end. A rear bracing member is positioned behind and parallel to the front spring finger by a support structure which fixes the displacement of the rear bracing member to the front spring finger.

Abstract: An improved analog CMOS comparator circuit is described. The improved circuit incorporates an additional CMOS device in the output stage of a conventional differential comparator. The additional device compensates for current imbalances which occur at relatively high common mode voltages thus allowing the improved comparator to operate over a wider range of common mode input voltages.

Abstract: This on/off power detector includes an input connected directly to a power source and input connected to the power source through a switch. The detector compares voltages on the two inputs to produce an output signal when the voltage on the switched input drops a predetermined amount below the voltage on the unswitched input, which is indicative of the switch being open. The detector is strobed on and off and only compares the input voltages to provide the output signal when it is in its strobed on condition.

Abstract: A processing circuit for efficiently amplifying radio frequency signals while generating minimal splatter includes a first channel having an envelope detector for generating a rectified envelope signal from a modulated radio frequency input signal provided thereto. The first channel includes a peak clipping circuit which clips portions of the rectified envelope signal having an instantaneous voltage less than a first selected threshold level. A second channel includes a symmetric clipping circuit for symmetrically clipping portions of the modulated radio frequency input signal which exceed a second voltage threshold level.

Abstract: An adjustable active filter includes a transconductance amplifier (60) and a current source (40, 42) which may be adjusted in value. The resonant frequency of the active filter may be adjusted upwards by increasing the bias current of the transconductance amplifier using a frequency trim up network (48). The resonant frequency may be adjusted downward by decreasing the bias current using a frequency trim down network (44). The trim is preferably accomplished by shorting out zener diodes (120, 122, 124, 126, 150, 152) which control the bias current of the transconductance amplifier.

Abstract: In accordance with the present invention, there is provided a Loran C cycle slip reduction technique that consists of sensing the signal to noise ratio and narrowing the phase locked loop bandwidth when a predetermined signal-to-noise threshold is exceeded.

Abstract: There is provided a method and a corresponding apparatus for establishing the proper bandwidth at one frequency in a microwave, dielectric resonator waveguide filter.Bandwidth is determined by the product of the resonant center frequency and the interresonator coupling coefficient. The interresonator coupling coefficient has been found to vary depending upon the interresonator spacing as well as the position at which the resonators intercept the electromagnetic field distributed across the waveguide.This method establishes the proper combination of field-intercepting position and interresonator spacing such that the proper bandwidth is established at one frequency.

Abstract: A low profile antenna structure includes a substantially planar conductive sheet having a substantially planar conductive member extending from one end at a normal angle. A driven radiating element and a parasitic radiating element are disposed adjacent the conductive sheet. A feed point is coupled to the driven element for coupling RF energy to and from the antenna. Both the driven and the parasitic elements are approximately one quarter wavelength long and are approximately parallel to one another and are situated approximately 1/20th of a wavelength apart.

Abstract: A low power, fast start up time crystal oscillator circuit has an amplifier portion powered from a one cell battery. The input stage of the amplifier portion is a common emitter amplifier circuit. A second stage includes a dual collector current mirror circuit having a current established at 3 times the input stage current. The output stage includes a current mirror circuit having a current established at 4 times the second stage current. A negative D.C. feedback circuit biases the amplifier portion. A single transistor interface circuit boosts and limits the output of the amplifier portion and permits the oscillator to drive other circuits that operate at higher voltages than the amplifier battery voltage.

Abstract: An improvement to a linear power amplifying system is disclosed which maintains the DC balance of the envelope feedback loop under adverse conditions, thereby improving the accuracy of the system. The improvement is realized through the addition of two differential amplifier stages to the feedback loop. A first differential amplifier 103 is added to the balanced outputs of the synchronous envelope detector 102, which is comprised of an active balanced modulator/demodulator device, to correct for the common-mode DC drift of the detector. An auxiliary feedback loop, comprised of a second differential amplifier 104 and a low-pass filter, compares the average DC value of the envelope error signal to a system reference voltage V.sub.R, and produces a loop gain error signal which corrects for variations in envelope feedback loop gain. The improvement provides envelope modulation transmitters with a substantial reduction in adjacent-channel interference and lower on-channel distortion.

Abstract: A signal processing circuit with enhanced response time includes a data limiter circuit having an input and an input capacitor having one terminal coupled to the input. A first selectively actuable voltage clamping circuit responds to a first comparing circuit and is coupled to the input for preventing the voltage at the input from exceeding a predetermined upper voltage. A second selectively actuable voltage clamping circuit is responsive to a second comparing circuit and is coupled to the input for preventing the voltage at the input from decreasing below a predetermined lower voltage.

Abstract: An RF receiver having a coupling capacitor connected between the back end of the receiver and the input to a data limiter circuit, a battery saver strobe feature which periodically turns the receiver ON and OFF and a precharge circuit for precharging the coupling capacitor. The receiver further includes a reference voltage stabilization circuit which prevents a received signal from reaching the output of the back end of the receiver during the precharging of the coupling capacitor in order to minimize the voltage offsets from the desired unmodulated carrier frequency reference voltage which results in erroneous data being decoded by the decoder portion of the RF receiver.

Abstract: A low current oscillator/buffer amplifier configuration is disclosed which provides a simple, inexpensive, low power oscillator with reduced harmonic output. Buffer 60 is coupled to the resonant tank circuit 58 of oscillator 50 by means of impedance transform network 70. This technique of tapping directly from the tank provides a buffered output signal having low harmonic content. Furthermore, impedance transform network 70 permits coupling feedback amplifier 52 to buffer amplifier 62 in a totem-pole amplifier stage configuration. This feature provides a significant current savings over conventional oscillator/buffer circuits. The instant invention is particularly well adapted for use as reference frequency oscillators in portable radio applications.

Abstract: An electrical subassembly structure of two substrates has metalized portions located adjacent to the upper and lower edges on the back of each substrate. Clip on leads are attached to one substrate with a portion of each lead soldered to the lower edge metalized portion. The two substrates are electrically and mechanically joined by soldering upper edge metalized portions together and soldering the lower edge metalized portions of the other substrate to the lead portions.