Abstract: A frequency converter circuit includes an input voltage-to-current converter which delivers signal current to a tuned IF circuit via a current steering circuit controlled by a local oscillator. In a preferred embodiment voltage-to-current conversion is effected without introducing unwanted harmonics by a double-gate MOSFET. Current steering is performed by a pair of push-pull connected transistors alternately driven into saturation by the local oscillator so that they alternately deliver signal current to the tank circuit in opposite senses. A current-limited diode clamps the output signal level in response to high input current levels to prevent over-driving an output filter.

Abstract: A remote control receiver for a television receiver remote control system having a memory capacitor and a field-effect transistor readout to provide a direct control voltage is shown. Circuit means illustrated as a diode connected in series with the memory capacitor limits the magnitude of the charge stored by the memory capacitor to prevent the field-effect transistor from being driven beyond cut-off by an excessive amount.

Abstract: A single-sideband radiotelephone system includes a single-sideband transmitter which initially broadcasts two frequency-spaced tones simultaneously for a predetermined time interval, and thereafter broadcasts the two tones alternately in a unique code pattern to access a predetermined receiver. Each single-sideband receiver in the system includes a pair of detectors each having a narrow bandpass, the center frequencies of which are spaced apart by the difference in frequency of the transmitted tones. The center frequencies of the detectors are simultaneously varied relative to the initial two-tone broadcast while maintaining the frequency differential therebetween; and simultaneous detection of both tones will terminate the frequency varying mode of operation. The subsequently transmitted unique code pattern is then sensed by the detectors, the code pattern decoded, and the selected receiver is enabled to receive any subsequently broadcasted information.

Abstract: A method of eliminating multi-path propagation and time scattering effects on a radio transmitter channel and predominantly a short-wave channel when binary series of 1 and 0 bits are transmitted. Two frequency shift systems are used each having a 1 signal and a 0 signal frequency transmitted during a predetermined part of each bit interval, preferably half an interval. The signal frequencies are received time-selectively within a time slot having a length corresponding to the predetermined part of each bit interval. According to one embodiment a 1 bit is transmitted (received) by transmission (reception) of the 1 signal frequency of the first FSK system during the first half of the bit interval, followed by the 1 signal frequency of the second FSK system while the decision on the transmitted bit is taken on the basis of the superimposed bit information contributions of the two FSK systems. A device for carrying the method into effect is described.

Abstract: Frequencies which respectively identify a particular transmitter, and a particular program content, and which are in a very low frequency range (from between 20 to 125 kHz can be recognized, and ditigal output control signals derived representative of whether one, or both, or none of these frequencies are present by use of a frequency selection input circuit, controlled by a change-over switch to initially select recognition of the transmitter identification which, if positive, is applied through a storage circuit having a storage time substantially longer than the switch-over rate, to provide an output signal if the selected transmitter is recognized, and hold that output signal during switch-over of the program content identification signal which, if present, will be fed back through a logic circuit to hold the output of the transmitter identification circuit as identified, and if not present, permit continued switch-over of the frequency identification circuit to continue to store transmitter identificatio

Abstract: A device for indicating the intensity of the vertical component of an incnt electromagnetic field independently of the frequency or the direction of the field uses a dual-loop antenna, current transformers and a means for combining voltage signals. The two antenna loops are planar and the planes of the loops are disposed orthogonally to each other. The loops are arranged to intersect at a common central axis, and the loops are thus symmetrically disposed about the axis. When a source of electromagnetic radiation is incident on the antenna, a current is generated in the loops which is then transformed into a voltage and combined to produce an output which is independent of frequency, of the direction of the field, and is thus representative of the total vertical field intensity.

Abstract: In a preferred embodiment, a pillow including a tubular flexible material having a space defined within the tube divided into a sealed central space portion having pillow stuffing therein, and adjacent the central sealed portion there being at opposite ends thereof open-ended space-defining portions respectively each invertible over and around the sealed central space portion and one over and around the other when both are in an inverted state, with one end portion having adjacent an end thereof nearest the sealed central space portion two apertures extending through the tubular flexible material and with the other end portion having adjacent an end thereof most distant from the sealed central space portion two apertures located to become aligned with the apertures of the other end portion when both are inverted around and over the sealed central space portion of the tubular flexible material, and a radio receiver and speaker combination of miniature size and of substantially flattened shape located between t

Abstract: A citizens band transceiver assembly to be mounted on a motorcycle, or other similar vehicle, is provided which includes a bracket having a continuous tubular member configured to enclose a rectangular area, the bracket further having a base on which the tubular member is mounted, and a plurality of suction cups mounted on the underside of the base to mount the bracket on the top of the gasoline tank of the motorcycle. Belt fasteners are also secured to the base to receive the ends of a belt looped around under the gas tank, and which serves as a further support for the bracket on the motorcycle. A transceiver unit itself is supported on the tubular member by a hook and hand-operated lock which permit the unit to be held securely in place on the bracket, and yet to be readily removed from the bracket, when so desired.

Abstract: A communication system comprising a transmitter for radiating a carrier frequency signal, which may be modulated, to a data station. The station includes a rectifier for rectifying the received carrier signal to provide energy to the station elements. A data source at the station produces a data signal representative of the information to be transmitted. A harmonic generator produces harmonics of the carrier signal and the harmonic signal is modulated with the data or information signal. An antenna radiates the modulated harmonic signal to a receiver which demodulates the received signal to extract the information therefrom. Thus, a completely self-contained and economic system is provided, since the carrier signal per se supplies the energy to operate the data station.Additionally, the communication system may include a carrier signal having an address encoded therein and the station may comprise an address decoder so that only a selected addressed station will transmit the desired data at any one time.

Abstract: Transcoder for digital differential phase modulation designed for accumulating, separately, partial trains of pulses which are mutually shifted and whose rhythm is an integral fraction of that of the original train. The partial accumulations are finally gathered together in a common adder. The invention enables a differential modulation on adjacent bits at a speed which is not limited by the accumulation loop delay.

Abstract: A delay circuit provides a flat delay versus frequency characteristic over a first band of frequencies by combining two delay equalizers having opposite signed and equal magnitude slopes of delay versus frequency over two different bands of frequencies. The first frequency band is translated to a second band which is applied to the first of two delay equalizers. The latter has a transfer characteristic which is a substantially constant slope of delay versus frequency for a band encompassing and much wider than said second band. The output of the latter element is translated back to the first frequency band. The first band, either prior to the initial frequency translation or subsequent to the second frequency translation, is applied to a second delay equalizer. The characteristic slopes of the two delay equalizers are of substantially equal magnitude but of opposite sign.

Abstract: Data channel gain-variation distortions are reduced by the following combination of operations. Successively occurring data items are cumulatively added in modulo fashion thereby providing a sequence of partial sums. An exponentiating circuit is introduced to provide an exponential function of the partial sums. The exponentiated partial sums are then recorded or transmitted on a data channel wherein the signals are distorted by relatively slow gain variations thereof. The received distorted signals are applied to a logarithmic circuit wherein the multiplicative gain variation distortions are converted to additive distortions. The logarithmically converted signals are applied to a subtractor that sequentially provides the differences in modulo fashion between successively occurring signals from the logarithmic circuit thereby yielding the data items with the distortions substantially reduced.

Abstract: A TV channel indicator wherein the tuner shaft carries a program disc having a plurality of cam sticks, each of which has a cam surface corresponding to a respective channel. There is a panel of leaf switches which play against the cam surfaces to close the switches in a manner dictated by the cam surface configuration, thereby selectively energizing the segments of a seven-segment numerical display to provide illuminated channel numbers corresponding to the tuner shaft position. Tuning of the tuner shaft brings the cam surfaces into registration with the switch ends.

Abstract: A bit stream with a bit rate equaling the frequency of a train of accompanying clock pulses is transcoded into a two-level signal voltage having a reduced rate of changeover compared with the rate of alternation between 0 and 1 bits. Upon any shift from one kind of bit (e.g., 0) to the other kind of bit (e.g., 1), a transition between signal-voltage levels occurs in the middle of a clock-pulse cycle; the first bit of the first-mentioned kind (0) in a succession of a plurality of such bits, after a shift from the other kind of bit (1), is translated into a transition between signal-voltage levels occurring at the end of the corresponding clock-pulse cycle. Transcoding is accomplished with the aid of a three-stage shift register whose stage outputs are logically combined.

Abstract: A control circuit for use with an amplifier is disclosed which includes an amplifier circuit having an input transistor, a driving transistor and an output transistor, a negative feedback circuit consisting of a parallel connection of a capacitor and a resistor and connected between the output terminal of the output transistor and the base of the driving transistor of the amplifier circuit. It also includes a transistor having its collector and emitter connected to the negative feedback circuit, a charging and discharging circuit connected to the base of the last mentioned transistor, and a voltage source connected to the charging and discharging circuit through a switch. The operation of the amplifier circuit is controlled by instantly making the switch on through the charging and discharging circuit and the transistor.

Abstract: The present invention relates to an AM-FM receiver of the superheterodyne variety having a novel bias supply circuit wherein a common filter capacitor may be used for the bias supply, the AGC function in AM operation, and the AFC function in FM operation. The B+ bias is supplied through a controllable current source which adjusts the bias in accordance with the detector output. In the FM mode setting, automatic frequency control of the local oscillator is provided by bias adjustment. In the AM mode setting, automatic gain control of the IF amplifier and of the AM section of the tuner is provided by bias adjustment. The invention has preferred application to integrated circuit fabrication.

Abstract: A low power consumption, compact portable stereo radio transmitter and a receiver therefor, the transmitter having two audio processing channels each for receiving inputs from two stereo pickup stations and including amplifier circuits with selector switches providing a mode of even harmonic generation, a mode of odd harmonic generation, and a mode of undistorted amplification, a 38 KHz oscillator, flip flop coupled to the oscillator to provide a 19 KHz pilot signal, a difference amplifier and a balanced mixer to produce a double-sideband suppressed carrier signal centered on 38 KHz, and an amplifier for combining the balanced mixer output, the pilot signal and the two channel output and modulating a carrier signal. The receiver includes amplifier, detector, and decoder circuitry to receive the radio signals from the transmitter and produce stereo audio signals for driving a standard stereo amplifier.

Abstract: A radio receiver having adjustable squelch means and including demodulator means, intelligence processing means including gating means, and squelch circuit means for controlling the gating means. The squelch circuit includes voltage dividing means which controls the amplitude of a squelch drive signal and/or a reference signal. Squelch control adjustment means provides variable resistance paths around each of the divider network resistive elements.

Abstract: A broadband waveguide mixer suitable for the microwave and millimeter wave regions is described. The mixer is characterized by having a unique dual-guide mixer mount through which extends two parallel and spaced waveguides. The RF wave and the local oscillator wave are respectively impressed on the two waveguides via a hybrid coupler. A pair of crossbars extend through each waveguide. A pair of diodes connected back-to-back are disposed in each waveguide and are connected to the respective crossbars. Each pair of diodes has a polarity opposite to that of the other pair. The output is derived from a coaxial cable connected to the adjacent ends of the two crossbars. The input signals may be applied by a folded hybrid tee or a short slot hybrid coupler to simplify the input structure. The mixer has low noise and broadband performance.