Abstract: An electronic tuning device displays broadcasting station name letters and frequency numbers which are memorized in advance by pressing a preset button and a memory entry button thereon.

Abstract: A radio communications system operational within the medium frequency range for underground mine communications, coupling MF carrier signals into existing conductive channels extending to within the mine and devices within the mine and coupled to the conductive channel for receiving the MF carrier signals and communicating with portable and mobile transceivers operational within the MF frequency range and in the common seam mode.

Abstract: A combined duplexer/mixer especially for use in an FMCW millimetric radar system has a waveguide section containing a fin line or suspended strip structure for responding to the linearly polarized radar return signal passing through the section in one direction while permitting passage of the orthogonally polarized, outgoing signal passing in the other direction. The fin line is coupled via double balanced mixer diodes to an IF output line to produce an IF signal by mixing the return signal with a portion of the outgoing signal tapped off by a field distorting probe, ridge section or like coupling means.

Abstract: A detector for indicating reception disturbances during frequency modulated ultrashort wave broadcast reception, particularly in power vehicles, has a detector for indicating frequency disturbance deviations in high frequency or intermediate frequency carriers and an amplitude modulation detector for indicating disturbance amplitude modulation in the high frequency or intermediate frequency carrier, and an evaluating circuit with two inputs arranged so that the output signals of the detectors are supplied to the respective inputs of the evaluating circuit and an output signal of the evaluating circuit depends both on the disturbance amplitude modulation and the frequency disturbance deviation.

Abstract: An emergency locating transmitting (ELT) system comprising a legislated ELT modified with an interface unit and connected by a multiwire cable to a remote control monitor (RCM), typically located at the pilot position. The RCM can remotely (1) test the ELT by disabling the legislated swept tone and allowing transmission of a single tone, (2) turn the ELT "on" for legislated ELT transmission, and (3) reset the ELT to an "armed" condition. The RCM also provides visual and audio indications of transmitter operating condition as well as ELT battery condition. Removing the RCM or shorting or opening the interface input connections will not affect traditional ELT operation.

Abstract: An RF-AM transmitter includes a pulse amplifier responsive to a pulse width modulated (PWM) signal derived in response to an information signal. A low pass filter converts pulses derived by the power amplifier into a variable amplitude signal that is DC coupled to a power supply for an RF amplifier. An amplifier system including the pulse and RF amplifiers has stray capacitance coupled to a modulator which derives the PWM signal; the stray capacitance lengthens narrow modulator output pulses so they are excessively long. The amplitude of only the narrow pulses is reduced by a resistor-capacitor timing circuit in series with a switch to substantially preserve the narrow pulse area. The switch provides a low impedance path from the timing circuit to a reference potential terminal when current initially flows in the circuit during pulse transitions and throughout the length of each of the short duration pulses.

Abstract: A superheterodyne receiver in which unwanted lowering of the RF gain due to the presence of an interference signal outside the band of the desired signal is substantially eliminated. Levels of the outputs of both the RF amplifier and first mixer of the circuit are detected. The two level detection signals so produced are summed, and the sum signal applied to the gain control input terminal of the RF amplifier.

Abstract: A receiver suitable for use at very high frequency bands in which an antenna output is filtered, amplified and then mixed with a local oscillator in a frequency convertor to provide an intermediate frequency. The intermediate frequency is provided to a quadrature detector which directly converts the intermediate frequency into two baseband signals whose phases differ by 90.degree.. The baseband signals are independently amplified and demodulated in a common demodulator which provides a single output signal.

Abstract: The selective calling and dialling arrangement of a mobile radio station forms radio telegrams addressed to a specific subscriber, interprets received pulse telegrams and controls a radio device and a control device arranged in the mobile radio station. To that end the selective calling and dialling arrangement comprises a first store in which constants identifying a specific country are stored, a program store, a data store and a microprocessor. Commands and system constants are stored in the program store. For subsequent changes in such system constants without the necessity of changing the program stored in the program store, the system constants are stored in a second store, which is connected to the microprocessor via an input/output arrangement.

Abstract: Data to be switched is preceded by a header containing routing information for establishing a connection via a switch, and is accompanied by additional information which indicates the start of the header, in response to which a connection is established, and the end of the data, in response to which the connection is terminated. The switch is a non-saturating, non-blocking, full matrix time switch which uses the routing information to establish a connection within one tdm frame, whereby connections for data of any type (including switch control information) and of arbitrary duration can be handled efficiently. An incoming channel can be connected to any free channel or to a specified outgoing channel of any output port, and contention resolution is provided for simultaneous requests for connection to a single outgoing channel. Interconnections among crosspoint nodes are reduced and simplified using token ring and systolic interconnection techniques.

Abstract: A communication system which includes two digital terminal stations connected to each other by a digital communication line. The communication system includes data terminals adapted for operation on an analog communication line which transmits main data and control data. The data terminal has two modems for transmitting respective data. Correspondingly, the digital terminal station has two modems which modulate and demodulate the respective data signal for transmitting the data from the digital communication line through the analog communication line and vice versa. The data transmission between two data terminals through the digital terminal stations is completed in one transmission call.

Abstract: A method of reading detectable conditions of a non-planar, image bearing surface by utilizing an array of discrete thin film photosensitive elements which are formed on a flexible substrate.

Abstract: Direct relay equipment includes a first antenna, a second antenna, an up direction circuit connected from the first antenna via a first circulator to the second antenna via a second circulator, and a down direction circuit connected from the second antenna via the second circulator to the first antenna via the first circulator. In the up direction circuit and the down direction circuit, the received signal having a frequency f.sub.1 from the first (or second) antenna is amplified by a microwave amplifier, the output of the microwave amplifier is converted to a signal having a frequency f.sub.2 (sending frequency), the signal having the frequency f.sub.2 is amplified by the same amplifier, and the amplified signal having a frequency f.sub.2 is sent from the second (or first) antenna.

Abstract: A color sensor array in which vertical output lines correspond to different colors. The reading order and the reading periods for each color are adjusted in one of two ways. Separate vertical shift registers are provided for each color and the separate vertical shift registers are selectively enabled. Alternatively all color are simultaneously read but the color lines are selectively coupled to one output line.

Abstract: A remote control device comprises a control input unit, a transmission unit, a receiving unit, a reply unit and a command control circuit. The control input unit outputs a control signal. The transmission unit stores the control signal in a first memory circuit and transmits a light signal based on the control signal. A main device controlled by the remote control unit receives in a first receiver circuit and stores in a second memory circuit the signal from the transmission unit. The main device has a reply signal unit for transmitting a return signal based on the signal from the receiving unit to a second receiver circuit of the remote control device. The command control circuit compares the signal received by the second receiver circuit and the signal stored in the first memory circuit. When these compared signals are in agreement, the command control circuit outputs to the transmission unit a signal based on the signal stored in the second memory circuit thereby to cause the operating device to operate.

Abstract: A passenger entertainment system having direct coupled individual seat receivers. Direct coupling of receivers to the passenger entertainment power and intelligence information signals is provided through a seat track transmission line consisting of one or more conductors associated with the seat track and running parallel to the seat track.

Abstract: A radio frequency transmitter simultaneously transmits both a local oscillator frequency and that frequency modulated by an information content signal. A receiver receives a carrier wave that is at the opposite edge of a channel from that of the local oscillator. The transmitted and received information signals can be of opposite type sidebands.

Abstract: A method and apparatus for adapting a portable radio transceiver (10) for configuration in electronic communication with a main console of a fixed or mobile communication system. The apparatus employs a bracket (36) which serves to extend, by cables 52, 54, various functional input terminals at the console to function contacts (44, 46) at the bracket (36). The transceiver (10) includes apparatus (34) for mating the transceiver (10) to the bracket (36). The bracket (36) carries a track (50) for accepting the track rider mating apparatus (34) of the transceiver (10).

Abstract: A communication device wherein leader pulses which continue for a predetermined time period are transmitted prior to the transmission of data from its transmitter; its receiver is rendered intermittently operative at a cycle shorter than half the continuation time of said leader pulses by means of a cycle operation controlling means to thereby become operative for a short time at a duty lower than 1/10; while the receiver is operating, it is detected by a detector means whether or not the leader pulses are transmitted; and when the transmission of the leader pulses is detected by the detector means, the receiver is kept operative for a predetermined time period by an operation holder means.

Abstract: In a digital optical submersible repeater the electronic and opto-electronic components are housed in an hermetically sealed modular assembly (20, 60, 70) of a first regenerator module (20) for one fibre (7, 6a), a second regenerator module (60) for the second fibre (6, 7a) of the pair of fibres, and a power module (70) for extracting power from the power feed conductor of the cable. In each regenerator module (20) the transmit laser (8) and the receive PINFET diode are on diametrically opposed faces, and power feed and optical signal feed are disposed in spaces between the modules and the inside surface of the repeater housing (1). The modular assembly is resiliently secured to the bulkhead (2).