Abstract: A high speed data interface unit that is fully compatible with existing, trunked, land mobile voice transceivers is provided. Data rates of up to 4800 baud using bilevel modulation are achievable without the use of dedicated data transceivers, or the designation of a dedicated data channel. The data interface includes a microprocessor based modem having data pulse formation, data recovery, and pulse filtering circuits that optimize available channel bandwidth for communication of digital data.

Abstract: A method and apparatus for distributively interconnecting a plurality of land mobile trunked transmission communication systems into a wide area network includes a plurality of distributive radio network terminal (RNT) switch means and a unique signaling protocol and a switching protocol especially adapted for communication of control signals in the subaudio band for interconnecting the trunked transmission communications systems into a wide area network that provides an expanded feature set of radio communications capabilities.

Abstract: An electrical energy source is created by the combination of a light emitting polymer material having at least one light emitting surface emitting light energy of a specified frequency bandwidth and a photovoltaic cell having a light collecting surface and a pair of electrical contacts. The light collecting surface of the photovoltaic cell is optically coupled with the light emitting surface of the light emitting polymer material. An open-circuit voltage is generated between the pair of electrical contacts as a result of the absorption of emitted light energy from the light emitting polymer material by the photovoltaic cell. The light emitting polymer comprises a mixture of a polymer labelled with a tritium and an organic compound which emits light energy when subjected to radiation generated by the tritium. The organic compound is at least partly bonded to the polymer and the mixture is translucent at the specified frequency bandwidth of the light energy.

Abstract: An alternate home channel for a land mobile transmission trunked communication system designates one of a plurality of repeaters for a given site or coverage zone as an alternate home repeater. The control signals transmitted over the subaudio band for all home channels repeaters in that site are also duplicatively transmitted over the subaudio band of the alternate home repeater. Each mobile transceiver will be programmed with two channel numbers. One for the home repeater and the other for the site alternate home repeater. When the power is turned on, the mobile transceiver determines which repeater to monitor by scanning both the home and alternate home channels. When a valid control message is detected on either channel, that channel becomes the monitor channel. Operation of the mobile transceiver is then generally similar to prior operation, with the exception that the monitor channel (either home or alternate home channel) is used instead of just the home channel.

Abstract: An electrical interconnect or switch device for interconnecting electrical and electronic elements on a printed circuit board uses a carbon/graphite trace is used to connect electrical contact pads on a ceramic or similar substrate. The substrate surface has a plurality of electrically conductive contact pads and a plurality of isolation regions defined on the substrate surface such that each of the contact pads is separated from the remaining contact pads by at least one of the isolation regions. Each of the contact pads may be electrically connected to one or more of the circuit elements on the printed circuit board and a trace means, preferably a carbon/graphite pencil lead, is used to selectively electrically interconnect two or more of the contact pads by tracing between the selected contact pads across at least one of said isolation regions, thereby electrically interconnecting the circuit elements associated with the selected contact pads.

Abstract: A unique data recovery circuit which is able to recover transmitted digital data with a data clock embedded therein. No initial timing signals are required for operation of the data recovery circuit. Instead the data clock is recovered from the received data and used to synchronize the flow of data through the circuit. Noise pulses and other anomalous transients are rejected by the circuit so that the data output accurately corresponds to the data transmitted. Operation of the invention is achieved through a number of expedients which include a random access memory delay line which delays interpretation of the data until the data clock has been recovered. A uniquely integrated delay switching network is utilized to switch recovery of the clock from the received data to the delayed data. A phase locked loop and an integrate, sample and dump circuit are also employed, both of which use asynchronous ripple counters to achieve the primary objective of the invention which is to recover the data transmitted.

Abstract: A radio frequency transponder is provided that combines high signal sensitivity in the receive mode and variable frequency capability in the transmit mode in a low component and power efficient design. A single tuned amplifier acts as the externally quenched oscillator of a superregenerative receiver when the transponder is operated in the receive mode, and as the carrier frequency generator when the transponder is operated in the transmit mode.

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 frequency detector completely implemented with digital logic circuitry is disclosed. The frequency detector hereof employs a unique phase locked loop digitally implemented with asynchronous ripple counters, and a digitally implemented amplitude comparator and signal integrator. The detector is especially adapted for implementation in CMOS hardware, or similar hardware having low current drain characteristics. The selectivity of the detector can be set to a narrow bandwidth for excellent noise discrimination characteristics.

Abstract: A minature right angle coaxial connector is provided that enables a coaxial cable to be connected to a standard SMB mating connector. A stamped and formed interface is housed in the connector that has outwardly oriented multiple spring leaf barbs for securing the interface to the inner surface of the connector, and inwardly oriented multiple spring leaf barbs that secure a dielectric to the interface. The unique nature of the multiple spring leaf barbs on the interface makes it possible to diecast, instead of machine, the connector housing parts, and eliminates the need for precious metal plating to ensure conductivity between parts.

Abstract: A miniature interface is provided that allows connection of a coaxial connector, used to terminate a coaxial cable, to a printed circuit board. The interface comprises a hollow tubular conductive body portion having a dielectric disposed therein and legs depending from a flange at the lower end of the body portion. When in place, the legs extend through holes in the circuit board, but the body portion rests above the circuit board on pads located on the lower surface of the flange. The pads serve to isolate the conductive body portion from the circuit board and allow solder to flux be washed out after a wave soldering process is used to affix the interface to the printed circuit board.

Abstract: A simple, low cost latching mechanism is provided that can be assembled without the use of tools and that permits both the top and bottom covers of a radio chassis to be quickly and easily latched to or detached from the chassis. The mechanism includes a latch member having a pair of latch arms biased by an integral coil spring towards a latched position, and an open faced support member for the latch member that allows for easy assembly of the mechanism. Release tabs extend through an exterior chassis wall for selectively shifting the latch arms to a released position to free the covers. A locking cam is also provided to selectively lock the latch arms in the latched position.

Abstract: A solid state radio frequency switching circuit is provided that exhibits up to 25 db isolation between output ports. The circuit integrates the switching versatility of a pin diode switch with the excellent signal isolation of a quarter wavelength combiner.

Abstract: An easy to manufacture, yet durable electrical probe contact is provided which is especially designed for connecting test equipment leads and patch cords to a variety of probe tips. The contact hereof includes a stamped and formed coupling portion that electrically and mechanically couples a wire lead to a screw machined or cold pressed probe tip. The manufacturing advantages inherent in stamped and formed contacts are thereby combined with the durability of screw machined and cold pressed tips. Moreover, the coupling portion is especially designed to receive a variety of tips, including the desirable banana plug type tip.

Abstract: A miniature multiturn electrical capacitor is provided that includes low cost, high precision, die cast components and a unique spring biasing means to ensure electrical contact and torque between the rotor and the housing of the capacitor to enhance capacitor performance. The spring biasing means comprises a circular spring which resists compression in the radial direction and engages the inside surface of the flexible tubular rotor to bias the rotor against the internally threaded housing. The torque thus created promotes precise rotor positioning within and electrical contact with the housing.

Abstract: A new low profile miniaturized air dielectric variable capacitor for use in hybrid circuits. A very cost effective, low priced variable capacitor that combines precision with a low profile is disclosed for use in hybrid circuits and other applications where space requirements are tight. The new capacitor uses a unique design to achieve an extremely low profile, less than 0.127 inches, for varying capacitive ranges. The new design is achieved by creating the stator as part of the circuit layout or design. The stator is actually formed on the surface of the substrate by a thick film metallization or by copper etching and one or many capacitors can be formed as part of the circuit layout. Thereafter, a metallic conductive housing, internally threaded, is positioned over the stator. Internal to the housing is an externally threaded rotor having an adjusting knob or screw extending through the housing.

Abstract: A method of metallizing through holes in dielectric substrates with a metallizing material comprising forming a hole in the substrate utilizing laser techniques, depositing a layer of a dielectric on the side wall of the hole and then depositing a layer of a metallizing material onto the dielectric layer.

Abstract: A solderless coaxial cable connector for securely holding coaxial cable without indentation to the cable dielectric and offering a high strength joint at the connector. A conductive cylindrical body having four annular ratchet teeth keeps the connector from rotating when mated. The small end of the body accomodates a screw sleeve or a crimp sleeve for the outer conductors of the coaxial cable connector. The large end of the body accommodates a tubular insulator with a bore for a crimp type contact for a solid or stranded center conductor of the coaxial cable. A female nut is held in place at the center portion of the body between the large diameter section and the sleeve, either crimp or screw, to act as a coupling nut when the connector is mated.

Abstract: A rapid channel skip system for radio receiver having a single channel skipping switch to inhibit the radio receiver from receiving any of selected channels of a plurality of channels of predetermined frequencies while scanning repetitively those channel selected to be received. A clock oscillator having a scan frequency controls the scanning time of channels to be received and a skip oscillator having a skip frequency oscillates for one cycle to skip over a channel. The channel skipping switch is utilized to skip, inhibit, bypass, look around, etc., any channel of a plurality of channels a listener does not wish to receive when the rapid channel skip system connected between the squelch control and the oscillator of the radio receiver has stopped on a channel while scanning in the scan mode or has been stepped to a particular channel by the channel stepping switch in the manual mode by actuating the switch.

Abstract: A channel skip memory system for radio receiver having a single channel skipping switch to inhibit the radio receiver from receiving any of selected channels of a plurality of channels of predetermined frequencies while scanning repetitively those channels selected to be received. The channel skipping switch is utilized to skip, inhibit, bypass, look around, etc., any channel of a plurality of channels a listener does not wish to receive when the channel skip memory system connected between the squelch control and the oscillator of the radio receiver has stopped on a channel while scanning in the scan mode or has been stepped to a particular channel by the channel stepping switch in the manual mode by actuating the switch. If the channel skipping switch is actuated a second time when utilizing resettable memory elements on an inhibited channel in the manual mode, the channel is enabled. The channel stepping switch is not functional during the scanning mode.