Abstract: Two or more signal paths are provided for receiving a radio frequency signal. One or more signal paths include conventional bandpass filters for eliminating interference and noise signals. One or more remaining signal paths include reduced filtering devices for increasing the sensitivity of a radio frequency receiver to the desired signal. Each of the receiving paths is coupled to a respective radio frequency amplifier. Provided that each radio frequency amplifier has equivalent current-source output impedances, the output signals from each amplifier are added constructively if they are in-phase. If the output signals are out-of-phase, a phase inverter inverts the phase of one signal so that the signals may be added constructively. The combined signals of the two or more radio frequency amplifiers pass through various signal processing components associated with conventional superheterodyne receivers. A control unit produces gain variation signals for controlling the gain of each radio frequency amplifier.

Abstract: In a BS (direct broadcast by satellite) timer recording mode, a constant voltage diode for controlling 18 V is directly inserted in a power circuit. Alternatively, a delay circuit is inserted at the input of a switching circuit for switching the constant voltage diode, thus absorbing the switching time difference between 140-V control and 18-V control. Therefore, the secondary side output voltages can be prevented from being increased, and the output voltages can be stabilized both in the BS timer recording mode (light load powering) and in the television mode (maximum load powering).

Abstract: In a digital radio communications system, a transmit signal is delayed and sent on a first diversity channel and a nondelayed version of the signal sent on a second diversity channel. At the receiving site, first and second diversity channel signals are recovered and normalized into first and second constant-amplitude signals. Predominant components of the constant-amplitude signals are phase-and-amplitude aligned with each other by feedback loops including phase-and-amplitude alignment circuits, an adder and an AGC amplifier. The output of the AGC amplifier or the output of the subtracter is selected and applied to a matched filter to which a decision feedback equalizer is coupled.

Abstract: A method and apparatus for controlling electrical power to a satellite broadcast receiver forming a part of a television device. The television device receives a command receiving a command (e.g. from a remote controller) to turn off electrical power. The television device determines if broadcast satellite recording is currently being executed, for example by an external VTR connected to an output port of the television device. If broadcast satellite recording is being executed, power is turned off power to a portion of the television device while retaining electrical power to the satellite broadcast receiver. If broadcast satellite recording is not being executed, power is turned off to the broadcast satellite receiver also.

Abstract: A diversity reception apparatus which has a plurality of antennas and in which one of the antennas having the best receiving condition is automatically selected and connected to a broadcasting signal receiver. The diversity reception apparatus has a feature in that after demodulated signals, obtained by the receiver respectively corresponding to the plurality of antennas, are converted into digital signals by an A/D converter, the best demodulated signal and the antenna corresponding thereto are selected by comparing the digital signals with each other, and that the width of a switch driving pulse from a switch driving pulse generator is made not more than 3 .mu.s.

Abstract: An operation control system includes a GPS receiver unit and a radio telephone unit. The GPS receiver unit includes a GPS antenna and a GPS signal receiver circuit connected thereto. The radio telephone unit includes a telephone antenna and a transmitter circuit connected thereto. The transmitter circuit transmits a call channel signal through the telephone antenna during the radio telephone unit being in an ON-CALL MODE and a control channel signal during an OFF-CALL MODE. The system is designed to set the transmitter circuit operative and the GPS signal receiver circuit inoperative during the ON-CALL MODE. On the other hand, the system allows alternate operations of the transmitter circuit and the GPS signal receiver circuit during the OFF-CALL MODE.

Abstract: A system and process for continuous reception of information by a mobile receiver unit passing among a plurality of spaced transmitters with each transmitter configured to individually transmit signals to the mobile receiver unit. The mobile receiver unit has a pair of scanning receivers controlled by a switching control module. The module causes one of the scanning receivers to lock onto signals transmitted from one of the transmitters while causing the second scanning receiver to scan signals transmitted by the transmitters in the reception range of the scanning receiver. Once the strength of the signal locked onto by the first scanning receiver falls below a predetermined minimum signal strength, the second scanning receiver locks onto the best suited received signal and the first scanning receiver is caused to commence scanning, the roles of the scanning receivers thus being reversed.

Abstract: A process or the production of glyoxylic acid involving the enzymatic oxidation of glycolic acid. The process provides a commercially practical method involving the reaction of glycolic acid in an aqueous solution at a starting concentration range of 200 mM to 2,500 mM in the presence of oxygen, glycolate oxidase and catalase at a pH of 7 to 10.

Abstract: Carrier frequencies different in frequency from each other are modulated with broadcast signals different from each other, and the thus modulated signals are transmitted through a single transmission line and are suited for reception and demodulation. A programming circuit allows programming of a plurality of different programs, with each program being able to be programmed to activate any selected receivers of a plurality of receivers, and to tune each of the selected receivers to any selected carrier frequency. The different programs are stored in a memory, and each of the receivers is connected to a speaker. A selection circuit allows a user to select any one of the different programs to output the broadcast signals at selected frequencies from selected speakers.

Abstract: The antennas of a cellular telephone system are each connected to a signal divider/combiner array which/divides combines the antenna connecting path(s) into a plurality of antenna-radio/radio-antenna connecting paths. The divider array aspect is used for signal reception and the combiner array aspect is used for signal transmission. Each of these antenna connecting paths is connected to a controllable switch which in turn selectively couples it to/from a second plurality of radio transceivers. The antenna transmission/receive paths comprising the signal divider/combiners are embodied as strip type transmission lines in a multi layer PCB with all the paths having equal transmission losses. Micro vias are provided to permit electrical access to the various layers. The controllable switches are surface mounted on the outside of the PCB and are coupled to the various dividers/combiner through the micro vias.

Abstract: A portable radio communication apparatus includes a first antenna that can extend away from, or be retracted towards, an apparatus housing. The apparatus includes a second, usually flat antenna mounted within or around the outer periphery of the housing. When the first antenna is extended away from the housing, it is connected via a switch to a node, in turn, connected via respective filters to both a transmitter and a diversity receiver. At this time, the second antenna is connected to the diversity receiver via a respective filter. When the first antenna is sufficiently retracted towards the housing, a switch, mechanically coupled to the first antenna, disconnects the first antenna from the node, connects the second antenna to such node, and disconnects the second antenna from the diversity receiver.

Abstract: A diversity receiver includes first and second receivers, a first switch, a comparator, a second switch, and a controller. The first and second receiver have receiver antennas and generate demodulated signals and electric field detection outputs in accordance with received electric fields, respectively. The first switch performs switching between the demodulated signals from the first and second receivers in accordance with an output switching control signal and outputs a selected demodulated signal. The comparator compares the electric field detection outputs from the first and second receivers, respectively, and supplies the output switching control signal to the first switch. The second switch turns on/off a power source of the first receiver in accordance with a power source switching control signal.

Abstract: A polarity switch for connection between a dual antenna system and a satellite television receiver to permit multiple receivers to simultaneously receive channels of different polarity includes a pin diode switch and input circuitry to decode the standard receiver signal previously used to rotate the antenna feed of a single feed antenna.

Abstract: A diversity reception of signals involves first and second mobile receivers which recover first and second baseband signals. The first and second receivers have first and second wave detectors, respectively, for generating output voltages corresponding to the strength of an FM modulated signal. When the difference in output voltages between the first and second detectors exceeds a predetermined value, a comparator gives an output detection signal. An adder circuit combines the first and second recovered baseband signals. First and second switching circuits selectively cut off the lower level one of the first or second recovered signal, which is then being supplied to the adder circuit. A third switching circuit adjusts the gain of the adder circuit. When the comparator does not give an output detection signal, the first and second switching circuits feed both the first and second recovered baseband signals to the adder circuit.

Abstract: An improved polarity switch for connection between a dual antenna system and a satellite television reception system has a first embodiment which utilizes a pin diode switch between the dual antenna system and each of a plurality of receivers to permit use of the receiver to select one of the two antenna feeds for decoding and display at that television set. A second embodiment is also disclosed which utilizes an electromechanical relay to isolate the antenna feeds from each receiver.

Abstract: A first multi-port hybrid coupler is formed by n2.sup.n-1 (where n is an integer equal to or greater than 2) hybrid couplers alone, which are divided into n stages, each including 2.sup.n-1 hybrid couplers. A signal input to any one of N (=2.sup.n) input terminals of the first stage is distributed equally to N output terminals of the nth stage. The N output terminals of the nth stage of the first multi-port hybrid coupler are connected to N amplifiers at the input side thereof, respectively, and the N amplifiers are connected at the output side to a second multi-port hybrid coupler. The second multi-port hybrid coupler is identical in construction with the first multi-port hybrid coupler, but its input terminals and output terminals are reverse from those of the latter and the input terminals of the second multi-port hybrid coupler are connected to the N amplifiers in an order reverse from the order of arrangement of the output terminals of the first multi-port hybrid coupler.

Abstract: An input circuit is provided for a television receiver for amplifying and transforming the input signals into an intermediate frequency signal. The output of the mixers is fed via intermediate-frequency bandpass filters to respective decoupling diodes, which are switched on depending on the selected receiver frequency range. The output of the decoupling diodes is fed to an impedance transformer such as an emitter follower and its output in turn is entered into an intermediate-frequency amplifier.

Abstract: A diversity receiver which comprises two pairs of antennas and tuners and a comparator for comparing two signals obtained from said two tuners so that one of the tuners is selected in response to the result obtained in the comparator includes an antenna switching circuit and an operating antenna indicating circuit which are connected to the comparator so that the antenna associated with the selected tuner by the operation of the antenna switching circuit is indicated in the operating antenna indicating circuit.

Abstract: A channel selector characterized in that a plurality of receivers capable of simultaneously performing a receiving operation have a main part of a phase-locked loop frequency synthesizer connected in common thereto, the frequency synthesizer having a programmable frequency divider, a phase comparator, a reference oscillator and a reference frequency divider. The frequency synthesizer is controlled so that a local oscillation frequency corresponding to a determined frequency close to a broadcast signal of a desired receiving channel is synthesized, and one of a plurality of search tuning systems searches and tunes the broadcast signal from the local oscillation frequency.

Abstract: Device for receiving radio call messages, preferably on board ships, which device comprises a number of receivers (1) for different frequencies from various stations and/or transmitters and means for processing the messages. The output of each receiver is connected to the input of a shift register (4) of which the output signal is a binary signal having the value "1" or "0" and each output is fed to the input of an identifier (11) for determining the pertinence of the messages to the relevant ship. The outputs of the identifier or of the identifiers (11) are connected to a switching unit (14), which, in case the identifier means (11) has identified a message pertinent to the relevant ship, connects the appropriate shift register to a store (13) available at that moment. A cyclic scanner (18) then quickly and successively reads out the completed and stored messages and transfers them to a terminal station for further storing and processing.

Abstract: A circuit for coupling a citizens band transceiver and a broadcast band receiver to a standard automobile antenna. The circuit is comprised of an impedance transforming network connected in series with the standard automobile antenna and a parallel-tuned circuit in series with the broadcast band receiver. The series-tuned network is comprised of a split capacitance for stepping the impedance down from the citizens band transceiver to the lower impedance of a standard automobile antenna. The series-tuned circuit also includes a tuning coil for matching the output of the network to the particular automobile antenna. In series between the automobile antenna and the broadcast band receiver is a parallel-tuned circuit comprised of a capacitor and a tuning coil. To prevent multiplication and excessive voltages in the event the broadcast band receiver should become disconnected, a limiting resistor connects the parallel-tuned circuit to ground.

Abstract: A multi-purpose radio of the AC or battery operated type which includes connections for an auxiliary unit which is an alarm device of the ultrasonic type in which the transducers of the alarm device are mounted on the radio cabinet. The output of the alarm device is applied to the audio frequency amplifier section of the radio.