Abstract: A diversity receiver for receiving digital signals, particularly, but not exclusively, digital private mobile radio signals, comprises first and second reception branches (10,12) which frequency down convert respective input signals to the zero IF signals which are digitized and combined in a maximal ratio combiner (22) and the result is applied to a digital demodulator (23). The first and second branches are asymmetrical with the first branch (10) being fully specified and the second branch (12) being deliberately degraded relative to the first branch (10).

Abstract: A radio transmission system comprises a phased-array radio apparatus for optimizing reception in a multipath transmission environment. In the phased-array radio apparatus, phase shifting is performed after down-conversion of received RF signals. Phase control and beam-forming are simple. By applying a zero-IF or low-IF receiver structure, the complete structure can easily be fully integrated.

Abstract: In a signal amplifier system, a microphone (2) is connected to an echo canceller (16) via a decorrelator (6). The output signal of the echo canceller (16) is amplified by an amplifier (14) and fed to a loudspeaker (18). The echo canceller (16) is included to avoid instability caused by undesired feedback of the signal coming from the loudspeaker (18) through a feedback path (11). To improve the stabilizing effect of the echo canceller (16), the decorrelator (6) is included for decorrelating the signal coming from the microphone (2) and the signal transmitted by the loudspeaker (18).

Abstract: The invention relates to a semiconductor device including an amplifier, and a mobile telecommunication terminal comprising this semiconductor device. The amplifier has a very high frequency a.c. signal and comprises a last stage but one of depletion-layer MESFET transistors (T3) and a last transistor stage (T4) of the same type, coupled by a d.c. isolation capacitor (C4). This capacitor (C4) forms with the intrinsic diode (.increment.4) of the transistor (T4) of the last stage a series-arranged rectifier circuit. The latter imposes a shift of the mean level of the a.c. signal on the terminals of said isolation capacitor once the amplitude of the positive part of this a.c. signal has exceeded the conduction threshold of the intrinsic diode (.increment.4). This shift of the mean level (-1.5 volts) is used as a negative voltage (-VG) for biasing the coupled gates of all the stages of the amplifier circuit.

Abstract: The present invention is directed to new electrode structures for use in fluorescent lamps in which a tungsten base structure is provided with electron emissive materials including one or more of barium titanate, barium zirconate, barium strontium zirconate, barium cerium oxide, barium tantalate, and barium strontium yittrium oxide. Amounts of MgO may be added to improve or change emitter properties. A composite electrode structure can be formed by way of coating a tungsten coil with a slurry of this material, or providing powdered mixtures of both the electron emissive material and tungsten material and sintering this powdered material into a high density composite electrode structure.

Abstract: A locking plate for releasably securing a circuit breaker to a module includes a back portion for supporting a circuit breaker, legs connected to the back portion for releasably engaging a terminal of the circuit breaker and for releasably securing the locking plate to the circuit breaker and means for releasably securing the locking plate to a module. The legs may be angled to facilitate slidable engagement with the terminal of the circuit breaker. The locking plate may also include a flange for offsetting the circuit breaker from the module when the circuit breaker is mounted on the module. The locking plate may also include a handle guard for preventing a switch on the circuit breaker from inadvertently being toggled.

Abstract: A circuit comprising a transistor (T1) is connected in series to a resistor (RM) for measuring the line current; the whole is connected to the terminals (1,2) of the line. According to the invention, a light-emitting diode (18) is connected in series to a variable current source (20), the whole being connected in parallel to the emitter/collector path of the transistor (T1), and the variable current source, which receives a monitoring signal that represents the line current, produces a current that varies between a zero current and a maximum current for an average line current that varies between a low threshold and a high threshold.

Abstract: A programmed electronic ballast circuit including a voltage maintenance circuit to ensure that the integrated circuit continues to oscillate and drive the half-bridge inverter until the DC bus voltage falls to a level insufficient to permit the fluorescent bulbs at the output to ignite. Additionally, the voltage maintenance circuit drives the voltage of the integrated circuit down to a level whereby proper resetting of the integrated circuit and proper preheating of the florescent bulb filaments is assured.

Abstract: A navigation system for a vehicle determines a route to be followed which includes a maneuver location in which the vehicle is to carry out a given maneuver. The system issues different kinds of instructions relating to the maneuver in different windows. The system can determine the position of these windows relative to the maneuver location on the basis of various instantaneous traffic conditions and on the basis of anticipated vehicle behavior.

Abstract: A selective call system comprises at least one base station which transmits address code words at a predetermined data rate. High rate telescript information having a length of more than 500 characters, for example, an E-mail message, is transmitted at a data rate greater than that used for sending address code words. In the event of the system comprising a simulcast system, intersymbol interference (ISI) may occur and in order to reduce the effects of ISI on the decoding the telescript information while avoiding an unnecessarily large drain on a secondary station's batteries, the telescript information as received for a specific secondary station is stored and subsequently equalized in non-real time. The secondary station can comprise a mobile terminal unit and may include a transmitter for transmitting acknowledgement or other response signals, for example, such as spread spectrum signals. The acknowledgement signals may be used for locating the mobile terminal unit.

Abstract: A navigation device for a land vehicle with means for generating a multi-element anticipatory speech message, and a vehicle comprising such device. A navigation device for a land vehicle senses vehicle displacement and stores map data. Matching of the displacement to the map data produces actual position and motion of the vehicle. Under control of user input, an intended route from an actual position to a destination is calculated. Under control of actual motion and with respect to selected elements of the intended route an anticipatory speech message is generated from a speech message directory. The message comprises a sequence of a message location prefix, a message action advice, and a message outcome suffix. The elements of the sequence may be represented in the directory by synthetic or recorded natural speech.

Abstract: An FSK zero IF receiver has means (DEM) for producing representations of demodulated modulating signals as a series of narrow pulses having a repetition rate greater than the symbol rate of the modulating signals and an adjustable symbol slice demodulator (54 to 66) for determining the data. The demodulator has means for adjusting a symbol slice threshold value in dependence of the pulse like representations of the deviation frequencies which may be different as a result of drifting between the local oscillator and nominal transmitter carrier frequencies (f.sub.L and f.sub.C).

Abstract: A picture display device having an evacuated envelope (1) comprises a first wall (2) which is provided with a display screen (3), and a second wall (5), and is provided with an internal vacuum support (11) between the two walls (2, 5). The internal vacuum support (11) comprises a dielectric plate at least at the side facing the first wall (2), which plate is arranged opposite the display screen (3) and is provided with cavities (12) at the location of the pixels (4R, 4B, 4G) of the display screen (3). The internal vacuum support (11) accommodates cavities (12) which constitute a lateral system of ducts. The continuous exhaust path of the internal vacuum support (11) communicates via the exhaust cavity (25) with an exhaust connection (9).

Abstract: A method of positioning a printed circuit board in a component placement machine and holding it in a plane condition. The exertion of a couple on two mutually opposed edge portions of a printed circuit board presses the printed circuit board flat onto a support.

Abstract: A method of, and system for, communicating messages in an environment which is subject to fading, in which data to be transmitted is encoded and formatted, a checksum is determined for said encoded and formatted data and in which the checksum is added to an address code word which is concatenated with the encoded and formatted message code words to form a message. A receiver is energized for receiving transmissions in its predetermined frame. In response to recognizing its address code word the concatenated code words are decoded and stored. As each code word is stored, substantially simultaneously a checksum is computed for the message assembled so far and is compared to the checksum in the address code word, if and when they are equal it is concluded that a complete message has been received and further analysis of the stored message is terminated.

Abstract: A multiple access digital transmission system including a transmitter for transmitting at least one modulated data stream, and at least one receiver for receiving, via a multipath transmission channel, a transmitted signal which includes the modulated data streams. The receiver includes a resolver for resolving at least one path for at least one multipath received modulated data stream and a channel estimator for estimating channel path delays in the received modulated data streams. The receiver includes a generator for generating an interference reduced signal from the received signal, the interference reduced signal being fed to the channel estimator.

Abstract: A method of manufacturing a shadow mask of the nickel-iron type, in which an aperture-patterned sheet of a nickel-iron alloy comprising 35-37% by weight of Ni and less than 0.1% by weight of each constituent of the group of Mn, Cr and Si and at most 0.9% by weight of Co is given a thermal treatment for obtaining an ASTM grain number of .gtoreq.7, and the sheet thus obtained is given the desired shape of a shadow mask having a thermal expansion coefficient of .ltoreq.0.9.times.10.sup.-6 /.degree.C.

Abstract: A device for applying exactly dosed quantities of a viscous medium on support surfaces including a backing plate with an upper side and a lower side and at least one through hole, a dosing plate having at least one through hole and an upper side and a lower side which rests on the upper side of the backing plate, while it is possible to change the positions of the backing plate and the dosing plate relative to one another through shifting of the dosing plate or backing plate, an internally hollow tube whose outer wall is connected with exact fit to the whole wall of the hole of the backing plate at one end of the tube for each through hole of the backing plate, a die which can be passed through the through holes of the dosing plate and of the backing plate and through the internally hollow tube, for each through hole of the backing plate, and a wiper device operating parallel to the upper side of the dosing plate, by means of which a viscous medium can be introduced into the through hole of the dosing plate.

Abstract: A radio transceiver including a counter for outputting a DC compensation signal, an amplifier for receiving a input signal having a DC component and for receiving the DC compensation signal and forming a signal difference between the input signal and the DC compensation signal and a comparator for comparing the signal difference and a reference signal. The counter increases and decreases the DC compensation signal based on the output of the comparator such that the incrementation or decrementation of the counter is based on the DC component of the signal difference.

Abstract: A communications system includes a network formed by several geographically distributed, interconnected nodes, each of which defines a service area. Each node has stores registration details for at least one of several of subscriber units, the node being the home node for such at least one station. Each node is responsive to a subscriber unit registering with a node other than its home node for causing registration details relating to that subscriber unit to be stored at those of the interconnected nodes lying on a path between the home node and the node at which registration has most recently occurred.