Abstract: A relay for control of a network protector located on a low voltage side of a transformer with a set of three phases, the relay having at least one route for power to be provided to the relay from at least one of the set of three phases taken from a transformer side of the network protector so that the relay may have power and be functional before the network protector is closed to provide power into a dead network.

Abstract: A relay for control of a network protector located on a low voltage side of a transformer with a set of three phases, the relay having at least one route for power to be provided to the relay from at least one of the set of three phases taken from a transformer side of the network protector so that the relay may have power and be functional before the network protector is closed to provide power into a dead network.

Abstract: Where two or more antenna beams may receive signals from the same cellular communication system user, post-reception beam channel gain variations may obscure choice of the channel providing the strongest user signal. Thermal atmospheric noise, assumed to equally enter each beam, is utilized as a standard signal level in order to calibrate the relative gain factor for each channel. Thermal noise level is measured by use of a single common receiver (32) sequentially coupled to each channel (22-25) to listen for lowest signal levels during inactive intervals, over periods of time which may extend for hours. Lowest signal levels provide thresholds for each channel from which gain correction factors are developed. When a user signal is received in two channels, the gain correction factors are employed to select the channel providing the best signal, on a substantially real time basis. A long-term lowest signal level monitoring algorithm is described.

Abstract: A relative time offset is measured between transmission of a downlink signal from a cellular radio network base station, and a reference signal (e.g., sync word) included in an uplink signal received at the base station from a network subscriber. If the measured time offset is within a determined range, the uplink signal is judged to originate from a subscriber which is validly assigned to the base station, and the base station will continue to track the valid uplink signal. If the relative time offset is outside the determined range, the uplink signal is judged invalid, e.g., to originate from an interfering co-channel subscriber assigned to a remote base station. The receiving base station will then inhibit tracking of the invalid uplink signal.

Abstract: A system and technique for detecting a recurring signal, for example, a synchronization pulse contained in an information signal stream modulated on a carrier signal, wherein the recurring signal has a known duration (.tau.) and a known period (T). The signal carrier is demodulated such that the recurring signal exhibits a certain characteristic amplitude variation over its duration .tau., and the demodulated signal carrier is sampled at intervals less than .tau. thereby obtaining signal samples exhibiting the amplitude variation of the recurring signal. The signal samples are applied to an input of a coincidence network including at least one delay circuit which provides a delay corresponding to the period T of the recurring signal to a passing signal sample, and input and output terminals of each delay circuit are coupled to different inputs of an associated coincidence gate circuit. Each coincidence gate circuit produces an output whenever its input signal samples coincide with one another.

Abstract: A high frequency push-pull amplifier which includes an improved output circuit to eliminate spurious emissions, typically low frequency parametric oscillations. The output circuit includes a low pass filter with an inductive input so as to avoid a series resonance to any harmonic of the desired output signal of the amplifier. A resistive termination is provided to any of the in phase signal components between the push-pull amplifier and the low pass filter. Also, to inhibit any tendency towards parametric oscillations, the variation in output capacitance with respect to collector voltage of the transistors is minimized by placing a capacitor in parallel with the collector capacitance, which is several times the collector to emitter capacitance of the transistors at their normal collector voltage.