Abstract: Frequency scanning means and method comprising a broadband signal discriminator means for receiving and delivering signals within its frequency band, detecting means receiving signals delivered by the discriminator means and providing output signals related to the frequencies of the received signals, signal generating means selectively providing output signals corresponding to the frequencies of signals within the band of said discriminator means, and signal processing means receiving the output signals of said detecting means and said generating means and delivering an output signal for each signal delivered by said discriminator means having a frequency selected by said generating means, and including gating means receiving signals from the discriminator means and the processing means and delivering signals from the discriminator means during receipt by the gating means of signals from the processing means.

Abstract: Apparatus for demodulating phase modulated signals is described. The latter signals are produced by modulation of a carrier or harmonically related carriers. The modulated signal, constituted by consecutive modulation sections, is coupled to an analogue multiplier, the output of which is connected to an integrator. The integrator produces the demodulated signal. A pulse generator produces a sequence of pulses, each of which occurs within a given modulation section. The duration of each pulse equals the reciprocal of the fundamental frequency. A carrier corresponding in frequency and synchronized with the transmitted carrier is produced in the receiver. The transmitted carrier and receiver-produced carrier are coupled to the multiplier. The latter carrier is switched prior to its application to the multiplier using the output of the pulse generator.

Abstract: In the switching circuit, the output signal from a high-gain differential amplifier is caused to reverse polarity by means of the switching of a pair of field-effect transistors. A resistor is connected in series with the inverting lead of the differential amplifier, and a signal source is connected to the resistor at an input terminal. The field-effect transistors are used to connect the non-inverting lead of the differential amplifier alternately between the input terminal and ground. This causes the amplifier output to reverse polarity, and thus provides a very accurate, low-offset means of switching the output of the amplifier. The switching circuit is used in a modulator which permits output pulses to be modulated in width and/or frequency. The reversible output signals of the switching circuit are added to the modulating input signal and the sum is integrated. A level detector changes the polarity of its output voltage whenever the output of the integrator reaches either of two fixed levels.

Abstract: An electron beam tube for time multiplexing a plurality of signal channels on an extremely high frequency carrier includes an electron gun, a deflection system for causing the electron beam generated by the electron gun to sweep in a circular path past a plurality of individual electrodes which are excited with signals corresponding to the signals of individual channels, for modulating the beam with the channel signals, and a target for collecting the modulated beam to produce a time multiplexed output signal. The output signal may be amplified within the tube.

Abstract: A concatenated surface wave device having delay line capabilities for use in correlating electric signals of various types and forms including analog signals, binary signals, and binary modulated signals, said device including means forming a specially constructed conductive surface pattern over which the signals to be correlated are propagated, said surface pattern including input transducer means at a location where input signals to be correlated are introduced for propagation over the surface, a plurality of tap locations on the surface at spaced locations extending away from the input transducer means, and means for sampling a propagated signal at selected surface locations including at selected ones of said tap locations to determine the locations of places where the signals to be correlated are in agreement and are and are in disagreement. The subject correlator also includes means by which signal components can be introduced at selected tap locations along the device.

Abstract: The spark plug has been designed so as to, be capable of being disassembled for cleaning, have a substantially full shield for the spark gap end of the center electrode portion, enable the center electrode to be readily replaced, if desired, enable partial cleaning of the spark plug gap area without removal of the spark plug from an associated engine, and have a substantially full gas seal defined between the base of the spark plug and the spark plug insulative sleeve.

Abstract: Portable, plugable electrical test equipment signals the presence or absence of radio frequency energy within a predetermined frequency spectrum, as on a CATV or MATV video distribution system. The equipment comprises a cascaded bandpass filter, radio frequency amplifier, coupling-detector network, and operational amplifier to selectively energize a light emitting diode when a sufficient level of energy in the requisite frequency range is sensed.In accordance with one aspect of the present invention, the coupling-detector network includes circuitry for quiescently biasing the inverting and noninverting inputs of the operational amplifier to a state such that the LED is not activated. The circuitry further includes as an integral part thereof detector structure for reversing the relative potential amplitudes impressed on the amplifier inputs when a sufficient quantum of the subject radio frequency energy is coupled to the composite test equipment, such that an appropriate output indication is generated.

Abstract: Digital logic apparatus for demodulating a received phase-modulated carrier wave wherein phase-shifts between successive signalling intervals encode data elements. A shift register serially stores periodic samples of a squared version of the received wave. Exclusive-OR gates compare pairs of stored wave samples, each pair comprising a sample from a previous signalling interval and a sample from a current signalling interval. At least one of the exclusive-OR gates derives synchronizing signals for a local timing generator. For each data element, an integrator is associated with one of the exclusive-OR gates to accumulate a count related to the time during which pairs of similar samples are sensed by its exclusive-OR gate during each signalling interval. The integrator registering the highest count at the end of a given data interval signifies the data element received during that interval.

Abstract: Frequency summing device comprising a summing element effecting the summing of the output signals of a first multiplier receiving a signal whose frequency is f and a signal whose frequency is F and of a second multiplier receiving the signal whose frequency is f and the signal whose frequency is F after dephasing by 90.degree.. The dephasing by 90.degree. is obtained by a complex circuit comprising three elementary dephasers in series provided with an attenuator and an adder effecting the sum of the output signals of the attenuator and of the first dephaser.

Abstract: Disclosed herein is circuitry for producing a signal proportional to the rate of recurrence of a periodic input signal applied to the circuitry. When an input pulse is received a timing circuit is energized to charge a capacitor to a predetermined level. The capacitor is then discharged through a resistance circuit having resistance portions which are electronically switched in and out of the circuit so that the discharge, rate of the capacitor defines the desired rate function. Then, upon commencement of a subsequent pulse a sample and hold circuit is actuated to sample the discharge level of the capacitor to provide an accurate indication of the pulse rate.

Abstract: A digital phase-locked loop in which an error signal representing the difference between the phases of an input signal and an output signal is converted to a digital signal having a time-varying value. A programmable divider means is provided to produce a pulse control signal having a frequency which varies in accordance with the time-varying value of the digital signal. The pulse control signal controls the number of pulses which are deleted from a reference clock signal to produce an intermediate signal which in turn is fed to a feedback counter for producing the output signal, the phase of which depends on the number of deleted pulses, so that the phase of the output signal effectively follows the phase of the input signal.

Abstract: A selected part of the envelope of a fabricated electric lamp is made light-reflecting by spraying it with a coating composition that contains aluminum flakes of such minute size that they inherently arrange themselves in planar relationship and form a specular film as the composition dries. A protective coating of a suitable heat-resistant material, such as silicone plastic, is then sprayed over the reflective film and cured. The protective coating can also contain aluminum particles in order to fill voids that may be left in the thin specular film and to make the latter more opaque.

Abstract: Apparatus for and method of inspecting transparent containers of the type used for food and beverages for the presence of dirt, foreign objects and manufacturing defects, such as birdswings. The apparatus includes illuminating each container from different angles and in a sequential order, and processing the illuminated images by photo-electronic scanning apparatus to obtain a response on a change in the illumination level within an electronic window of an amount sufficient to actuate a container reject mechanism.

Abstract: The arc tube of an electric discharge lamp is surrounded by a reflective filter. The filter selectively reflects arc discharge radiation outside the visible range to which the arc tube wall is transparent and to which the arc plasma is optically thick, so that the reflected radiation is preferentially absorbed by the plasma and not by the arc tube wall.

Abstract: Ideally, when a signal is quantized, the range of the quantizer should be matched to the power of the signal. Disclosed herein is adaptive quantizer apparatus which utilizes a particular quantizing scheme for those communications where the power of the signal to be quantized is unknown, but remains constant for the duration of a communication. The amplitude range of an adaptive quantizer is adjusted during an initial training period to a value appropriate to the power of the applied input signal. This is accomplished by successively altering the amplitude range by a multiplicative quantity that depends upon the amplitude of the quantizer output signal and upon the time elapsed since the onset of the training period.