Abstract: 1. A photoconductive target for a pickup tube comprising a layer of porous lead telluride on a transparent conductive layer, said porous lead telluride having a resistivity of approximately 10.sup.-11 ohm cm when maintained at a temperature substantially equal to liquid nitrogen temperature.

Abstract: In a color cathode ray tube deflection apparatus having a deflection yoke with horizontal, vertical and quadrupole windings and affixed to a color cathode ray tube, a quadrupole convergence circuit includes a quadrupole winding coupled to a source of substantially parabolic-shaped horizontal and vertical frequency signals and coupled by a signal clamping circuit which is, in turn, shunted by an impedance varying in proportion and an opposite direction to variations in the impedance of the clamping circuit as determined by the value of the substantially parabolic-shaped vertical frequency signal whereby convergence at the corners of a cathode ray tube is enhanced.

Abstract: A generator vibrates low frequency sound vibrations and magnetic fields with superimposed high frequency noise which upsets the habits of rodents and most burrowing animals. The sounds are transmitted to the ground by the generator being connected to a pipe or shaft embedded in the ground, to buildings, structures or to water pipes which run underground. The circuitry permits random frequencies to be generated at random intervals by the use of cycling thermostats in circuit with the sound generator. The thermostats cycle due to the heat of the coils or resistors or from an electronic randomizing control circuit.

Abstract: Photocathode having a transparent conductive undercoating to provide a radial voltage distribution across the cathode surface. The conductive undercoating is in the form of radially spaced rings made of chromium deposited on a glass substrate. Over the substrate and the conducting undercoating is provided a resistive layer comprising chromium having a thickness of about 50 Angstroms. Over the resistive chromium layer is deposited a photoemissive layer of antimony, potassium, sodium and cesium. The radially spaced conductive rings are connected to sources of different voltage to produce a desired voltage distribution across the resistive chromium layer.

Abstract: An identification system including a transmitter, a receiver, a decoding subsystem, and a passive transponder identifier. One passive transponder identifier of the invention is a surface acoustic wave device provided with pad means for applying and removing pressure on a substrate of the device at preselected locations. A second identifier of the invention is a microacoustic shear bulk wave device. The passive transponder identifiers are programmed to produce a characteristic coded electronic reply in response to an electromagnetic signal interrogation.

Abstract: In a switched vertical deflection circuit, two SCR switches couple horizontal retrace pulses to a capacitor. A modulator couples pulse width modulated gating pulses to the SCR's. The SCR's couple to the capacitor successively smaller portions of the horizontal retrace pulses during a first part of the vertical trace interval and successively larger portions during a second part for developing in a vertical deflection winding a sawtooth vertical deflection current. The modulator couples gating pulses to one of the SCR's during the vertical retrace interval for substantially loading the horizontal deflection circuit during the vertical retrace interval for preventing undesired oscillations within the horizontal deflection circuit.

Abstract: A horizontal electron beam crossover correction circuit for an in-line color cathode ray tube having an associated toroid-wound deflection yoke with first and second horizontal deflection windings each having first and second winding portions coupled to a horizontal deflection signal source includes an adjustable impedance shunting at least one of the winding portions of one of the first and second horizontal deflection windings for controlling current flow in one with respect to the other of the winding portions.

Abstract: A color cathode ray tube (CRT) provides excitation of a plurality of noncontiguous picture elements disposed substantially in a matrix configuration of rows and columns on the inside surface of a video screen formation included within the tube, with a hollow electron beam provided by a modulatable, hollow beam electron gun assembly within the tube, each picture element including a plurality of different color phosphors deposited in a determined concentric geometric pattern, the screen formation further including a high work function dielectric material disposed interposingly with the picture elements of the matrix configuration for providing a negative electrostatic field gradient in a direction opposite to that of the incident hollow electron beam horizontally deflected across the screen by a deflection circuit, to cause registration of the beam with each successive picture element and to cause, in combination with the deflection circuit, the beam to step from the center of one picture element to the center

Abstract: 1. An electron multiplier comprising wall means of secondary electron emissive material defining a spiral passage, means for providing a current flow through said wall means to supply electrons for secondary emission, a resistance means provided in said wall means and connected in parallel across a portion of the spiral passage defined by said wall means to provide more uniform current multiplication along said passage length.

Abstract: In a top-bottom pincushion correction circuit having a saturable reactor with a control winding coupled to a source of deflection current at a horizontal scan frequency and an output winding coupled to a source of deflection current at a vertical scan frequency, a means coupled to the control winding unbalances the waveform applied thereto from the source of deflection current at a vertical scan frequency to provide asymmetric top-bottom pincushion correction.

Abstract: The transducer unit includes a rigid hollow casing. The casing defines through its cylindrical wall a plurality of sound-transmitting windows. A hydrophone having an elastomer core is removably positioned in the bore of the casing opposite to the windows. A pressure transducer element is embedded inside the core. The core is slightly compressed so as to form plugs for the windows.

Abstract: A diamond marker generator circuit generates a diamond-shaped marker making a spot or point on a curve of an input signal being measured.Despite changes in the display or sweep rate of the input signal, the marker's size is kept constant, and its intensity or contrast is maintained at a constant level relative to the intensity of the curve.One marker is generated above the curve to mark a current point of interest to a user. One or more markers are generated below the curve to mark previous points of interest.

Abstract: A high voltage power supply system particularly adapted for rapid switching of high voltage applied to an anode of a beam penetration color cathode-ray tube. Energy for making the rapid transition between voltage levels is stored in two energy storage inductors, one for upward transitions and the other for downward transitions. When it is desired to change the voltage applied to the cathode-ray tube, the appropriate one of the storage inductors is coupled through a controlled switch to the anode causing the voltage applied to the anode to change at a rapid rate. The voltage rises until the desired voltage level corresponding to a desired output color is reached at which time the switch is turned off and the storage inductor recharged. A tracking high voltage supply maintains the anode at the predetermined voltage level once that level has been reached.

Abstract: A modulatable, hollow beam electron gun assembly includes an electron-optical (E-O) column having a fixed diameter ring, dispenser type cathode assembly for providing a hollow electron beam through thermionic emission from a hollow cylindrical cathode element, first and second control grid assemblies, a first anode assembly and a second anode assembly, which in combination with a beam modulator assembly comprises an electrostatic coaxial lens assembly. The grid and anode assemblies provide control of the emitted beam current density.

Abstract: Today's cathode ray tube oscilloscopes are widely used throughout the world and form an important basic tool in many industries. An apparatus to modulate the cathode ray display intensity, thereby enhancing the oscilloscope's capabilities in that it can now make more accurate measurements and, in effect, increase its band width, is disclosed. The apparatus to facilitate this effect is light weight, low cost, and easily connected to almost all oscilloscopes now in use.

Abstract: A method for the comparative vector measurement of keyed radio signal pulses arriving nearly simultaneously at several radio receivers, particularly DME pulses, which can exhibit great level differences. The pulses at each receiver are individually fed to an amplifier or attenuator having an amplification or attenuation, respectively, which can be adjusted in distinct steps, whose reduction or increase, respectively, takes place automatically with the rise of the leading edge of the respective signal pulse. After passing through the respective amplifier or attenuator of the receivers, the instantaneous amplitudes of the measuring signals are measured at a specific measured time which is common to all receivers.

Abstract: Apparatus is provided for preventing the generation of an excessively high voltage by the high voltage circuit of a CRT device, such as a television receiver, thereby avoiding the danger of producing injurious X-ray radiation and further minimizing the potential fire hazard attributed to such an excessively high voltage. A flyback transformer is connected to a resonant capacitor and is driven by a switching device synchronized with horizontal scanning pulses so that flyback pulses are produced during the normal retrace intervals in the horizontal deflection. A relatively low voltage power supply is coupled to the switching device to apply an operating voltage thereto. A first detecting circuit is coupled to the flyback transformer for detecting a high frequency component included in the flyback pulses in the event of a malfunction of the resonant capacitor, such as a disconnection of that capacitor, which high frequency component causes an excessively high voltage to be produced by the high voltage circuit.

Abstract: The beam forming means and static convergence correcting means in a color cathode ray tube are arranged to provide for proper convergence of the beams at regions remote from the center of the screen and closer to the corners. The resulting misconvergence at the center of the screen is then corrected by dynamic convergence correcting means which produces less beam distortion then if it had to correct misconvergence at the corners.

Abstract: A brightness control circuit for use with light emitting (LED) displays, or comparable electronic displays that are energized from a source of DC potential that supplies periodic pulses of constant peak current to the display elements, the display brightness being controlled as a function of the pulse duty cycle so as to achieve a uniform and continuous control of the display over a relatively wide range of brightness levels, extending particularly into the lower brightness region. Energizing current is coupled to the display by a transistor switching means actuated at a given frequency and with a duty cycle that is a function of the brightness control setting.

Abstract: A side pincushion correction circuit having an impedance circuit in series with the deflection coil. A controlled switch coupled in a branch of the impedance circuit is operated at times during the second half of the horizontal retrace interval which are progressively advanced during the first half of vertical interval and retarded during second half of vertical interval. Enhanced inside pincushion distortion correction is provided when the impedance circuit includes a capacitor coupled in series with the switch.