Abstract: A range resolving ground line sensor having the capability to determine range along the length of a pressure sensitive type line or cable by providing a time limited pulse of bias voltage which propagates down and back along the line and therefore provides a time history of the impedance changes as a function of distance (time) along the line.

Abstract: A facility for monitoring in the near field, the carrier-frequency and sideband signals radiated by a DVOR ground station is provided. In a first embodiment the monitor antenna is located outside the circle in the near field, and a controllable phase shifter compensates for the phase shifts caused by the different path lengths between the radiators of the circular array and the monitor antenna. In a second embodiment, the central radiator is used as the monitor antenna. The sideband signals received by this monitor antenna are modulated in a controllable phase shifter whose control is synchronized with the switching sequence of the commutator.

Abstract: A plurality of detector units oriented in line to form a linear array to detect intrusions such as footsteps upon the ground under which the array is buried, the coil connections and sometimes the magnet polarities of successively adjacent detector units in the array being reversed so as to cancel out disturbances arriving in a broad frontal manner and caused by spurious events, but to avoid cancellation of disturbances of a localized near-field nature, and the individual detector units comprising variable reluctance units especially constructed to provide high sensitivity, to be protected from hazards of their environment, and to provide elongated zones of sensitivity in a flexible construction.

Abstract: A method of operating a storage tube having a secondary electron emissive storage target includes applying selected bias voltages to the target during the writing and erasure steps to control the electron emission ratio, which during writing is less than unity and which during erasure is greater than unity.This permits the voltage on the target during writing to be of the same order as the voltage present during reading, and this enhances the resolution and performance of the tube.

Abstract: A method and apparatus for testing a plurality of geophones disposed in either a series or series-parallel arrangement for both their activity and distortion. The activity of geophones is checked by applying a plurality of constant amplitude current pulses to the geophones and measuring the peak value of the resulting voltage. The distortion of the geophones is measured by applying a constant amplitude sinusoidal current to the geophones and detecting the harmonics of the resulting voltage.

Abstract: A direction finding receiver contained in a hand held portable housing with a ferrite rod antenna mounted in and protruding through the housing so that when the antenna axis points to the radio frequency signal source to be direction found, a null is obtained in the signal level. The antenna is coupled to the receiver circuit which comprises a broadband fixed tuned radio frequency amplifier having low sensitivity, a modulation oscillator used to modulate the broadband fixed tuned rf amplifier by tone injection when a steady carrier is present, a demodulator for demodulating the rf signal, and an audio amplifier for amplifying the demodulated signal.

Abstract: A horizontal deflection system with a transformer coupled driver including separate turn-on and turn-off drivers coupled to first and second input windings of the driver transformer is shown. The output winding of the driver transformer is loosely coupled to the first input winding to provide a sawtooth drive current to the horizontal output transistor sufficient to maintain the horizontal output transistor in saturation without wasting excessive power. The output winding is tightly coupled to the second input winding to provide a sharp turn-off pulse to the horizontal output transistor.

Abstract: A radio frequency receiver is responsive to signals radiated by a remote transmitter. The receiver includes at least one pair of antennas separated by approximately one-half wavelength at the transmitter frequency. The phases of the signals detected by the antennas are compared for the purpose of determining the relative direction to the transmitter.

Abstract: A display control circuit for automatically displaying a sampled test signal on a CRT display, or the like, where the test signal is received at an unknown period following a trigger. The circuit first establishes a base line referenced level, then the sampling of the test signal is controlled by a varied pedestal voltage or counter potential until the magnitude of the sampled test signal exceeds the base line reference level by a predetermined potential. The pedestal voltage or counter potential required to establish this predetermined potential is used for delaying the start of the display sweep following the trigger.

Abstract: A circuit is a combination of a switched mode power supply and a TV deflection circuit. It features a pair of switches and a pair of inductors that are tuned to selected frequencies so that when the switches are off, the inductor voltages have a half sine wave shape.

Abstract: A horizontal deflection system with a transformer coupled driver including separate trace and retrace drivers coupled to an input winding or windings of the driver transformer is shown. A feedback or pulse forming means is connected from the transformer to the input of the retrace driver for providing a pulse to the retrace driver in response to termination of the trace drive signal by the trace driver.

Abstract: A novel approach for generating four symmetrically located beams from a printed antenna using a corporate feed system is described. One approach used to generate four low side lobe beams utilizes a planar aperture. The second approach generates four low side lobe beams from a cylindrically shaped aperture. The generation is accomplished without the use of active phase shifting devices. The output phase function of the feed can be reversed which causes the beam to be pointed equally in the opposite direction. The radiating elements are designed to be symmetrical about the center of the aperture in a direction orthogonal to the radiating elements. By placing identical feeds at both ends, four beams can be obtained, each pointed in a direction symmetrically located about the normal to the antenna. Such an approach is applicable to both planar arrays and cylindrically shaped arrays.

Abstract: This invention relates to an improvement in the art of navigating, detecting and tracking moving objects, position finding, mapping and such subjects employing a plurality of stations and variational measurements.

Abstract: A television cathode ray tube has associated therewith a power supply for developing discrete supply voltages. A general purpose electron gun is depicted for receiving supply voltages from the power supply to produce a sharply focused beam of electrons at the cathode ray tube screen. The gun comprises associated cathode means and grid means for producing a beam of electrons, and novel focus lens means. The focus lens means receives electrons from the cathode means and a predetermined pattern of voltages from the power supply and comprises at least three electrodes for establishing a single, continuous electrostatic focusing field characterized by having an axial potential distribution which, at all times during tube operation, decreases smoothly and monotonically from a relatively intermediate potential to a relatively low potential spatially located at a lens intermediate position, and then increases smoothly, directly and monotonically from said relatively low potential to a relatively high potential.

Abstract: Disclosed is an apparatus and method for determining the presence and position of a moving object within a static field. Basically, the invention utilizes a photocathode in combination with a storage mesh whereby a distributive charge may be stored upon the mesh indicative of light levels within the field. Positive and negative write operations are exercised at different points in time and are superimposed upon the storage mesh. The mesh is then read by means of deflection coils in combination with an aperture plate so as to sequentially scan the storage mesh and emit output signals correlated with the charges upon the mesh after positive and negative write cycles have been exercised. The invention incorporates the fundamental structures of an optical image correlator tube and an image dissector tube.

Abstract: Constant width drive pulses developed by a pulse generator are shifted in phase relative to control signals locked to synchronizing signals to maintain a predetermined phase relationship between deflection signals produced by a deflection circuit and the control signals.

Abstract: The invention is a control circuit for driving a position indicator along a map screen in an aircraft flight data display. The control circuit is electrically coupled to a navigational system from which it receives digital information. The control circuit includes a decoder for decoding this information and a pair of digital to analog converters for converting the decoded information to a first analog signal and a second analog signal. These two analog signals drive a pair of servo motors which are mechanically coupled to the position indicator.

Abstract: A system employing electrical storage tube device and more particularly to scan conversion systems in which stored electrical data is erased and replaced with new electrical data wherein the improvement comprises means for controlling the fading or rate of erasure of the stored electrical data when the storage tube device employs a single electron gun for purposes of reading, erasing, and writing.

Abstract: A field output circuit in which for preventing vertical bounce of the picture and of linearity errors a feedback alternating current path is provided which includes a field frequency clamping circuit. In one embodiment the clamping circuit may be formed by the field oscillator constituted as a capacitive sawtooth generator.

Abstract: Disclosed is a system for receiving a signal from a known direction and rejecting interfering signals arriving from other directions. The system makes use of an antenna unit having multiple output ports, each responsive to signals from a different selected region of space. The output port correspondong to the region of space, which includes the direction of the desired signal, is coupled directly to an output combiner while the antenna ports corresponding to the remaining regions of space are combined to form a reference signal. Means are provided to form a correction signal in response to the reference signal and output signal for suppressing interfering signals arriving from other than the selected region of space.