Abstract: A technique for reducing radio frequency signal navigation errors in systems such as Loran-C and the like, comprising the use of an orthogonally crossed pair of antenna windings on a ferrite cross, tuned to the carrier radio frequency to generate from the received signals both in-phase and quadrature circulating current components, and providing for the eliminating only of the quadrature current components.

Abstract: A frequency-hopping intrapulse frequency modulation Loran-C navigation pulse technique, preferably using a flat-topped pulse shape and a novel 16-ary phase hopping scheme, and a novel improved high-power solid-state switch for dynamic antenna modulation tuning.

Abstract: A frequency-hopping intrapulse frequency modulation Loran-C navigation pulse technique, preferably using a flat-topped pulse shape and a novel 16-ary phase hopping scheme, and a novel improved high-power solid-state switch for dynamic antenna modulation tuning.

Abstract: Frequency modulation switching apparatus for rapidly increasing and decreasing the frequency within radio-frequency pulses of radio wave pulse trains transmitted by an antenna having series inductance and capacitance, the apparatus having, in combination, a solid state four-terminal rectifier bridge circuit with opposing pairs of bridge terminals connected with one pair of opposing terminals shunting said inductance and said capacitance; and series-connected staturable and linear inductors and an SCR switch connected between the other pair of opposing terminals of the bridge circuit, whereby the high-speed triggering of the SCR on effects corresponding high-speed frequency increasing or decreasing of the frequency within the radio-frequency pulse to provide the desired frequency modulation therein

Abstract: A method and apparatus for increasing the potential digital bit data rate potential for communication-to-be-added to Loran-C radio-frequency pulse navigation transmitters and the like without affecting the navigation capability and integrity of the system, involving frequency-sweeping the pulse carrier frequency between critical lower and upper limits with respect to the pulse carrier frequency during the parts of each pulse following the initial part used for navigation timing.

Abstract: A novel loop antenna containing a thin-walled ferrite box or other hollow; magnetic core structure of high permeability (considerably greater than 100), particularly useful for crossed loop antennas, and of optimal geometry and configuration for minimum volume, weight and space.

Abstract: A technique for optimizing the impedance match between a plurality of pulse generators and a high-Q tuned load by equally advancing and retarding the phase of equal groups of pulse generator modules with respect to the load voltage. The sum output current is in phase with the coupling network voltage and produces alternating pulse generator sinewave outputs of successive plus and minus equal phase shifts with respect to the load voltage.

Abstract: A relatively wide d.c. pulse generating system providing rise times normally attainable only with much narrower pulse width generation, comprising a plurality of sequentially operated groups of d.c. pulse generating modules achieving the combination of zero current SCR-switching and rapid magnetic switching and providing very high reliability and efficiency, and with the feature of continuously variable pulse width control and overall amplitude contouring, as for controlling applications such as plasma ion implantation where non-uniform contours of ion depth penetration normally would otherwise obtain.

Abstract: A method of apparatus for integrating Loran-C and satellite navigation system technologies in a manner in which the Loran-C navigation signal transmissions are further modulated to provide a communications signal and a supplemental navigation signal, timed to provide additional position information, and used to smooth user position and velocity data between augmentation data messages and between adding and deleting or losing satellite contributing signals.

Abstract: The invention relates to a novel high-speed actuated high-voltage RF switch for such purposes as the cold switching of short very high current RF pulses in applications such as solid-state Loran-C transmitters and the like, as for switching between coupling/output networks thereof. The switch comprises planar upper and lower unconnected pairs of longitudinally extending input and output bus strips electrically connectable by the transverse insertion of planar link strips slightly separated therefrom and the rapid compression thereof against the adjacent end portions of the unconnected input and output bus strips, enabling rapid switching absent wear of the contact surfaces, but with the provision of adequate spacing for high voltage operation and adequate contact pressure to eliminate current arcing.

Abstract: In a Loran-C message communication system a method of obviating errors in navigation locking caused by sampling reception at the conventional symmetrical pulse modulation time intervals in advance of and in delay from the normal transmission interval, through rendering the pulse modulation assymetrical to a degree that compensates for different cycle amplitudes at sampling points above and below the desired sixth zero crossing used for navigation position determination.

Abstract: A method of and apparatus for exciting harmonic generation of radio frequency in a tank resonant circuit by bipolar spaced, half-cycle pulses, wherein the period of the tank resonant frequency oscillations is 1/N the period between successive pulses of similar polarity, where N is an odd integer greater than unity.

Abstract: Method and apparatus of obviating cycle-locking slippage errors in reception of Loran-C and similar radio-frequency signals covered by receiver location acceleration effects and other distortion effects simulating the same, that comprises, receiving the radio-frequency signals and producing data by sampling and tracking the cycles of the signal with a time-constant filter sufficiently fast to accommodate for the largest acceleration to be experienced by the receiver location to avoid cycle slippage in locating a predetermined cycle zero crossing, and independently post-filtering sufficiently slowly to smooth the data and without interaction with said sampling.

Abstract: A dynamic antenna tuning system particularly adapted for VLF frequency-shift (as opposed to on-off) keyed transmitters, employing saturable magnetic switching amplifiers providing variable tuning inductance between the antenna and transmitter and controlled to effect a gradual and not abrupt switching of the radio frequency during on-off transitions to enable narrow VLF frequency spectrum operation.

Abstract: An improved priming and sweep-out circuit in which losses are obviated or minimized by transferring energy resulting from such processes back to the power supply, and wherein a single common storage inductance is used in a secondary winding circuit of a saturable-core inductor transformer, the primary of which is series-connected in the SCR-switching energy storage and discharge pulse generating circuit, to serve both in the priming and sweep-out functions, and wherein reset circuit inductance does not participate in the energy transfer or storage functions.