Accession Number : ADD002781

Title :   Synchronized Turn-Off of VLF Antennae.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C

Personal Author(s) : Firman,Carl M

Report Date : 09 Sep 1975

Pagination or Media Count : 7

Abstract : A sample of an RF signal being transmitted is obtained and the zero current crossover point of that sample signal is detected. A switch is operative upon actuation to change the resonance of the transmitting antenna and an enabling means is employed to control such actuation, the enabling means being responsive to the concurrence of a frequency shift command signal and the output signal of the zero current crossover detector. A means is provided for selectively varying the actuation of the switch to a point in time slightly before the zero current crossover point of the actual signal being transmitted for minimizing the transient signal load on the switch means when the frequency being transmitted is switched off.

Descriptors :   *Switching circuits, *Patents, Antennas, Very low frequency, Silicon controlled rectifiers, Frequency shift

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE