GB579673A - Means for pulsing radio frequency oscillators - Google Patents

Abstract

579,673. Pulse signalling. STANDARD TELEPHONES. & CABLES, Ltd. Nov. 19, 1943, No. 19414. Convention date, Nov. 23, 1942. [Classes 39 (i) and 40 (v)] Pulse potentials for exciting a radio-frequency oscillator by application to its anode circuit are also applied to a readily-excitable device such as a spark-gap associated with a resonant radiator, the device emitting radiation and setting the main oscillator into oscillation with a minimum delay. The resulting radiofrequency pulses are thus timed evenly with respect to the applied pulse potentials, and are of even and increased amplitude. As shown, the pulse potentials are generated at 31 and are applied to the anode circuits of a push-pull valve oscillator having tuned anode, grid and cathode circuits 18, 24, 30. The pulses are also applied to one side of a spark-gap 34, the other side of which is connected to a radiating conductor 36 about a quarter-wave long. The conductor 36 quickly bursts into oscillation and by radiation starts the valve circuit into oscillation. The spark-gap may comprise cylindrical carbon electrodes in coaxial relation, supported on axial metal rods which are screwed into metal binding-posts to provide axial adjustment (Fig. 2, not shown). The conductor 36 and the lead from the pulse producer 31 are secured by screws to the binding-posts, which are supported on an insulating base. The invention has particular application in radio detection systems, and in time-modulated pulse systems such as are described in Specifications 511,222 and 523,575.