GB404455A - A vacuum electric discharge tube containing rarefied gas or vapour and for the production, amplification, or reception of high frequency oscillations - Google Patents

Abstract

404,455. Discharge apparatus. NAAMLOOZE VENNOOTSCHAP MACHINERIEENEN APPARATEN FABRIEKEN, 30, Croeselaan, Utrecht, Holland. Dec. 29, 1932, No. 36791. Convention date, March 3. [Class 39 (i).] An apertured diaphragm is arranged between the anode and the cathode of a gas or vapour-filled tube shutting off a region of space near the anode from the rest of the tube, and the size of the aperture is of the same order of magnitude as the distance of the diaphragm from the anode, so that when the tube is worked with strengths of current such that the voltage drop adjacent the anode increases with the current, the tube generates, amplifies or receives high-frequency, particularly short-wave, oscillations. In one form, Fig. 2, the anode 3 is surrounded by a metallic casing 4 having an aperture 5 whose size is comparable with the mean free path of the gas ions. A number of apertures may be used, and the diaphragm may be fused into the glass wall, or separated therefrom by a narrow gap. The cathode may be a filament or a mercury pool. The diaphragm may be coupled to the external circuit. Two or more diaphragms may be used with a single anode.- Characteristic curves, shewing the effect of varying the size of the aperture, and dimensions of a typical tube are given.