GB458631A - Improvements in or relating to magnetron tubes - Google Patents

Abstract

458,631. Magnetrons. PINTSCH AKT.- GES., J., 71, Andreasstrasse, Berlin. Feb. 6, 1936, Nos. 3675, 3676, 3677, and 3678. Convention dates, Feb. 28, 1935, April 10, 1935, June 4, 1935, and June 4, 1935. [Class 39 (i)] A magnetron for ultra-short wave use has a cathode of filamentary form and a split anode surrounding the cathode, the segments of which anode are extended longitudinally to form a resonator, and the discharge space is bounded at its ends by conductive screens. In one form, Fig. 1, the cathode 1 is surrounded by a four-part anode of which one opposite pair of segments 3 is terminated by a plate 9 carrying the aerial 14 whilst the other pair 2, 4 is terminated by a plate 10. The discharge space is bounded by screens 6, 7 of which the screen 7 is supported on the outer of two concentric leads 19, 21. The lead 21 is supported by an insulator 22 from the shortcircuiting plate 8. The cathode is supported by a hook 26, a wire 25 which carries the plate 6, and an insulator 24 on the plate 9. A resonator of length n#/2 or (2n - 1).#/4 may be excited by a series of cathodes at each potential loop. The envelope may be a metal vessel to which the outer resonator 24 is connected. In a modification, Fig. 8, an indirectly-heated cathode 51 is surrounded by a two-part anode 52 and a series of metal screens 53, connected to a common lead are provided. With a directly-heated cathode, the common lead may be resistive so that decreasing biasses may be applied to successive screens. The cathode supports may be extended to shield the ends of the cathode, Fig. 10 (not shown). The screens may be combined to form a single helical surface. A straight wire in the middle of a hair-pin or four-wire cathode may be used for control purposes. The screens may in all cases be insulated or connected to the cathode or one or more may be positively biassed and used for modulating.