GB659820A - Improvements in and relating to ultra high frequency electron discharge devices - Google Patents

Abstract

659,820. Velocity-modulated tubes. BRITISH THOMSON-HOUSTON CO., Ltd. Nov. 28, 1947, No. 31558. Convention date, June 22, 1945. [Class 39 (i)] In a reflex velocity-modulated tube the cavity resonator 32 is supported within a cylindrical aperture of the anode block 29, and is coupled through a narrow slot 57 with a transverse slot 56 forming a rectangular waveguide. Opposite the mouth of the wave-guide is a vitreous window 62 supported through a thimble 61 in an opening of the envelope. A groove 66 surrounding the mouth of the waveguide 56 forms a half-wave choke, and a corresponding half-wave choke 67 is provided outside the window 62. The anode block 29 rests on a dielectric disc 24 supported by a metallic ring 25 secured to a corrugated heatconductive member 28. The corrugated member 28 is provided with a longitudinal slot so as to lock with the thimble 61. The cavity resonator 32 comprises a cylindrical member 33, a conical member 34, and a flexible diaphragm 35. The diaphragm 35 and a flange 41 on the member 33 form a radial half-wavelength short-circuited transmission line. Tuning is effected by moving the flexible diaphragm 35 by micrometer head 81 acting through rod 78, cross-piece 48 and cylinder 46. A fine tuning adjustment is obtained by varying the voltages of the various electrodes. The reflector electrode 44 is supported by a dielectric cylinder 45 secured within the cylinder 46. The indirectlyheated cathode 12 is mounted on an insulating disc 19 which abuts the shoulder 18 of a focusing cylinder 16 so that both cathode and focusing cylinder are retained within a metallic thimble 17. The thimble 17 is mounted on the dielectric disc 24. Specification 20001/44, (open to inspection under Sect. 91), is referred to.