GB594284A - Improvements in high frequency electrical oscillators - Google Patents

Abstract

594,284. Velocity-modulated tubes. DAUNT, J. G., ROAF, D., and WRIGHT, C. S. Oct. 12, 1943, No. 16668. [Class 39 (i)] In electron oscillators of the velocity modulation type, the resonator chamber 25, Fig. 4 (Comp.), is wholly disposed within the envelope 10, and is coupled by an annular gap 27 to a cavity 24 adapted to pass power to an external load as, for example, a wave guide and slot 29. In the embodiment shown, a single resonator and reflecting electrode 23 are used. The resonator and output cavity' are formed by suitably shaping two copper discs 15, 17 which are butt-welded to glass tubes 10, 16, with an additional tube 18 to reinforce the seal. A stiff copper tube 19 is welded to the disc 17 and is closed by a glass cap to complete the envelope, Fig. 1 (not shown). Tuning is effected by longitudinal movement of the tube 19 which distorts the disc 17 and varies the spacing of the poles of the resonator chamber 25. The tuning mechanism is shown in Fig. 5 (Comp.), and comprises a C-spring 40, one limb of which is fixed to the envelope and the other to the tube 19 ; the spring is brased to bring the poles of the resonator towards one another. A rod 56 bears on a lever 53, and is adjustable to give a pre-setting of the tuning, fine adjustment being effected by a screwthreaded shank 50 bearing on the end of the lever. In a modification, Fig. 2 (not shown), the glass tubes 16, 18 are omitted and the outer edges of the discs 15, 17 are connected together directly ; an all metal device is described with reference to Fig. 3 (not shown). The Provisional Specification also .describes an oscillator of the reflex type, in which the inner resonator chamber F, Fig. 1 (Prov.), is formed of a rigid part A bolted to a copper disc K and connected by a thin copper disc C, to the depending flange of an upper member B, adapted to slide in a copper disc L. The discs K, L are sealed through the envelope I and are closed by a ring N to form the output cavity U which can be tuned by a plunger O, and has an output consisting of a concentric line Q. Coupling between the output cavity and the resonator chamber F is by a slot P in the defending flange of the member B. The reflector D is carried by and insulated from the member B and is also connected through a flexible closure disc M to a yoke V adjustably mounted on two standards S, T fixed to the stationary framework of the device whereby the tuning of the resonator F is effected. Specifications 545,779, 555,162, 582,441, 582,442 and 588,133, [Group XXXVI], are referred to.