GB562211A - Improvements in or relating to electron discharge devices - Google Patents

Abstract

562,211. Thermionic valves. EDWARDS, B. J., and PYE, Ltd. Dec. 18, 1942, No. 18028. [Class 39 (i)] An electron discharge device has a group of similar control electrodes G], G2, G3, G4, G5, G6, G7, G8 and G9 disposed in the space between a common cathode C and anode A so that each of these control electrodes is spaced the same distance as the others from said cathode and anode and screening electrodes D disposed partitionwise between said control electrodes so as to screen each of them from the others. In the construction shown, the control electrodes are coplanar and in the forms of sectors of circles. The screens D may be connected to a surrounding metal ring which may be earthed or each screen may have a separate connection. In an alternative construction the cathode is in a rod form and is surrounded by a cylindrical anode, the control electrodes being in the form of a series of rings of equal diameter surrounding the cathode. The apparatus is intended primarily as a mixer, the various signals to be mixed being placed in circuit each with an independent control electrode. The proportion of the mixing can be varied by adjusting the grid bias on the various control electrodes. Alternatively, a second set of control electrodes similar to the first may be interposed between the cathode and anode to obtain the same result.