GB1498553A - Electron tube - Google Patents

Abstract

1498553 Thermionic valves L S ANDREENKO J K LESISH and O K BARYSHEVA 12 April 1976 14873/76 Heading H1D In a coaxial, e.g. transmitting, valve a central cage cathode 1 is surrounded successively by control grid 4 and screen grid 7, and by the anode 1; the screen grid 7 has an inner set of main conductors 8 aligned with those of the control grid, and to reduce distortion carries an adddtional outer set 9 aligned with each of the gaps between the main conductors 8 (Fig. 1, not shown), or with every second gap (Fig. 2, not shown), or with every third (see Fig. 3). The radial displacement from the main to the additional conductors lies between 0À5-1À25 (Figs. 5, 6, 7, not shown), preferably 1À0, times the pitch of the main conductors 8. The lateral cross-section of the additional conductors 9 is between 0À5-1À5 (Figs. 5, 8, 9, not shown), preferably 1À0, times that of the main conductors 8. The cathode cage members 2 run in a cylinder between holder members 3 and 24, surrounded (Fig. 4, not shown) by helical control grid conductors 5 fixed to the outside of a ring of tubes 6 between cooling water header 14 and cavity 16: the main and additional conductors of screen grid 7 are fixed respectively to the inside and outside of a second ring of tubes 10 lying between cooling water header 17 and cavity 19. Ceramic insulation 20, 21, 26, 25 complete the envelope: between the anode, the two water headers 17 and 14 and the two cathode terminal members.