Triode thermionic tube

Claim 1

AN ELECTRON DISCHARGE DEVICE ADAPTED FOR OPERATION AT A GIVEN FREQUENCY ABOVE 1000 MC./S. COMPRISING AN ENVELOPE, A CATHODE WITHIN SAID ENVELOPE HAVING A FLAT ELECTRON EMISSIVE SURFACE WHICH INCLUDES A POROUS TUNGSTEN CAP CONTAINING BARIUM STRONTIUM OXIDE AND WHICH PROVIDES AN ELECTRON BEAM OF HIGH CURRENT DENSITY; AN ANODE WITHIN SAID ENVELOPE HAVING A FLAT ELECTRON RECEIVING SURFACE DISPOSED OPPOSITE SAID ELECTRON EMISSIVE SURFACE; A CONDUCTIVE DISC HAVING AN APERTURE THEREIN FOR THE PASSAGE OF SAID ELECTRON BEAM INTERPOSED BETWEEN SAID ELECTRON-EMISSIVE SURFACE AND SAID ELECTRON RECEIVING SURFACE, SAID DISC BEING SEALED INTO THE WALL OF THE ENVELOPE; A CONDUCTIVE RING SUPPORTED BY SAID DISC; AND A PLURALITY OF THIN SPACED PARALLEL WIRES STRETCHED OVER THE RING CONSTITUTING A GRID, SAID WIRES HAVING A LENGTH AND SPACING AT WHICH THAT PART OF SAID WIRES BETWEEN SAID RING AND SAID ELECTRON BEAM HAS A GIVEN VALUE OF SELF-INDUCTANCE LG, SAID WIRES DEFINING WITH THE EMITTING SURFACE AND THE RECEIVING SURFACE A CATHODE SPACE AND AN ANODE SPACE, RESPECTIVELY, THE SELF-IN-