US2751521A - Duplex tube - Google Patents

Description

June 19, 1956 E. G. DORGELO DUPLEX TUBE Filed Aug. 6, 1955 INVENTOR gi fduard Gerhards/s D07 GIO United States Patent O DUPLEX TUBE Eduard Gerhardns Dorgelo, Eindhoven, Netherlands, as-

signor to Hartford National Bank and Trust Company, Hartford, Colm., as trustee Application August 6, 1953, Serial No. 372,726

Claims priority, application Netherlands September 2, 1952 2 Claims. (Cl. 315-39) The invention relates to electric discharge tubes in which two semi-cylindrical grids, a common screen grid and two semi-cylindrical anodes are arranged to surround a common cathode.

The anodes of such tubes are frequently supported from lead-in studs. However, if very short waves, meter and decimeter waves, are used, the tubes have a limitation in that the losses in the comparatively thin lead-in studs greatly increase with the frequency. However, increasing the thickness of the lead-in studs entails structural difficulties.

According to the invention, in an electric discharge tube in which two semi-cylindrical grids, a common screen grid and two semi-cylindrical anodes are arranged to surround a common cathode, the anodes are united at the non-supported end of the other electrodes so as to form a cylinder open at one end which for the greater part of its length comprises two diametrically opposed cuts, the anodes being supported from a conductive cylinder of smaller diameter, sealed directly into the tub wall and enclosing an axial conductor which, within the space enclosed by the anodes, merges into a coupling loop.

When the tube is to be operated, the only thing required is to connect the external circuit to the axial conductor formed by the cylinder and its internal conductor. The coupling loop and the axial conductor may be proportioned such that the external load circuit conforms to the impedance of the anode system.

Since the anode is supported from a cylinder it is possible for the thermal conduction to reach an adequate value. lf required, the cylindrical conductor may be additionally cooled without the tube.

The invention will now be described with reference to the accompanying diagrammatic drawing, in which:

Figs. l and 2 are cross-sectional views of a duplex tube according to the invention taken parallel to and at right angles to its axis respectively.

Referring now to the figures, a glass tube wall 1 has a base 2. The base 2 has several studs 3 sealed into it 2,751,521 Patented June 19, 1956 upon which are supported an indirectly heated cathode 4 and two semi-rod-grids 5.

Upon a at disc 6 sealed in the wall is supported through a cone 7 a screen grid 8 which also consists of rods. The anodes form a cylinder 9 in which wide sawcuts 10 are formed. The anode 9, which is made of molybdenum, is soldered to a ferro-chromium cylinder 11 which is internally coated with a layer of copper 12. An internal conductor 13 merges into a coupling loop 14 within the anode cylinder.

Some few cooling lns provided on the ferro-chromium cylinder 11 are designated 15.

What is claimed is:

l. An electric discharge tube comprising an envelope, an electrode system disposed in said envelope, said electrode system including a common cathode, two semicylindrical grids, a common screen grid and an anode mounted in that order, means supporting said cathode and grids at one end, said anode comprising a cylinder of given diameter open at one end and including a pair of diametrically-opposed slots extending from the open end of said cylinder toward the other end, a conductive cylinder of diameter smaller than said given diameter sealed directly in said envelope, said conductive cylinder supporting said anode, an axial conductor extending through said conductive cylinder, and means coupling said axial conductor to the space enclosed by the anode.

2. An electric discharge tube comprising a vitreous envelope, an electrode system disposed in said envelope and including a common cathode, two semi-cylindrical grids, a common screen grid and an anode mounted in that order and surrounding one another, means at one end of said envelope supporting said cathode and grids at the end adjacent said one end, said anode comprising a cylinder of given diameter open at one end and including a pair of diametri'cally-opposed slots extending from the open end of said cylinder substantially toward the other end thereof, said open end of said anode cylinder facing said one end of said envelope, said slots deiining two semi-cylindrical anode portions aligned with said two semi-cylindrical grids, a conductive cylinder of diameter smaller than said given diameter sealed directly in the other end of said envelope and secured to and supporting said anode cylinder at its other end, an axial conductor extending lengthwise through said conductive cylinder, and a coupling loop connected to said conductor and disposed within a portion of the space dened by the anode cylinder.

References Cited in the le of this patent UNITED STATES PATENTS 2,351,744 Chevigny .lune 20, 1944 2,423,819 Chevigny July 8, 1947 2,466,063 Varian Apr. 5, 1949

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