On the Cover The Moorhead vertical-anode version or the British “R” valve of WW1 In this issue
Category: Magazines
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Vol. 8, No. 2
On the Cover “Life tests on continous evacuation of 304TL / March 8, 1943” Shows impromptu test rig at Eimac’s Salt Lake City plant. Subject: 304TL triode is at upper center of photo, attached to a vacuum manifold atop an oil diffusion pump. An ion-guage tube is on the same manifold, to the left. A...
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Vol. 4, No. 5
On the Cover The “Liberty Valve” as once sold by the Radio Apparatus Co. of Pottstown, Pa In this issue
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Vol. 7, No. 6
On the Cover A pre-prototype leading to the Eimac 304T, from an affidavit filed by Ronald H. Gordon, laboratory glassblower. He certified having made the tube “before1940.” The objective was to contest, successfully, a claim of inventing a “plurality of grids in an envelope” in a patent application by Harold Zahl of the Signal Corps....
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Vol. 7, No. 3
On the Covers Two halves of a composite four-tube photo, from the De Forest Radio Co. A 10-1/2 X 19-1/2 print of this image turned up in the recent Boyer Estate auction conducted by the CC-AWA group. This is quasi-historic stuff: spired article in Raadio News, May, 1930. In this issue
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Vol. 7, No. 1
On the Cover A reproduction of De Forest catalog art: images of the 500 and 504A triodes. The artist’s originals can be yours, via the CC-AWA auction planned for March. See p. 1 for details. In this issue