Category: Magazines

On the Cover Five 320A triodes, each rated at 150 KW dissipation, under test, probably at the Bell Labs radio site at Whippany, NJ. In this issue

On the Cover Three VAC-M lightning protectors In this issue

On the Cover The Moorhead vertical-anode version or the British “R” valve of WW1 In this issue

On the Cover A British E1190 600- MHz power triode In this issue

Front Cover, Rear Cover Upper, & Rear Cover Lower Just Qvistad, LA9DL, and part of his tube collection. Various European receiving Tubes. The front row has the Lorenz DF41W at left, and a group of rare RFT (East German) miniature “gnome” types: EAA171, UCH171, UB171, etc. Rear row: three Loewe multi-unit tubes at left, two...

On the Cover Some “unborn” Kellogg AC tubes. As Alan Douglass describes them: A Friend just presented me with a cigar box containing these four specimens, along with poop sheets for the McCullough and Kellogg tubes. Evidently someone toured the plant and fished souvenirs from the scrap barrel. These look earlier than any finished tubes...

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...

On the Cover One variation of the Schickerling T.V.T. tube In this issue

On the Cover The “Liberty Valve” as once sold by the Radio Apparatus Co. of Pottstown, Pa In this issue

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....