Category: Magazines

On the Cover The beginning of a product line: William Housekeeper of the Western Electric Co. enginneering staff holding a 100-kW developmental tube made with the knife-edge copper-to-glass seal that he had patanted in 1919. In this issue

The RCA “Selling Fool” doll, a retailer display aid designed ca. 1926 by the major cover/commercial artist Maxfield Parrish. The “Fool” replaced the “Radiotron Man” figure as seen on the Feb. cover, although Web postings about the doll often use the “Radiotron” name. RCA’s $5 price for a quqetet of dolls is ironic – this...

On the Cover The RCA VHF receiving tetrode of 1935. See editorial page for details. Photo: Boyer Estate, courtesy of Robert Lozier. Drawing: RCA Standardizing Notice 3-1-839, in Dowd-RCA Archive, a holding of the AWA Museum.

Some thermionic jollity for the season, courtesy of Bengt Svensson   In this issue

On the Cover The Eimac X-1, a developmental triode from May, 1942, using the bulb and base of a 250T, with new anode and heavier filament taking 25 anps instead of 10.5. In this issue

Hisashi Ohtsuka (right), enjoying his 2009 Schrader Award plaque with Dr Yukawa, museum director of the University of Electro_Communicationon Tokyo. Photos: Hisashi Ohtsuka   In this issue

On the Cover Eduard Willi, Swiss tube-history author (see p. 2, depicted with a Signum G 2 H 34 rectifier. In this issue

The mount drawing for the now-eBaygenic “single-plate” 2A3 audio triode, with its 20 filaments. This original version carried a reputation for being hard to amke in terms of equal tension on the filaments, and was soon superseded by new designs. The note about the tensioning springs testifies to this diffuculty. Image: RCA Standardizing Notice 3-1-2A3,...

On the Cover The vanishingly rare GL-8009, a version of the 880 triode with two extra posts for the grid leads, introduced by GE in 1942. While “intended for television service’ on prewar tv channels, its frequency rating for full power was no more than that of the 880, or 25 MHz. In this issue

On the Cover The Eitel_McCoullough 4-250A tetrode of 1948. In this issue