Category: Volume 6

On the Cover The Eimac X272 developmental tetrode from 1944 – a 4-125A with three radial pins added to reduce lead inductance. In this issue

On the Cover This appears to be British Post Office “Valve Amplifing No. 1,” made by BTH, as discussed in Keith Thrower’s British Radio Valves – The Vintage Years; 1904-1925. The photo is of a sample in the long-abolished tube museum at Bell Laboratories. Photo: Bell Labs, courtesy of Jerry Vanicek. In this issue

On the Cover One version of the George Clark receiving tube, Fig. 1 of Bill Condon’s article that starts on Page 2. In this issue

On the Cover The 6324 commutator tube. See page 3. In this issue

On the Cover An RCA Labs Doojigger, or maybe a yhingamabob. See article on p.2. In this issue

On the Cover An early, labeled version of the Westinghouse WD-11. See Bill Condon’s article on p.2. In this issue