On the Cover An ad for the British “Catkin” receiving tube. The name is a diminutive form derived from CAT (“Copper Anode Triode”). In this issue Vacuum Tubes Used in the First Trans-Atlantic Flight High-Voltage Processing of Big PowerTubes The Eimac View: Conditioning of Large Radio-Frequency Power Tubes Internal Control Symbols for RCA Tubes RCA...
On the Cover Part of a collection of WWII tubes at the Evans Signal Laboratory, a unit of the Signal Corps Engineering Laboratory in New Jersey. In this issue
On the Cover On The Cover: Promotion of the Belgian tube marketing firm. In this issue
On the Cover Cover of a 1932 booklet from the Arcturus Radio Tube Company. In this issue
On the Cover On The Cover: Promotion of the Dutch tubemaker Thermion Radio-Lampenfabriek. In this issue
On the Cover The “Voltage Amplifier Tube – Huth” with a clip-in ballast resistor matched to its filament drain, from the Dr. Erich F. Huth Gesselschaft just after WW1. In this issue
On the Cover The Telefunken 201, a field-effect device using a sprayed-zinc coating as the control electrodet. In this issue