Please contact the contributing institution for more information regarding the copyright status of this object.
Description
In 1906, inventor Lee de Forest improved upon Fessenden's vacuum tube, creating what he called the triode, or "Audion." (It was patented in January 1907). After further experimentation in 1911-12, the Audion was used as a detector of radio signals, an amplifier of audio, and an oscillator for transmitting, making possible great advancements in transcontinental telephony and radio broadcasting. This rare dual tantalum filament de Forest Audion was handmade by H.W. McCandless & Co. of New York (an automotive lightbulb maker) in 1908, the only year double filament audion tubes of this type were made. The glass tube was mated to a standard candelabra lightbulb screw base. The grid is the usual zig-zag formation (made by bending wire between nails hammered into a piece of wood). The single plate has a single anchor wire. The filament supports come up from the screw base, rather from a glass press. The contact was soldered externally to the base to make contact. The base insulation is glass, rather than porcelain. The cap is tarred over, covering the exhaust tip.
Type
image
Identifier
3A3D6904-B2FC-467F-9247-384037920960 2003-1-2
Subject
Audion Vacuum-tubes Nineteen hundreds (Decade) Inventors Inventions De Forest, Lee
If you're wondering about permissions and what you can do with this item, a good starting point is the "rights information" on this page. See our terms of use for more tips.
Share your story
Has Calisphere helped you advance your research, complete a project, or find something meaningful? We'd love to hear about it; please send us a message.
