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This category is for the Audion, the first three-terminal (triode) electronic vacuum tube, invented by Lee De Forest in 1906, and other early three-terminal tubes invented around that time, such as the Lieben-Reisz tube.


This category has the following 2 subcategories, out of 2 total.

Media in category "Audion"

The following 36 files are in this category, out of 36 total.