Open main menu

Wikimedia Commons β


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 3 subcategories, out of 3 total.

Media in category "Audion"

The following 39 files are in this category, out of 39 total.