7AK7

The 7AK7 is a pentode vacuum tube (thermionic valve). According to its manufacturer, Sylvania, it was "designed for service in electronic computers".
The tube was developed in 1948, designed at the request of L. D. Wilson for use in the Whirlwind computer.
Significant attention was directed towards its manufacturing process in order to ensure the part's
reliability. Dubbed the "computer tube", it became the standard tube for all computers into the late 1950s.