5965

The 5965 is a miniature twin triode vacuum tube (thermionic valve). One of its manufacturers, Sylvania, states that it was “designed for use in high-speed digital computers”.^[1]

5965
Classification	Triode
Service	Digital computers
Height	1+15⁄32 in (37 mm)
Diameter	7⁄8 in (22 mm)
Cathode
Cathode type	Unipotential
Heater voltage	6.3 V or 12.6 V
Heater current	450 mA or 225 mA
Anode
Max voltage	200 V
Max current	100 mA
Socket connections
9A Pin 1 – Unit 2 Anode (Plate) Pin 2 – Unit 2 Grid Pin 3 – Unit 2 Cathode Pin 4 – Unit 2 Heater Pin 5 – Unit 1 Heater Pin 6 – Unit 1 Anode (Plate) Pin 7 – Unit 1 Grid Pin 8 – Unit 1 Cathode Pin 9 – Heater mid-tap (bottom view)
References
https://web.archive.org/web/20230314212705/https://frank.pocnet.net/sheets/137/5/5965.pdf

According to an MIT Project Whirwind memorandum, the tube was developed for IBM by GE, primarily for use in the IBM 701 calculators, and was designated as a general-purpose triode tube.^[2] The tube was also labeled as E180CC.^[3]

Vacuum tube logic module from a 700 series IBM computer featuring 5965 tubes.

See also

• 7AK7, a popular type of tube found in early digital computers
• 25L6, another type of tube found in early computers

References

1. Sylvania. Engineering Data Service. 5965. November 1953.
2. Frost, H. B. (May 4, 1953). "Memorandum M-2135: Some notes on current tube types" (PDF). MIT. p. 3. Archived from the original (PDF) on 28 March 2021. Retrieved 12 February 2024.
3. Wyatt, Allan. "5965". The Valve Museum. Retrieved 12 February 2024. It is also labelled as a E180CC showing that the two Types are equivalent.