7AK7
ClassificationPentode
ServiceDigital computers
Height3+5⁄32 in (80 mm)
Diameter1+3⁄16 in (30 mm)
Cathode
Cathode typeCoated Unipotential
Heater voltage7.0 V (6.3 V nominal)
Heater current800 mA
Anode
Max dissipation Watts8.5 W
Max voltage200 V
Socket connections
8V-L-O

Pin 1 – Heater
Pin 2 – Anode (Plate)
Pin 3 – Grid 2 (Screen)
Pin 4 – Grid 3 (Suppressor)
Pin 5 – n.c.
Pin 6 – Grid 1 (Control)
Pin 7 – Cathode

Pin 8 – Heater
References
https://web.archive.org/web/20221114011216/http://www.nj7p.org/Tubes/PDFs/Frank/137-Sylvania/7AK7.pdf

The 7AK7 is a pentode vacuum tube (thermionic valve). According to its manufacturer, Sylvania, it was "designed for service in electronic computers".[1]

7AK7 vacuum tubes in a 1956 UNIVAC I computer

The tube was developed in 1948,[2] designed at the request of L. D. Wilson for use in the Whirlwind computer.[3] Significant attention was directed towards its manufacturing process in order to ensure the part's reliability.[4] Dubbed the "computer tube",[5] it became a popular tube for computers for a while.[2] IBM, however, switched to more compact miniature tubes, starting with the IBM 604 in 1948.

See also

References

  1. ^ Sylvania. Engineering Data Service. 7AK7. July 1953.
  2. ^ a b Green, Tom (2010). Bright Boys: The Making of Information Technology. CRC Press. p. 141. ISBN 978-1568814766.
  3. ^ Wilson, L. D. (1954). "Tube Reliability in the Univac". Proceedings of the National Electronics Conference. Vol. 10. National Engineering Conference, Incorporated. pp. 699–703.
  4. ^ David R. Brown, T. F. Clough, and P. Youtz. Investigation of 7AK7 Processing, Emporium, Pa., March 2, 1948. URI: http://hdl.handle.net/1721.3/38986
  5. ^ Haigh, Thomas; Priestley, Mark; Ropefir, Crispin (2016). ENIAC in Action: Making and Remaking the Modern Computer. MIT Press. p. 211. ISBN 9780262334419.
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