Engineering:7AK7

From HandWiki
Short description: Pentode vacuum tube
7AK7
ClassificationPentode
ServiceDigital computers
Height3 532 in (80 mm)
Diameter1 316 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

  • 25L6, another type of tube found in early computers

References

  1. Sylvania. Engineering Data Service. 7AK7. July 1953.
  2. 2.0 2.1 Green, Tom (2010). Bright Boys: The Making of Information Technology. CRC Press. p. 141. ISBN 978-1568814766. https://archive.org/details/Bright_Boys_The_Making_of_Information_Technology_by_Tom_Green_2010. 
  3. Wilson, L. D. (1954). "Tube Reliability in the Univac". 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.