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0B2
0B2, also known as OB2 (the letter 'O' instead of the number '0'), is a two electrode, inert gas filled, cold cathode voltage re­gu­la­tor valve (tube) with B7G base, introduced in 1945 by Hytron in Salem (MA, USA) [1] and manufactured by various manufacturers. It was one of the last voltage stabilizer val­ves that were developed before semiconductors took over.

➤ 0B2 datasheet (Tung-Sol)
➤ 0B2 datasheet (Philips)


Pinout as seen from the bottom of the valve

0B2 on this website
4-piece (or 2-piece) valve-based spy radio set
Specifications
  • Va
    108 V
  • Ia (min)
    5 mA
  • Ia (max)
    30 mA
  • Istart
    75 mA (10 sec max)
  • ΔV
    3.5 V (Ia = 5-30 mA) 1
  • Vign
    127 V (133 V max.)
  • Cshunt
    0.1 µF
  • Tamb
    -55°C to +90°C
  • Base
    B7G
  • Height
    61 mm max. (67 mm with contacts)
  • Diameter
    19 mm max.
  1. Over 500 hours of operation, ΔV = 4V (max.).
Equivalents
  • 108C1
  • 6074
  • CV1833
  • G108/1K
  • QS1208
Datasheets
  1. 0B2 - Voltage Regulator
    Tung-Sol, USA, 1 June 1958. 1

  2. OB2 — Voltage Stabiliser
    Philips, 4 April 1955. 9 pages. 1

  3. 0B2 — Cold cathode voltage regulator
    Amperex, July 1955.
  1. Obtained via Frank Philipse [3].
References
  1. Various contributors, 0B2
    Radiomuseum website. Accessed 28 April 2026.

  2. The Valve Museum, 0B2
    Accessed 28 April 2026.

  3. Frank's Electron Tube Data Sheets
    Accessed 28 April 2026.
Further information
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© Crypto Museum. Created: Tuesday 28 April 2026. Last changed: Tuesday, 28 April 2026 - 08:22 CET.
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