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Tube Database (7,341 tube types · 1,270 archive entries)

Pre (2,630 tube types), Other (2,603 tube types), Power (1,292 tube types), Rectifier (816 tube types)
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25B8GT vacuum tube outline illustration

Tube-number record

25B8GT

0 archive entries

25B8GT is a tube type in the TubeDatabase archive (class: Duplex Pentode-Triode). Recorded specifications: brand Ken-Rad, year 1939, construction Pentode, and socket Octal. The archive does not yet hold a photographed example of this type.

BrandKen-Rad
ClassDuplex Pentode-Triode
BaseOctal
Filament25 V @ 150 mA

Construction

Primary TypePentode
EnvelopeGlass
Sections2

Filament / Heater

Heater NotesVoltage between heater and cathode should be kept at a minimum if direct connection is not possible

Absolute Maximum Ratings

Audio Performance

Typical Operation

ModePlate VGm (µmhos)Rp (Ω)µPlate mA
Pentode Section100 V20001850003707.6 mA
Triode Section100 V150075000112.50.6 mA

Application Notes

The Ken-Rad 25B8GT is a cathode type duplex tube consisting of a pentode unit and a triode unit within a single envelope.

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    Key Features
    • Cathode type duplex tube
    • Glass envelope
    • Octal base