Tube-number record
239
0 archive entries
239 is a tube type in the TubeDatabase archive (class: Remote Cut-off Pentode). Recorded specifications: construction Pentode, base Phenolic, and maximum plate voltage 250 V. The archive does not yet hold a photographed example of this type.
ClassRemote Cut-off Pentode
Filament6.3 V @ 300 mA
Construction
Primary TypePentode
EnvelopeGlass
Base MaterialPhenolic
Sections1
Filament / Heater
Heater NotesValues normalized from 0.3A
Absolute Maximum Ratings
Plate Voltage250 V
Grid 2 Voltage90 V
Audio Performance
Key Features
- Remote cut-off characteristic
- Super-control amplifier
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| RF Amplifier | 250 V | 1050 | 750000 | — | 5.8 mA |
Application Notes
Used primarily as an RF or IF amplifier in mobile or battery-operated receivers.
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