Tube-number record
EF 8
0 archive entries
EF 8 is a tube type in the TubeDatabase archive (class: Low-noise RF Pentode / Selectode). Recorded specifications: construction Pentode, socket Side-contact (P-base), and maximum plate voltage 250 V. The archive does not yet hold a photographed example of this type.
ClassLow-noise RF Pentode / Selectode
BaseSide-contact (P-base)
Construction
Primary TypePentode
EnvelopeGlass
SectionsSingle
Filament / Heater
Heater NotesIndirectly heated cathode
Absolute Maximum Ratings
Plate Voltage250 V
Grid 2 Voltage250 V
Audio Performance
Key Features
- Low noise
- Variable transconductance (Selektode)
- Beam-forming grid for reduced screen current
- Optimized for shortwave performance
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| RF Amplifier | 250 V | — | 450000 | — | 8 mA |
Application Notes
Specifically designed as an input stage for receivers to minimize noise. Features an additional grid between the control grid and screen grid to align electron paths.
Datasheets
Datasheet: EF8.pdf
Download PDFLoading datasheet...
Datasheets courtesy of Frank Philipse via Frank's Electron Tube Data Sheets.
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