Tube-number record
QP 25
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BrandMazda
ClassBattery Double Pentode Output Valve
BaseOctal
Construction
Primary TypePentode
EnvelopeGlass
SectionsDouble
Filament / Heater
Absolute Maximum Ratings
Plate Voltage120 V
Grid 2 Voltage120 V
Audio Performance
Power Output1.2 W
Key Features
- Quiescent Push-Pull (QPP)
- Accurately matched pentode sections
- No extra battery tappings required for screens
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| Quiescent Push-Pull (90V Battery) | 83.5 V | — | — | — | 3.2 mA |
| Quiescent Push-Pull (108V Battery) | 100 V | 3000 | — | — | 3.85 mA |
| Quiescent Push-Pull (120V Battery) | 110 V | — | — | — |
Application Notes
Recommended for use in battery portables. Bias should be obtained by resistance in the negative H.T. lead, by-passed with a 50 µF condenser. Total quiescent anode current at 110V screen should not be less than 3.5 mA.
Datasheets
Datasheet: QP25.pdf
Download PDFLoading datasheet...
Datasheets courtesy of Frank Philipse via Frank's Electron Tube Data Sheets.
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