Tube-number record
Z21
0 archive entries
BrandMarconi
Class2-volt H.F. Pentode
Base7-pin (non-miniature)
Construction
Primary TypePentode
Envelope125 x 41mm
Filament / Heater
Absolute Maximum Ratings
Audio Performance
Key Features
- Screened pentode
- Variable mu characteristic not required
- Sensitive grid detector
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| As leaky grid detector (HT 120V, 50k Load) | 45 V | — | — | — | 1.5 mA |
| As leaky grid detector (HT 120V, 0.25M Load) | 45 V | — | — | — | 0.3 mA |
| As leaky grid detector (HT 150V, 50k Load) | 65 V | — | — | — |
Application Notes
When used as a detector the grid leak should be returned to filament positive and the screen should be decoupled with 0.5uF. Other uses for the valve are as L.F. amplifier, as oscillator and as H.F. amplifier.
Datasheets
Datasheet: Z21.pdf
Download PDFLoading datasheet...
Datasheets courtesy of Frank Philipse via Frank's Electron Tube Data Sheets.
0 results