Tube-number record
4C21
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BrandGeneral Electric
ClassGeneral Purpose Triode
BaseJumbo
Construction
Primary TypeTriode
EnvelopeT-18
Sectionssingle
Filament / Heater
Absolute Maximum Ratings
Plate Voltage1250 V
Plate Dissipation100 W
Grid 1 Voltage-400 V
Cathode Current175 mA
Audio Performance
Typical THD5%
Power Output19.7 W
Key Features
- General Purpose
- Air cooled
- Vertical mounting only
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| Class A A-F Amplifier | 1250 V | 3600 | 3600 | 12 | 60 mA |
| Class B A-F Power Amplifier (per tube) | 1250 V | — | — | — | 520 mA |
| Class C R-F Power Amplifier | 1250 V | — | — | — |
Application Notes
The normal value of grid leak for Class C operation is approximately 5000 ohms. If self-bias is used, cathode resistor should be approximately 1000 ohms. Ventilation of bulb required at high frequencies.
Datasheets
Datasheet: 4C21.pdf
Download PDFLoading datasheet...
Datasheets courtesy of Frank Philipse via Frank's Electron Tube Data Sheets.
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