Tube-number record
812A
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BrandRCA
ClassPower Triode
Base4-pin
Construction
Primary TypeTriode
EnvelopeST19
Base MaterialMicanol
Sections1
Filament / Heater
MaterialThoriated Tungsten
Absolute Maximum Ratings
Plate Voltage1500 V
Plate Dissipation65 W
Grid 1 Voltage-200 V
Cathode Current175 mA
Audio Performance
Power Output340 W
Key Features
- Thoriated Tungsten Filament
- High-mu Triode
- Push-Pull AF or RF service
- Self-rectifying oscillator support
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| AF Power Amplifier - Class B (CCS) | 1250 V | — | — | 29 | 260 mA |
| AF Power Amplifier - Class B (ICAS) | 1500 V | — | — | 29 | 310 mA |
| RF Power Amplifier - Class C Telegraphy (CCS) | 1250 V | — | 3000 | 29 |
Application Notes
When used in the final amplifier of a transmitter designed for break-in operation and oscillator keying, a small amount of fixed bias must be used to maintain the plate current at a safe value.
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