Tube-number record
247
0 archive entries
247 is a tube type in the TubeDatabase archive (class: Power Pentode). Recorded specifications: construction Pentode, socket 5-pin, maximum plate voltage 250 V, and maximum plate dissipation 7 W. The archive does not yet hold a photographed example of this type.
ClassPower Pentode
Base5-pin
Construction
Primary TypePentode
EnvelopeST-14
SectionsSingle
Filament / Heater
Absolute Maximum Ratings
Plate Voltage250 V
Plate Dissipation7 W
Grid 2 Voltage250 V
Audio Performance
Power Output2.5 W
Key Features
- Power output pentode
- Large 5-pin base
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| Class A Amplifier | 250 V | 2500 | 38000 | 95 | 32 mA |
Application Notes
Commonly used in the output stage of early AC-operated radio receivers.
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