Tube-number record
478
0 archive entries
478 is a tube type in the TubeDatabase archive (class: Triode-Pentode). Recorded specifications: construction Multi-section, maximum plate voltage 250 V, and maximum plate dissipation 2.5 W. The archive does not yet hold a photographed example of this type.
ClassTriode-Pentode
Filament3.5 V @ 100 mA
Construction
Primary TypeMulti-section
EnvelopeGlass
Sections2
Filament / Heater
Absolute Maximum Ratings
Plate Voltage250 V
Plate Dissipation2.5 W
Audio Performance
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| Typical | 180 V | 2500 | 8000 | — | 9 mA |
Application Notes
Early triode-pentode often used in specialized radio receiver designs.
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