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33 tube: datasheets and technical data
Explore available pinout, electrical data and related types for the 33 vacuum tube.
The 33 is a power-output pentode for battery or DC-operated radio receivers. Compared with an output triode drawing similar plate current, its screen and suppressor grid permit greater amplification and output power. Cunningham states that the suppressor is internally connected to the filament. The coated filament requires 2 V DC at 0.26 A. It has a five-pin base and is intended for vertical mounting. Its modest consumption suited sets designed around battery life.
The sheets give two typical class A operating points: at 135 V on both plate and screen, −13.5 V on the grid and a 7 kΩ load, output is about 0.7 W; at 180 V, −18 V on the grid and a 6 kΩ load, RCA reports about 1.4 W. These are different arrangements to compare with the actual output transformer and bias. An early Cunningham sheet lists 135 V as the maximum, whereas a later RCA sheet also describes operation at 180 V. Check the sheet relevant to the specimen and circuit before raising the voltage. With resistance coupling, RCA limits DC resistance in the grid circuit to 1 MΩ with self-bias and 0.5 MΩ without it.
Tube images
Pinout and connections
Base: UY-Base, 5 Pins (USA, April 1927) (Codex=Hy)
Electrical data
Filament
- Filament voltage Vh
- 2 V
- Filament current Ih
- 0.26 A
Datasheet PDF
EL84 ECC83 12AX7 EL34 6L6GC 300B KT88 GZ34
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