ID: 
1249
Maker's Name: 
Unknown
Dimensions: 
11 × 11 × 21.5 cm

The 833A triode was used as the final Class C stage in plate modulated AM broadcast transmitters. It was clamped in a base that supplied filament power. At full ratings, it required forced air cooling.

The 833A valve is popular with Tesla coil experimenters as it is readily available second-hand at low prices. It is rugged and simple to operate.