FU33
Triode · DHT · Special · 1965
“Chinese 833A. Affordable transmitting triode power.”
Power triode delivering 350W for push-pull and SET designs
GAIN FACTOR0
PLATE IMPEDANCE0kΩ
TRANSCONDUCTANCE0mA/V
GAIN35%
POWER100%
DRIVE92%
LINEARITY83%
EXECUTIVE SUMMARY
The FU33 is a directly-heated triode from Chinese, introduced around 1965. It provides a gain factor (μ) of 35 with 7800Ω plate resistance. Commonly used in transmitting (set) applications. Chinese 833A. Affordable transmitting triode power.
APPLICATIONS
SET outputPush-pull output
Generic triode transmitting (set) stage
• PA/public address
VS 833A
HISTORY
Introduced1965ManufacturerChineseEquivalents833A, 833C
Late ProductionSPECIFICATIONS
Heater Voltage10V
Heater Current10A
Max Plate Voltage3000V
Max Power350W
Sensitivity4.5 mA/V
Gain Factor35
Internal Impedance7.8kΩ
PinoutSpecial
Era1965
RarityCommon
SPICE model not yet available. Loadline calculator requires calibrated Koren parameters.