809
Triode · DHT · UX-5 · 1938
“Compact transmitting triode.”
Power triode delivering 30W for push-pull and SET designs
Datasheet ↗SPICE
GAIN FACTOR0
PLATE IMPEDANCE0kΩ
TRANSCONDUCTANCE0mA/V
GAIN6%
POWER75%
DRIVE99%
LINEARITY95%
TYPICAL OPERATING POINT
EXECUTIVE SUMMARY
The 809 is a directly-heated triode from RCA, introduced around 1938. It provides a gain factor (μ) of 6 with 1330Ω plate resistance. Commonly used in transmitting applications. Compact transmitting triode.
APPLICATIONS
SET outputPush-pull outputHeadphone output
Generic triode transmitting stage
• Headphone amp• PA/public address
HISTORY
Introduced1938ManufacturerRCAEquivalentsNone
Pre-WarSPECIFICATIONS
Heater Voltage6.3V
Heater Current2.5A
Max Plate Voltage750V
Max Power30W
Sensitivity4.5 mA/V
Gain Factor6
Internal Impedance1.3kΩ
PinoutUX-5
Era1938
RarityModerate