Data: MediumMedium quality — at least 60% of universal parameters and pins are present, but some key data is missing. Verify specific values against datasheets before critical use.
Larger half-wave mercury-vapor rectifier (1250 mA avg, 10000 V PIV); same Jumbo 4-pin bayonet base family
Electrical Specifications
Rectifier
Peak Inverse VoltagePeak Inverse Voltage (max)5,000V
Peak Anode Current (surge)Peak Anode Current (max)1,000mA
Max DC Output Current (total, not per-anode)Max DC Output Current250mA
Heater
Heater VoltageFilament Voltage2.5V
Notes
Mercury-vapor tube — must be operated within the specified condensed-mercury temperature range. Outside this range, tube life and performance degrade significantly.
Filament must be applied before anode voltage to allow mercury vapor pressure to stabilize.
Uses Jumbo 4-pin bayonet base (1918 pattern) — physically larger than the standard UX4 base. Not interchangeable with UX4-based tubes.
Radiomuseum classifies this as 'Half-Wave Vacuum Rectifier' but other sources indicate mercury-vapor fill. The 2.5 V / 5 A filament and high PIV rating are consistent with mercury-vapor transmitting rectifier practice.
Higher current capacity than the 816 (250 mA avg vs 125 mA) but lower PIV (5000 V vs 7500 V).
Peak anode current rating of 1000 mA allows use in capacitor-input filter circuits with appropriate series resistance.
Pin Layout — UX4
1Filament
2Anode
3No Connection
4Filament
Socket-Compatible Tubes ⚠ Not electrically compatible