80

Rectifier — DHT — UX4

Known Equivalents & Substitutes

CV617VT-801821

Similar Tubes (Not Drop-In Compatible)

5Y3GT

Octal-based equivalent with identical ratings and characteristics — not pin-for-pin compatible due to different base (UX4 vs Octal)

5Y4G

Octal-based equivalent with identical ratings and characteristics but different pinout — not pin-for-pin compatible

Same UX4 base but higher current rating (225 mA vs 125 mA) and higher filament current (3.0 A vs 2.0 A)

Same UX4 base, mercury-vapour rectifier — much lower voltage drop but requires controlled warm-up sequence and has limited life

Electrical Specifications

Absolute Maximum

Anode Voltage (max)AC Voltage per Plate (max RMS)350V

Rectifier

Peak Inverse VoltagePeak Inverse Voltage1,400V

Voltage Drop (typical)Voltage Drop (at 125 mA DC)60V

Max C-input Filter CapacitorMax C-input Filter Capacitor10µF

Notes

Directly heated (filament cathode) — observe heater warm-up time before applying B+ to protect the tube and filter capacitors.
Maximum steady-state peak plate current per plate is 400 mA. Maximum transient peak plate current is 2.2 A per plate.
Voltage drop of 60 V at 125 mA DC per plate, providing natural current-limiting 'soft start' characteristics.
Input condenser (capacitor-input filter): limited to 10 µF maximum per the datasheet.
The rating chart shows operating regions for capacitor-input and choke-input filter configurations at various RMS supply voltages.
One of the most widely-used rectifiers of the pre-war era; found in virtually every AC-operated radio receiver of the 1930s.

Pin Layout — UX4

1Anode 1 (Plate 1)

2Filament

3Anode 2 (Plate 2)

4Filament

Socket-Compatible Tubes ⚠ Not electrically compatible

References

DC Output Current (max)DC Output Current (max)125mA

Peak Anode Current (surge)Peak Plate Current (per plate)400mA

Heater

Heater VoltageHeater Voltage5V

Heater CurrentHeater Current2A