5X4

Rectifier — DHT — Octal

Known Equivalents & Substitutes

5X4G5X4GACV1852

Similar Tubes (Not Drop-In Compatible)

Electrically identical but different Octal pinout — plates on pins 4/6 vs 3/5

Electrically identical but uses UX4 (4-pin) base

Electrical Specifications

Absolute Maximum

Anode Voltage (max)AC Voltage per Plate (max RMS)450V

Rectifier

Peak Inverse VoltagePeak Inverse Voltage1,550V

Voltage Drop (typical)Voltage Drop (at 225 mA DC)58V

Max C-input Filter CapacitorMax C-input Filter Capacitor40µF

DC Output Current (max)DC Output Current (max)225mA

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

Heater

Heater VoltageHeater Voltage5V

Heater CurrentHeater Current3A

Notes

Directly heated (filament cathode) — observe heater warm-up time before applying B+ to protect the tube and filter capacitors.
Electrically identical to 5U4G and 5Z3 but NOT pin-compatible. The 5X4 has plates on pins 3 and 5, filaments on pins 7 and 8; the 5U4G has plates on pins 4 and 6, filaments on pins 2 and 8. The 5Z3 uses a 4-pin UX4 base. Socket wiring must be changed to substitute between these types.
Only produced in ST (shoulder) glass envelope — all specimens are effectively 5X4G. There is no metal or GT variant.
Primarily used by Zenith; RCA radios of the same era used the pin-compatible 5U4G instead.
Relatively high voltage drop (~58 V at 225 mA) compared to indirectly-heated rectifiers like 5AR4/GZ34 (~15 V). This provides natural 'soft start' characteristics valued in audio equipment.

Pin Layout — Octal

1No Connection

2No Connection

3Anode 1 (Plate 1)

4

References