274A — Rectifier, UX4 | Tubeofile

274A

Rectifier — DHT — UX4

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Western Electric

↗ TDSL ↗ Radiomuseum

Known Equivalents & Substitutes

WE274ACV2603

Similar Tubes (Not Drop-In Compatible)

274B

Later WE type with higher current rating — different maximum ratings, not a direct drop-in replacement

4274A

STC (Standard Telephones & Cables) equivalent designation for the 274A — same UX4 base and 5V/2A filament but may have slightly different ratings per STC specs

5Z3

Same UX4 base and 5V filament, higher current rating (225 mA vs 200 mA) and higher filament current (3.0 A vs 2.0 A) — not a direct substitute

Same UX4 base but lower current rating (125 mA) and lower max voltage — predecessor generation rectifier

CV1451

British CV designation listed as normally replaceable but slightly different per radiomuseum

Electrical Specifications

Absolute Maximum

Anode Voltage (max)AC Voltage per Plate (max RMS, choke-input)550V

Rectifier

Peak Inverse VoltagePeak Inverse Voltage1,500V

Max C-input Filter CapacitorMax C-input Filter Capacitor4µF

DC Output Current (max)DC Output Current (max)200mA

Notes

Directly heated (filament cathode) — observe heater warm-up time before applying B+ to protect the tube and filter capacitors.
Choke-input filter preferred over condenser-input filter for better regulation and longer tube life.
With choke-input filter: max 550 V RMS per plate at 200 mA, or 660 V RMS at 160 mA (maximum operating condition).
With condenser-input filter: max 450 V RMS per plate at 150 mA (maximum with 4 µF capacitor).
Input condenser should preferably not exceed 4 µF with condenser-input filter.
A less severe operating condition should be selected wherever possible — tube life at maximum conditions may be shorter.
Double the listed rectified current may be obtained by connecting the two plates together and using one tube in each side of the circuit.
Socket: Western Electric 143B or equivalent standard four-contact type.
Mounting: vertical or horizontal. If horizontal, filament planes should be vertical.
A development of Bell Telephone Laboratories, American Telephone and Telegraph Company, and Western Electric Company.

Pin Layout — UX4

1Anode 1 (Plate 1)

2Filament

3Anode 2 (Plate 2)

4Filament

Socket-Compatible Tubes ⚠ Not electrically compatible

5Z3 80 82 83 83V

References

https://frank.yueksel.org/sheets/136/2/274A.pdf