31

Power Triode — DHT — UX4

RCA

Known Equivalents & Substitutes

VT-31CV947

Similar Tubes (Not Drop-In Compatible)

Companion 2V battery DHT with same filament voltage and UX4 base, but designed as detector/voltage amplifier with higher mu (~9.3) and lower current (3mA vs 12mA)

45

UX4-base DHT power triode with similar low-mu characteristics (mu=3.5 vs 3.8) but 2.5V/1.5A filament and much higher power capability (1.6W vs 0.185W)

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Plate Voltage (max)180V

Typical Operating

Anode Voltage (typical)Plate Voltage (typical)180V

Grid 1 Bias VoltageGrid Bias-30V

Anode CurrentPlate Current12.3mA

Anode ResistancePlate Resistance

Heater

Heater VoltageFilament Voltage2V

Heater CurrentFilament Current0.13A

Notes

DHT tube: the filament serves as the cathode; there is no heater-cathode isolation.
Designed for 2V dry-cell (battery) filament supply at 0.13A. The first American 2V battery-type output tube.
GE Essential Characteristics: Va=180V, Vg=-30V, Ia=12.3mA, ra=3600 Ohm, gm=1.05 mA/V, mu=3.8.
Raytheon data gives Ia=8mA and ra=4100 Ohm at the same Va=180V, Vg=-30V operating point — discrepancy likely due to different measurement conditions or sample variation.
No Pa_max or Rg_max is specified on known datasheets.

Pin Layout — UX4

1Filament (f-)

2Plate (Anode)

3Grid

4Filament (f+)

Socket-Compatible Tubes ⚠ Not electrically compatible

12A 26 2A3 30 300B 40 45 50 71A 801A 841 842 845 UX112A UX199

References