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Power - Triode ·Triode

252A

General-purpose Western Electric power triode with an oxide-coated filament and published Class-A operation. Its documented operating point provides roughly 7–8 W output, making audio-frequency power amplification a principal practical role.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
UX4
Base pins
4
Nominal heater
5 V / 2 A

Description

Western Electric general-purpose triode with a 5.0 V, 2.0 A oxide-coated filament and a published Class-A operating point.

Socket description

Medium-shell UX 4-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
UX4
Base pins
4
Nominal heater voltage
5 V
Nominal heater current
2 A
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

1 physical section, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
1700 Ω
Transconductance
0.00305 S
Amplification factor
5.08
Max plate voltage
550 V
Max plate dissipation
38 W
Max cathode current
90 mA

Maximum safe plate voltage 500 V. Representative published characteristics use the 500 V, -75 V maximum-operating table point for gm and mu; 1700 ohm plate resistance also published.

Source-dependent data

Operating conditions by source

Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.

Data set 01

1933 Western Electric Tubes

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate-grid capacitance

    12 pF

    Published direct interelectrode capacitance

  • Plate-filament capacitance

    4 pF

    Published direct interelectrode capacitance

  • Grid-filament capacitance

    6.5 pF

    Published direct interelectrode capacitance

Data set 02

1956 Western Electric Tubes

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Heater Voltage

    5 V

  • Heater Current

    2 A

  • Maximum Plate Voltage

    550 V

  • Maximum Plate Dissipation

    38 W

  • Plate Voltage

    450 V

    ClassA

  • Plate Current

    60 mA

    ClassA

  • Power Output

    7 W

    ClassA

Characteristic

  • Amplification Factor

    5.1

    ClassA

  • Transconductance

    3450 µS

    ClassA

  • Plate Resistance

    1500 ohm

    ClassA

Data set 03

2026 Western Electric 200s

Published operating points and test conditions from this source.

SECTION 1

Triode

Capacitance

  • Grid To Plate Capacitance

    12 pF

  • Grid To Filament Capacitance

    6.5 pF

  • Plate To Filament Capacitance

    4 pF

Other

  • Maximum Plate Current

    90 mA

    ManuallyAdjustedGridBiasOrSelfBias

  • Power Output

    8.3 W

    PlateVoltage=500V;GridBias=-70V;LoadResistance=4000ohm

Characteristic

  • Plate Resistance

    1500 ohm

    PlateVoltage=500V;GridBias=-70V

  • Transconductance

    3450 uS

    PlateVoltage=500V;GridBias=-70V