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Power - Tetrode (NOT beam) ·Tetrode

254A

Western Electric thoriated-tungsten transmitting tetrode rated for Class-B RF service with approximately 10 W catalog output. Designed for radio-frequency power amplification.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
MEDIUM4BAYONET
Base pins
4
Nominal heater
5 V / 3.25 A

Description

Western Electric transmitting tetrode with a thoriated-tungsten filament, rated for B-RF service and a catalog power output of 10 W.

Socket description

Medium 4-contact bayonet base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
MEDIUM4BAYONET
Base pins
4
Nominal heater voltage
5 V
Nominal heater current
3.25 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

Tetrode

X-ray radiationInterelectrode capacitances
Plate resistance
80000 Ω
Transconductance
0.001 S
Amplification factor
80
Max plate voltage
750 V
Max plate dissipation
20 W
Max screen dissipation
5 W
Max cathode current
60 mA

Screen-grid operating potential 175 V is typical/operating data, not promoted as a maximum voltage.

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

1956 Western Electric Tubes

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Other

  • Filament Voltage

    5 V

  • Filament Current

    3.25 A

  • Maximum Plate Voltage

    750 V

  • Maximum Plate Current

    60 mA

  • Maximum Plate Dissipation

    20 W

  • Maximum Frequency

    1 MHz

  • Plate Voltage

    750 V

    B-RF

  • Plate Current

    27 mA

    B-RF

  • Power Output

    10 W

    B-RF

Characteristic

  • Amplification Factor

    80

    B-RF

  • Transconductance

    1000 µS

    B-RF

Data set 02

2026 Western Electric 200s

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Capacitance

  • PlateToControlGridCapacitance

    0.1 pF

  • PlateToFilamentAndScreenCapacitance

    9.4 pF

  • ControlGridToFilamentAndScreenCapacitance

    4.6 pF

Other

  • Screen Grid Voltage

    175 V

  • Maximum Frequency

    15 MHz

    FullRatings

  • NominalPowerOutput

    30 W

    ClassC;PlateVoltage=750V