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Voltage - Triode (single) ·Triode

275A

General-purpose receiving triode for voltage amplification, detection, oscillator, or Class-A service as documented by the manufacturer.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
MEDIUM4BAYONET
Base pins
4
Nominal heater
5 V / 1.2 A

Description

General-purpose directly heated triode.

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
1.2 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
1000 Ω
Transconductance
0.0027 S
Amplification factor
2.9
Max plate voltage
300 V
Max plate dissipation
17 W
Max cathode current
80 mA

Published ratings and characteristics promoted from the approved datasheet.

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

    3.2 pF

    Published direct interelectrode capacitance

  • Grid-filament capacitance

    6.8 pF

    Published direct interelectrode capacitance

Data set 02

1956 Western Electric Tubes

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

  • HeaterOrFilamentVoltage

    5 V

  • HeaterOrFilamentCurrent

    1.2 A

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

    6.8 pF

  • Plate To Filament Capacitance

    3.2 pF