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Voltage - Triode (single) ·Triode

272A

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
10 V / 320 mA

Description

Western Electric general-purpose triode with a 10.0 V, 0.32 A heater-type cathode and a published Class-A operating point.

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
10 V
Nominal heater current
320 mA
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
7400 Ω
Transconductance
0.00075 S
Amplification factor
5.6
Max plate voltage
200 V
Max plate dissipation
1.4 W

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

    2.8 pF

    Published direct interelectrode capacitance

  • Plate-cathode capacitance

    2.6 pF

    Published direct interelectrode capacitance

  • Grid-cathode capacitance

    3.4 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

    10 V

  • Heater Current

    320 mA

  • Maximum Plate Voltage

    200 V

  • Maximum Plate Dissipation

    1.4 W

  • Maximum Heater-Cathode Voltage

    100 V

  • Plate Voltage

    140 V

    ClassA

  • Plate Current

    5.4 mA

    ClassA

  • Power Output

    0.12 W

    ClassA

Characteristic

  • Amplification Factor

    5.6

    ClassA

  • Transconductance

    750 µS

    ClassA

  • Plate Resistance

    7400 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

    2.8 pF

  • GridToHeaterCathodeCapacitance

    3.4 pF

  • PlateToHeaterCathodeCapacitance

    2.6 pF