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Tube Tinker — Electron Tube Database
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Voltage - Triode (single) ·Triode

264B

Small directly heated Western Electric audio triode designed for low microphonic noise and high input resistance, with silver-plated contacts to minimize contact noise.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
MEDIUM5
Base pins
5
Nominal heater
1.5 V / 300 mA

Description

Small filamentary triode for audio-frequency amplification where low microphonic noise and high input resistance are important. Silver-plated base contacts are used to minimize contact noise.

Socket description

Medium 5-contact transmitting-tube base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
MEDIUM5
Base pins
5
Nominal heater voltage
1.5 V
Nominal heater current
300 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
12400 Ω
Transconductance
0.00058 S
Amplification factor
7.2
Max plate voltage
100 V

Representative operating point: 100 V plate, -8 V grid, 2.10 mA. 100 V maximum plate voltage is explicitly published in earlier sheet within PDF.

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

2026 Western Electric 200s

Published operating points and test conditions from this source.

SECTION 1

Triode

Capacitance

  • Grid To Plate Capacitance

    5.3 pF

  • Grid To Filament Capacitance

    3.5 pF

  • Plate To Filament Capacitance

    2.2 pF

Other

  • Plate Current

    2.1 mA

    PlateVoltage=100V;GridBias=-8V

  • MicrophonicNoiseOutput

    -43 dB re 1V

    PlateVoltage=100V;GridBias=-8V;Load=100kohm