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Voltage Tetrode ·Tetrode

246A

Screen-grid tetrode intended for receiver voltage amplification, detector, oscillator, or general Class-A service as documented by the manufacturer.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
MEDIUM4BAYONET
Base pins
4
Nominal heater
3.3 V / 100 mA

Description

Western Electric general-purpose tetrode with a 3.3 V, 0.1 A oxide-coated filament 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
3.3 V
Nominal heater current
100 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

Tetrode

X-ray radiationInterelectrode capacitances
Plate resistance
325000 Ω
Transconductance
0.00051 S
Max plate voltage
180 V
Max screen voltage
67.5 V

Promoted fields mapped from published ratings/characteristics; additional published values preserved in parameter table.

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

  • Heater Voltage

    3.3 V

  • Heater Current

    100 mA

  • Maximum Plate Voltage

    180 V

  • Maximum Screen Voltage

    67.5 V

  • Plate Voltage

    135 V

    ClassA

  • Plate Current

    1.5 mA

    ClassA

Characteristic

  • Amplification Factor

    285

    ClassA

  • Transconductance

    390 µS

    ClassA

  • Plate Resistance

    725000 ohm

    ClassA

Data set 02

2026 Western Electric 200s

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Characteristic

  • Filament Current

    0.1 Amperes

    Filament Current 0.10 Amperes

  • Filament Voltage

    3.3 Volt

    Filament Voltage 3.3V olts

  • Screen-Grid Voltage

    45 Volt

    Screen-Grid Voltage 45 45 67.5

  • Control-Grid Voltage

    -1.5 Volt

    Control-Grid Voltage —1.5 —1.5 —3.0

  • Average Plate Current—Milliamperes

    1 Milliamperes

    Average Plate Current—Milliamperes 1. 50 1. 55 2. 85

  • Average Plate Resistance—Ohms

    725000 Ohms

    Average Plate Resistance—Ohms 725,000 830,000 325,000

  • Average Mutual Conductance—Micromhos

    390 Micromhos

    Average Mutual Conductance—Micromhos 390 400 510

  • Average A m p l i fi c a t i o n Factor

    285

    Average A m p l i fi c a t i o n Factor 285 335 165

  • Filament current

    0.1 ampere

    Filament current 0.100 ampere, d.c.

  • Nominal fi l a m e n t voltage

    3.3 volt

    Nominal fi l a m e n t voltage 3.3 volts

  • are shown as functions of plate voltage for several values of control-grid voltage in Figures

    3 volt

    are shown as functions of plate voltage for several values of control-grid voltage in Figures 3 and 4

  • for screen-grid voltages of

    45 volt

    for screen-grid voltages of 45 and 67.5 volts, respectively. The plate, screen-grid, and control-grid

  • Corresponding amplification factor and plate resistance characteristics are given in Figures

    8

    Corresponding amplification factor and plate resistance characteristics are given in Figures 8, 9,

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    0.1 AMPERE

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Other

  • Plate Voltage

    135 Volt

    Plate Voltage 135 180 135 Max.