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Tube Tinker — Electron Tube Database
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Specialized - Cathode Ray ·CathodeRay

31G12

Twenty-one-inch rectangular cathode-ray tube for large-screen oscilloscopes, using electrostatic focusing, 90-degree magnetic deflection, a gray aluminized face, and T9 long-orange-afterglow screen.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
-
Socket code
-
Base pins
12
Nominal heater
6.3 V / 600 mA

Description

21-inch diagonal rectangular cathode-ray tube for large-screen oscilloscopes, with 90-degree magnetic deflection, electrostatic focusing, grey aluminised face, and T9 long-orange-afterglow screen.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
-
Base pins
12
Nominal heater voltage
6.3 V
Nominal heater current
600 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

Cathode Ray

X-ray radiationInterelectrode capacitances
Max plate voltage
16000 V

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

1961 AEI Industrial Valves

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Other

  • MinimumSecondFourthAnodeVoltage

    12 kV

  • MaximumThirdAnodeVoltage

    700 V

  • MaximumFirstAnodeVoltage

    400 V

  • Maximum Heater Cathode Voltage

    180 V

    HeaterNegative

  • Peak Heater Cathode Voltage

    400 V

    WarmupMaximum1Minute

Characteristics

  • GridAllCapacitance

    9 pF

  • CathodeAllCapacitance

    65 pF

Data set 02

1961 Associated Electrical Industries

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Other

  • MinimumSecondFourthAnodeVoltage

    12 kV

  • MaximumThirdAnodeVoltage

    700 V

  • MaximumFirstAnodeVoltage

    400 V

  • Maximum Heater Cathode Voltage

    180 V

    HeaterNegative

  • Peak Heater Cathode Voltage

    400 V

    WarmupMaximum1Minute

Characteristics

  • GridAllCapacitance

    9 pF

  • CathodeAllCapacitance

    65 pF