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Specialized - Cathode Ray ·CathodeRay

31E12

Twelve-inch aluminized radar cathode-ray tube with electrostatic focusing, magnetic deflection, and long-afterglow screen options. Designed for radar display service, it retains echo information between successive sweeps.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
B12A
Socket code
-
Base pins
12
Nominal heater
6.3 V / 600 mA

Description

Twelve-inch aluminised radar cathode-ray tube with electrostatic focus, magnetic deflection and long-afterglow screen options.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
B12A
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

B12A - 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
12000 V

CRT electrode ratings and operating data preserved in parameter rows.

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

1960 Mazda

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Other

  • MinimumFinalAnodeVoltage

    8 kV

  • MaximumFirstAnodeVoltage

    400 V

  • Maximum Heater Cathode Voltage

    130 V

    HeaterNegative

  • TypicalFinalAnodeVoltage

    12 kV

  • TypicalFirstAnodeVoltage

    300 V

Data set 02

1961 AEI Industrial Valves

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Other

  • MaximumFinalAnodeVoltage

    12 kV

    DesignCentre; absolute maximum 14 kV

  • MinimumFinalAnodeVoltage

    8 kV

  • MaximumFirstAnodeVoltage

    400 V

  • Maximum Heater Cathode Voltage

    150 V

    HeaterNegative DC

  • TypicalFinalAnodeVoltage

    12 kV

  • TypicalFirstAnodeVoltage

    300 V

  • TypicalThirdAnodeFocusVoltage

    0 V

    Mean

  • GridBiasCutoff

    -77 to -33 V

    250mm focused line

  • PeakToPeakModulatingVoltage

    24 V

    Modulation up to 150 uA

Characteristic

  • Grid Earth Capacitance

    9 pF

  • CathodeEarthCapacitance

    7 pF

  • SecondFourthAnodeToExternalCoatingCapacitance

    1500 pF

    Includes CRT92/7 holder

  • T6ScreenPersistence

    50 s

    Long yellow afterglow

  • T7ScreenPersistence

    175 s

    Very long orange afterglow

  • MaximumOverallLength

    485 mm

  • MaximumDiameter

    307 mm

  • MaximumNeckDiameter

    35.5 mm

Data set 03

1961 Associated Electrical Industries

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Other

  • MinimumFinalAnodeVoltage

    8 kV

  • MaximumFirstAnodeVoltage

    400 V

  • Maximum Heater Cathode Voltage

    130 V

    HeaterNegative

  • TypicalFinalAnodeVoltage

    12 kV

  • TypicalFirstAnodeVoltage

    300 V

Characteristics

  • Grid Earth Capacitance

    9 pF

  • CathodeEarthCapacitance

    7 pF

  • AnodeExternalCoatingCapacitance

    1500 pF