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Specialized - Cathode Ray ·CathodeRay

804TM

Eight-inch diagonal rectangular television monitor CRT with magnetic focusing, 90-degree magnetic deflection, and a metal-backed screen for professional direct-view monitoring.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
B12A
Socket code
-
Base pins
12
Nominal heater
6.3 V / 300 mA

Description

Eight-inch diagonal rectangular television monitor cathode-ray tube with magnetic focus, 90-degree magnetic deflection, and metal-backed screen.

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
300 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
15000 V

Ratings, characteristics, typical operating points, and capacitances were extracted from the supplied Ferranti 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

1963 Ferranti

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Characteristic

  • HeaterOrFilamentVoltage

    6.3 V

  • HeaterOrFilamentCurrent

    300 mA

  • FocusingMethod

    Magnetic

  • DeflectionMethod

    Magnetic

  • Deflection Angle

    90 degree

  • ScreenConstruction

    Metal-backed

  • CathodeToAllCapacitanceMaximum

    8 pF

  • GridToAllCapacitanceMaximum

    8 pF

Other

  • FirstAnodeVoltageMinimum

    250 V

  • FirstAnodeVoltageMaximum

    600 V

  • SecondAnodeVoltageMinimum

    8000 V

  • SecondAnodeVoltageMaximum

    15000 V

  • HeaterCathodeVoltageMaximum

    200 V

    HeaterNegative

  • HeaterCathodeVoltageMaximum

    150 V

    HeaterPositive

  • CathodeResistanceMaximum

    10 Mohm

  • GridResistanceMaximum

    1.5 Mohm

  • FirstAnodeVoltage

    300 V

  • GridDriveFor100uABeamCurrent

    25 V