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644DM

Six-inch cathode-ray display tube with magnetic focusing and magnetic deflection and a metal-backed screen for high-resolution applications. Ferranti specifies anode capability to approximately 30 kV.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized

Sections: 1
Base: B12A
Socket code: -
Base pins: 12
Nominal heater: 6.3 V / 300 mA

Description

Six-inch cathode-ray display tube with magnetic focus/deflection and a metal-backed screen for high-resolution applications.

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: 30000 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
ScreenConstruction
Metal-backed
UsefulScreenDiameterMinimum
127 mm
CathodeToAllCapacitanceMaximum
8 pF
GridToAllCapacitanceMaximum
8 pF

Other

FirstAnodeVoltageMaximum
850 V
SecondAnodeVoltageMaximum
30000 V
HeaterCathodeVoltageMaximum
200 V
HeaterNegative
HeaterCathodeVoltageMaximum
200 V
HeaterPositive
FirstAnodeVoltage
600 V
SecondAnodeVoltage
25000 V
ScreenResolution
1000 lines
50fps