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521AM

Five-inch high-resolution triode cathode-ray display tube with magnetic focusing and magnetic deflection. Ferranti specifies high-voltage anode capability to approximately 25 kV for fine-detail display applications.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized

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

Description

Five-inch high-resolution triode cathode-ray display tube with magnetic focus and magnetic deflection.

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: 25000 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
60 degree
ScreenConstruction
Metal-backed
UsefulScreenDiameterMinimum
110 mm
GridVoltageForVisualCutoff
AnodeVoltage/125
CathodeToAllCapacitanceMaximum
8 pF
GridToAllCapacitanceMaximum
8 pF

Other

HeaterCathodeVoltageMaximum
200 V
HeaterNegative
HeaterCathodeVoltageMaximum
200 V
HeaterPositive
GridCathodeResistanceMaximum
1.5 Mohm
Anode Voltage
20000 V
ScreenResolution
1000 lines/in
ScreenCentre