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

21DEP4

Twenty-one-inch direct-view monochrome television picture tube with magnetic deflection and a P4 display screen. Manufacturer documentation places it in the high-voltage receiver CRT family, with construction optimized for bright rectangular picture presentation.

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

Description

Sylvania 21DEP4 direct-view monochrome television CRT with electrostatic focus, magnetic deflection, and Aluminized P4 white. Published high-voltage ratings, focus/cutoff ranges, capacitances, and typical operating conditions were extracted.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
-
Base pins
-
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
19800 V

Published Sylvania high-voltage CRT ratings and typical operating conditions promoted/extracted from supplied 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

1965 Sylvania Electronic Tubes Vol3

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Characteristic

  • Heater Voltage

    6.3 V

  • Heater Current

    600 mA

  • FocusingMethod

    Electrostatic

  • DeflectionMethod

    Magnetic

  • Phosphor

    Aluminized P4 white

  • DeflectionAngles

    110-degree magnetic

  • Cathode To All Capacitance

    5 pF

  • Grid1 To All Capacitance

    6 pF

  • ExternalConductiveCoatingToAnodeCapacitanceMaximum

    2500 pF

  • ExternalConductiveCoatingToAnodeCapacitanceMinimum

    2000 pF

Other

  • AnodeVoltageMaximum

    19800 V

  • AnodeVoltageMinimum

    10000 V

  • FocusingElectrodeVoltageRangeMaximum

    -550 to +1100 V

  • Grid2VoltageMaximum

    550 V

  • Grid2VoltageMinimum

    200 V

  • Grid1NegativeBiasMagnitudeMaximum

    155 V

  • Grid1PositivePeakVoltageMaximum

    2 V

  • HeaterCathodeVoltageMaximum

    450 V

    Warmup<=15s;HeaterNegative

  • HeaterCathodeVoltageMaximum

    200 V

    AfterWarmup

  • HeaterCathodeVoltageMaximum

    200 V

    HeaterPositive

  • Anode Voltage

    17000 V

  • FocusingElectrodeVoltage

    0 to +400 V

  • Grid1VoltageForCutoff

    -35 to -72 V

  • Grid1CircuitResistanceMaximum

    1.5 Mohm