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

2AP1A

Small oscilloscope and instrument CRT with electrostatic focusing, electrostatic deflection, and P1 phosphor. Manufacturer documentation provides approximately 2 kV maximum anode capability for compact waveform display.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
-
Socket code
OCTALCRT8
Base pins
-
Nominal heater
6.3 V / 600 mA

Description

Electrostatically focused and deflected oscilloscope/instrument CRT with P1 phosphor.

Socket description

Octal 8-contact CRT base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
OCTALCRT8
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
2000 V
Max screen voltage
500 V

Electrostatic-focus/electrostatic-deflection CRT.

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

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Characteristic

  • Heater Current (approx) . .. . . . .06 Ampere

    6 A

    Heater Current (approx) . .. . . . .06 Ampere

  • Anode No. 2 Voltage 1,100 Volts dc

    1.1 V

    Anode No. 2 Voltage 1,100 Volts dc

  • Anode No. 1 Voltage 550 Volts dc¢

    550 V

    Anode No. 1 Voltage 550 Volts dc¢

  • And any Deflection Plate . 660 Volts

    660 V

    And any Deflection Plate . 660 Volts

  • Anode No. 2 Voltage? . .. . . 1,000 Volts dc

    1 V

    Anode No. 2 Voltage? . .. . . 1,000 Volts dc

  • Anode No. 1 Voltage for Focus . 137 to 300 Volts dc¢ SYLVANIA ELECTRIC

    300 V

    Anode No. 1 Voltage for Focus . 137 to 300 Volts dc¢ SYLVANIA ELECTRIC

  • Grid Voltage Required for Cutoff? -30 t0 -90 Volts dc¢ PRODUCTS INC.

    -90 V

    Grid Voltage Required for Cutoff? -30 t0 -90 Volts dc¢ PRODUCTS INC.

  • 2. Brilliance and defmition decrease with decreasing Anode No. 2 Voltage. In general, Anode No. 2 Vo

    2 V

    2. Brilliance and defmition decrease with decreasing Anode No. 2 Voltage. In general, Anode No. 2 Voltage should

Data set 02

1965 Sylvania Electronic Tubes Vol3

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Characteristics

  • Focusing method

    Electrostatic

  • Deflection method

    Electrostatic

  • Heater voltage

    6.3 V

  • Heater current

    600 mA

  • Fluorescence

    Green

Application

  • Application

    Oscilloscope / precision instrument display

Other

  • Typical anode-2 voltage

    1100 V

  • Typical anode-1 focus voltage

    550 V

  • Anode-2 voltage maximum

    1500 V

Data set 03

1971 RCA HB3 Binder 1 of 7

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Other

  • Heater voltage

    6.3 V

  • Heater current

    600 mA

  • Peak heater-cathode voltage, heater negative

    125 V

  • Typical final accelerating anode voltage

    1500 V

  • Maximum deflecting electrode voltage

    550 V

Construction

  • Focusing method

    Electrostatic

  • Deflection method

    Electrostatic

  • Phosphor

    P1

Characteristic

  • Fluorescence

    Green

  • Persistence

    Medium

Capacitance

  • Grid #1 to all other electrodes capacitance

    8 pF

    Approximate

Application

  • Application

    Oscillograph/cathode-ray display