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

6990

Five-inch tone-display storage CRT with distinct electrostatic writing and viewing guns. Both gun systems operate at high voltage, enabling information to be written, stored, and repeatedly viewed on the same screen.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
2
Base
-
Socket code
-
Base pins
-
Nominal heater
6.3 V / 600 mA

Description

5-inch tone-display storage CRT with distinct electrostatic writing and viewing guns.

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

2 physical sections, each with unique specifications.

Section 1

Cathode Ray

X-ray radiationInterelectrode capacitances
Max plate voltage
12000 V
Rectifier max heater-cathode voltage
125 V

Writing gun of tone-display storage CRT; device-specific storage-mesh/collector/collimator data retained as parameters.

Section 2

Cathode Ray

X-ray radiationInterelectrode capacitances
Max plate voltage
12000 V
Rectifier max heater-cathode voltage
125 V

Viewing gun of tone-display storage CRT; device-specific storage-mesh/collector/collimator data retained as parameters.

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

1955 Vacuum Tube Products

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Characteristic

  • Heater Voltage

    6.3 V

    WritingGun

  • Heater Current

    600 mA

    WritingGun

Other

  • Grid 1 Negative Bias Maximum

    200 V

    WritingGun

  • Deflecting Electrode Peak Voltage

    500 V

    WritingGun

  • Deflecting Electrode Circuit Resistance Maximum

    50 Mohm

    WritingGun

  • Typical Screen Voltage

    8000 V

  • Typical Cathode Voltage

    -1400 V

    WritingGun

  • Typical Grid 1 Voltage

    -30 to -20 V

    WritingGun

  • Typical Focus Voltage

    -1100 V

    WritingGun

SECTION 2

Cathode Ray

Characteristic

  • Heater Voltage

    6.3 V

    ViewingGun

  • Heater Current

    600 mA

    ViewingGun

Other

  • Storage Mesh Peak Voltage Maximum

    25 V

  • Collector Mesh Voltage Maximum

    500 V

  • Collimating Cylinder Voltage Maximum

    500 V

  • Viewing Gun Anode Voltage Maximum

    500 V

    ViewingGun

  • Typical Collector Mesh Voltage

    200 V

  • Typical Collimating Cylinder Voltage

    120 V

  • Typical Viewing Gun Anode Voltage

    185 V

    ViewingGun

  • Typical Grid 1 Voltage

    -50 to -30 V

    ViewingGun