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

FW208

Seven-and-a-half-inch magnetically focused direct-view storage cathode-ray tube. ITT documentation gives approximately 12 kV operation and identifies electronic storage as its primary function rather than continuously refreshed display.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
-
Socket code
-
Base pins
-
Nominal heater
6.3 V / 1.4 A

Description

7.5-inch magnetically focused direct-view storage cathode-ray tube.

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
1.4 A
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
12000 V

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

1962 ITT

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Characteristic

  • Heater Voltage

    6.3 V

  • Heater Current

    1.4 A

  • Typical Viewing Screen Voltage

    10000 V

  • Collector Voltage

    150 V

  • Write Cathode Voltage

    -2500 V

  • Useful Display Diameter

    6 in

  • Cathode Preheat Time

    30 s

  • Flood Heater Current

    1.4 A

  • Write Heater Current

    600 mA

Other

  • Maximum Viewing/High-Voltage Electrode Potential

    12000 V