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Specialized - Cathode Ray ·CathodeRay

21FVP4

Twenty-one-inch direct-view monochrome television picture tube with magnetic deflection and high-voltage operation. Manufacturer documentation describes its focusing system, picture-screen construction, and receiver-display characteristics for large-screen television service.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
B7-208
Socket code
-
Base pins
7
Nominal heater
6.3 V / 450 mA

Description

21FVP4 is a picture tube using published focusing and magnetic deflection. The source specifies a P4 screen and publishes CRT accelerating/anode ratings, control and focusing-electrode limits, heater-cathode limits, capacitances, and operating or deflection characteristics.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
B7-208
Socket code
-
Base pins
7
Nominal heater voltage
6.3 V
Nominal heater current
450 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

B7-208 - 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
23000 V

CRT maximum accelerating/anode/ultor voltage is promoted to MaxPlateVoltage; additional electrode ratings, capacitances, operating conditions, focus/deflection and optical data are preserved 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

1971 RCA HB3 Binder 1 of 7

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Capacitance

  • Cathode to all other electrodes

    5 pF

  • External conductive coating to anode capacitance

    - to 2300 pF

Other

  • Minimum anode/ultor voltage

    1000 V

  • Maximum grid 2 voltage

    550 V

  • Maximum grid 1 negative-bias voltage

    155 V

    NegativeBias

  • Maximum grid 1 positive-bias voltage

    0 V

    PositiveBias

  • Maximum grid 1 positive-peak voltage

    2 V

    PositivePeak

  • Maximum grid 1 negative-peak voltage

    220 V

    NegativePeak

  • Peak heater-cathode voltage

    450 V

    HeaterNegativeWarmup

  • Peak heater-cathode voltage

    300 V

    HeaterNegativeOperating

  • Peak heater-cathode voltage

    200 V

    HeaterPositive

  • Typical anode/ultor voltage

    20000 V

Characteristic

  • Faceplate light transmission

    46 %

    Approximate