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Specialized - Ballast ·Ballast

4A21

Iron-wire ballast tube designed to regulate approximately 1.62 A over an 11–15 V operating range.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
4T
Socket code
IO
Base pins
4
Nominal heater
-

Description

The 4A21 is an iron-wire ballast tube with a mean current of 1.62 A over an 11 to 15 V operating range.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
4T
Socket code
IO
Base pins
4
Nominal heater voltage
-
Nominal heater current
-
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

4T - 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

Ballast

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Ballast-tube electrical quantities do not map to ordinary active-electrode promoted fields; 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

1968 General Electric Co

Published operating points and test conditions from this source.

SECTION 1

Ballast

Characteristic

  • Mean Current

    1.62 A

  • Mean Current Range

    1.59 A to 1.65 A

  • Voltage Range

    11 to 15 V

Other

  • Maximum Continuous Current

    1.7 A

  • Ambient Temperature Range

    -30 to 80 C