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Voltage Regulator ·VoltageRegulator

447A

Two-electrode inert-gas cold-cathode voltage-reference and trouble-indicator tube, maintaining approximately 82 V while providing a visible red discharge glow.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
UX4
Base pins
4
Nominal heater
-

Description

The 447A is a two-electrode inert-gas-filled cold-cathode tube designed primarily for voltage-reference and trouble-indicator service; its cathode red glow is visible through a hole in the anode.

Socket description

Medium-shell UX 4-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
UX4
Base pins
4
Nominal heater voltage
-
Nominal heater current
-
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

Voltage Regulator

X-ray radiationInterelectrode capacitances
Max cathode current
8 mA
Regulator voltage
82 V
Regulator minimum current
2 mA
Regulator maximum current
8 mA
Regulator starting voltage
115 V
Regulator maintaining voltage
82 V

Visible red cathode glow through anode opening.

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

2026 Western Electric 400s

Published operating points and test conditions from this source.

SECTION 1

Voltage Regulator

Characteristic

  • Anode Breakdown Voltage

    110 to 120 V

  • Anode Voltage Drop at 4 mA

    81 to 83 V

  • Regulation 2–4 mA

    - to 0.5 V

  • Coverage Current

    - to 4 mA