439A

Ten-stage cold-cathode gas-discharge stepping tube for continuous pulse counting and registration, providing both visual and electrical indication and supporting decade-chain operation.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized

Sections: 1
Base: -
Socket code: -
Base pins: 19
Nominal heater: -

Description

Western Electric 439A is a ten-stage cold-cathode gas-discharge stepping tube for continuous pulse counting or registration, with visual and electrical registration and decade-chain operation.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: -
Base pins: 19
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

CounterSelectorSwitch

X-ray radiationInterelectrode capacitances

Max cathode current: 10 mA
Regulator starting voltage: 300 V
Regulator maintaining voltage: 110 V

Multi-cathode stepping/counting discharge structure represented as Other section; key anode/cathode discharge ratings promoted.

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

CounterSelectorSwitch

Other

Maximum average cathode current
3 mA
Minimum average cathode current
1 mA
Maximum pulse rate
1000 pulse/s

Characteristic

Normal-cathode anode breakdown voltage maximum
275 V
Output-cathode anode breakdown voltage maximum
300 V