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Specialized - Traveling Wave ·TravelingWave

444A

Medium-power helix traveling-wave amplifier around 6 GHz, designed primarily as a transmitting amplifier in long-distance radio-relay repeater stations.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
-
Socket code
UX4
Base pins
-
Nominal heater
6.3 V / 920 mA

Description

The 444A is a medium-power helix-type traveling-wave amplifier for applications in the 6000-megacycle frequency region, intended primarily as a transmitting amplifier in long-distance radio-relay repeater stations.

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
-
Nominal heater voltage
6.3 V
Nominal heater current
920 mA
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

TravelingWave

X-ray radiationInterelectrode capacitances
Max cathode current
50 mA

Helix-type traveling-wave amplifier section; non-grid microwave electrodes retained 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

2026 Western Electric 400s

Published operating points and test conditions from this source.

SECTION 1

TravelingWave

Characteristic

  • Accelerator Anode Voltage

    2700 V

  • Accelerator Anode Current

    - to 0.6 mA

  • Helix Voltage

    2400 V

  • Helix Current

    - to 0.4 mA

  • Collector Voltage

    1200 V

  • Power Output

    5 to - W

  • Gain at 5 W Output

    32.5 dB

  • Noise Figure

    - to 30 dB

Other

  • Accelerator Anode Voltage Maximum

    - to 3000 V

  • Accelerator Anode Current Maximum

    - to 2 mA

  • Accelerator Anode Power Maximum

    - to 2.5 W

  • Helix Voltage Maximum

    - to 2700 V

  • Helix Current Maximum

    - to 2 mA

  • Helix Power Maximum

    - to 2.5 W

  • Collector Voltage Maximum

    - to 2000 V

  • Collector Power Maximum

    - to 80 W

  • Heater-Cathode Voltage Maximum

    -45 to 45 V