TH478

Very-high-power vapor-cooled transmitting triode for RF power-amplifier service. Approximately 150 kW plate dissipation, 15 kV capability, and very high transconductance support exceptionally demanding fixed transmitter installations.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: -
Base pins: -
Nominal heater: 17.5 V / 310 A

Description

High-power vapor-cooled transmitting triode for RF power-amplifier service.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: -
Base pins: -
Nominal heater voltage: 17.5 V
Nominal heater current: 310 A
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

Triode

X-ray radiationInterelectrode capacitances

Transconductance: 0.14 S
Amplification factor: 80
Max plate voltage: 15000 V
Max plate dissipation: 150000 W
Max grid dissipation: 3500 W
Max cathode current: 40 A

Promoted maximum ratings/characteristics mapped semantically from the printed ratings tables; additional published electrical data are preserved in TUBE_SECTION_PARAMETER.

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

1972 Thomson CSF

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Filament Starting Current Maximum
900 A
Cathode-Grid Capacitance
200 pF
Grid-Anode Capacitance
100 pF
Anode-Cathode Capacitance
2.5 pF
DC Cathode Current Maximum
40 A
Frequency Full Load Maximum
30 MHz
Typical Anode Voltage
12000 V
Typical Output Power
250 kW