BR175

Forced-air-cooled tungsten-filament Marconi transmitting triode for HF amplifier and oscillator service. Its 12.5 kV plate rating and 4 kW dissipation support substantial high-voltage communications transmitter power.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: -
Base pins: -
Nominal heater: 22 V / 60 A

Description

The Marconi BR175 is a forced-air-cooled tungsten-filament transmitting triode for hf amplifier and oscillator 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: 22 V
Nominal heater current: 60 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

Amplification factor: 50
Max plate voltage: 12500 V
Max plate dissipation: 4000 W
Max grid dissipation: 600 W

Highest published service maximums promoted; cooling and operating conditions preserved in 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

1955 Marconi

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Heater/filament voltage
22 V
Heater/filament current
60 A
Maximum plate voltage
12500 V
Maximum plate dissipation
4000 W
Maximum grid dissipation
600 W
Maximum frequency at full ratings
50 MHz
Maximum filament starting current
90 A

Characteristic

Amplification factor
50

Capacitance

Grid-plate capacitance
27 pF
Plate-cathode capacitance
1.5 pF
Grid-cathode capacitance
39 pF

Construction

Cooling
Forced air