CAT20C

Water-cooled transmitting triode for high-power HF amplification and Class B modulation. Approximately 75 kW plate dissipation and 20 kV capability provide enormous RF or audio-modulator power for major transmitter installations.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: -
Base pins: -
Nominal heater: 31.5 V / 230 A

Description

Water-cooled transmitting triode for HF amplification and Class-B modulation.

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: 31.5 V
Nominal heater current: 230 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: 0.024 S
Amplification factor: 35
Max plate voltage: 20000 V
Max plate dissipation: 75000 W
Max grid dissipation: 3000 W
Max cathode current: 30 A

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

Characteristic

Filament Voltage
31.5 V
Filament Current
230 A
Amplification Factor
35
Transconductance
24000 uS

Other

Maximum Anode Voltage
20000 V
Maximum Anode Dissipation
75000 W
Maximum Grid Dissipation
3000 W
Maximum/Peak Cathode Current
30 A
Frequency at Full Ratings
20 MHz
Typical RF Output Power
52 kW
Class C

Capacitance

Anode-Grid Capacitance
40 pF
Anode-Cathode Capacitance
3 pF
Grid-Cathode Capacitance
54 pF

Construction

Cooling
Water plus seal air