CAT21

Water-cooled transmitting triode for VHF power-amplifier service to roughly 100 MHz. Approximately 20 kW plate dissipation and 10 kV plate capability support substantial communications and broadcast transmitter power.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: -
Base pins: -
Nominal heater: 12 V / 320 A

Description

Water-cooled transmitting triode for VHF amplifier service to 100 MHz.

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: 12 V
Nominal heater current: 320 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: 0.02 S
Amplification factor: 21
Max plate voltage: 10000 V
Max plate dissipation: 20000 W
Max grid dissipation: 1500 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
12 V
Filament Current
320 A
Amplification Factor
21
Transconductance
20000 uS

Other

Maximum Anode Voltage
10000 V
Maximum Anode Dissipation
20000 W
Maximum Grid Dissipation
1500 W
Maximum/Peak Cathode Current
100 A
Frequency at Full Ratings
100 MHz
Typical RF Output Power
394 kW
Class C, 10 kV

Capacitance

Anode-Grid Capacitance
1.1 pF
Anode-Cathode Capacitance
32 pF
Grid-Cathode Capacitance
42 pF

Construction

Cooling
Water plus seal air