F891

Federal water-cooled transmitting triode for audio-frequency modulation, RF power amplification, and oscillator service. Approximately 6 kW plate dissipation and 15 kV capability provide heavy-duty transmitter and modulator power.

Directly heatedCold cathodeCommon cathodeDissimilar

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

Description

Federal F-891 three-electrode transmitting tube for audio-frequency modulation, radio-frequency power amplification, and oscillator service. Its water-cooled anode is rated to dissipate 6 kW and its pure-tungsten filament is directly heated.

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: 8.5
Max plate voltage: 15000 V
Max plate dissipation: 6000 W
Max cathode current: 9 A

Published ratings/characteristics semantically audited; condition-specific operating values preserved in parameter rows.

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

1962 ITT

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

Amplification factor
8.5

Other

Maximum plate voltage
15000 V
Maximum plate dissipation
6000 W
Peak cathode current
9 A
Maximum/full-ratings frequency
20 MHz

Capacitance

Grid-plate capacitance
27 pF
Grid-filament capacitance
19 pF
Plate-filament capacitance
2 pF

Construction

Cooling method
Water

Data set 02

1962 ITT Industrial and Transmitting Tubes

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

Amplification factor
8.5
Peak cathode current
9 A

Other

Filament starting current
120 A
Maximum
Filament cold resistance
0.031 ohm
DC plate voltage
15000 V
ClassB Audio
Maximum signal DC plate current
2 A
ClassB Audio
Maximum signal plate input
20 kW
ClassB Audio
Plate dissipation
5 kW
ClassB Audio
DC plate voltage
12000 V
ClassC Telegraphy
DC grid voltage
-3000 V
ClassC Telegraphy
DC plate current
2 A
ClassC Telegraphy
DC grid current
150 mA
ClassC Telegraphy
Plate input
18 kW
ClassC Telegraphy
Plate dissipation
6 kW
ClassC Telegraphy
Typical DC plate voltage
10000 V
ClassC Telegraphy
Typical power output
10 kW
ClassC Telegraphy

Capacitance

Grid-plate capacitance
-
Published; OCR value unclear