F891R

Forced-air-cooled Federal transmitting triode for RF power amplification, oscillation, and Class B modulation. It provides 4 kW plate dissipation and plate ratings to 10 kV for substantial professional transmitter service.

Directly heatedCold cathodeCommon cathodeDissimilar

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

Description

Federal F-891-R three-electrode transmitting tube for RF power-amplifier, oscillator, and Class B modulator service. Its forced-air-cooled anode can dissipate 4 kW and the pure-tungsten filament may be operated from AC or DC.

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: 10000 V
Max plate dissipation: 4000 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
10000 V
Maximum plate dissipation
4000 W
Peak cathode current
9 A
Maximum/full-ratings frequency
20 MHz

Capacitance

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

Construction

Cooling method
Forced air

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
10000 V
ClassC RF
DC grid voltage
-3000 V
ClassC RF
DC plate current
2 A
ClassC RF
Plate dissipation
4 kW
ClassC RF
Typical DC plate voltage
10000 V
ClassC RF
Typical DC plate current
1.33 A
ClassC RF

Capacitance

Grid-plate capacitance
28 pF
Grid-filament capacitance
19 pF
Plate-filament capacitance
2.5 pF