4279A

Large directly heated power triode for high-power RF and amplifier service. Approximately 1.2 kW plate dissipation, 3 kV plate capability, and full ratings to roughly 20 MHz suit substantial transmitting stages.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: -
Base pins: -
Nominal heater: 10 V / 21 A

Description

The 4279A is a triode described in the Standard Valves datasheet, using a directly heated filament cathode and published operating data.

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: 10 V
Nominal heater current: 21 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

Plate resistance: 2000 Ω
Amplification factor: 10
Max plate voltage: 3000 V
Max plate dissipation: 1200 W
Max cathode current: 800 mA

Ratings and characteristics extracted from 4279A.pdf.

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

1937 Standard Valves

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

Total emission
8 A
Published datasheet value
Grid-anode capacitance
18 pF
Published datasheet value
Anode-filament capacitance
7 pF
Published datasheet value

Other

Maximum frequency for above ratings
20 MHz
Published datasheet value
Maximum direct grid current
100 mA
Published datasheet value

Data set 02

1946 Standard Telephone and Cables

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

Filament voltage
10 volts
Nominal filament curren
21 amps
Total emission
8 amps
Impedance
2000 ohms

Other

at anode current o
300 mA
Maximum direct anode voltage
3000 volts
Maximum direct anode curren
0.8 amps
Maximum ariode dissipation
1200 watts
Maximum direct grid curren
100 mA
Maximum frequency for above ratings
20 Mc
Maximum anode voltage for frequency o
40 Mc
Direct anode voltage 2,500
2000 volts
Grid bias —170
-110 volts
Direct anode current 0-300
0.375 amps
Anode dissipation 750
750 watts
Load impedance 4,500
2000 ohms
Undistorted output 155
85 watts
Direct anode voltage 2,500
2000 volts
Direct anode current per valve—zero signal 0-150
0.11 amps
Anode current per valve—maximum signal 0-800
0.8 amps
Anode dissipation 900
720 watts
Load resistance—anode to anode 2,800
2240 ohms
Maximum output—2 valves 2,200
1760 watts
Direct anode voltage 3,000 2,500 2,250 1,750 3,000
2500 volts
—650 |
-540 volts
Carrier output 600 600 900 830 1,600
1300 watts
Anode dissipation 1,200 1,200 450 395 800
700 watts