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Power - Tetrode (NOT beam) ·Tetrode

4278A

Standard Valves directly heated tetrode with manufacturer-published operating data. Its filamentary construction supports power-output applications in professional electronic equipment.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
-
Base pins
-
Nominal heater
10 V / 15.6 A

Description

The 4278A is a tetrode 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
15.6 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

Tetrode

X-ray radiationInterelectrode capacitances
Plate resistance
105000 Ω
Max plate voltage
750 V
Max screen voltage
600 V
Max plate dissipation
75 W
Max screen dissipation
50 W
Max grid dissipation
30 W
Max cathode current
600 mA

Ratings and characteristics extracted from 4278A.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

Tetrode

Characteristics

  • Total emission

    6 A

    Published datasheet value

  • Grid-anode capacitance

    0.6 pF

    Published datasheet value

  • Input capacitance

    31 pF

    Published datasheet value

  • Output capacitance

    294 pF

    Published datasheet value

Other

  • Maximum frequency for above ratings

    30 MHz

    Published datasheet value

Data set 02

1946 Standard Telephone and Cables

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Characteristic

  • Filament voltage

    10 volts

Other

  • gt Vp =

    3000 volts

  • Vgz =

    750 volts

  • Maximum anode voltage for frequency o

    50 Mc

  • Direct anode voltage 3,000 2,500 2,250 1,750 3,000

    2500 volts

  • Direct screen-grid voltage| 500 500 500 500 500

    500 volts

  • —220 |

    -220 volts

  • Carrier output 400 400 600 580 1,000

    850 watts

  • Anode dissipation 800 800 300 295 500

    400 watts

  • } SCREEN- GRID YOLTAGE=

    500 VOLTS