572B

High-mu graphite-anode power triode for Class AB, B, and C audio and RF amplification. Its 160 W plate dissipation and high amplification factor particularly suit grounded-grid linear RF and substantial audio-power service.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: SMALL4
Base pins: 4
Nominal heater: 6.3 V / 4 A

Description

High-mu graphite-anode power triode for Class AB, B and C RF and audio amplifiers, with 160 W plate dissipation and transmitting service capability.

Socket description

Small 4-contact transmitting-tube base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: SMALL4
Base pins: 4
Nominal heater voltage: 6.3 V
Nominal heater current: 4 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: 170
Max plate voltage: 2750 V
Max plate dissipation: 160 W
Max grid dissipation: 50 W
Max cathode current: 275 mA

Section values promoted from published characteristics and maximum ratings.

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

199X Svetlana

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

the
811 A
SourcePage1-2
Voltage (AC or DC)
6.3 V
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Current
4 A
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Grid to plate
6 pF
SourcePage1-2
Grid to filament
5.9 pF
SourcePage1-2
Plate to filament
0.8 pF
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Maximum frequency for full ratings
30 MHz
SourcePage1-2

Other

DC plate voltage
2750 V
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Plate dissipation
160 W
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DC Plate input
600 W
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DC Grid current
50 mA
SourcePage1-2
(frequencies to
30 MHz
TypicalOperation
DC plate voltage
2400 V
TypicalOperation
DC grid voltage
-2 V
TypicalOperation
Zero-signal DC plate current
45 mA
TypicalOperation
Single-tone DC plate current
250 mA
TypicalOperation
Driving power
50 W
TypicalOperation
Single-tone useful output power
300 W
TypicalOperation