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DA42

Indirectly heated high-mu power triode for Class B push-pull audio amplification. A pair can provide approximately 175 W output at around 1 kV plate supply, combining high gain with cathode isolation.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: -
Base pins: -
Nominal heater: 7.5 V / 1.2 A

Description

Indirectly heated power triode for Class-B push-pull audio amplification; about 175 W per pair.

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: 7.5 V
Nominal heater current: 1.2 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
Transconductance: 0.003 S
Amplification factor: 72
Max plate dissipation: 40 W

Applicable promoted ratings mapped semantically from the printed approximate-data/ratings tables; useful non-promoted operating, capacitance and service data retained in TUBE_SECTION_PARAMETER.

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

1955 Marconi

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Plate Resistance
2000 ohm
Anode-Grid Capacitance
4 pF
Anode-Cathode Capacitance
1 pF
Grid-Cathode Capacitance
32 pF
Two-Tube Class-B Output
175 W
ClassB;PushPull
Typical Plate Voltage
1000 V
ClassB
Maximum-Signal Plate Current
275 mA
ClassB
Peak Grid Drive
175 V
ClassB