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Power - Triode ·Triode-Triode

25N6G

Octal dual-triode dynamic-coupled power-output tube for high-quality AC/DC receiver audio, functionally corresponding to the 25B5.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
G-7WQ
Socket code
IO
Base pins
8
Nominal heater
25 V / 300 mA

Description

The octal-base counterpart of the 25B5, sharing its 25 V, 0.3 A heater and dynamic-coupled power-output characteristics for AC-DC receiver audio service.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
G-7WQ
Socket code
IO
Base pins
8
Nominal heater voltage
25 V
Nominal heater current
300 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

G-7WQ - Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

2 physical sections, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
11400 Ω
Transconductance
0.0022 S
Amplification factor
25
Max plate voltage
180 V

Input triode in a dynamically coupled pair. The source states ratings/characteristics are identical to 25B5 but does not reproduce separate fixed per-triode ratings; external 25B5 data was not imported.

Section 2

Triode

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Output triode in a dynamically coupled pair. The source states ratings/characteristics are identical to 25B5 but does not reproduce separate fixed per-triode ratings; external 25B5 data was not imported.

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

1938 Triadyne

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • PlateCurrentOutput

    45 mA

    ClassA;At 110 V

  • PlateCurrentInput

    7 mA

    ClassA;At 110 V

  • Load Resistance

    2000 ohm

    ClassA;At 110 V

  • Power Output

    2 W

    ClassA;At 110 V

  • Power Output

    3.8 W

    ClassA;At 180 V

Data set 02

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate voltage

    180 V

    ClassA

  • Input-plate supply voltage

    100 V

    ClassA

  • Grid voltage

    0 V

    ClassA

  • Plate current

    46 mA

    ClassA

  • Input-plate current

    5.8 mA

    ClassA

  • Load resistance

    4000 ohm

    ClassA

  • Power output

    3.8 W

    ClassA

Data set 03

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Heater voltage

    25 V

    Nominal

  • Heater current

    300 mA

    Nominal

  • Input plate voltage

    110 V

    ClassA; InputTriode; OperatingPoint1

  • Input plate voltage

    100 V

    ClassA; InputTriode; OperatingPoint2

  • Grid circuit resistance maximum

    1 Mohm

    ClassA

Characteristic

  • Input plate current

    7 mA

    ClassA; InputTriode; OperatingPoint1

  • Input plate current

    5.8 mA

    ClassA; InputTriode; OperatingPoint2

  • Transconductance

    2200 uS

    ClassA; InputTriode; OperatingPoint1

  • Transconductance

    2300 uS

    ClassA; InputTriode; OperatingPoint2

  • Amplification factor

    25

    ClassA; InputTriode; OperatingPoint1

  • Amplification factor

    35

    ClassA; InputTriode; OperatingPoint2

SECTION 2

Triode

Other

  • Heater voltage

    25 V

    Nominal

  • Heater current

    300 mA

    Nominal

  • Output plate voltage

    110 V

    ClassA; OutputTriode; OperatingPoint1

  • Output plate voltage

    180 V

    ClassA; OutputTriode; OperatingPoint2

  • Load resistance

    2000 ohm

    ClassA; OutputTriode; OperatingPoint1

  • Load resistance

    4000 ohm

    ClassA; OutputTriode; OperatingPoint2

  • Power output

    2 W

    ClassA; OutputTriode; OperatingPoint1

  • Power output

    3.8 W

    ClassA; OutputTriode; OperatingPoint2

  • Total harmonic distortion

    9 %

    ClassA; OutputTriode; OperatingPoint1

  • Total harmonic distortion

    9 %

    ClassA; OutputTriode; OperatingPoint2

  • Grid circuit resistance maximum

    1 Mohm

    ClassA

Characteristic

  • Output plate current

    43 mA

    ClassA; OutputTriode; OperatingPoint1

  • Output plate current

    46 mA

    ClassA; OutputTriode; OperatingPoint2