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Voltage - Dual Triode (similar) ·Triode-Triode

7N7

Low-mu double triode intended for phase-inverter and general voltage-amplifier service, providing two similar triode sections for audio-frequency and other low-frequency circuitry.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
8AC
Socket code
B8G
Base pins
8
Nominal heater
6.3 V / 600 mA

Description

The 7N7 combines two low-mu triodes for use as phase inverters or general voltage amplifiers.

Socket description

Loctal 8-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
8AC
Socket code
B8G
Base pins
8
Nominal heater voltage
6.3 V
Nominal heater current
600 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

8AC - 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
6700 Ω
Transconductance
0.003 S
Amplification factor
20
Max plate voltage
300 V
Max plate dissipation
2.5 W
Rectifier max heater-cathode voltage
90 V

Published promoted fields populated by semantic section ownership; identical repeated sections compressed.

Section 2

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
6700 Ω
Transconductance
0.003 S
Amplification factor
20
Max plate voltage
300 V
Max plate dissipation
2.5 W

Second physical triode section; added to align rows with SectionCount.

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

1948 Brimar Radio Valve Manual

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate Voltage

    250 V

    EachSection

  • Plate Current

    9 mA

    EachSection

  • Control Grid Voltage

    -8 V

    EachSection

  • Cathode Bias Resistor

    1100 ohm

    EachSection

Characteristic

  • Plate Resistance

    7700 ohm

    EachSection

  • Transconductance

    2600 µS

    EachSection

  • Amplification Factor

    20

    EachSection

Data set 02

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate voltage

    250 V

    ClassA;PerSection

  • Grid voltage

    -8 V

    ClassA;PerSection

  • Plate current

    9 mA

    ClassA;PerSection

Characteristic

  • Plate resistance

    7700 ohm

    ClassA;PerSection

  • Transconductance

    2600 uS

    ClassA;PerSection

  • Amplification factor

    20

    ClassA;PerSection

Data set 03

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

  • Plate Resistance

    7700 ohm

    AlternateOperatingPoint

  • Transconductance

    2600 uS

    AlternateOperatingPoint

Data set 04

1966 Tung Sol Electronic Tubes 2 of 4

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate_voltage

    250 V

    Section1,Section2,ClassA

Characteristic

  • Plate_current

    9 mA

    Section1,Section2,ClassA

  • Plate_resistance

    7700 ohm

    Section1,Section2,ClassA

  • Transconductance

    2600 uS

    Section1,Section2,ClassA

  • Amplification_factor

    20

    Section1,Section2,ClassA

Capacitance

  • Grid-to-plate capacitance

    3 pF

    Section1,Section2

  • Input capacitance

    3.4 pF

    Section1,Section2

  • Output capacitance

    2.4 pF

    Section1,Section2