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Voltage Dual Pentode ·Pentode-Pentode

1E7G

Directly heated twin power pentode containing two identical sections for push-pull audio output in battery-operated receivers.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
G-8C
Socket code
IO
Base pins
8
Nominal heater
2 V / 240 mA

Description

Directly heated twin-pentode power-amplifier tube; electrically identical pentode sections are compressed to one section row.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
G-8C
Socket code
IO
Base pins
8
Nominal heater voltage
2 V
Nominal heater current
240 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

G-8C - 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

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
260000 Ω
Transconductance
0.001425 S
Amplification factor
370
Max plate voltage
135 V
Max screen voltage
135 V

Representative row for two electrically identical pentode sections; promoted characteristics use first listed Class A1 condition.

Section 2

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
260000 Ω
Transconductance
0.001425 S
Amplification factor
370
Max plate voltage
135 V
Max screen voltage
135 V

Second physical pentode section; electrically identical twin section.

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 Raytheon Radio Receiving Tubes

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Maximum Plate Voltage

    135 V

    Published ratings

  • Maximum Screen Voltage

    135

    Published ratings

  • Plate Voltage

    135.6 V

    ClassA

  • Screen Voltage

    135

    ClassA

  • Grid Bias

    -4.5 V

    ClassA

  • Amplification Factor

    350

    ClassA

  • Plate Resistance Q

    0.22 Mohm

    ClassA

  • Transconductance

    1600 uS

    ClassA

  • Plate Current

    7.5 mA

    ClassA

  • Screen Current

    2 mA

    ClassA; Column1

  • Screen Current

    1 mA

    ClassA; Column2

  • Plate Voltage

    135.6 V

    ClassA; PushPull; TwoTubes

  • Screen Voltage

    135 V

    ClassA; PushPull; TwoTubes

  • Grid Bias

    -7.5 V

    ClassA; PushPull; TwoTubes

  • No-Signal Plate Current (total

    6.5 mA

    ClassA; PushPull; TwoTubes

  • No-Signal Screen Current (total

    2 mA

    ClassA; PushPull; TwoTubes

  • Load Resistance

    24000 ohm

    ClassA; PushPull; TwoTubes

  • Total Harmonic Distortion

    5 %

    ClassA; PushPull; TwoTubes

Data set 02

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Plate Current

    7.5 mA

    ClassA; OneSection; Plate 135 V

  • Power Output

    0.29 W

    ClassA; OneSection

  • Power Output

    0.575 W

    ClassA; PushPull; TwoSections

Data set 03

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Maximum plate voltage

    135 V

    EachSection

  • Maximum screen-grid voltage

    135 V

    EachSection

  • Plate voltage

    135 V

    ClassA EachSection

  • Screen-grid voltage

    135 V

    ClassA EachSection

  • Control-grid voltage

    -4.5 V

    ClassA EachSection

  • Plate current

    7.5 mA

    ClassA EachSection

  • Screen-grid current

    2.2 mA

    ClassA EachSection

  • Plate resistance

    260000 Ohm

    ClassA EachSection

  • Transconductance

    1425 uS

    ClassA EachSection

  • Load resistance

    16000 Ohm

    ClassA EachSection

  • Power output

    0.29 W

    ClassA EachSection

  • Plate voltage

    90 V

    ClassA EachSection 90V

  • Screen-grid voltage

    90 V

    ClassA EachSection 90V

  • Control-grid voltage

    -3 V

    ClassA EachSection 90V

  • Plate current

    3.8 mA

    ClassA EachSection 90V

  • Screen-grid current

    1.1 mA

    ClassA EachSection 90V

  • Plate resistance

    340000 Ohm

    ClassA EachSection 90V

  • Transconductance

    1150 uS

    ClassA EachSection 90V

  • Load resistance

    20000 Ohm

    ClassA EachSection 90V

  • Power output

    0.11 W

    ClassA EachSection 90V

  • Plate voltage

    135 V

    ClassA PushPull TwoSections

  • Screen-grid voltage

    135 V

    ClassA PushPull TwoSections

  • Control-grid voltage

    -7.5 V

    ClassA PushPull TwoSections

  • Plate current

    7 mA

    ClassA PushPull TwoSections

  • Screen-grid current

    2 mA

    ClassA PushPull TwoSections

  • Load resistance

    24000 Ohm

    ClassA PushPull TwoSections

  • Power output

    0.575 W

    ClassA PushPull TwoSections

Data set 04

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Filament Voltage

    2 V

    Nominal

  • Filament Current

    240 mA

    Nominal

  • Plate Voltage

    90 V

    ClassA1;EachPentode;PlateVoltage=90V

  • Screen Voltage

    90 V

    ClassA1;EachPentode;PlateVoltage=90V

  • Control Grid Voltage

    -3 V

    ClassA1;EachPentode;PlateVoltage=90V

  • Zero Signal Plate Current

    3.8 mA

    ClassA1;EachPentode;PlateVoltage=90V

  • Zero Signal Screen Current

    1.1 mA

    ClassA1;EachPentode;PlateVoltage=90V

  • Load Resistance

    20000 ohm

    ClassA1;EachPentode;PlateVoltage=90V

  • PeakSignalVoltage

    3 V

    ClassA1;EachPentode;PlateVoltage=90V

  • Total Distortion

    5.5 %

    ClassA1;EachPentode;PlateVoltage=90V

  • Power Output

    0.11 W

    ClassA1;EachPentode;PlateVoltage=90V

  • Plate Voltage

    135 V

    ClassA1;EachPentode;PlateVoltage=135V

  • Screen Voltage

    135 V

    ClassA1;EachPentode;PlateVoltage=135V

  • Control Grid Voltage

    -4.5 V

    ClassA1;EachPentode;PlateVoltage=135V

  • Zero Signal Plate Current

    7.5 mA

    ClassA1;EachPentode;PlateVoltage=135V

  • Zero Signal Screen Current

    2.2 mA

    ClassA1;EachPentode;PlateVoltage=135V

  • Load Resistance

    16000 ohm

    ClassA1;EachPentode;PlateVoltage=135V

  • PeakSignalVoltage

    4.5 V

    ClassA1;EachPentode;PlateVoltage=135V

  • Total Distortion

    4.5 %

    ClassA1;EachPentode;PlateVoltage=135V

  • Power Output

    0.29 W

    ClassA1;EachPentode;PlateVoltage=135V

  • Plate Voltage

    135 V

    ClassA1;PushPull;TwoPentodeSections

  • Screen Voltage

    135 V

    ClassA1;PushPull;TwoPentodeSections

  • Control Grid Voltage

    -7.5 V

    ClassA1;PushPull;TwoPentodeSections

  • Zero Signal Plate Current

    14 mA

    ClassA1;PushPull;TwoPentodeSections

  • Maximum Signal Plate Current

    21 mA

    ClassA1;PushPull;TwoPentodeSections

  • Maximum Signal Screen Current

    7 mA

    ClassA1;PushPull;TwoPentodeSections

  • PlateToPlateLoadResistance

    24000 ohm

    ClassA1;PushPull;TwoPentodeSections

  • PeakSignalVoltageGridToGrid

    15 V

    ClassA1;PushPull;TwoPentodeSections

  • Total Distortion

    5.5 %

    ClassA1;PushPull;TwoPentodeSections

  • Power Output

    0.474 W

    ClassA1;PushPull;TwoPentodeSections

Characteristic

  • Transconductance

    1150 uS

    ClassA1;EachPentode;PlateVoltage=90V

  • Amplification Factor

    390

    ClassA1;EachPentode;PlateVoltage=90V

  • Transconductance

    1425 uS

    ClassA1;EachPentode;PlateVoltage=135V

  • Amplification Factor

    370

    ClassA1;EachPentode;PlateVoltage=135V

Capacitance

  • ControlGridToFilamentCapacitance

    1.5 pF

    Section1

  • ControlGridToFilamentCapacitance

    7.5 pF

    Section2

  • Plate To Filament Capacitance

    12 pF

    Section1

  • Plate To Filament Capacitance

    12 pF

    Section2

  • ControlGridToPlateCapacitance

    0.9 pF

    Section1

  • ControlGridToPlateCapacitance

    0.9 pF

    Section2

  • ControlGridAToControlGridBCapacitance

    0.3 pF

    BetweenSections

  • PlateAToPlateBCapacitance

    2 pF

    BetweenSections

  • ControlGridBToPlateACapacitance

    0.16 pF

    BetweenSections

  • ControlGridAToPlateBCapacitance

    0.16 pF

    BetweenSections