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Voltage Pentode or Tetrode (under 100V) ·Diode-Diode-Pentode

6B8G

Receiving tube combining radio signal detection or control-voltage rectification with associated voltage amplification. Its detector function is integral to receiver signal processing and supports classification within the radio detector/converter family.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
3
Base
InternationalOctal
Socket code
IO
Base pins
8
Nominal heater
6.3 V / 300 mA

Description

Duo-diode high-gain pentode combining two diode sections with a pentode amplifier.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
InternationalOctal
Socket code
IO
Base pins
8
Nominal heater voltage
6.3 V
Nominal heater current
300 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

InternationalOctal - Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

3 physical sections, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
600000 Ω
Transconductance
0.001125 S
Amplification factor
285
Max plate voltage
300 V
Max screen voltage
126 V
Max plate dissipation
2.2 W
Max screen dissipation
0.3 W

Remote-cutoff pentode section.

Section 2

Diode

X-ray radiationInterelectrode capacitances
Max plate voltage
10 V
Rectifier nominal output current
1 mA

First diode section.

Section 3

Diode

X-ray radiationInterelectrode capacitances
Max plate voltage
10 V
Rectifier nominal output current
1 mA

Second diode 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

  • lax. Plate Voltage

    250 V

    Published table

Capacitance

  • D_WU4 Grid to Plate

    0.007

    Published table

  • Plate Voltage

    100 V

    Published table; Column1

  • Plate Voltage

    180 V

    Published table; Column2

  • Plate Voltage

    250 V

    Published table; Column3

  • Plate Voltage

    250 V

    Published table; Column4

  • Screen Voltage

    100 V

    Published table; Column1

  • Screen Voltage

    75 V

    Published table; Column2

  • Screen Voltage

    100 V

    Published table; Column3

  • Screen Voltage

    126 V

    Published table; Column4

  • Amplification Factor

    285

    Published table; Column1

  • Amplification Factor

    840

    Published table; Column2

  • Amplification Factor

    800

    Published table; Column3

  • Amplification Factor

    730

    Published table; Column4

  • Plate Resistance

    0.3 ohm

    Published table; Column1

  • Plate Resistance

    1 ohm

    Published table; Column2

  • Plate Resistance

    0.8 ohm

    Published table; Column3

  • Plate Resistance

    0.65 ohm

    Published table; Column4

  • Transconductance

    980

    Published table; Column1

  • Transconductance

    840

    Published table; Column2

  • Transconductance

    1000

    Published table; Column3

  • Transconductance

    1125

    Published table; Column4

  • Plate Current

    5.8 mA

    Published table; Column1

  • Plate Current

    3.4 mA

    Published table; Column2

  • Plate Current

    6 mA

    Published table; Column3

  • Plate Current

    9 mA

    Published table; Column4

  • Screen Current

    1.7 mA

    Published table; Column1

  • Screen Current

    0.9 mA

    Published table; Column2

  • Screen Current

    1.5 mA

    Published table; Column3

  • Screen Current

    2.3 mA

    Published table; Column4

  • Grid Bias

    -17 V

    Published table; Column1

  • Grid Bias

    -13 V

    Published table; Column2

  • Grid Bias

    17 V

    Published table; Column3

  • Grid Bias

    21 V

    Published table; Column4

  • Plate Supply Voltage

    250 V

    Published table; Column1

  • Plate Supply Voltage

    250 V

    Published table; Column2

  • Plate Supply Voltage

    250 V

    Published table; Column3

  • Screen Voltage

    45 V

    Published table; Column1

  • Screen Voltage

    50 V

    Published table; Column2

  • Grid Bias

    -5 V

    Published table; Column1

  • Grid Bias

    4.5 V

    Published table; Column2

  • Grid Bias

    3 V

    Published table; Column3

  • Plate Resistor

    0.5 ohm

    Published table; Column1

  • Plate Resistor

    0.25 ohm

    Published table; Column2

  • Plate Resistor

    0.027 ohm

    Published table; Column3

  • Plate Current

    0.25 mA

    Published table; Column1

  • Plate Current

    0.65 mA

    Published table; Column2

  • Plate Current

    5.4 mA

    Published table; Column3

Data set 02

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • Heater Voltage AC or DC 6.5 Volts

    6.5 V

    Heater Voltage AC or DC 6.5 Volts

  • Heater Current 0.3 Ampere

    300 mA

    Heater Current 0.3 Ampere

  • With an applied d-c plate voltage of 10 volts the space

    10 V

    With an applied d-c plate voltage of 10 volts the space

  • Heater Voltage 6.3 6.3 6.3 6.3 Volts (soTTOM VIEW)

    6.3 V

    Heater Voltage 6.3 6.3 6.3 6.3 Volts (soTTOM VIEW)

  • Grid Voltage -3 -3 -3 -3 Volts

    -3 V

    Grid Voltage -3 -3 -3 -3 Volts

  • Plate Current 5.8 3.4 6.0 9.0 Ma.

    9 mA

    Plate Current 5.8 3.4 6.0 9.0 Ma.

  • Screen Current 1.7 0.9 1.5 2.3 Ma.

    2.3 mA

    Screen Current 1.7 0.9 1.5 2.3 Ma.

  • Grid Bias Voltage** -17 -13 -17 -21 Volts

    -21 V

    Grid Bias Voltage** -17 -13 -17 -21 Volts

Data set 03

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Plate voltage

    250 V

    ClassA

  • Screen-grid voltage

    125 V

    ClassA

  • Grid voltage

    -3 V

    ClassA

  • Plate current

    10 mA

    ClassA

  • Screen-grid current

    2.3 mA

    ClassA

Data set 04

1961 Ferranti Technical Handbook

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Plate voltage

    250 V

    ClassA

  • Screen-grid voltage

    125 V

    ClassA

  • Control-grid voltage

    -3 V

    ClassA

  • Plate current

    2 mA

    ClassA

  • Screen-grid current

    2.3 mA

    ClassA

Characteristics

  • Transconductance

    1120 uS

    ClassA

  • Plate resistance

    600000 Ohm

    ClassA

  • Control-grid cutoff voltage

    -21 V

    ClassA

Capacitance

  • Input capacitance

    3.6 pF

    PentodeSection

  • Output capacitance

    9.5 pF

    PentodeSection

  • Grid-to-plate capacitance maximum

    0.01 pF

    PentodeSection

SECTION 2

Diode

Other

  • Diode current maximum

    1 mA

    Diode1

SECTION 3

Diode

Other

  • Diode current maximum

    1 mA

    Diode2

Data set 05

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Heater voltage

    6.3 V

  • Heater current

    300 mA

  • Plate current

    5.8 mA

    Typical operating conditions

SECTION 2

Diode

Other

  • Heater voltage

    6.3 V

  • Heater current

    300 mA

SECTION 3

Diode

Other

  • Heater voltage

    6.3 V

  • Heater current

    300 mA