Skip to main content
Tube Tinker — Electron Tube Database
Alternatives & variationsDownload PDF datasheet

Voltage - Triode (with diode, heptode or hexode) ·Heptode-Triode

6K8G

Glass-envelope triode-heptode converter combining local-oscillator and mixer functions for superheterodyne receivers. The triode supplies oscillation while the heptode provides frequency conversion and useful output isolation.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
8KV
Socket code
IO
Base pins
8
Nominal heater
6.3 V / 300 mA

Description

Glass version of the triode-hexode oscillator/mixer frequency converter.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
8KV
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

8KV - 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
Transconductance
0.003 S
Max plate voltage
125 V
Max plate dissipation
0.75 W

Promoted from printed maximum-rating/characteristic columns; additional published operating points and capacitances retained as parameters.

Section 2

Heptode

X-ray radiationInterelectrode capacitances
Plate resistance
600000 Ω
Transconductance
0.00035 S
Max plate voltage
300 V
Max screen voltage
150 V
Max plate dissipation
0.75 W
Max screen dissipation
0.7 W
Max cathode current
16 mA

Hexode mixer has no canonical SectionType; mapped to Other.

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 Raytheon

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • (For Conversion Transconduotance

    2 µS

    (For Conversion Transconduotance 2 umhos)

  • proximately 300C umhoa ohen the triode olate voltage is

    100 V

    proximately 300C umhoa ohen the triode olate voltage is 100 volts and the

SECTION 2

Heptode

Other

  • Hexode Socreen Current 6.2

    6 mA

    Hexode Socreen Current 6.2 6.0 ma

Data set 02

1948 Brimar Radio Valve Manual

Published operating points and test conditions from this source.

SECTION 1

Triode

Application

  • Service

    Oscillator

SECTION 2

Heptode

Application

  • Service

    Frequency changer/mixer

Data set 03

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Maximum Plate Voltage

    125 V

  • Maximum Plate Dissipation

    0.75 W

  • Oscillator Plate Current

    3.8 mA

    Triode oscillator

SECTION 2

Heptode

Characteristic

  • Plate Resistance

    600000 ohm

  • Conversion Conductance

    350 µS

    250 V hexode plate

Other

  • Maximum Plate Voltage

    300 V

  • Maximum Screen Voltage

    150 V

  • Maximum Plate Dissipation

    0.75 W

  • Maximum Screen Dissipation

    0.7 W

  • Maximum Cathode Current

    16 mA

Data set 04

1958 Brimar Radio Valve No 7

Published operating points and test conditions from this source.

SECTION 1

Triode

Application

  • Application

    Oscillator

SECTION 2

Heptode

Application

  • Application

    Frequency changer / mixer

Data set 05

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Oscillator-grid current

    0.15 mA

    Converter

  • Oscillator-grid resistor

    50000 Ω

    Converter

  • Oscillator-triode plate current

    3.8 mA

    Converter

SECTION 2

Heptode

Other

  • Plate voltage

    250 V

    Converter

  • Screen voltage

    100 V

    Converter

  • Control-grid voltage

    -3 V

    Converter

  • Plate current

    2.5 mA

    Converter

  • Screen current

    6 mA

    Converter

Characteristic

  • Plate resistance

    600000 Ω

    Converter

  • Conversion transconductance

    350 µS

    Converter

Data set 06

1961 Ferranti Technical Handbook

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Triode plate voltage

    100 V

    Oscillator

  • Triode plate current

    3.8 mA

    Oscillator

  • Oscillator grid current

    0.1 mA

    Point1

  • Oscillator grid current

    0.15 mA

    Point2

Capacitance

  • Triode input capacitance

    6.5 pF

  • Triode output capacitance

    3.4 pF

SECTION 2

Heptode

Other

  • Hexode plate voltage

    100 V

    Point1

  • Hexode screen-grid voltage

    100 V

    Point1

  • Hexode control-grid voltage

    -3 V

    Point1

  • Hexode plate current

    2.3 mA

    Point1

  • Hexode screen-grid current

    6.2 mA

    Point1

  • Hexode plate voltage

    250 V

    Point2

Characteristics

  • Hexode plate resistance

    400000 Ohm

    Point1

  • Conversion conductance

    330 uS

    Point1

  • Hexode plate resistance

    600000 Ohm

    Point2

  • Conversion conductance

    360 uS

    Point2

Capacitance

  • Hexode input capacitance

    4.6 pF

  • Hexode output capacitance

    4.8 pF

Data set 07

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • OscillatorAnodeVoltage

    100 V

    ConverterService

Characteristic

  • OscillatorAnodeCurrent

    3.8 mA

    ConverterService

SECTION 2

Heptode

Other

  • HexodePlateVoltage

    250 V

    ConverterService

  • HexodeScreenVoltage

    100 V

    ConverterService

Characteristic

  • HexodePlateCurrent

    2.5 mA

    ConverterService

  • HexodeScreenCurrent

    6 mA

    ConverterService

  • Conversion Transconductance

    350 uS

    ConverterService