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

6K8

Octal triode-heptode frequency changer for superheterodyne receivers. The triode supplies local oscillation while the heptode performs mixing, combining both front-end functions within one tube.

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

Description

Triode-hexode frequency converter combining an oscillator section and mixer section in one envelope.

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

Oscillator triode section.

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

1940 RCA

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

  • Heater voltage

    6.3 V

    Published nominal value

  • Heater current

    300 mA

    Published nominal value

SECTION 2

Heptode

Characteristics

  • Heater voltage

    6.3 V

    Published nominal value

  • Heater current

    300 mA

    Published nominal value

Other

  • Application

    Superheterodyne converter

    Triode oscillator plus hexode mixer

Data set 02

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

  • Hexode Plate Current

    2.5 mA

    Converter service

Data set 03

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 04

1960 Mazda

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • TypicalTriodePlateVoltage

    100 V

    TriodeSection

  • TypicalTriodePlateCurrent

    2.8 mA

    TriodeSection

SECTION 2

Heptode

Other

  • TypicalHexodePlateVoltage

    270 V

    HexodeSection

  • TypicalHexodePlateCurrent

    2.5 mA

    HexodeSection

Data set 05

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