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Voltage Radio Detector Converter ·Heptode

6A8

Metal-envelope pentagrid oscillator-converter for superheterodyne radio receivers. It combines local oscillation and mixing within one multi-grid tube, providing established frequency-changing performance for mains-powered receiving equipment.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
8A
Socket code
IO
Base pins
8
Nominal heater
6.3 V / 300 mA

Description

Sylvania 6A8 is a pentagrid frequency converter for superheterodyne receiver service, combining oscillator and mixer action.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
8A
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

8A - Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

1 physical section, each with unique specifications.

Section 1

Heptode

X-ray radiationInterelectrode capacitances
Plate resistance
360000 Ω
Transconductance
0.00055 S
Max plate voltage
300 V
Max screen voltage
100 V
Max plate dissipation
1 W
Max cathode current
14 mA

Published promoted fields populated from the datasheet; identical repeated sections compressed where applicable.

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

1935 RCA All Metal Radio Tubes

Published operating points and test conditions from this source.

SECTION 1

Heptode

Other

  • Plate voltage

    250 V

    AsFrequencyConverter

  • Screen voltage

    100 V

    AsFrequencyConverter

  • Anode-grid voltage

    200 V

    AsFrequencyConverter

  • Anode-grid supply voltage

    250 V

    AsFrequencyConverter

  • Total cathode current

    14 mA

    AsFrequencyConverter

  • Plate current

    3.3 mA

    Plate250V;Screen100V

  • Screen current

    3.2 mA

    Plate250V;Screen100V

  • Anode-grid current

    4 mA

    Plate250V;Screen100V

  • Oscillator grid current

    0.5 mA

    Plate250V;Screen100V

Characteristic

  • Conversion conductance

    500 uS

    Plate250V;Screen100V

Data set 02

1937 Raytheon Radio Receiving Tubes

Published operating points and test conditions from this source.

SECTION 1

Heptode

Other

  • Plate voltage

    100 V

    Converter

  • Screen voltage

    50 V

    Converter

  • Plate voltage

    250 V

    Converter

  • Screen voltage

    100 V

    Converter

  • Oscillator-grid resistor

    50000 Ω

    Converter

Characteristic

  • Conversion transconductance

    360 µS

    Converter

  • Plate resistance

    300000 Ω

    Converter

  • Conversion transconductance

    550 µS

    Converter

Data set 03

1940 RCA

Published operating points and test conditions from this source.

SECTION 1

Heptode

Other

  • HeaterVoltageNominal

    6.3 V

    Nominal

  • HeaterCurrentNominal

    300 mA

    Nominal

  • Maximum Plate Voltage

    250 V

  • Maximum Screen Voltage

    100 V

  • Maximum Cathode Current

    18 mA

Characteristic

  • Transconductance

    520 µS

    Typical

  • Plate Resistance

    600000 ohm

    Typical

Data set 04

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 1

Heptode

Characteristic

  • Transconductance

    550 µS

  • Conversion Transconductance

    550 µS

Other

  • Maximum Plate Voltage

    300 V

Data set 05

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Heptode

Other

  • Maximum plate voltage

    300 V

    Published handbook rating

  • Maximum screen voltage

    100 V

    Published handbook rating

  • Plate voltage

    250 V

    ClassA

  • Screen voltage

    100 V

    ClassA

  • Control-grid bias

    3 V

    ClassA

  • Plate current

    3.5 mA

    ClassA

  • Screen current

    2.7 mA

    ClassA

Characteristic

  • Plate resistance

    360000 ohm

    Published handbook characteristic

  • Transconductance

    550 µS

    Published handbook characteristic

  • Heater/filament voltage

    6.3 V

    Published heater/filament rating

  • Heater/filament current

    300 mA

    Published heater/filament rating

Data set 06

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Heptode

Characteristic

  • Conversion Transconductance

    550 uS

    Typical

Other

  • Screen Voltage

    100 V

    Typical