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

6AJ8

Versatile triode-heptode frequency changer for oscillator and mixer service, with additional RF, IF, and low-frequency amplifier applications documented by manufacturers. The triode provides local oscillation while the heptode performs frequency conversion.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
E9-1
Socket code
B9A
Base pins
9
Nominal heater
6.3 V / 300 mA

Description

General-purpose triode-heptode intended for AM, FM and television receiver frequency-converter and oscillator/mixer service.

Socket description

Small-button Noval 9-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
E9-1
Socket code
B9A
Base pins
9
Nominal heater voltage
6.3 V
Nominal heater current
300 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

E9-1 - 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
Plate resistance
19000 Ω
Transconductance
0.0037 S
Amplification factor
22
Max plate voltage
250 V
Max plate dissipation
0.8 W
Max cathode current
6.5 mA

Published ratings and characteristics promoted from the approved German source.

Section 2

Heptode

X-ray radiationInterelectrode capacitances
Plate resistance
700000 Ω
Transconductance
0.0024 S
Max plate voltage
300 V
Max screen voltage
300 V
Max plate dissipation
1.7 W
Max screen dissipation
1 W
Max cathode current
12.5 mA

Published ratings and characteristics promoted from the approved German source.

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

1953 RFT Rundfunk Technik

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • HeaterVoltageNominal

    6.3 V

    Nominal

  • HeaterCurrentNominal

    300 mA

    Nominal

  • Maximum Plate Voltage

    250 V

  • Maximum Plate Dissipation

    1.5 W

  • Maximum Cathode Current

    15 mA

Characteristic

  • Transconductance

    3800 µS

    Typical

  • Amplification Factor

    22

    Typical

  • Plate Resistance

    19000 ohm

    Typical

SECTION 2

Heptode

Other

  • HeaterVoltageNominal

    6.3 V

    Nominal

  • HeaterCurrentNominal

    300 mA

    Nominal

  • Maximum Plate Voltage

    300 V

  • Maximum Screen Voltage

    250 V

  • Maximum Plate Dissipation

    1.5 W

  • Maximum Screen Dissipation

    1 W

  • Maximum Cathode Current

    25 mA

Characteristic

  • Transconductance

    775 µS

    Typical

  • Plate Resistance

    1000000 ohm

    Typical

Data set 02

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 2

Heptode

Other

  • Maximum plate voltage

    300 V

    Published handbook rating

  • Maximum screen voltage

    125 V

    Published handbook rating

  • Plate voltage

    250 V

    ClassA

  • Screen voltage

    102 V

    ClassA

  • Control-grid bias

    2 V

    ClassA

  • Plate current

    6.5 mA

    ClassA

  • Screen current

    3.8 mA

    ClassA

Characteristic

  • Plate resistance

    700000 ohm

    Published handbook characteristic

  • Transconductance

    2400 µS

    Published handbook characteristic

  • Heater voltage

    6.3 V

    Published heater rating

  • Heater current

    300 mA

    Published heater rating

Data set 03

1961 Ferranti Technical Handbook

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

  • HeaterOrFilamentVoltage

    6.3 V

  • HeaterOrFilamentCurrent

    300 mA

SECTION 2

Heptode

Characteristic

  • Application

    Frequency changer RF or IF amplifier

Data set 04

1963 Amperex Condensed

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Typical plate voltage

    250 V

    Section1

  • Typical grid voltage

    0 V

    Section1

  • Typical plate current

    13.5 mA

    Section1

Characteristic

  • Amplification factor

    22

    Section1

  • Plate resistance

    33 kOhm

    Section1

  • Transconductance

    2400 uS

    Section1

SECTION 2

Heptode

Other

  • Typical plate voltage

    250 V

    Section2

  • Typical screen voltage

    100 V

    Section2

  • Typical control-grid voltage

    -2 V

    Section2

  • Typical plate current

    6.5 mA

    Section2

  • Typical screen current

    3.8 mA

    Section2

Characteristic

  • Transconductance

    650 uS

    Section2

Data set 05

1963 Hitachi

Published operating points and test conditions from this source.

SECTION 1

Triode

Capacitance

  • Interelectrode capacitances published

    1

    See source table

Data set 06

1999 Philips 0-D

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

  • Plate voltage

    100 V

  • Plate current

    10 mA

  • Transconductance

    2800 uS

  • Amplification factor

    22

Capacitance

  • Plate-grid capacitance

    1 pF

SECTION 2

Heptode

Characteristics

  • Heater voltage

    6.3 V

  • Heater current

    300 mA

  • Conversion transconductance

    700 uS

  • Plate voltage

    250 V

  • Screen voltage

    100 V

  • Plate current

    3 mA

  • Plate resistance

    1000000 ohm

    Minimum

Capacitance

  • Input capacitance

    4.8 pF