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

6Q7G

Glass-envelope double-diode high-mu triode for detector, AVC, and low-frequency voltage amplification. Paired diodes provide signal and control rectification while the triode supplies substantial subsequent gain.

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

Description

High-mu double-diode triode for detector and Class A voltage-amplifier service.

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

Diode

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

Promoted values and additional parameters were taken from the supplied Ferranti datasheet tables.

Section 2

Diode

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

Promoted values and additional parameters were taken from the supplied Ferranti datasheet tables.

Section 3

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
58000 Ω
Transconductance
0.0012 S
Amplification factor
70
Max plate voltage
300 V

Promoted values and additional parameters were taken from the supplied Ferranti datasheet tables.

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 3

Triode

Capacitance

  • Grid-to-plate capacitance

    1.3 pF

    Section1

  • Input capacitance

    2.7 pF

    Section1

  • Output capacitance

    4.5 pF

    Section1

Other

  • Plate voltage

    100 V

    ClassA

  • Grid bias

    -1.5 V

    ClassA

  • Plate current

    0.35 mA

    ClassA

  • Plate voltage

    250 V

    ClassA

  • Grid bias

    -3 V

    ClassA

  • Plate current

    1.1 mA

    ClassA

Characteristic

  • Plate resistance

    87500 Ω

    100VPlate

  • Transconductance

    800 µS

    100VPlate

  • Amplification factor

    70

    Section1

  • Plate resistance

    58000 Ω

    250VPlate

  • Transconductance

    1200 µS

    250VPlate

Data set 02

1948 Brimar Radio Valve Manual

Published operating points and test conditions from this source.

SECTION 1

Diode

Characteristic

  • Heater Voltage

    6.3 V

  • Heater Current

    300 mA

SECTION 3

Triode

Characteristic

  • Amplification Factor

    70

Data set 03

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 3

Triode

Other

  • Typical plate current

    1.1 mA

    ClassA

Data set 04

1958 Brimar Radio Valve No 7

Published operating points and test conditions from this source.

SECTION 1

Diode

Application

  • Application

    Signal detection

SECTION 3

Triode

Application

  • Application

    Audio-frequency amplification

Data set 05

1961 Ferranti Technical Handbook

Published operating points and test conditions from this source.

SECTION 1

Diode

Other

  • Diode plate voltage maximum

    200 V

    Diode1

  • Diode current maximum

    10 mA

    Diode1

SECTION 2

Diode

Other

  • Diode plate voltage maximum

    200 V

    Diode2

  • Diode current maximum

    10 mA

    Diode2

SECTION 3

Triode

Other

  • Plate voltage

    100 V

    ClassA

  • Control-grid voltage

    -1 V

    ClassA

  • Plate current

    0.8 mA

    ClassA

  • Plate voltage

    250 V

    ClassA

  • Control-grid voltage

    -3 V

    ClassA

  • Plate current

    1 mA

    ClassA

  • Peak output voltage

    49 V

    ResistanceCoupledAmplifier;Va=250V

  • Stage gain

    56 ratio

    ResistanceCoupledAmplifier;Va=250V

Characteristics

  • Transconductance

    1200 uS

    ClassA

  • Plate resistance

    58000 Ohm

    ClassA

  • Amplification factor

    70 ratio

    ClassA

Capacitance

  • Input capacitance

    2 pF

    6Q7G

  • Input capacitance

    1.8 pF

    6Q7GT

  • Output capacitance

    4 pF

    6Q7G

  • Output capacitance

    3.4 pF

    6Q7GT