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

6Q7

Double-diode high-mu triode for detector, AVC, and audio voltage-amplifier service. Paired diodes provide signal and control rectification while the triode supplies substantial first-audio voltage gain.

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

Description

High-mu double-diode triode combining detector/AVC diodes with a triode amplifier section.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
8
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

8 - 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

No fixed ratings are recorded for this section.

Published ratings and characteristics promoted where clearly stated; identical repeated diode/triode sections compressed where applicable.

Section 2

Diode

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Published source values promoted where applicable.

Section 3

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
68000 Ω
Transconductance
0.0012 S
Amplification factor
70
Max plate voltage
250 V

Published ratings and characteristics promoted where clearly stated; identical repeated diode/triode 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

1937 Raytheon Radio Receiving Tubes

Published operating points and test conditions from this source.

SECTION 3

Triode

Capacitance

  • Grid-to-plate capacitance

    1.5 pF

    Section1

  • Input capacitance

    5.5 pF

    Section1

  • Output capacitance

    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

1940 RCA

Published operating points and test conditions from this source.

SECTION 1

Diode

Characteristics

  • Heater voltage

    6.3 V

    Published nominal value

  • Heater current

    300 mA

    Published nominal value

Capacitance

  • Grid-to-plate capacitance

    1.5 pF

    Triode unit

  • Grid-to-cathode capacitance

    5.5 pF

    Triode unit

  • Plate-to-cathode capacitance

    5 pF

    Triode unit

SECTION 3

Triode

Characteristics

  • Heater voltage

    6.3 V

    Published nominal value

  • Heater current

    300 mA

    Published nominal value

  • Transconductance

    1200 µS

    Published operating characteristic

  • Amplification factor

    70

    Published operating characteristic

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

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Diode

Other

  • Heater voltage

    6.3 V

  • Heater current

    300 mA

  • Plate voltage

    300 V

    Typical operating conditions

  • Plate current

    0.81.0 mA

    Typical operating conditions

SECTION 2

Diode

Other

  • Heater voltage

    6.3 V

  • Heater current

    300 mA

  • Plate voltage

    300 V

    Typical operating conditions

  • Plate current

    0.81.0 mA

    Typical operating conditions

SECTION 3

Triode

Other

  • Heater voltage

    6.3 V

  • Heater current

    300 mA

  • Plate voltage

    300 V

    Typical operating conditions

  • Plate current

    0.81.0 mA

    Typical operating conditions