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Voltage - Dual Triode (dissimilar) ·Triode-Triode

6JK8

Dissimilar twin triode for FM tuner service, combining a frame-grid RF amplifier section with a second triode used for oscillator-mixer frequency conversion.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: 9AD
Socket code: B9A
Base pins: 9
Nominal heater: 6.3 V / 400 mA

Description

The 6JK8 is a dissimilar dual triode specifically designed for FM tuners, with separate oscillator and RF-amplifier sections.

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: 9AD
Socket code: B9A
Base pins: 9
Nominal heater voltage: 6.3 V
Nominal heater current: 400 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

9AD - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN1G1	A	G1 — Control Grid Chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9AD
PIN3K	A	K — Cathode Source transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9AD
PIN4H	—	H — Heater Chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9AD
PIN5H	—	H — Heater Chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9AD
PIN7G2	A	G2 — Screen Grid Chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9AD
PIN8P	A	P — Plate (Anode) Chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9AD
PIN9G3	A	G3 — Suppressor Grid Chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9AD

Section ratings

2 physical sections, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 8000 Ω
Transconductance: 0.0068 S
Amplification factor: 55
Max plate voltage: 165 V
Max plate dissipation: 1 W
Max cathode current: 22 mA

Published maximum ratings and characteristics promoted semantically from the approved source.

Section 2

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 5400 Ω
Transconductance: 0.013 S
Amplification factor: 70
Max plate voltage: 200 V
Max plate dissipation: 2 W
Max cathode current: 22 mA

Published maximum ratings and characteristics promoted semantically from the approved 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

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

Plate Resistance
8000 ohm
Transconductance
6800 µS
Amplification Factor
55

Other

Maximum Plate Voltage
165 V
Maximum Plate Dissipation
1 W
Maximum Cathode Current
22 mA
Plate Voltage
100 V
Oscillator section

SECTION 2

Triode

Characteristic

Plate Resistance
5400 ohm
Transconductance
13000 µS
Amplification Factor
70

Other

Maximum Plate Voltage
200 V
Maximum Plate Dissipation
2 W
Maximum Cathode Current
22 mA
Plate Voltage
135 V
RF amplifier section
Plate Current
10 mA
RF amplifier section

Data set 02

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Plate Voltage
100 V
Section1

Characteristic

Plate Current
5.3 mA
Section1

SECTION 2

Triode

Other

Plate Voltage
135 V
Section2

Characteristic

Plate Current
10 mA
Section2

Data set 03

1965 Westinghouse Data Book

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

Heater Voltage
6.3 V
Heater Current
400 mA
Grid-Plate Capacitance
1.4 pF
Input Capacitance
3 pF
Output Capacitance
1 pF
Plate Resistance
8000 ohm
Transconductance
6800 uS
Amplification Factor
55 ratio

Other

Plate Voltage
100 V
OscillatorMixer
Grid Voltage
-1 V
OscillatorMixer
Plate Current
5.3 mA
OscillatorMixer

SECTION 2

Triode

Characteristics

Grid-Plate Capacitance
0.05 pF
Input Capacitance
5 pF
Output Capacitance
4 pF
Plate Resistance
5400 ohm
Transconductance
13000 uS
Amplification Factor
70 ratio

Other

Plate Voltage
135 V
RFAmplifier
Grid Voltage
-1.2 V
RFAmplifier
Plate Current
10 mA
RFAmplifier

Data set 04

1966 Tung Sol Electronic Tubes 2 of 4

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Plate voltage
100 V
OscillatorSection
Grid voltage
-1 V
OscillatorSection
Plate current
5.3 mA
OscillatorSection

SECTION 2

Triode

Other

Plate voltage
135 V
RFAmplifierSection
Grid voltage
-1.2 V
RFAmplifierSection
Plate current
10 mA
RFAmplifierSection