8JK8

Dissimilar dual triode for FM tuners, combining a frame-grid RF amplifier section with an oscillator/mixer section to perform tuner amplification and frequency conversion.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: -
Base pins: -
Nominal heater: 8.4 V / 300 mA

Description

8JK8 is an explicitly covered designation on the 6JK8 source sheet. Dissimilar dual triode for FM tuners, combining a frame-grid RF amplifier with an oscillator/mixer section.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: -
Base pins: -
Nominal heater voltage: 8.4 V
Nominal heater current: 300 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

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: 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