Alternatives & variations Download PDF datasheet

Voltage Radio Detector Converter ·Pentode-Triode

6LJ8

Combined triode-pentode for oscillator, mixer, frequency-converter, RF, or IF service in television, communications, or mobile receivers.

Directly heatedCold cathodeCommon cathodeDissimilar

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

Description

Medium-mu triode and sharp-cutoff pentode used as a combined oscillator and mixer in VHF television receivers.

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: 9GF
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

9GF - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN1Base Pin	B	G1 — Control Grid Literal label 2G1; manufacturer confirmation pending	Unverified EIA Base Connections printed p132, 9GF
PIN2Base Pin	B	P — Plate (Anode) Literal label 2P; manufacturer confirmation pending	Unverified EIA Base Connections printed p132, 9GF
PIN3Base Pin	A	G3 — Suppressor GridGroup 9GF3 Literal label 1G3; manufacturer confirmation pending	Unverified EIA Base Connections printed p132, 9GF
PIN3Base Pin	—	K — CathodeGroup 9GF3 Literal label K; manufacturer confirmation pending	Unverified EIA Base Connections printed p132, 9GF
PIN4Base Pin	—	H — Heater Literal label H; manufacturer confirmation pending	Unverified EIA Base Connections printed p132, 9GF
PIN5Base Pin	—	H — Heater Literal label H; manufacturer confirmation pending	Unverified EIA Base Connections printed p132, 9GF
PIN6Base Pin	A	P — Plate (Anode) Literal label 1P; manufacturer confirmation pending	Unverified EIA Base Connections printed p132, 9GF
PIN7Base Pin	A	G2 — Screen Grid Literal label 1G2; manufacturer confirmation pending	Unverified EIA Base Connections printed p132, 9GF
PIN8Base Pin	A	G3 — Suppressor GridGroup 9GF8 Literal label 1G3; manufacturer confirmation pending	Unverified EIA Base Connections printed p132, 9GF
PIN8Base Pin	—	K — CathodeGroup 9GF8 Literal label K; manufacturer confirmation pending	Unverified EIA Base Connections printed p132, 9GF
PIN9Base Pin	A	G1 — Control Grid Literal label 1G1; manufacturer confirmation pending	Unverified EIA Base Connections printed p132, 9GF

Section ratings

2 physical sections, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 125000 Ω
Transconductance: 0.013 S
Max plate voltage: 280 V
Max screen voltage: 280 V
Max plate dissipation: 2 W
Max screen dissipation: 0.5 W
Max cathode current: 20 mA

Published ratings/characteristics promoted from supplied source; additional conditions retained in parameter table.

Section 2

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 5000 Ω
Transconductance: 0.008 S
Amplification factor: 40
Max plate voltage: 280 V
Max plate dissipation: 2 W
Max cathode current: 20 mA

Published ratings/characteristics promoted from supplied source; additional conditions retained in parameter table.

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

1964 RMA EIA

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

Plate Voltage
125 V
Screen Voltage
-
Grid Voltage
0 V
Plate Current
-
Screen Current
3.5 mA
Plate Resistance
125000 ohm
Transconductance
13000 uS
Grid To Plate Capacitance
0.02 pF
Input Capacitance
6 pF
Output Capacitance
3.5 pF
Application
VHF mixer

SECTION 2

Triode

Characteristic

Heater Voltage
6.3 V
Heater Current
400 mA
Plate Voltage
125 V
Grid Voltage
0 V
Plate Current
-
Amplification Factor
40
Plate Resistance
5000 ohm
Transconductance
8000 uS
Grid To Plate Capacitance
2 pF
Input Capacitance
3.5 pF
Output Capacitance
2 pF
Application
VHF oscillator

Data set 02

1968 General Electric Co

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Maximum Plate Voltage
280 V
Maximum Screen Voltage
280 V
Maximum Plate Dissipation
2 W
Maximum Screen Dissipation
0.5 W
Maximum Cathode Current
20 mA

Characteristic

Plate Resistance
125000 ohm
Transconductance
13000 uS
Interelectrode Capacitances Published
true

SECTION 2

Triode

Other

Maximum Plate Voltage
280 V
Maximum Plate Dissipation
2 W
Maximum Cathode Current
20 mA

Characteristic

Plate Resistance
5000 ohm
Transconductance
8000 uS
Amplification Factor
40
Interelectrode Capacitances Published
true

Data set 03

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Plate Voltage
125 V
ClassA
Screen Voltage
125 V
ClassA
Cathode-Bias Resistor
33 ohm
ClassA
Plate Current
12 mA
ClassA
Screen Current
3.5 mA
ClassA
Control Grid Cutoff Approximation
-4 V
ClassA

SECTION 2

Triode

Other

Heater Voltage
6.3 V
Nominal
Heater Current
400 mA
Nominal
Plate Voltage
125 V
ClassA
Cathode-Bias Resistor
68 ohm
ClassA
Plate Current
13 mA
ClassA
Control Grid Cutoff Approximation
-6.5 V
ClassA
Peak Heater-Cathode Voltage
200 V
Average Heater-Cathode Voltage
100 V