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Voltage Radio Detector Converter ·Pentode-Triode

4LJ8

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

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
-
Socket code
B9A
Base pins
9
Nominal heater
4.3 V / 600 mA

Description

Medium-mu triode plus 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
-
Socket code
B9A
Base pins
9
Nominal heater voltage
4.3 V
Nominal heater current
600 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
5000 Ω
Transconductance
0.008 S
Amplification factor
40
Max plate voltage
280 V
Max plate dissipation
2 W
Max cathode current
20 mA

Promoted from published maximum-ratings/characteristics tables; additional source values are retained in TUBE_SECTION_PARAMETER.

Section 2

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 cathode current
20 mA

Promoted from published maximum-ratings/characteristics tables; additional source values are retained in TUBE_SECTION_PARAMETER.

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

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Heater Voltage (ac/dc) 4.3 5.6

    6.3 V

    Published in approved 4LJ8 target entry; Section1

  • Heater Current 0.6 0.45

    400 mA

    Published in approved 4LJ8 target entry; Section1

  • Plate Voltage 280

    280 V

    Published in approved 4LJ8 target entry; Section1

  • Cathode Current 20

    20 mA

    Published in approved 4LJ8 target entry; Section1

  • Grid-No.l (Control-Grid) Voltage, Positive-bias value 0

    0 V

    Published in approved 4LJ8 target entry; Section1

  • Plate Dissipation 2

    2 W

    Published in approved 4LJ8 target entry; Section1

  • For grid-No.2 voltages up to

    140 V

    Published in approved 4LJ8 target entry; Section1

  • For grid-No.2 voltages between 140 and

    280 V

    Published in approved 4LJ8 target entry; Section1

  • For fixed-bias operation 1

    0.5 MΩ

    Published in approved 4LJ8 target entry; Section1

  • For cathode-bias operation 0.5

    0.25 MΩ

    Published in approved 4LJ8 target entry; Section1

  • Heater Voltage (ac/dc)

    6.3 V

    Published in approved 4LJ8 target entry; Section1

  • Heater Current

    450 mA

    Published in approved 4LJ8 target entry; Section1

  • Heater to Cathode (Each Unit)

    3.2 pF

    Published in approved 4LJ8 target entry; Section1

  • Plate Voltage 330

    350 V

    Published in approved 4LJ8 target entry; Section1

  • Grid-No.2 (Screen-Grid) Supply Voltage

    330 V

    Published in approved 4LJ8 target entry; Section1

  • Plate Dissipation 2.5

    2.5 V

    Published in approved 4LJ8 target entry; Section1

  • For grid-No. 2 voltages up to

    165 V

    Published in approved 4LJ8 target entry; Section1

  • For grid-No.2 voltages between 165 and

    330 V

    Published in approved 4LJ8 target entry; Section1

  • Plate Voltage 125

    125 V

    Published in approved 4LJ8 target entry; Section1

  • Grid-No.2 Voltage

    125 V

    Published in approved 4LJ8 target entry; Section1

  • Grid No.l Voltage —1

    -2 V

    Published in approved 4LJ8 target entry; Section1

  • 0.5

    0.25 MΩ

    Published in approved 4LJ8 target entry; Section1

  • 1

    0.5 MΩ

    Published in approved 4LJ8 target entry; Section1

Characteristic

  • Plate Voltage 125

    125 V

    Published in approved 4LJ8 target entry; Section1

  • Grid-No.2 Voltage

    125 V

    Published in approved 4LJ8 target entry; Section1

  • Plate Resistance (Approx.) 5000

    125000 Ω

    Published in approved 4LJ8 target entry; Section1

  • Transconductance 8000

    13000 µS

    Published in approved 4LJ8 target entry; Section1

  • Plate Current 13

    12 mA

    Published in approved 4LJ8 target entry; Section1

  • Grid-No.2 Current

    3.5 mA

    Published in approved 4LJ8 target entry; Section1

  • 30 nX —6.5

    -4 V

    Published in approved 4LJ8 target entry; Section1

  • 5400

    150000 Ω

    Published in approved 4LJ8 target entry; Section1

  • 8500

    6000 µS

    Published in approved 4LJ8 target entry; Section1

  • 13.5

    12 mA

    Published in approved 4LJ8 target entry; Section1

  • 10 iiA —8

    -14 V

    Published in approved 4LJ8 target entry; Section1

Capacitance

  • Grid to Plate

    1.8 pF

    Published in approved 4LJ8 target entry; Section1

  • and Internal Shield

    3.2 pF

    Published in approved 4LJ8 target entry; Section1

  • Internal Shield

    5.5 pF

    Published in approved 4LJ8 target entry; Section1

  • Shield

    3.8 pF

    Published in approved 4LJ8 target entry; Section1

SECTION 2

Pentode

Other

  • Heater Voltage (ac/dc) 4.3 5.6

    6.3 V

    Published in approved 4LJ8 target entry; Section2

  • Heater Current 0.6 0.45

    400 mA

    Published in approved 4LJ8 target entry; Section2

  • Plate Voltage 280

    280 V

    Published in approved 4LJ8 target entry; Section2

  • Cathode Current 20

    20 mA

    Published in approved 4LJ8 target entry; Section2

  • Grid-No.l (Control-Grid) Voltage, Positive-bias value 0

    0 V

    Published in approved 4LJ8 target entry; Section2

  • Plate Dissipation 2

    2 W

    Published in approved 4LJ8 target entry; Section2

  • For grid-No.2 voltages up to

    140 V

    Published in approved 4LJ8 target entry; Section2

  • For grid-No.2 voltages between 140 and

    280 V

    Published in approved 4LJ8 target entry; Section2

  • For fixed-bias operation 1

    0.5 MΩ

    Published in approved 4LJ8 target entry; Section2

  • For cathode-bias operation 0.5

    0.25 MΩ

    Published in approved 4LJ8 target entry; Section2

  • Heater Voltage (ac/dc)

    6.3 V

    Published in approved 4LJ8 target entry; Section2

  • Heater Current

    450 mA

    Published in approved 4LJ8 target entry; Section2

  • Heater to Cathode (Each Unit)

    3.2 pF

    Published in approved 4LJ8 target entry; Section2

  • Plate Voltage 330

    350 V

    Published in approved 4LJ8 target entry; Section2

  • Grid-No.2 (Screen-Grid) Supply Voltage

    330 V

    Published in approved 4LJ8 target entry; Section2

  • Plate Dissipation 2.5

    2.5 V

    Published in approved 4LJ8 target entry; Section2

  • For grid-No. 2 voltages up to

    165 V

    Published in approved 4LJ8 target entry; Section2

  • For grid-No.2 voltages between 165 and

    330 V

    Published in approved 4LJ8 target entry; Section2

  • Plate Voltage 125

    125 V

    Published in approved 4LJ8 target entry; Section2

  • Grid-No.2 Voltage

    125 V

    Published in approved 4LJ8 target entry; Section2

  • Grid No.l Voltage —1

    -2 V

    Published in approved 4LJ8 target entry; Section2

  • 0.5

    0.25 MΩ

    Published in approved 4LJ8 target entry; Section2

  • 1

    0.5 MΩ

    Published in approved 4LJ8 target entry; Section2

Characteristic

  • Plate Voltage 125

    125 V

    Published in approved 4LJ8 target entry; Section2

  • Grid-No.2 Voltage

    125 V

    Published in approved 4LJ8 target entry; Section2

  • Plate Resistance (Approx.) 5000

    125000 Ω

    Published in approved 4LJ8 target entry; Section2

  • Transconductance 8000

    13000 µS

    Published in approved 4LJ8 target entry; Section2

  • Plate Current 13

    12 mA

    Published in approved 4LJ8 target entry; Section2

  • Grid-No.2 Current

    3.5 mA

    Published in approved 4LJ8 target entry; Section2

  • 30 nX —6.5

    -4 V

    Published in approved 4LJ8 target entry; Section2

  • 5400

    150000 Ω

    Published in approved 4LJ8 target entry; Section2

  • 8500

    6000 µS

    Published in approved 4LJ8 target entry; Section2

  • 13.5

    12 mA

    Published in approved 4LJ8 target entry; Section2

  • 10 iiA —8

    -14 V

    Published in approved 4LJ8 target entry; Section2

Capacitance

  • Grid to Plate

    1.8 pF

    Published in approved 4LJ8 target entry; Section2

  • and Internal Shield

    3.2 pF

    Published in approved 4LJ8 target entry; Section2

  • Internal Shield

    5.5 pF

    Published in approved 4LJ8 target entry; Section2

  • Shield

    3.8 pF

    Published in approved 4LJ8 target entry; Section2