Alternatives & variations Download PDF datasheet

6JL8

Medium-mu triode for voltage amplification or phase inversion combined with a sharp-cutoff pentode for power amplification.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: 9DA
Socket code: B9A
Base pins: 9
Nominal heater: 6.3 V / 450 mA

Description

Miniature dissimilar dual-section tube containing a medium-mu triode for voltage amplification or phase inversion and a sharp-cutoff pentode for power amplification.

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: 9DA
Socket code: B9A
Base pins: 9
Nominal heater voltage: 6.3 V
Nominal heater current: 450 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

9DA - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN12P	B	P — Plate (Anode) Chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 131, 9DA
PIN22G1	B	G1 — Control Grid Chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 131, 9DA
PIN32K	B	K — Cathode Chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 131, 9DA
PIN4H	—	H — Heater Chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 131, 9DA
PIN5H	—	H — Heater Chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 131, 9DA
PIN61P	A	P — Plate (Anode) Chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 131, 9DA
PIN71G2	A	G2 — Screen Grid Chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 131, 9DA
PIN81G1	A	G1 — Control Grid Chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 131, 9DA
PIN91G3	A	G3 — Suppressor GridGroup 9DA9 Chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 131, 9DA
PIN9IS	A	IS — Internal ScreenGroup 9DA9 Chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 131, 9DA
PIN9K	A	K — CathodeGroup 9DA9 Chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 131, 9DA

Section ratings

2 physical sections, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 7500 Ω
Max plate voltage: 150 V

Section 1 extracted from 6JL8.pdf.

Section 2

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 60000 Ω
Max plate voltage: 300 V
Max screen voltage: 150 V

Section 2 extracted from 6JL8.pdf.

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

1938 Raytheon

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

BCComponent + v v v v v s v v b e e s e e e e e e e s
100 V
BCComponent + v v v v v s v v b e e s e e e e e e e s 100 volts g #
Totad DCoond Peak + + « + v« v v v v 0 v o 200
200 V
Totad DCoond Peak + + « + v« v v v v 0 v o 200 200 volts
Plote voftage . . . . . . . . . . . .. 330
330 V
Plote voftage . . . . . . . . . . . .. 330 330 volts . TERMINAL CONNECTIONS
Positive DC grid #1 voltege. . . . . . . 0
0 V
Positive DC grid #1 voltege. . . . . . . 0 0 volts . . . )
Grid 82 dissipation
1.1 W
Grid 82 dissipation . . . . . . . . . . --- 1.1 watts :
Plate resistance {approx.). . . . . . . . . e e 7500
60000 Ω
Plate resistance {approx.). . . . . . . . . e e 7500 60000 ohms
Peak AF grid #1 voltage . . . . .« « . . o . . .. e
3 V
Peak AF grid #1 voltage . . . . .« « . . o . . .. e 3 volts
Moax.—signal platecurrent. . . . . . . . . . L ... o
30 mA
Moax.—signal platecurrent. . . . . . . . . . L ... o 30 ma
Load 1eSistance . = v ¢ « v 4 4 s e v e w4 s . . v e
5000 Ω
Load 1eSistance . = v ¢ « v 4 4 s e v e w4 s . . v e 5000 ohms
Max.~signdl power output. . . .« . . . 4 . e .. en
1.8 W
Max.~signdl power output. . . .« . . . 4 . e .. en 1.8 watts

Capacitance

Input: gl to (htk+g2+g3+int. shield)
11 pF
Input: gl to (htk+g2+g3+int. shield) . . . . . . . . . . .. .. 11.0 pf :
Grid to plate: (gtoph . . . . . . . . ... L
4.4 pF
Grid to plate: (gtoph . . . . . . . . ... L. 4.4 pf :
Triode grid 10 penwdc‘plare
0.018 pF
Triode grid 10 penwdc‘plare .................. 0.018 pf :
Pentode gl to triode plote . . . . . . . . oL L.,
0.005 pF
Pentode gl to triode plote . . . . . . . . oL L., 0.005 pf
Pentode plate to triode plate. . . . . . . . . . L oL L L,
0.17 pF
Pentode plate to triode plate. . . . . . . . . . L oL L L, 0.17 pf .