Voltage Triode Tetrode ·Tetrode-Triode
High-mu triode and multi-grid section for television synchronization functions and video amplification.
The 6JA8 combines a high-mu triode for sync separation, clipping and phase inversion with a pentode designed for television video-amplifier service.
Small-button Noval 9-contact
General specifications
Properties common to every published source and operating point.
Electrical assignments shared by every tube using this base designation.
| Terminal | Section | Connection | Evidence |
|---|---|---|---|
| PIN12K | B | K — Cathode EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 131, 9DX |
| PIN22G1 | B | G1 — Control Grid EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 131, 9DX |
| PIN32P | B | P — Plate (Anode) EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 131, 9DX |
| PIN4H | — | H — Heater EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 131, 9DX |
| PIN5H | — | H — Heater EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 131, 9DX |
| PIN61G3 | A | G3 — Suppressor GridGroup 9DX6 EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 131, 9DX |
| PIN6IS | A | IS — Internal ScreenGroup 9DX6 EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 131, 9DX |
| PIN61K | A | K — CathodeGroup 9DX6 EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 131, 9DX |
| PIN71G1 | A | G1 — Control Grid EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 131, 9DX |
| PIN81G2 | A | G2 — Screen Grid EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 131, 9DX |
| PIN91P | A | P — Plate (Anode) EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 131, 9DX |
2 physical sections, each with unique specifications.
Section 1
High-mu triode section.
Section 2
Video-amplifier tetrode section.
Source-dependent data
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.
Data set 01
Published operating points and test conditions from this source.
Plate Voltage
200 V
Triode typical operation
Plate Current
3.5 mA
Triode typical operation
Plate Voltage
200 V
Pentode typical operation
Screen Voltage
135 V
Pentode typical operation
Plate Current
18 mA
Pentode typical operation
Screen Current
4 mA
Pentode typical operation
Data set 02
Published operating points and test conditions from this source.
Heater Voltage
6.3 V
Heater Current
750 mA
Amplification Factor
70 ratio
Plate Resistance
17000 ohm
Transconductance
4000 uS
Maximum Plate Voltage
300 V
Plate Voltage
200 V
Grid Voltage
-2 V
Maximum Plate Voltage
330 V
Maximum Plate Dissipation
5 W
Maximum Screen Supply Voltage
330 V
Maximum Screen Dissipation
1.5 W
Grid-Plate Capacitance
0.1 pF
Input Capacitance
11 pF
Output Capacitance
4.8 pF
Data set 03
Published operating points and test conditions from this source.
Plate voltage
200 V
TriodeSection
Grid voltage
-2 V
TriodeSection
Plate current
3.5 mA
TriodeSection
Plate voltage
200 V
PentodeSection
Grid 2 voltage
135 V
PentodeSection
Grid 1 voltage
-1.5 V
PentodeSection
Plate current
18 mA
PentodeSection
Grid 2 current
4 mA
PentodeSection