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Tube Tinker — Electron Tube Database
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Voltage Triode Pentode ·Pentode-Triode

8JT8

No short description is recorded for this tube.

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

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
7.7 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
37000 Ω
Transconductance
0.0027 S
Amplification factor
100
Max plate voltage
330 V
Max plate dissipation
1 W

Section 2

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
50000 Ω
Transconductance
0.02 S
Max plate voltage
330 V
Max plate dissipation
4 W
Max screen dissipation
1.1 W

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

1970 Sylvania Technical Manual

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate Voltage

    250 V

  • Grid Voltage

    -2 V

  • Plate Current

    1.5 mA

SECTION 2

Pentode

Other

  • Plate Voltage

    200 V

  • Screen Voltage

    100 V

  • Grid Voltage

    0 V

  • Plate Current

    17 mA

  • Screen Current

    3.5 mA