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Voltage Triode Pentode ·Pentode-Triode

8A8

No short description is recorded for this tube.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: -
Base pins: -
Nominal heater: 8.4 V / 300 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: 8.4 V
Nominal heater current: 300 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

Transconductance: 0.005 S
Amplification factor: 20
Max plate voltage: 250 V
Max plate dissipation: 1.5 W
Max cathode current: 14 mA

Section 2

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 400000 Ω
Transconductance: 0.0062 S
Max plate voltage: 250 V
Max plate dissipation: 1.7 W
Max screen dissipation: 0.5 W
Max cathode current: 14 mA

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
100 V
Grid Voltage
-2 V
Plate Current
14 mA

SECTION 2

Pentode

Other

Plate Voltage
170 V
Screen Voltage
170 V
Grid Voltage
-2 V
Plate Current
10 mA
Screen Current
2.8 mA