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Voltage - Triode (single) ·Triode

3A108A

Repeater triode designed for telephone transmission-amplifier service, issued as an A-series replacement version for communications repeater equipment.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
MEDIUM4BAYONET
Base pins
4
Nominal heater
2 V / 250 mA

Description

Repeater triode, A replacement version.

Socket description

Medium 4-contact bayonet base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
MEDIUM4BAYONET
Base pins
4
Nominal heater voltage
2 V
Nominal heater current
250 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

1 physical section, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
50000 Ω
Amplification factor
30
Max plate voltage
190 V

Published triode ratings/characteristics promoted from the approved datasheet.

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

1946 Standard Telephone and Cables

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Grid-anode capacitance

    5 pF

    Direct inter-electrode capacitance

  • Grid-filament capacitance

    5 pF

    Direct inter-electrode capacitance

  • Anode-filament capacitance

    2.5 pF

    Direct inter-electrode capacitance