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Power - Pentode (NOT beam) ·Pentode

N18

Directly heated miniature battery power pentode with flexible 1.4/2.8 V series-parallel filament operation.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
B7G
Base pins
7
Nominal heater
2.8 V / 50 mA

Description

The Marconi N18 is a directly heated miniature output pentode with series/parallel filament.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
B7G
Base pins
7
Nominal heater voltage
2.8 V
Nominal heater current
50 mA
Parallel heater voltage
1.4 V
Parallel heater current
100 mA
Series capable
Yes

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

Pentode

X-ray radiationInterelectrode capacitances
Max plate voltage
90 V
Max screen voltage
90 V

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

1955 Marconi

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Series filament voltage

    2.8 V

  • Series filament current

    50 mA

  • Parallel filament voltage

    1.4 V

  • Parallel filament current

    100 mA

  • Maximum plate voltage

    90 V

  • Maximum screen voltage

    90 V

Application

  • Primary application

    Directly heated miniature output pentode with series/parallel filament.