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Specialized - Switching Tube ·Tetrode

GN20

Cold-cathode gas tetrode for relay, control, and pulse-switching service, using gas-discharge conduction for rapid high-current control.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
IO
Base pins
8
Nominal heater
-

Description

The Ferranti GN20 is a argon-filled cold-cathode tetrode for relay/control pulse service up to about 250 A peak.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
IO
Base pins
8
Nominal heater voltage
-
Nominal heater current
-
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

Tetrode

X-ray radiationInterelectrode capacitances
Max plate voltage
420 V

Cold-cathode gas-discharge tetrode section.

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

1963 Ferranti

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Other

  • Maximum Static Anode Voltage

    420 V

  • Maximum Working Anode Voltage

    420 V

  • Maximum Mean Anode Current

    80 mA

  • Maximum Repetition Frequency

    250 Hz

  • Typical Supply Voltage

    360 V

  • Trigger Pulse Amplitude

    150 V

    Minimum where specified

  • Charging Resistor

    4000 ohm

  • Peak Inverse Anode Voltage

    400 V

  • Maximum Average Trigger Current

    10 mA

Characteristics

  • Minimum Working Anode Voltage

    350 V

  • Static Trigger/Striking Voltage

    75-125 V

  • Peak Anode Current

    250 A

    Pulse