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Tube Tinker — Electron Tube Database
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Specialized - Switching Tube ·RelayControlSwitch

GR20

Cold-cathode DC relay triode with two starters and a keep-alive electrode, suitable for control and counting circuits requiring stable switching.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
B9A
Base pins
9
Nominal heater
-

Description

Cold-cathode DC relay triode with two starters and keep-alive electrode, suitable for control and counting circuits.

Socket description

Small-button Noval 9-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
B9A
Base pins
9
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 0

RelayControlSwitch

X-ray radiationInterelectrode capacitances
Max cathode current
30 mA

Cold-cathode switching/relay/display section; device-specific glow-discharge values preserved in parameter table.

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

1962 Cerberus

Published operating points and test conditions from this source.

SECTION 0

RelayControlSwitch

Characteristic

  • BreakdownVoltageAK

    300 to 350 V

  • SustainingVoltageAK

    105 to 114 V

Other

  • Cathode Current

    4 to 30 mA

  • Anode Supply Voltage

    180 to 270 V

  • KeepAliveAnodeCurrent

    - to 20 uA