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Specialized - Switching Tube ·RelayControlSwitch

313C

Three-electrode inert-gas cold-cathode control tube for relay and switching circuits. Gas ionization provides abrupt controlled conduction without a heater.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
-
Socket code
UX4
Base pins
-
Nominal heater
-

Description

Three-electrode inert-gas-filled cold-cathode control tube.

Socket description

Medium-shell UX 4-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
UX4
Base pins
-
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

RelayControlSwitch

X-ray radiationInterelectrode capacitances
Max cathode current
35 mA

Promoted fields audited from printed ratings/characteristics; remaining published values preserved as parameters.

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

2026 Western Electric 300s

Published operating points and test conditions from this source.

SECTION 1

RelayControlSwitch

Characteristic

  • Average Cathode Current •

    10 milliamperes

    Average Cathode Current • 10 100 milliamperes

  • Peak Inverse Anode Current (Note

    2 milliamperes

    Peak Inverse Anode Current (Note 2). . . 5 milliamperes

  • Starter Breakdown Voltage (Note

    3 Volt

    Starter Breakdown Voltage (Note 3) 62 70 89 volts

  • Anode Voltage Drop at

    20 Volt

    Anode Voltage Drop at 20 milliamperes 68 75 90 volts

  • Inverse Current at

    -120 Volts

    Inverse Current at -120 Volts Anode Potential (Note 5)- - -

  • Note

    4 volts

    Note 4: With 15 volts overvoltage (15 volts above starter breakdown voltage) with tube in total

  • Note

    5 volt

    Note 5; Negative anode voltage applied through ROOO ohms. Starter connected to anode through