Skip to main content
Tube Tinker — Electron Tube Database
Alternatives & variationsDownload PDF datasheet

Rectifier - Half Wave ·Rectifier

U31

Marconi indirectly heated half-wave rectifier for voltage-doubler and capacitor-input power supplies, providing moderate current in series-heater equipment.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
IO
Base pins
-
Nominal heater
26 V / 300 mA

Description

The Marconi U31 is a indirectly heated half-wave rectifier for voltage-doubler and capacitor-input service.

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
-
Nominal heater voltage
26 V
Nominal heater current
300 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

Rectifier

X-ray radiationInterelectrode capacitances
Rectifier peak inverse voltage
710 V
Rectifier nominal output current
120 mA
Rectifier peak forward current
720 mA
Rectifier max heater-cathode voltage
350 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

Rectifier

Other

  • Heater/filament voltage

    26 V

  • Heater/filament current

    300 mA

  • Peak inverse voltage

    710 V

  • Nominal/maximum output current

    120 mA

  • Peak anode current

    720 mA

  • Maximum heater-cathode voltage

    350 V

  • Surge anode current

    2.4 A

Construction

  • Rectifier topology

    Half-wave