263A

Full-wave argon-filled rectifier using two anodes and a common oxide-coated cathode. Designed for low-voltage DC supplies requiring stable output over a broad temperature range, each rectifier section supports substantial peak current.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: MEDIUM5
Base pins: 2
Nominal heater: 2.5 V / 15 A

Description

Full-wave thermionic argon-filled rectifier using two anodes in one bulb and a common oxide-coated cathode, intended for low-voltage DC supplies requiring stable output over a wide ambient-temperature range.

Socket description

Medium 5-contact transmitting-tube base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: MEDIUM5
Base pins: 2
Nominal heater voltage: 2.5 V
Nominal heater current: 15 A
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

2 physical sections, each with unique specifications.

Section 1

Rectifier

X-ray radiationInterelectrode capacitances

Rectifier peak inverse voltage: 100 V
Rectifier peak forward current: 6 A
Rectifier forward voltage drop: 8 V

Representative row for two identical rectifier paths sharing a common cathode. Source gives 100 V maximum continuous/peak potential between electrodes and 6 A maximum peak plate current.

Section 2

Rectifier

X-ray radiationInterelectrode capacitances

Rectifier peak inverse voltage: 100 V
Rectifier peak forward current: 6 A
Rectifier forward voltage drop: 8 V

Second physical rectifier section added for full-wave/double-anode structure.

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 200s

Published operating points and test conditions from this source.

SECTION 1

Rectifier

Characteristic

AnodeCathodeVoltageDrop
8 V
Approximate

Other

Maximum Peak Plate Current
6 A
MaximumPotentialBetweenElectrodes
100 V
RequiredHeatingTime
120 s
LoadCurrent
4 A
SinglePhaseDoubleHalfWave;1Tube;LoadPotential=25V
LoadCurrent
10 A
ThreePhaseY;3Tubes;LoadPotential=40V

SECTION 2

Rectifier

Characteristic

AnodeCathodeVoltageDrop
8 V
Approximate
AnodeCathodeVoltageDrop
8 V
Approximate

Other

Maximum Peak Plate Current
6 A
Maximum Peak Plate Current
6 A
MaximumPotentialBetweenElectrodes
100 V
MaximumPotentialBetweenElectrodes
100 V
RequiredHeatingTime
120 s
RequiredHeatingTime
120 s
LoadCurrent
4 A
SinglePhaseDoubleHalfWave;1Tube;LoadPotential=25V
LoadCurrent
4 A
SinglePhaseDoubleHalfWave;1Tube;LoadPotential=25V
LoadCurrent
10 A
ThreePhaseY;3Tubes;LoadPotential=40V
LoadCurrent
10 A
ThreePhaseY;3Tubes;LoadPotential=40V