This is an AEG 1S/3iII Thyratron designed in 1941 for use as a radar pulse modulator. With 1,000 Volts on the anode this valve could supply a peak pulse of 500 Amps at a repitition rate of 500 pulses per second.
This helium filled Thyratron was designed for the FuG-200 Hohentwiel Airbourne Radar. The same FuG-200 was later modified to become the FuMo-series U-Boat radars. Not that they ever used them when installed, the paranoia of British cm-radar equipped aircraft was deeply entrenched. They had themselves passive detectors by than, and knew the passive detector always had the advantage.
The outer mesh is actually the grid! Note also the very large heat-shielded cathode cylinder.Thanks to Thomas Van de Velde for identifying this Tyhratron and giving details of the attached PDF file.
The balloon envelope is 75 mm in diameter and, excluding the special base pins, is 180 mm tall.
References: Thomas Van de Velde, Hand Jucker. Type S1/3iII was first introduced in 1941.
Absolute Maximum Operating Conditions¶
PDF scanned from an original document held by the museum
Updated October 27, 2015.