The EN31 thyratron is a high frequency type. Mullard describe the EN31 as a thyratron for use in HF timebases and control equipment. The maximum pulse repetition rate is given as 150 kHz. The control ratio is 35 and the voltage drop across the conducting valve is 33 Volts. It is an early type introduced by Mullard and was probably used in radar equipment.
An interesting feature is the mesh anode. The anode lead to the top cap is encased in glass.
The central control element has heat radiating fins at the top.
Another view.
Through the outer gauze can be seen part of the inner electrodes. Heat radiating fins are attached top and bottom.
The centre structure is the control element. The anode lead is encased in glass.
The classic envelope is 40 mm in diameter and, excluding the IO base pins, is 100 mm tall.
References: Data-sheet & 1040. Type EN31 was first introduced in 1947. See also1947 adverts.
