The CV2638 is a mercury-argon thyratron with a peak anode current of 6 Amps at 1,250 volts and thus a peak pulse capability of 7.5 kW. This pulse can be repeated at a maximum of 150 times a second. Ideal for a small radar transmitter.
The KB/R identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the R identifies the maker as Ferranti, Gem Mill Oldham, pre July 1947.
The screening cylinder makes observation of the inner details difficult but a small diameter flat cathode can be seen with the heater below. The screen has a slot in the top dome facing the anode.
Within the screen can be seen the mesh electrode. The main assembly is firmly attached to the pinch stem by a collar. The fixing nut and bold are in the foreground.
The domed anode is attached only to the top of the envelope and top cap.
The classic envelope is 52 mm in diameter, and excluding the IO base pins is 146 mm tall.
