The CV2943 (commercially the ESU76) is a high power half wave mercury vapour rectifier from the early 1950's.
The KB/EA identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the EA identifies the maker as Edison Swan, Ponders End.
The emitting surface is enclosed.
A closer view.
The classic envelope is 54 mm in diameter, and including the GES base is 170 mm tall.
Reference: Data-sheet. Type CV2943 was first introduced in 1953. See also1953 adverts.
