The CV574 is a full wave vacuum rectifier and identical to the 6X5GT.
The KB/FE identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the FE identifies the maker as STC, Oldway (Additional to Paignton factory 'F').
The commercial 6X5GT.
Two identical anodes mounted in opposition and rotated through 90°.
The wide glass tube envelope is 29 mm in diameter and, excluding the IO base pins, is 68 mm tall.
