The CV207 is a triode based on the ACP4. The data-sheet gives the design use as television scanning circuits for 405 line television.
The KB/E identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the E identifies the maker as Thorn-AEI, Brimsdown.
The control grid has radiating fins at the top of the supports. The cathode is rectangular.
This shows the box anode ribbed to give dimensional stability to the thin nickel sheet.
A closer view.
The classic envelope is 38 mm in diameter, and excluding the B5 base pins is 110 mm tall.
