The CV277 is a half wave vacuum rectifier based on the VX6010. The heater needs a warm-up time of 15 seconds minimum before HT is applied.
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 high voltages involved require the use of ceramic insulators.
The anode is shaped for greater surface area and thus heat dissipation capability.
Thanks to Mark Mallison for sending the images.
The wide glass tube envelope is 32 mm in diameter, and excluding the IO base pins is 82 mm tall.
