The CV1985 is a high μ twin amplifier triode. The prototype was the 6SL7GT.
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 two small triode units with extended anode sides to facilitate fixing and to add additional heat dissipation.
The maximum front to back dimension of the anodes is 6 mm.
The wide glass tube envelope is 29 mm in diameter and, excluding the IO base pins, is 66 mm tall.
