The CV11025 (SF17S) valve is a selected special quality version of the 6F17 miniature RF and pulse tetrode. The design is for pulse amplification.
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 ITT name and the Commercial Type designation 6F17S.
The mica discs are doubled to confer vibration resistance. The control grid is wound on copper supports, passes flat across the cathode, and has a heat radiating fin at the top. The extra metal within the anode forms the beam plates.
The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 46 mm tall.
