The CV2209 is a miniature HF pentode. Typical operating conditions are found in the attached data-sheet.
The CV2017 is the same valve but with tapes welded to the pins.
The prototype was the Mazda designed CV1116 that was fitted with an MO base cap.
The KB/EN identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the EN identifies the maker as Thorn-AEI, Sunderland.
The anode seen as two plates separated by a strap. The suppressor grid is close wound and thus can be used as an additional control grid.
Obscured by the inner coating is the anode with the strap on the right.
The thin glass tube envelope is 18 mm diameter and excluding the B7G base pins, is 47 mm tall.
Reference: Data-sheet. Type CV2209 was first introduced in 1952. See also1952 adverts.
