The CV1039 is a full wave rectifier. The CV number was the new name for Navy NU17, Army AU3A, RAF VU39 and the GPO POVT142. Thus one specification and purchase replaced the four individual departments procurement process.
The KB/ZD identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the ZD identifies the maker as MO Valve Company, Dover, pre Dec 1956.
The twin rectifier sections.
A close-up of the Type designation and KB/ZD.
The B4 base pins - two parts where the outer is split and squashed so that when inserted it grips the base.
Thanks to Mark Mallison for sending the images.
The classic envelope is mm in diameter, and excluding the B4 base pins is mm tall.
