The CV2240 (commercial 3B4) is a miniature RF output pentode designed for Class C operation up to 100 MHz. It is described as directly heated with instant warm-up for use in portable equipment where saving battery life is important.
The KB/D identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the D identifies the maker as Mullard Radio Valve Co., Mitcham.
The anode is ribbed for extra strength and has side flanges for extra heat radiating surface area.
The anode seen edge on. The extra heat sinking is located in the place where most heat is produced.
The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 45 mm tall.
Reference: Data-sheet. Type CV2240 was first introduced in 1955. See also1955 adverts.
