The CV4049 and the B7G based version the CV4007 are special quality double diodes. The commercial versions are the M8237 and the M8212 on a B7G base. Electrically they are the same. The prototype was the CV283, commercially the 6AL5.
The maximum PIV is quoted as 360 Volts.
The KB/DC identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the DC identifies the maker as Mullard Radio Valve Co., Whyteleafe.
The two diodes are separated by an electrostatic screen.
Face view of one diode.
The thin glass tube envelope is 18 mm in diameter and, excluding the 7 lead-out wires is 38 mm tall.
References: Data-sheet, 1040 & 3002. Type CV4049 was first introduced in 1956. See also1956 adverts.
