The CV1264 full wave rectifier is a higher power device than most full wave rectifiers at 500 Volts at 250 mA. The valve is directly heated. The maximum reservoir capacitor is 16 µF and the minimum effective series resistance has to be 200 Ω.
The KB/Z identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the Z identifies the maker as MO Valve Company, Hammersmith.
This CV valve is identical to the commercial Type and this is a Mullard FW4-500 with the addition of the CV identification. But made by M-OV.
The twin anodes folded and stitched together.
The rectifier is directly heated and the oxide coated ribbon filaments can be seen to be held in the hook ends of the tensioning springs.
The classic envelope is 50 mm in diameter, and excluding the B4 base pins, is 110 mm tall.
