The CV1120 is equivalent to the SU2150A from Cossor. Several manufacturers made these EHT rectifiers to the same nominal specification but the Cossor design proved to be the best performing over time. Both Mullard and M-OV manufactured supposed equivalents to the SU2150A but in each case the valves were redesigned to suit factory production methods. The UK Navy insisted on the 'real thing from Cossor.
The maximum reservoir capacitor is 0.25 µF, and the minimum series resistance is 10 kOhms.
Like the original Cossor design the anode is supported from the base on glass rods. The anode is a cylinder and within can be seen the cathode and twin supports - the cathode has no other top support.
The oxide coated cathode on the left with the two supports on the right. The anode cylinder is welded to support rods either side that are set into the glass rods.
The top cathode support mica.
Slightly enhanced to show the cathode coating.
The classic envelope is 49 mm in diameter at its widest and excluding the B4 base pins the valve is 115 mm high.
