The SU2150A is equivalent to the SU2150A from Cossor. Several manufacturers made these EHT rectifiers to the same nominal specification but the Cossor saddle design proved to be the best performing over time.
This exhibit shows a more conventional construction with a vertical anode cylinder and is possibly badged Cossor but made by another company.
The maximum reservoir capacitor is 0.25 µF, and the minimum series resistance is 10 kOhms.
The heater passes four times along the length of the cathode tube. The anode is supported on long glass rods.
Internally the coated cathode top is supported on a mica plate that is held in place by two vertical rods.
A close-up of the oxide coated cathode.
A closer view of the electrodes. The cathode tune has a reduced diameter at the top. The main top mica support clamps the rod securely.
The classic envelope is 49 mm in diameter and, excluding the B4 base pins, is 113 mm tall.
