[drh4683]

Originally Posted by dieseljeep

The "N" chassis, 23V set had some kind of a crude looking adjustment device on the CRT neck, made of Masonite. Don't remember what it did. I was the only 23V Zenith that used it.

Ah, yes! Those were the big post-deflection purity rings! Zenith did it that way on the M and N line 23" sets. Very large and bulky apparatus and was secured with heavy copper braided cables that curved around the bell of the CRT. An unusual approach to purity adjustment. Not sure why Zenith did it that way in the beginning as I think the rest of the industry was using the much smaller and simpler purity ring assembly at the end of the tube.