[Nadanutcase]

Sure, I understand how a tapped primary is usually laid out. The reason for my decision, aside from the fact that this set will almost certainly never need to operate a 220V, is that the primary leads (and secondary center tap) enter the transformer below the chassis while the leads to the jumper plug pass through the top along with the leads from the secondary, the recitifer filament and the B+ from the rectifier to the filter, so that adds to the complexity of how the leads are routed inside the transformer and that MAY have contributed to the failure of the transformer. In this picture the bottom socket is the jumper plug:

http://i791.photobucket.com/albums/yy193...b16b7a.jpg

With a simple, single primary, there'd be nothing connected to the jumper socket. In my book, simple is good & more reliable.

Thanks for the lead to Chuck Schwark's file. I am new to this forum, I'll try to figure out how to find it, but I may be back for some tips.