Original poster: "Loudner, Godfrey by way of Terry Fritz <twftesla-at-qwest-dot-net>" <gloudner-at-SINTE.EDU> Hello All There is a very strange variac on ebay with item # 1721022882. It has the classic EI core, but has sliding carbon brushings on the windings. It came from a 100 kilowatt x-ray machine. Godfrey Loudner