Still plugging away (web-searching/reading/learning), but so far I have spreadsheet-arized the calculations to make experimentation with different coils, materials, etc, easier, but I have one questions at this time... I know it's bad (preferred?) to overlap turns on a specific coil, but how about overlapping different coils? If I use the max turns for a toroid (for a given wire gauge) for the primary, can I just overlap the one or more secondaries over that? ANyone interested in the spreadsheet let me know. I won't voluntarily waste the bandwidth. Cheers, -Neil. --- [This E-mail scanned for viruses] -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics