I found a few websites with some good info in case you haven't seen them yet the first one has a ton of useful stuff written by a guy that works for NASA and has been experimenting with the F75.
http://www.dankowskidetectors.com/
http://www.fisherlab.com/hobby/documents/DankowskiIntelligence5thed.pdf
http://www.fisherf75.com/index.html
If anyone else has any useful websites I'd love to see them.
F75, Excal 1000