a senior member PM'ed me this link to a 1974 Popular Mechanics issue that has an article on:
ESS Heil
Dahlquist
Ohm Walsh
Magnaplanar
EV interface A
and 5 or 6 other non conventional ones
really interesting reading..thx Paul :)
http://books.google.com/books?id=DNU...page&q&f=false
