I found this very nice website with a section about Homebrew Butterfly
Capacitor with many photographs.
http://hps.infolink.com.br/py1ahd/gallery21.htm
Does anybody knows where in UK (preferrable in Dorset or London) can I
get aluminum foil, 0.5 centimeters thickness?
Make contact with the Flight Refuelling Amateur Radio Society
(
www.frars.org.uk), based near Poole. They will tell you where to find
sheet metal in Dorset.
--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek