Original poster: "Steve Cook" <steve-at-g8cyerichmond.freeserve.co.uk> I was looking for pictures of a Rhigi spark gap, and came across a great site with a nice picture of an early rotary gap as used by Marconi on this site <http://www.marconicalling-dot-com>http://www.marconicalling-dot-com I really fancy getting one but its a bit of overkill on my small coils.