Original poster: Liviu Vasiliu <teslina-at-yahoo-dot-com> Hi list I made some modifications on my last vttc (with GU 81 M tube). Results: 18 inches sparks and some place for some more power. Many thanx for Fabio Mcgyver for some good ideas. http://www.geocities-dot-com/teslina/gu81mpage.html Enjoy teslina