After a lifetime of failed attempts I finally made a successful Conical Coil, 20 AWG, 2.5 x 7" x 16" tall on a white polyethylene traffic cone (never saw one prior, got it at a thrift store). Its powered by a 1930s/40s Aloe Diathermy Machine modified to power external coils. http://www.electrotherapymuseum.com/2015/ConicalAloe/content/index.html http://www.electrotherapymuseum.com/2010/AloeDiathermy/index.htm A fun project...it makes 10" brush and sparks and the sparks are hot and noisy. The set consumes slightly under 1/2 KW on high power.Jeff Sent via the Samsung GALAXY S® 5, an AT&T 4G LTE smartphone _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla