Primary coil

The primary coil is made out of 1/4" thin walled copper pipe. With a lower power system like ours we chose a 45 deg angle as some people beleve that this helps to transfer more energy from the primary to the secondary. This primary is used with our BM1, 2 & 4 coils, for the BM3(Also known as Frankenstine ) we went for a flat primary, which has 13 turns of 1/4" copper pipe and is mounted on 4 adjustable nylon rods so the primary coil can be brought closer to the secondary for greater energy transfer.

In the past we used to use a croc clip to attach the HV tank circuit to the primary coil but this has never been very satisfactory. I saw this idea on the Tesla mailing list. It is a common 30A 240v AC fuse holder.