These are some shots of my new 2.5" coil during initial testing.

The specifications:
Tank Circuit
one 7.5/20 NST, 10nf MMC and 4 segment RQ/TCBOR spark gap.

~11.7 turns of bare 4AWG solid wire.

Approx. 1300 turns of 32AWG magnet wire around a piece of 2" PVC pipe(2.5" OD). Winding length is 12.75" and total length of the coilform is about 18.5". Many coats of polyurethane.

Toroid from 3" dryer duct approx. 9" overall diameter.

Spark length is about 12" right now.


These are a few shots to a grounded target. These were taken while running a 7.5/20 NST. Maximum spark length is about 12". Shown running with it's new primary.
And here is a short video clip. (626kB)