Re: A little design help

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Original poster: FutureT@xxxxxxx 

Jonathan,

For the 6" toroid I'd use a secondary 3" dia x 12" to 15" tall.
I'd wind it with #28 wire.  A smaller secondary would be OK
also.  For example it could be 2.5" x 12" tall using #30 wire.
You could even use a 2" x 10" secondary if you want the
coils to be really compact.  For the Primary I'd use 1/8"
copper refrigeration tubing, as many turns as needed to tune.
Or you can use solid #12 or #10 PVC insulated wire close
wound, but it's harder to make the tap point.  The insulated
wire does make a compact primary however.  For a spark
gap, I'd use a simple 4 section series static gap.  For
the capacitor, I'd use something rather small in value
such as 0.005uF.  This way the coil will run at a high
breakrate and give nicely coalesced sparks.  The 6"
toroid can probably support sparks up to 20" in length
or so.  Such small coils can give very nice looking
sparks.  I remember Sue Gaeta built a similar coil
and it gave about 18" sparks I guess, using the same
toroid.  I'm not sure exactly what the specs of her coil
was.  I'm not sure of the capacitor value she used.  I seem
to remember that she used a 5/60 NST.

Others may be able to offer tested designs of this type of TC
because I don't really have a lot of experience building
this type of coil.

John