Re: LTR vs. more primary turns

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <dgoodfellow-at-highstream-dot-net>

If you start on the transformer end of the project, let's say you are
building a coil based on a 12/60 neon matched up with a .02uf capacitor
bank, then by what means do you determine the ideal parameters to construct
the secondary from? I am very interested in how you determine this, because
I had a situation where I thought that I was powering a coil with a 12/60,
but it turned out to really be a 9/60. With the 9/60, the coil was producing
sparks about 30" long. When I realized my mistake, I installed my 12/60 to
the system, expecting even better performance. If there was a performance
improvement, it was about impossible to see. Effectively, the output looked
identical despite my experimenting with the tap point and the spark gap. I
felt that the only way to longer sparks on that particular instance, without
changing out the secondary, would have been by using a larger toroid. The
coil was fashioned after John Freau's tt 42 as far as turns, height,
diameter. I still think that he uses some kind of Voodoo magic to get 42"
sparks from a 12/30 neon, (grumble grumble).
     If you have a way to determine the optimal secondary for a given
transformer, I am all ears!
Thanks, Dave






 > What John said is true. Starting from a given secondary is not the
 > best way to design a good coil. You should be starting from the
 > capabilities of your chosen supply. That is exactly how I design
 > coils. Once you've wound the secondary, you're stuck with it for
 > better or worse.
 >
 > Regards,
 > Malcolm