Re: secondary diameter vs. toroid minor diameter

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 9/30/02 1:24:11 AM Eastern Daylight Time, tesla-at-pupman-dot-com
writes:


>
> Someone once recommended to me that the toroid minor diameter be
> slightly smaller than the secondary diameter, the idea (roughly) being
> that breakout is more likely to occur where radius of curvature is less,
> and you obviously don't want breakout from the secondary.
>
> Make sense?



Bill,

Maybe.  There is some shielding of the secondary near the
top where the voltage is highest, so that may protect the
secondary some.  In Richard Hull's magnifier, the resonator
was 4" in diameter, and the main toroid was about 12" in
minor diameter.  The resonator was heavily shielded by
toroids above and below however.


>
> For my next coil (slow in progress), I have a 9" by 30" spun aluminum
> toroid (the last bulk buy), and am planning on using a 10.75" diameter
> PVC secondary form.  Reasonable?  What diameter secondaries are others
> using with those toroids?



That sound's like a reasonable diameter to me.  It's important
that the coil form be tall enough also, to prevent breakdown.

John