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RE: primary coil increase to 3/8 (.375") From 1/4,1/4 spacing.

Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>

Hi John,

I broke out a email you wrote in 97 regarding this and notch quench. I
realize that the increased tubing diameter reduces the r component of the
impedance and therefore benefits the current capacity. But it seems to me
that the arc space effects the coupling much as raising and lowering the
secondary which in turn has an effect on the diameter of the primary which
in turn has effect on the magnetic field shape.

Are you speaking to the inverse square law here? I am a bit confused as the
ratio's dimensions often spoke about here that must have some synergy in the
shape of the field albeit much less than the lower turns of the secondary.
Am I with you at all here? What effect of this field('s) does this have on
the inductive rise further up the coil? What conceptually have I misplaced?

Comments welcomed,
Jim Mora


-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx]
Sent: Friday, July 08, 2005 3:30 PM
To: tesla@xxxxxxxxxx
Subject: Re: primary coil increase to 3/8 (.375") From 1/4,1/4 spacing.

Original poster: FutureT@xxxxxxx

In a message dated 7/8/05 3:49:15 AM Eastern Daylight Time,
tesla@xxxxxxxxxx writes:


>a pancake 3/8 tube with like spacing and a 1.5" arc space? The secondary is
>a 8.25" 35.5" 22AWG. I seem to remember Richard Quick or some one post that
>the aspect ratio to fully envelope the coil should be around 2/3? In this
>case it comes out to ~ 26" but is taped at 10.85 with a 40NF Beefy MMC cap
>using Java Tesla.


Jim,

the primary doesn't really envelope the coil, rather it couples mostly
into the bottom of the secondary.  So it doesn't matter
if the primary is wide or not.  Wideness will only affect the coupling.
You do want the coupling to be as tight as possible without
getting racing sparks or flashovers.  The reason for using
3/8th inch tubing is to handle the high currents without too
much loss.  I would imaging that at such power levels as you
are proposing, you would want to use 3/8" tubing.  I'm not
sure how much difference in performance you'll actually see.
Richard Hull ran his Nemesis coil up to 11kW or more and
used 5/8" primary tubing.

John