RE: Toroid question

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

Original poster: "Lau, Gary by way of Terry Fritz <teslalist-at-qwest-dot-net>" <Gary.Lau-at-hp-dot-com>

There are many things that may affect a coil's performance.  I also ran a 
15/60 NST, and have gotten up to 60" from it.  Choice of cap value and 
construction make a big difference.  With a static gap, I've found a value 
of .02uF to be optimum.  A salt water cap has high losses as compared with 
an MMC construction, so investing in an MMC is probably your best bet.

I have also found that a single sucker-type gap performs better than an 
RQ-type multigap.  And airflow through the gap regardless of type is very 
important.

If a top load's size is near the upper limit for a given coil & power 
supply, you may need a tack or breakout point.  But with a 15/60 power 
supply, a 4" toroid should be on the small side, and you should be getting 
multiple streamers without needing a breakout point.  I'd look to improving 
the cap and gap.  You should ultimately need a larger topload with a 15/60 
power supply.

Good luck,
Gary Lau
MA, USA


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

I run a TC of  moderate size. Recently I built a toroid from 4" semi-rigid
ducting around some pie plates. I have a 15/60 NST, saltwater capacitor, and a
R. Quick style gap. Problem: this toroid doesn't  discharge without help
from a
thumbtack. It seems to me from reading others' web pg.s that it should.
Also, I am puzzled by the seeming discrepancy in spark length from one TC to
the next (12" up to three feet)  when it seems that similar components (15/60,
or 12/60 NSTs ) are being used.
    It seems that now I have succeeded in building one, I have  been bitten by
the desire for longer sparks ;- ))  .
Any ideas on either of these topics are most appreciated!
Robert Hanford