Re: ideas to drop resonant freq?

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

Original poster: "cd by way of Terry Fritz <twftesla-at-qwest-dot-net>" <vbprg1-at-hotmail-dot-com>

I am new to all  this (once again probably not the best person to ask)
correct me if I am wrong...
but I think increaseing top load will decrease frequency.
I read somewhere that the top load or torus counts as extra wire added to
the secondary.
So therefore if you add a larger topload you can drop the resonant
frequency. Just like you had built a larger or taller secondary coil.
I do know for a fact that a larger top load will mean you have to tap
further out on the primary to achieve resonance. Which is what I think you
are trying to acomplish.
Maybe Just build another torus and stack them...or get a big ball, A sphere
has the most surface area, and therefor the most capacitance. The more
capacitance the more added wire effect.....

Hope that helps
Chris Dowdy


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, July 22, 2002 7:03 PM
Subject: ideas to drop resonant freq?


> Original poster: "Laurence Davis by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <meknar-at-hotmail-dot-com>
>
> I've tried various things to drop the resonance on my coil. its tapped at
> between the 4th and 5th turn. its using a about 2500w with 4 12kv/30ma
NSTs.
> I've learned a few things in the process, but haven't dropped the freq
yet.
>
> heres a list of what I've tried. I'm looking for suggestions on what to
try
> or what to test.
>
> 1) tried wrapping a new secondary. but miscalculated, and have fewer turns
> than first secondary (which will raise resonance, right?).
>
> 2) removed 300ft spool of RG6/u that was being used to connect to my
ground
> rods.  essentially an air core inductor.
>
> 3) removed 1 or 2 NSTs to better match resonant cap needed. here's my
logic
> on that.  java tesla calc says resonant cap for 12kv/120ma is 26nf or so.
> which my cap is within 5pct or so.  supposing that cap value needed is
more
> than what i have, then reducing number of NSTs will reduce the cap reqd.
> therefore will lower resonance. it didn't.
>
> 4) learned that there are "diminishing returns" from increasing the spark
> gap distance. Also interrelated was the top load required changes per the
> spark gap dist.  meaning: the spark length maximum is not at a wide open
> spark gap. (does this sound accurate?) this I would guess affects charging
> time of the cap.  in essence, there is an "optimum" spark gap maximum
> distance with regard to spark output(which could be read as spark length,
> more or less branches, decibel level, etc)
>
> 5) next tries will include a smaller dia secondary with less turns, and a
4"
> secondary with more turns. significantly. perhaps 30-50% more.  and a
larger
> cap that is adjustable AND in a smaller box.  i'll aim for 40nf with 5nf
> steps, and break the last 5nf into 5x1nf.
>
> experimentation helps me see the truth behind the math.  I wish i had a
> stronger grasp of the fundamentals behind it all.  with time it will come.
> thanks for any comments.
>
> Larry.
>