Tuning coils:Questions and Observations

To: "'Tesla List'" <tesla-at-pupman-dot-com>
Subject: Tuning coils:Questions and Observations
From: Tesla List <tesla-at-stic-dot-net>
Date: Tue, 3 Feb 1998 14:21:38 -0600
Approved: tesla-at-stic-dot-net

----------
From:  Matthew Mills [SMTP:mattmills-at-mindless-dot-com]
Sent:  Tuesday, February 03, 1998 1:02 PM
To:  Tesla List
Subject:  Re: Tuning coils:Questions and Observations

Yeah I had a temporary small gap set up as i normally use an 8 electrode RQ
style cylindrical gap.

Tesla List wrote:

> ----------
> From:  Bert Hickman [SMTP:bert.hickman-at-aquila-dot-com]
> Sent:  Sunday, February 01, 1998 7:38 PM
> To:  Tesla List
> Subject:  Re: Tuning coils:Questions and Observations
>
> Tesla List wrote:
> >
> > ----------
> > From:  Matthew Mills [SMTP:mattmills-at-mindless-dot-com]
> > Sent:  Sunday, February 01, 1998 12:35 PM
> > To:  Tesla List
> > Subject:  Tuning coils:Questions and Observations
> >
> > Hi, I was reading with interest the post by (was it) Julian Green, about
> > how one can tune the coil easily and safely using only 5 volts input
> > into the NST (or 10volts here in New Zealand) and holding a fluorescent
> > tube near the upper terminal. Well, I went home and what d'ya
> > know.....it works!  I havent heard of this method before, why has noone
> > else suggested this easy way?
>
> With the gap firing with small gap spacing I assume = low power tuning.
> If this is being done without the gap firing, then this is the first
> time I've heard of this technique - please explain.
>
> >
> > I have a range of coils wound by myself and by others, the ones wound by
> > another guy "tune" when the primary is tapped at 18 turns which is quite
> > high while my coil of similar dimensions tunes at the 5th turn  (this is
> > with a top load).  This I have put down to his coils using a lot thinner
> > wire and so have up to 2000 turns, while mine are quite thick wire
> > having only 600-900 turns.
>
> Your supposition is correct. Doubling the turns quadruples the secondary
> inductance, halving the self-resonant frequency (all other things being
> the same).
>
> >
> >  It is also interesting to note that his coils are wound anti-clockwise
> > when looking down on them while mine are wound clockwise.  Does this
> > make a difference?  I have never heard of a mention of direction of
> > winding in all my texts on telsa coil building.
>
> For simple 2-coil systems, it doesn't matter.
>
> >
> > While testing with only 10 volts going into my bank of 4 NST's i still
> > managed to get 2 inch sparks emanating from the unloaded top wire!
> >
> > Any answers to my questions or discussion on my observations?
> >
> > Matt.
>
> With small gap spacing and gap firing(?)...
>
> -- Bert --