Re: Yet another first coil question

Subject:  Re: Yet another first coil question
  Date:   Thu, 5 Jun 1997 22:30:19 -0600
  From:   "DR.RESONANCE" <DR.RESONANCE-at-next-wave-dot-net>
    To:   "Tesla List" <tesla-at-pupman-dot-com>

To: Matt McArthur

If you can locate a local neon sign shop and somehow manage to make a
with the manager to allow you to "borrpw" a 12 KV 30 ma neon sign
transformer you might notice a small gain in performance.  Also try a
tree decoration with alum foil (smaller discharge electrode) as it
like your "load" might be too large for your light bulb terminal. 
try a smaller terminal or try a slightly larger xmfr (more drive
Also try a brief blast of compressed air or small fan to blow air
your sparkgap while it is running -- improves quenching and might

Try elevating the sec. coil in 1/4 to 1/2 inch increments with some
plywood to see if this adjustment of "coupling factor" improves your

This should get you going in the right direction.


> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-poodle.pupman-dot-com
> Subject: Yet another first coil question
> Date: Thursday,June 05,1997 8:59 PM
> Subject:  Yet another first coil question
>   Date:   Wed, 4 Jun 1997 16:55:26, -0500
>   From:   RSNV02D-at-prodigy-dot-com ( MATT MCARTHUR)
>     To:   Tesla-at-pupman-dot-com
> Hello all,
>  I have been silently watching this list for a month or 
> so now (except when I argued on how caps work) and
> I finally finished my first coil.  I am using a 10KV 23mA 
> OBIT transformer with a .0061 uF leyden jar cap. My 
> primary is 7" in diameter, with a total of 10 turns -at- 
> about 6" tall. The secondary is 3.5" PVC with 486 turns
> of .025 enameled wire.  My supposive operating 
> frequency is around 600KHz. 
>   I am running two series gaps made out of brass angle
> brackets and carriage bolts. My discharge terminal is 
> pretty cheesy, its a large globe 60 watt light bulb covered 
> with aluminum foil.
>   The only problem I am having is that after I fire it up and 
> tune the primary at about 7 - 8 turns (depends on the
> spark gap spacing) I only get 6 inch sparks at most.  The 
> sparks sre pretty weak too. The bottom of the secondary 
> is earth grounded and the discharge was to a spool of chicken 
> wire that was also grounded.
>   The only thing that I can think of that is wrong is primary 
> secondary coupling. The secondary sits almost all the
> way down in the primary.  I just read a post that said
> something about raising the secondary to about an inch and
> a half above the primary to improve coupling.
>   Could someone please help me out here!!!???
>    Thanks 
>       --Matt