Re: coil spark size??? (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sat, 11 Aug 2007 13:57:49 -0400
From: Crispy <crispy@xxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: coil spark size??? (fwd)

Just a quick side note about OBITs: I made a coil with an OBIT once, and
it appeared to be very stable.  Even with adjusting the spark gap to its
maximum length (that it would still fire) and no filter on the hv, the
OBIT survived without problems.

Chris

On Sat, 2007-08-11 at 08:46 -0600, Tesla list wrote:
> ---------- Forwarded message ----------
> Date: Thu, 09 Aug 2007 19:00:21 -0700
> From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Re: coil spark size??? (fwd)
> 
> Hi j?,
> 
> Your operating well into resonance with the parallel OBIT's. You might 
> want to double your capacitance to keep the voltages tame as well as the 
> bps (it's a little high right now, but not terribly). I personally have 
> not run an OBIT and not sure how it fairs say compared to an NST's 
> secondary over volt problems. On most toroids of home-brew design, 
> corrugated ducting or similar is used and this causes various streamers. 
> In other words, completely normal. I'm sure you could increase spark 
> length on this coil however. The gap and the cap value are two good 
> places to start.
> 
> 12" sparks are ok, but it can be increased. Typically, one might calc 
> about 31" for the power, but in the case of being as close to resonance 
> as you are, I would actually expect more like 43". Thus, I think the 12" 
> of spark length is showing that you could certainly make some 
> improvements. Cap, gap, and topload are the areas to concentrate on to 
> achieve that.
> 
> Take care,
> Bart
> 
> Tesla list wrote:
> 
> >---------- Forwarded message ----------
> >Date: Fri, 10 Aug 2007 18:50:25 +0000
> >From: jhowson4@xxxxxxxxxxx
> >To: Tesla list <tesla@xxxxxxxxxx>
> >Subject: coil spark size???
> >
> >hey guys i am just wondering if the spark size that i am getting is about
> >right these specs
> >
> >spark lenght max 12in but at the same time there is about 7-8 smaller
> >sparkes ( i am wondering if that is because of my toroid size)
> >
> >
> >specs about 600khz coil height is about 20in primary is an invers cone
> >tapped at about 5 turns primary cap is .01uf home made using polyethylene
> >and tin foil. you know the stuff I can afford in high school
> >
> >transformers are 2 23 millamp 10,000v OBIT transformers wired in parallel
> >soon to be 4 of the same in parallel
> >
> >spark gap is 2 bolts seperated by under a 1/2 inch on the blowing end of
> >my dads shopvac i am on vacation so i probably will repost this with more
> >accurate specs once i get home
> >
> >
> >
> >
> >
> >  
> >
> 
> 
>