Re: tesla virgin no more ! but need help

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

Original poster: Esondrmn-at-aol-dot-com 

In a message dated 2/4/04 5:32:58 PM Pacific Standard Time, 
tesla-at-pupman-dot-com writes:

Steve,

You don't say what size the topload (toroid?) is but if it is approximately 
12" in diameter, then the coil should tune when tapped at turn 7 with about 
a .023 ufd capacitor.  So, you should be in the ballpark with the original 
two strings of twelve .15 ufd caps in parallel which would be .025 ufd as 
you have calculated.

I agree with Bart and suspect some problem with the caps.  If they are not 
arcing through the case to something else, they may be the wrong type of 
capacitor.

Ed Sonderman


>I have been building my first coil (Researched this lists archives for over
>a month ,along with all the websites Thanks), and had first sparks
>on Saturday  WOW!!!, about  15 inches, but having some problems, I cannot
>figure out, and need some expert advise
>
>     Spark gap , static type with 6 ,1" diameter x2" long copper pipes laid
>out flat, gap spacing about 1mm  with fan
>.  MMC with 2 strings 12 each string(24total of 1600kv .15uf poly's.Total
>value .025 uf ??? ( can someone check this)
>      I am presently powering this coil with 15/30 NST
>
>first light was great, ran the coil 10-15 short runs 12-24 inch
>sparks.   Then the  spark gap would only fire for about a second and stop,
>after inspecting the MMC realized I had burned 2 caps up ( big holes in two
>caps together in series), I replaced these caps, and added 3 more per
>string( now qty 15- .15uf 1600kv each per string x 2 strings)) but same
>problem, after some evals, my present  situation remains the same , if I
>remove the parallel connection between the 2 strings of 15 caps, and use
>each string alone, the gap fires ( but no sparks from top load( I can get
>spark from topload with breakout), but if I reconnect the 2 strings of caps
>, same problem, gap only fires for about a second or two, and nothing, I
>have tried the coil using a smaller NST (9/30 )   and the coil works well
>all components working with about 15" sparks.
>
>4" secondary 1050 turns ,24awg, 21.5 " coil length
>12 turn primary 1/4 od, 1/4 spacing( tuned at about 7 turns)
>
>I suspect the MMC  configuration, but cannot figure this out !! I thought
>15 x1600kv caps would suffice for a 15/30 nst (15 x 1600=24kv
>any help would be greatly appreciated
>
>Steve