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Coil just won't fire...

Subject: 
        Coil just won't fire...
  Date: 
        Mon, 14 Apr 1997 16:58:57 -0400 (EDT)
  From: 
        Tim Maleske <maleske-at-worldchat-dot-com>
    To: 
        tesla-at-pupman-dot-com


>       Mike...my partner and I have met with a problem. We have built a coil
>(description to follow) that just won't fire.We can tease a few 6 inch
>arcs from it using a grounded rod, but it will not fire in free
>air. Before I go on, I'll decribe this tiresome albatross to you.
>       
>       Secondary
>       The total winding lenth of this 3 1/2" coil using #26 copper wire is 17
>1/4 ".The length of the PVC pipe is about 22 3/4" long,leaving about 2
>1/2" at the top as a header and 3 1/8" at the bottom (the top and bottom
>numbers represent pipe with no windings).
>The ends of the pipe are sealed with plexiglass and the top has a 1/4-20
>X 1/2" bolt sticking out the top as a means to secure a torid.The copper
>wire from the winding is terminated at this bolt.
>       
>       Capacitors
>The capacitors we are using are 6 long necked beer bottles filled with
>sea salt and motor oil.The total capacitance of these bottles is about
>.0043 uF.We did have one of these capacitors fail while trying  our
>first coil (too large a spark gap) but these seem to be alright now.
>       
>       Primary
>Our primary coil is made from .375" copper tube wound in conical form
>with.375" spacing.The form and spacing is maintained with a wooden and
>plexiglass form.In total there are just over 15 turns on this coil
>       
>       Transformer
>Our transformer is a 9KV 120 mA neon .
>       
>       Spark Gap.
>The spark gap is made from 2 pieces of 3 1/2" X 3" X 1/16" copper plate
>set up over a quenching fan and set at between .020" - .030".
>
>       Torid
>We have 2 torids that we tried.One was  20"X4" made from Aluminum dryer
>duct held together with pizza pie plates and Aluminum tape.The other was
>about 8"X 2 1/2" styrofoam covered in aluminum tape.
>
>We have built a control pack that engages/disengages the capacitors and
>bleeding resistors. This control also houses the autotransformer that we
>use to control the primary voltage to our neon transformer.
>When we attempt to fire this coil there appears to be nothing
>wrong. There are no stray arcs,there is no overheating anywhere in the
>ciruit. When we turn up the autotransformer to produce 180 Volts at the
>neon primary we are drawing around 20 + amps (we did trip a breaker
>while setting our spark gap ). We have plenty of arcing at the spark gaps
>(the safety gap does not fire) We allowed this coil to try for about 10
>minutes in total without any physical failure (ie we could still draw 6
>inch sparks from the torid when we finally gave up). We even tried to use
>an old secondary that we have laying around...It did not do any 
>better. We were able to get the 6" arcs by tuning the primary out to it's
>maximum setting of 15 + turns. We were drawing 20 + amps and the power
>was not  being consumed by over heating and/or sparks, so we were
>wondering, could this be a coupling problem? If anyone has a suggestion
>or idea we would very much appreciate the help. 
>
>                                       Two VERY distraught coilers
>
>