Re: New to tesla coils

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

Original poster: "Harold Weiss" <hweiss-at-new.rr-dot-com> 

Hi Sean,

Some form of protection is definatly needed.  It can be as little as a spark
gap from each NST output to ground, or can be as complex as Terry's filter.
I currently am building a Terry filter for my coil after an arcover.  The
arcover happened across the outputs of the RC filter that I had.  If that
had gotten into the NST's they would be dead.

The copper tube gap works well.  Jeff Larson has a unique one that allows
him to vary the spacing in realtime.

Making a flat spiral primary works best.  Use 1/4" O.D. copper refrigeration
tubing spaced about 1/4" apart.  Before you build it, follow Dr. R's advice
on building a scrap wire primary.  Tapping the primary is the best way to
tune your coil. When I started, I used to tune with the capacitors.  It does
not work very well.

Before I started using Glyptal and AC-43, I used to use Minwax fast drying
polyurathane varnish.  Before you wind, coat the tube inside and out, as PVC
is hydroscopic.  That will keep the PVC from absorbing water.  Polyurathane
varnish can crack and chip off when cold, or subjected to hot and cold
cycling.  It is good enough to get you started, and not that expensive.

Good luck on your bidding for that NST!

David E Weiss

 >
 > Also, is a filter absolutely required?  I looked at the Terry gap, is
 > there an easier way?
 >
 > I'm going to make a static gap with a bunch of copper tubes (adjustable)
 >
 > I'll probably make a torroid from aluminum dryer duct.
 >
 > I will probably try to make the primary adjustable.  What size copper
 > tubing is best?
 >
 > For the secondary a 4" pvc tube, what type of glyptal should I use?
 > Also, is there an alternative to ac-43 (they seem to be located in New
 > Jersey)
 >
 > Ok, I am bidding on a transformer on ebay, 12kv 60ma as brooksshaman
 > (please don't bid on it)
 >
 > Am I forgetting anything?
 >
 > Any other info is greatly appreciated as well.  Thanks for all the
 > replies.
 >
 > --
 >
 > sean <sean-at-nc.rr-dot-com>
 >
 >
 >