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Re: Newbie with questions...



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

Hi MCP,

It doesn't sound as bad as my first coil.  What is your streamer length?  As
far as your second question, the coil of wire will have capacitance just as
the topload does.  It can be suprising how much capacitance that it does
have.  When I hooked up my electric waterfall the first time, I had to
retune the coil just to get it working right.  On the third try I shortened
the wire to it two feet, and that brought it back into tune.  The added
interturn capacitance of the coil is higher than when the wire is straight
out, thus bringing your coil back into tune.

Welcome to the list, and may your streamers be long and plentiful!

David E Weiss


 > Original poster: The MCP <ejkeever-at-comcast-dot-net>
 >
 > Hello, everyone. I just signed up and have some questions to ask about
some
 > aspects of coiling.
 >
 > I've built a small (tabletop-size) tesla coil for fun, and I am observing
some
 > very odd behavior from it. But first, I should provide some basic info.
 >
 > The secondary is a .75" PVC pipe (I got excited and built it before doing
 > enough research), with about 10.5 inches of 32 gauge magnet wire on it,
about
 > 1000 turns. The helical primary is 5 inches in diameter, ~3.5 inches tall,
 > with 5 turns.
 >
 > The main tank circuit has a smallish 5000/20 NST and currently a single
 > 40KV/2nF cap from TDK that I picked up for $30.
 >
 > The spark gap is a simple static gap, currently separated by about .125
 > inches, using the tips of a pair of screws. When these wear out, I can
just
 > replace them with fresh ones. The gap can be set for up to 1/2 or so inch
 > separation.
 >
 > Currently, the whole thing is in a highly experimental state. By that I
mean
 > that very little is set in stone; Almost all the major connections are
either
 > twisted together or clipped. So you've got a lot of latitude to change
 > things.
 >
 > Anyway, on to my questions. First of all, I'm wondering if I've got any of
the
 > components grossly off-key. Comment away.
 >
 > Second, I've found something odd( to me at least). One day, just for the
heck
 > of it, I took off the topload and stretched the wire straight out. Nothing
 > much happened. But when I took the 6 inches or so of wire and wound them
into
 > a small spiral (about 7 turns, 3/8 inch diameter, 1 inch long), the coil
 > worked almost as well as with the big copper topload so I abandoned it.
Can
 > someone tell me why?
 >
 > Thanks for taking the time to slog through all this and answer my probably
 > silly questions!
 >
 >
 >