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RE: Capacitor Help



Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>

Hi Malcolm:

I assume you meant to say 27 AWG?  If your secondary is 4" diameter, you
want the winding length to be roughly 5 times as long, or 20".  Using 27
AWG, that should work out to about 1300 turns - perfect.  Note that
there is nothing magical about the 5:1 aspect ratio or the 1300 turns.
You could be off by a factor of 30% (a number I picked from the air) and
it would still work.  Don't bother counting turns.

The thing you should pay attention to is the relationship of the plane
of the primary to the lowermost turn of the secondary.  They should be
assembled to be adjustable so you can vary the coupling, plus and minus
1 vertical inch relative to each other.  The final position can't be
determined until you run it.

You haven't worked out the details to know how many primary turns you'll
need yet, but it's very possible you may need more than 7.  On the
subject of primaries, one of the tricks to a neatly wound primary is to
use more than 4 comb supports - probably 6 minimum.

I noticed in the photos you posted you had a couple of toggle switches
neatly mounted on the base.  With most well-performing coils, one
generally wants to keep much further away from the base to avoid being a
target.

Also on your 2-bolt gap, be sure to use a 2nd nut on each bolt to
tightly secure it, or you will find that arcing is occurring on the
threads between the stationary nut and the bolt.

Regards, Gary Lau
MA, USA



> Original poster: "MalcolmTesla" <tesla@xxxxxxxxxxxxx>
>
> I started making my primary.  I'll give a link to a picture below.
It's
> made from 25 feet of 1/4" ice maker copper tubing.  There are 7 full
turns
> and a little more on the sides.  As you can see in the pic the overall
> diameter is about 17 ~ 18" depending on where you measure.  Inside
diameter
> starts around 6 ~ 7".
> The wire I've ordered for the secondary is 17 AWG (1.3 lbs on the
way).  My
> PVC is 4" diameter.
> When winding my secondary should I pay more attention to counting
turns or
> more attention as to how far up the PVC the windings go?  Someone had
> mentioned about 18", others have said 1300 to 1500 windings.  Now that
you
> see my primary and have more information what do you guys recommend?
> Thanks
> :)
>
> Oh and this pic is after spending some time bending the tubing, it's
not
> fastened down yet, just loosely laying there so it looks a little
sloppy.  I
> must say I have great respect for you guys that have such perfect
looking
> primary's.  How on earth do you guys bend them up so neatly?
>
> http://www.v8-ranger.com/temp/tesla/7.jpg
>
> Thanks
> Malcolm