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Re: Short secondary (fwd)



---------- Forwarded message ----------
Date: Sun, 2 Aug 1998 22:26:41 -0500
From: "Robert W. Stephens" <rwstephens-at-headwaters-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Short secondary (fwd)

> Date:          Sun, 2 Aug 1998 22:07:58 -0600 (MDT)
> To:            tesla-at-pupman-dot-com
> Subject:       Re: Short secondary (fwd)
> From:          Tesla List <tesla-at-pupman-dot-com>

> 
> 
> ---------- Forwarded message ----------
> Date: Sun, 2 Aug 1998 16:14:35 -0700
> From: Terry Perdue <terryp-at-halcyon-dot-com>
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: Re: Short secondary
> 
> Tesla gurus -
> 
> I started winding my secondary today, and ran out of wire prematurely -
> rats! The spool I had picked up at a swap meet appeared unused, with a paper
> wrap over it claiming it to be 9.5 pounds. I didn't even consider that it
> might be short. I ran out after hand winding about 425 turns (17") on a 6"
> diameter form. My intention was to wind about 900 turns. Should I start over
> :-( or shorten the form and use what I've got? Can anyone estimate what
> percentage discharge length I might be sacrificing? My goal was 3', using
> one 15kV 60mA NST, Terry Fritz's new gap design, 1/4" copper pancake, .01
> polyprop. xray cap., and 24" x 5" toroid.
> 
> Comments appreciated.
> 
> Terry Perdue
> 

Terry,

I'm sure no-one will mind if you use that 425 turn coil as-is.  It 
should still  be adequate to give 3 feet of discharge if you get everything 
else just right.  And if it doesn't, so what?  The excersize wasn't 
wasted time, you just learned something useful.  At that
point you can spend more money and time and wind another secondary. 
Heck, wind 3, compare what is needed to make them all fly, analyze 
their differences and become wiser from the experience.  The learning 
is in the doing.

If you've already made your primary coil, don't throw it away. Use it tapped 
in to a lower effective L for this shorter secondary resonator.

Too bad about that coil though, you could have been getting 10 feet 
plus out of that sucker if it were only 5 turns longer.  : )

Too many coilers worry about counting turns.  Forget about it.  I once
developed 6 foot streamers from a secondary coil that had just 160 
turns.  It is the inductance and voltage holdoff geometry that is 
important in this major component.

Good luck and have fun.

Robert W. Stephens
Director
Lindsay Scientific Co.
RR1 Shelburne, ON Canada L0N-1S5
Tel or AutoFax: 1-519-925-1771    
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