* Original msg to: davidl-at-ieway-dot-com
 * Carbons sent to: usa-tesla-at-usa-dot-net

Quoting davidl-at-UNIX.IEWAY.COM (David Lawrence):

 > Somebody help me, please.
 > I have a question that I hope someone can give me a clue! 
 > My coil configuration is this: Primary consist of 10 turns of 
 > heavy stranded copper cable (the kind used for grounding panels) 
 > wound an a 12" tall form with a diameter of 24"

After a series of experiments followed with some deductive logic, it
has been determined the the use of braided ground strap should be
avoided in RF (read Tesla coil) applications. I don't mean to throw
a bucket of water on your project, but the primary coil Q will be
significantly higher if you switch to using smooth strap or smooth
copper tubing for your primary conductor.

 > Secondary consist of 920 turns of #25 enameled wire wound on a 4' 
 > form with a diameter of 12". I am configuring it for 1/2 wavelength. 
 > This means I have two live ends on the secondary.

The wire diameter is much too small for this sized coil. The small wire
diameter has excessively high RF resistance, which will really chop in-
to your coil performance.

 > My question is this; The spacing on the secondary is such that I 
 > could not use any kind of spacer line and still have it wound evenly 
 > across the distance of the form. I tried different sizes and finally 
 > I resorted to 5 or 6 close turns with a 1/8 space in between. This is 
 > the closest I have come to complete even coverage, but alas I am not 
 > satisfied with it. Any suggestions?

Quoting Ed Sonderman:

 ES> Despite what many old books suggest, you want close wound coils for
 ES> Tesla secondaries.  You want all the inductance you can get.  It also
 ES> increases the self capacitance but this is balanced out with the
 ES> toroid. 

Ed is correct. Space winding should avoided. This practice should be

Richard Quick

... If all else fails... Throw another megavolt across it!
___ Blue Wave/QWK v2.12