Primary Construction

 * Original msg to: Jbiehler-at-teleport-dot-com
 * Carbons sent to: usa-tesla-at-usa-dot-net

Quoting Jerry Biehler <jbiehler-at-TELEPORT.COM>:

> I got the copper tubing today. I got it at the a local hardware
> store. The normal price for it was $.69 a foot, but since I got
> a hundred feet I got it for $50 for two rolls of 50 feet. (This
> is half inch tubing).

This is right about on the money. You got the right material for
the job at the right price.

> What is the disance I should have between turns? 

 3/8 of an inch, or .375 inches

This is a pretty good general purpose airspace for primary coils
operating with 15 kvac rms inputs. You can space a little wider,
but I would not gap the turns any closer.

> And what diameter should I make the center hole?

The secondary coil needs 1-1/2 to 2 inches of space between the
base of the coil and the first turn on flat helical or inverted
conical section ("saucer") primary. To allow this room all around
you need to make the inside turn of the primary between three and
four inches greater in diameter than the secondary coil. Go a
little wider still rather than a little smaller. With the length
of conductor you are going to use, a slightly roomier primary
design will allow you to fire larger diameter secondary coils
down the road. It is OK to giver yourself a little room to grow.

Richard Quick

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