Re: Tuning Questions

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Esondrmn-at-aol-dot-com 

In a message dated 2/27/04 3:24:31 PM Pacific Standard Time, 
tesla-at-pupman-dot-com writes:


>The software is telling me that I need 15.75 turns on the primary, I
>currently have 14.5. Before I add the extra wire and start adjusting I was
>wondering how sharp of a "Q" is a tesla coil circuit? I would not expect it
>to be very narrow. In other words I don't expect to see much difference
>adding or removing one turn. Instead of adding another turn or two why
>can't I just reduce the size of the toroid (the major diameter that is,
>still using 4" duct)? Using heating duct, it is very easy to do. Are there
>any adverse affects reducing its size?
>
>I also noticed that grounding the case of the NST and the bottom of the
>secondary to earth ground didn't make much difference in spark. Adjusting
>the spark gap doesn't seem to make much difference either unless I go too
>wide or too narrow although I didn't make any actual measurements for
>either test. Adding a sharp point to the toroid, like a piece of wire,
>gives me about 18" sparks. Without the wire I get small break outs all
>around the toroid. I don't know with a 12,000v,
>30ma NST how much bigger I should expect. I will be playing around with the
># of primary turns to see. Is there any way to ball park measure the
>differences during tuning other than visual?
>
>JC


JC,

Neither of my coils have a real sharp tuning point.  However, one full turn 
on the primary does make quite a difference.  Yes, you can raise the 
frequency of the secondary by reducing the size of the toroid and thus 
require fewer turns for tuning in the primary.  Of course, you could also 
increase the primary tank capacitor by a small amount.

Ed Sonderman