Fwd: Tuning Questions

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

Original poster: Terry Fritz <teslalist-at-twfpowerelectronics-dot-com>


>To: tesla-at-pupman-dot-com
>From: JOSEPH CACCIATORE <jocatch-at-us.ibm-dot-com> (by way of Terry Fritz 
><teslalist-at-twfpowerelectronics-dot-com>)
>Subject: Tuning Questions
>
>
><<<<<<<<<<<<<<<Third attempt to get this posted>>>>>>>>>>>>>
>
>
>I am now in the process of tuning my new coil. Short videos and pictures 
>at my site, http://www.joecool-dot-org/joes_tesla_coil.htm.
>
>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