Re: First Coil

In a message dated 99-09-07 08:10:18 EDT, you write:

<< Original Poster: "Gary White" <wtdog-at-hotmail-dot-com> 
> I am going to build my first tesla coil using a 9Kv 30Ma NST.  I want to 
> a 3.5" secondary.  How long should it be, what size primary should I use, 
> and how long will the streamers be using this size?  Any input would help.  
> Thanks.
> Gary White


I'm seeing some evidence that a physically larger TC is more  efficient
for the same power input.  Might be good to use a 4.25" secondary,
although it probably won't make a lot of difference.  I like to use thinner
wire such as # 28 magnet wire, and I would make the coil about 24"
tall at least.  This will allow you to upgrade to a larger NST if the future.
If this will be a permanent design and you want it to be as small as
possible, then you can make the sec shorter, for instance 18" or so.

I just built a small TC as a test;  I used a 3" by 12" secondary , #28
wire, flat primary of #12 stranded close wound PVC ins wire, a 3" by
10" smooth toroid, 120bps sync rotary gap, and a 7.5kV, 30 ma NST.
This gave a 14" spark output.   A 9kV, 30ma would probably give about
a 17" spark.

John Freau