Re: 10 Questions to help me construct my first TC

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 12/15/02 12:25:35 PM Eastern Standard Time, 
tesla-at-pupman-dot-com writes:


>1. Most folk agreed on 1.5 to 2x LTR, for the tank cap. But someone
>recommended resonant, to "squeeze the most power out". I chose resonant
>too, for that reason, but now I have some doubts. How much more power do
>you really get from a resonant power supply


Steve,

You won't get any more power using a resonant supply, but much
depends on the NST itself.  Some give more power with just 120volts
in at reso.  Often folks use 140volts input, and things tend to even out in
the wash.  NSTs vary somewhat in their characteristics and their
resonance "band".

, and is there more danger of

>blowing the NST?


Yes, unless you keep the spark gap narrow, and then you'll get
shorter sparks perhaps.


>2. I noticed you were talking a much bigger topload than what I have just
>now. That combination of pizza pans and flex duct is going to be like
>15"-18" in overall diameter. I also saw it said that the O.D. of the
>topload should be the same as the wound length of the secondary, which for
>my rig would be 20".


I missed where the person said that.  I did see where they said
the dia of the secondary should equal the toroid minor diameter.
Often the toroid can or should be smaller in overall diameter than
the length of the secondary.  Much depends on the power input
and the size of the coil, etc.  For my old research coil which used
a 12/30 NST, I used (for a time) a 5" x 20" ducting toroid.  Any
larger than that gave no benefit.  The secondary was 4" x 23".
I got the same spark length using
a smooth spun 4" x 13" toroid.  For your coil with the 10/25 NST,
I would not make the toroid too big.  I'd limit it to perhaps 3" x 12"
or 4" x 13".  If your NST happens to be "robust" and is giving
multiple streamers now, then you may benefit from a larger toroid.
Otherwise you probably won't.

I'm wondering if the bigger topload would help me get

>longer sparks: I'm just getting 17.5" (between a breakout point and another
>grounded point)


If you're getting multiple simultaneous streamers now, then there's
a good chance a larger topload will help to give longer sparks.

John