NST power rating con

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

Original poster: Thomas <tom-at-pwrcom-dot-com.au> 

The more I look into this the more proof I get that the actual power
available from an NST is only half of the face plate values' product, i.e.

P =(V x I)/2

It's the only way I could get this to work out:

http://www.users.bigpond-dot-net.au/broken.trout/Rotary_eqns.pdf

Also it gives an extremely close value (+10%err) for spark length when half
the secondary VA is used for P in: L = 1.7sqrt(P) for my coil.

I think the +10% length measured is due to the primary cap being resonant
with the NST, and a slightly too wide spark gap.

Why is this con(fidence trick) by NST manufacturers not mentioned on any
Tesla coil design web sites (that I've seen)?

It's almost as bad as the *peak music power* con used by cheap audio gear
manufacturers.

Tom L.