[TCML] Double-layer secondary coil

[otmaskin5 at aol.com]

I thought Gary Weaver's post of 3 or 4 weeks ago was interesting.? He reported getting ~10% increased spark length after winding another layer of wire over the first layer of his secondary.? 

I'm trying to understand the principle behind the increased performance.? It seems clear that the additional layer reduces the secondary coil's resistance?by about half which would support longer sparks.? But it seems like the double-layered coil would also reduce inductance which would reduce spark length.

I'm not sure what the the additional layer's?impact is on the secondary's inductance.? I believe 2 identical coils wired in parallel would reduce total inductance by 1/2, but does the double layer configuration also have an effect I'm not taking into consideration???If so, is there a formula to calculate secondary inductance in this configuration?? 

Or does the reduction in resistance somehow out-weigh the reduction in inductance in terms of spark length?? 

I'd appreciate any thoughts on this.? Thanks, Dennis Hopkinton MA
________________________________________________________________________
More new features than ever.  Check out the new AOL Mail ! - http://webmail.aol.com