Re: All pain no gain

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

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

In a message dated 3/8/01 9:48:38 PM Pacific Standard Time, tesla-at-pupman-dot-com 
writes:

<< 
 I'm curious. Do you have a bit more dimensional info on your primary?
 JavaTC, JHCTES, Ed Sonderman's
 Spreadsheet, WinTesla, etc.. are all very close to one another. For the
 most part, we all use the same calc's,
 however, there are a few calcs we go about differently for different
 reasons. I suspect there are dimensions
 which are off one way or another due to the degree the tap point you
 indicated is off. JavaTC shows about 18
 turns if I use similar inputs to Johns. But, everyone is kind of guessing
 at a few unknown dimensions. If the
 program is that far off I'd like to find out why. Others have used it with
 excellent results at first light.
 Yours is the first case I've heard otherwise which is partially why I'm
 interested in your input dimensions vs.
 your actual measurements.
 
 For TPI, simply count the turns in an inch and verify this at different
 points (this isn't exact, but it's as
 close as you'll get without counting the entire coil - as I once did). This
 helps fine tune the secondary which
 of course affects the resonant frequency and thus primary calcs. I would
 also back up John about measuring the
 cap and verifying all dimensions. They do make a difference regardless of
 which program you use. I personally
 like to use them all.
 
 Keep us posted.
 
 Take care,
 Bart A.
  >>
Bart,

The idea of different programs producing different numbers is expected I 
guess.  It would be nice if we could rely on the programs to produce 
consistent results, within a few percent anyway.  I will supply the data on 
my smaller coil here and maybe others could run it on their programs and 
report back.  In this situation, I am solving for the primary tap point.
Secondary: 3.0" O.D.  closewound,  winding length 13.1", #28 wire, using 72.7 
turns per inch
Toroid capacitance" 18 pf
Primary:  5.8" I.D., diameter of wire .10", spacing between turns .35" (not 
center to center - but actual clearance), flat spiral 
Primary tank capacitor:  .009 ufd

I calculate the proper tap point should be 10.9 turns.

Ed Sonderman