Why the difference in Fo WinTesla & Fantc?

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

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

   Hello, I have recently posted some questions to this group regarding my 
first attempt at a TC.  I had some primary inductance differences in Win 
tesla.  I have recently tried the Fantc also.  Now, my coil is pretty well 
totally built off of Win tesla's program to resonate at 500Khz.  Putting 
the same info into Fantc shows a secondary resonate at 580-610Khz depending 
on height from ground plane.  If the Fantc is right, then my coil is WAY 
out of tune, but if Win Tesla is right, then I should be.  Could you please 
help me with this problem?  Any info you may offer will be great!!

Thanks, Brad K.

Spec's:
SECONDARY:  Built on 2" PVC = 2.37" x 22.2" Tall of 22 gauge Magnet 
wire.  The actual TPI I ended up with was 36.28 which yields 781.15 turns & 
485'.  My Tested after built = 3.825mH     Win Tesla = 
3.68mH     Fantc  =  LDS=3.91mH

TORROID:  From above secondary Win Tesla shows a 4.25" x 13.45" Torroid 
being 19.47pF.  Fantc shows this at 14.97pF I used AL duct tubing and foil 
for the top and bottom plates.  It is wrapped on a cardboard form to hold 
shape.  The built dimensions are exactly that above.  How do you test this 
C?

PRIMARY:  Primary is wrapped on 4" 1/8" thick clear Acrylic.  I used 6 
gauge wire and have a total of seven turns.  The final coil width was 
2".  I had asked on this before and tested actual Inductance is 
.005945mH.  Win Tesla .0097.  Using formula.0054mH and I was answered fantc 
showed .0055 I believe.  I have since finished the spark gap and tank 
wires.  The connecting wire is 6ga stranded power cable.  With these on I 
retested the whole primary inductance with tank wires.  I now 
test  .0095uH  This should be the TRUE FINAL inductance.  This is all of 
the wire that will be in there.

NEON:  Franceformer 6000v -at- 30ma.  the max cap would = .0133uF.  I don't 
want to blow the ballast so I thought I would run a smaller cap.

SPARK:  4-1/4" Brass Tubes adjustable spacing.  This makes a 3-series gap.

TANK CAP:  I am going to use a sort of adjustable MMC setup for tuning the 
primary.  I have Hi-Q .005uF -at- 4Kv and have hooked up 18 total.  3-series & 
6-parralled.  This totals 12Kv and tested at .0107uF.   Going from the 
actual final inductance this should be 499.1 Khz.  I have some others so I 
can change the C if I need to.

Now, win tesla shows that with the above stats, my secondary will resonate 
at 505 Khz, but it's Inductance was low.  Using the formula plus win 
tesla's Torroid C and self C shows now a Fo at 495.6Khz.  Pretty close to 
my tank and the whole 500Khz starting point.  Here's the kicker, Fantc, (as 
long as I inputed everything right) shows the resonance test at 589-610 
Khz!!!   That's a HUGE difference.  Before I fire this up for the first 
time I thought I should ask you experts.  Sorry for being so long, I just 
wanted you to have all of the info.  Also, my last post I found I messed up 
on parameters, but these shown are right.

Thanks for your help and sorry for asking so many questions.  I hope they 
don't sound dumb.

Thanks, Brad K.