Re: 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>

Thanks Bart,

      Thanks for all of the info and pics!  I did find that I had inputted 
the primary in a bit wrong under Radius.  I used the 2" Inside and for the 
other radius 2" plus .08".  My primary looked bent, but seeing your pic and 
layout, I understand I messed it up.  It does show a much more accurate L 
as you showed.

On the Torroid, you show it down over the secondary quite a bit.  Will this 
work better than bottom plate flush with the secondary, 2" up from 
secondary or like you show it "sunk" into the secondary?

My primary IS a helical coil.   Sorry I noticed that I hadn't written that 
on the post.

 >Use your measurement. Due to the small inductance to begin with on this
 >coil, the cabling is obviously significant. The shorter, the better. If you
 >can reduce lengths, it will help. As it is now, 4uH of cabling inductance
 >will mean the actual tuning on your coil will be less than 7 turns. You do
 >realize the coils h/d ratio is large? I'm not sure how this coil is going
 >to perform.

I have a question here, doesn't the Inductance of the whole primary plus 
tank wires determine the total Tank Inductance?  I was hoping to then 
shorten the wires to adjust frequency.  If with no wires im at .0059mH and 
with all wires .0095mH (as tested), this would allow for a cap range from 
.0175uF - .0108uF while still maintaining the 500khz.  That goes from under 
my ballast max to well over, so can I just tune my tank wiring for 
this?  Is the reason for keeping tank wires short so that most of the 
inductance is in the actual primary?  Like in my case if the tank wires 
have essentially doubled my inductance, then the energy stored would also 
be split 1/2 in tank wires and 1/2 in Coil??

 >Well, due to the tuning issues you will be running into, I wouldn't go up
 >in capacitance. Reducing capacitance will allow more turns.

      Yes, I thought that reducing C would be best, and also make less work 
for the ballast.  This is why i went to .0107 on the MMC, to better match 
my tested inductance at 500Khz.  I have been told though that these Caps 
will not work for this high of frequency.  My RLC tested them with a Q= .1 
or less.

I do know that my H/D ended up rather high.  Most seem to like from 3:1-6:1 
whereas I'm 10:1  what does this affect?

Where would you set the spark gap if I have 3 total Gaps and 6Kv?

Also, I do have tested Q ratings for both the primary and secondary.  My 
RLC has that function.  The primary's Q= .25 and the secondary's Q= 3  What 
does this tell me other than the relationship of true reactance to resistance?

Thanks for your advice and pics!  This will help me get used to the Fantc 
better.
Thanks, Brad K.