Re: Ok, what is an LTR cap.

[Tesla729-at-cs-dot-com (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Hi Garry,

That would be LARGER THAN RESONANT. Normally, the natural
resonance of the power xfmr determined by the current and voltage
rating of the xfmr output and the mains frequency dictates a certain
size of cap. for resonant charging -at- the mains frequency (60 hz in
the US, 50 hz in Europe). I'm having a little trouble putting my finger
on the exact formula at the moment, but other more knowledgable 
members could rattle it right off for you. But, basically a 12 or 15 KV
30 mA NST -at- 60 hz will need approximately 10 nF of tank capaci-
tance to be resonant. However, NSTs are notorious for succumbing
to the HV kickback peaks caused by operating with a resonant sized
cap, so many coilers opt for a larger than resonant sized cap. which
in turn keeps the HV kickbacks to a more managable level by the in-
creased surge impedance. So instead of using a 10 nF cap with a 30
mA NST, they may use a 15 or 20 nF cap. Of course, there are limi-
tations to how far one can go with this as a 30 mA NST would not be 
able to charge a grossly oversized cap properly within the 8 or 10 msec 
duty cycle of 50 or 60 hz operation, so the output would  decrease at 
this point.

I hope this explains it somewhat for you. I'm sure more knowledgable
list members will respond as well with better explanations, though.

Hang in There,
David R.