Re: Awsome first light !! but...

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

Original poster: "The Big Giant Kevin by way of Terry Fritz <twftesla-at-qwest-dot-net>" <neo4s-at-hotmail-dot-com>


>Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
>
>Hi Kevin,
>
>At 12:20 AM 8/1/2001 -0500, you wrote:
> >WOW, 8 inch streamers, at 40 volts on the variac. Help from the list was
> >invaluable; I could not have done it without you guys, thanks to everyone.
> >But… I couldn’t seem to get the variac over 40 or 50 volts then my 
>capacitor
> >safety gap would start to fire. I set the cap safety gap to fire at 12 kV.
> >Why was it so active with only 5 kV out of my NST? Tuning seemed to help
> >reduce the safety gap firing, but not much. I didn’t spend a great deal of
> >time tuning. I was in a small metal shed; it was 95 degrees outside, and 
>110
> >degrees inside. Florida sucks in the summer, nothing but mosquitoes and
> >humidity. Could tuning be my problem here? Nothing special in my setup,
> >12/30 NST, Terry protection, static gap with fan, LTR cap, line filters.
> >Thanks for any help, Kevin
> >
>
>While your safety gap may have been set for 12kV, what was your main gap set
>to?  It sounds like your main gap was set to something higher and allowed
>the safety to fire.
>
>As a side issue, it's generally not recommended to use a safety gap alone
>across your cap.  With no safety gap current-limiting, the discharge current
>could potentially be bad for your cap.  Also, it's impossible for the cap
>voltage to ever be any higher than the voltage across your main gap.
>Whatever your main gap is set to will also limit the cap voltage, and the
>cap-gap is redundant.
>
>Gary Lau
>MA, USA
>
>What size primary cap do you have?  I would guess the system is resonant
>and the main gap is having some problem where it's firing voltage is going
>higher as it opperates.
>
>Please don't change the safety gaps since that should not be the problem.
>
>Cheers,
>
>	Terry



Primary cap is 9.3 nF, LTR with my 12/30 NST. So a cap safety gap is 
unnecessary? And if I use one, I should have a current limiting resistor? 
What value resistor and what wattage would be good? I’m sure this has been 
covered, but I couldn’t find any info in the archive. How do I go about 
tuning this thing? Leave the cap safety gap at 12 kV and close the main gap 
down? Tune, widen main gap slightly, retune, and repeat? When do I stop 
widening the main gap, when it gets to 12 kV? Although Terry supplied my 
caps cheaply and quickly (thanks), Id hate to reorder. Thanks for any help, 
Kevin