Re: Some Q's

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

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

Jon, 
  About the best rule of thumb for your primary cap that I can offer is that
you need to size it to allow a sufficient number of turns for tuning.  I made
one coil whose tuning is so sharp(ie big primary cap), that if I tap the
primary a mere two inches from the sweet spot, the output practically went to
nil.  There are no hard and fast rules for this.  You must balance tunability
vs. your power supply(and maybe availability of materials as well in some
cases).  I would suggest using a minimum cap size of 1.5 times the impedance
match(LTR cap), but you can use as much as 4 (and maybe more) times that
resonant cap value easily provided you design the coil to be tunable.   
   I can't answer the spark gap question without going  back through old
letters, so I will let you find that.  My newest gap uses about 3 pounds of
tungsten electrodes that came from a high power induction furnace, so I haven't
delved into the triggered gap. 
Mike 


>
> SO, for a four inch coil, with 15KV input, what should the absolute 
> maximum capacitance be? Also, where can I get a look at some of those 
> spark gaps you guys are talking about? I was just going to build a 
> modified Richard Quick gap, but not if there is something better with a 
> similar amount of work. I DO want homemade stuff, not bought. 
> Thanks, 
> Jon