RE: Door knob caps

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

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Gary.Lau-at-compaq-dot-com>

The value of a Tesla Coil's tank capacitor is rather critical.  One can
deviate somewhat and compensate by adjusting the number of turns on the
primary or secondary, but the cap value does have to be of a certain
size.  If your design calls for a 1500pF cap (which is on the small end
of the usual size), you can deviate by maybe a couple hundred pF, but
using a value of only 200-400 pF just won't cut it.  While salt water
caps are a bit messy and perhaps a bit lossy, you can easily get a value
close to your 1500pF target with just two 12 oz. bottles.  Much easier
to source than doorknob caps.

Gary Lau
MA, USA


Original poster: "Tracy Fort by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<theforts-at-home-dot-com>

OK   forgive the ignorance as I know this is a newbie question for
sure...I'm attempting the construction of my first coil and the
particular
directions that I'm using call for 3 door knob caps wired in parallel
for a
total capacitance of 1500 Pico farads. These are 15kv caps. In the
directions it says not to worry about the capacitance too much. My
question
is this: How much can   I vary from that capacitance? I have found some
50pf
caps at 15kv. Can I use these caps? Do I need to add caps to get the
capacitance up around 400 pf? Or can I run less capacitance say around
200
pf?

Any help would be appreciated,

Tracy