This discussion was about determining capacitor Q.

 > I would try running a Q test on the capacitor. It may not be 
 > designed for High pulse current service.

> What would be some quantative ways to test the 'Q' of a capacitor?  
> Or would you just hook it up and see how well it works in a coil?
 MG> You could just hook it up, but I would use low power, like less 
 MG> than 500 watts. A better and maybe safer way is if you have 
 MG> access to a signal generator that will provide a least a 1v 
 MG> p-p output, and a VTVM or other hi-z meter with a RF probe, 
 MG> or even a scope. 

I know that everybody out there does not have a scope. But if a 
person has been coiling for a year or more, and has built enough
coils to know that further investment will not end up gathering
dust, then a scope is a consideration. A scope, frequency gener-
ator and frequency counter are a real value in determining all 
types of variables in Tesla coil work.

This is one area where a scope with a frequency generator leaves
no doubt. The capacitor can be placed in the tank circuit and
grid peaked right at the operation frequency of the coil system.
The height of the grid peak can be directly compared with other
capacitors swapped in for just this purpose. This gives specific
and meaningful Q values if the setup is not varied between swapping

In all the ways I have tried to measure capacitor Q, this method
gives the best data.

Richard Quick 
... If all else fails... Throw another megavolt across it!
___ Blue Wave/QWK v2.12