resonant cap / measuring impedance ?

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

Original poster: "Laurence Davis by way of Terry Fritz <twftesla-at-qwest-dot-net>" <meknar-at-hotmail-dot-com>

Lets just say I have an unknown transformer output.  I don't know the
voltage or current and I want to calculate the resonant cap required
for it.  To be specific, resonant charging with 120bps / 60hz static gap. 
How would I do that?

Is there a meter that will measure impedance? (I bet there is)
Is impedance and voltage output the only numbers I need?
If I remove shunts from a transformer, does that change the impedance or
is that merely a function of the secondaries impedance/frequency 
relationship? (which would mean.. no, shunt removal would not...  unless
the shunts affect the inductance of the secondary.)

larry.\