Mini coil earth?

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

Original poster: Thomas <tom-at-pwrcom-dot-com.au> 

I would like to build a portable mini coil that can be used for indoor
demonstrations, where an RF earth is not available.

Is there a way to safely operate a mini coil (NST 6kV 30mA supply) using
only the building earth?

The bulk of a twin system is too much to be really portable, and a bipolar
system is not the sort of effect I am after.

I suppose a decent surge filter could do the job of filtering transients and
RF from the mains, but would there still be a potential rise on the building
earth, and could this cause problems if other nearby equipment is connected
to (say) a dedicated telecommunications earth?

Any other suggestions?