[Elecraft] Best way to secure RF ground from 2nd floor?

[Alan Bloom]

Grounds can serve three purposes: lightning protection, power line
safety, or RF ground.  These are three very different things, requiring
very different ground methods.

For an RF ground, forget about a wire to earth ground.  It will almost
always be too long to present a low impedance at RF.  Even if you can
tune out the reactance by adjusting the length to a multiple of 1/2
wavelength or by using a tuner, it will still have RF current flowing in
it and so will still radiate RF.

A better method is to use a counterpoise wire.  This is like a single
radial, 1/4 wavelength long, connected to the chassis of the antenna
tuner.  One counterpoise is needed for each band of interest.

Al N1AL