Matt,
Please explain how you can sheild something without grounding it. Doesn't the energy need some place to go?
Wrong metaphor for RF energy. It's not water. A ground is not a storm drain. Imagine two conductive spheres ( earth and moon ? ) and an RF generator in a box sitting *peacefully* in space. Classical 3-body problem. The DC potential that exists between any of them has absolutley no effect on a wave travelling anywhere ( unless you want to get into the topic of nonlinear materials ). So forget about everything in the scene except that generator in the box. Shielding consists solely of preventing the wave from getting out of the box into free space where it can be detected. There is nothing special about *any* of the DC references. Earth may be special ( source of women and beer ) but not to a wave. Besides, chaining my laptop to a giant copper spike in a geologically suitable region is out of the question. Just shielding it would make an already heavy ThinkPad into a main battle tank. Mike