David wrote:
What would you define RF ground as? There seem to be a lot of different
ideas.



David:

Ground can be a relative thing. What I have always found to be good
advice is that EVERY ground, at some point, be allowed to reach a low
ohmic earth ground (best possible if it all occurs at the exact same
earth ground point--or no current flows and there is no voltage
potential between such grounds.) For example, although a dipole needs
no rf ground directly at the point it connects to the feed-line, the rig
hooked to such an antenna and feed-line should be given a good earth ground.

If the above is coupled with a good understanding, awareness, and
practice of avoiding "ground loops", I think one can claim to have a
good and adequate grounding system. Ground loops are well discussed in
books, mags, and internet pages, etc.

In planes and outer space the earth ground can be ignored, your crafts
metallic shell will serve.

Regards,
JS