On the surface, this sounds like a stupid question, but how do I know
my shortwave wire dipole antenna is picking up all it can?


Just look at ground around the antenna. If you do not see any stations rejected
and dropped in the mud, then your antenna is doing fine job and picking up
everything it can.

Get some books on antennas and propagation, it is fascinating reading and will
answer many questions and provide food for some experimentation in your quest
in hearing everything.

BUm