"Dave" wrote in
:

Okay, well, all I am trying to do is build something that will pick up
weak signals from a given direction, while ignoring signals and noise
from other directions. Ideally, it would not introduce a great deal
of noise from any source (unlike the loop I currently am experimenting
with.) I am not overly enamored of complex designs, and don't really
care what it looks like so long as it meets the above criteria. Do
you know of any fairly simple designs that would meet this
description? If tuning is possible, that would be a plus.

For your MW RO application, I would look at a multi turn (unshielded)
loop, untuned or tuned, but with an effective balun isolating the outer
surface of the outer conductor of the coax feed line from the loop.

I responded originally to your question about shielded loops. Shielding
is only one way to improve loop balance, and most explanations of
shielded loops are flawed.

Google for some designs, and be suspicious of purported shielded loops.

BTW, loops have pattern symmetry about the plane of the loop, so they
don't favour signals from only one direction. Think of them more as
having two diametrically opposed narrow reject regions in the patter, the
two accept regions are much broader. If you want maximum rejection,
balance the loop wrt the feed line and everything else near it.

Owen