"William Mutch" schreef in bericht
the shielded loop performs this way is that near field noise is
cancelled while far field signal is only attenuated by some factor
relating to capture area. In my temporary rooftop mount I was unable to
easily check out the effect of broadside null.

William,
I have done some work on local QRM reduction during the last
few years. Summarized on:
http://home.plex.nl/~jmsi/
Most important is avoiding any coupling with the coax/feedline.
With small magnetic loops this is easy to accomplish and my
guess is that this is why loops are less susceptible for local QRM.
That is why I choose small loops instead of small dipoles.

73 de Jan PA0SIM