Not easy with a portable radio with a built in rod antenna. Simply move the
radio for best reception.
For radios using an external antenna (and preferrably with an S meter), you can
phase just about any two antennas together to get a steerable, unidirectional
pattern. I can throw out two 100 ft pieces of wire on the ground and null local
'super pest' 1290khz (5 kw and 3 miles away) down enough to hear stations under
at night.
Take a look at this:
http://www.qsl.net/wa1ion/index.html
Read some of the articles and get a feeling for what you can do, especially the
"broad band phasing" unit (scroll down a bit).
Questions?
Ask here !
jw
K9RZZ
Milwaukee