AM DXers are all familiar with the tuned loops
you can use to boost range. But we are all familiar
also with the constant tweaking and tuning of the loop.
A few years ago, I make an untuned loop and had a good
time tuning it day and night times, up in the mountains
of Maine. So this time, I brought my plain Sony ICF-S10MK2
pocket AM/FM radio, and parts for the loop.
OK...how you make one: you make a big rough single loop
of wire (clipped to itself at the end) on a dining table, hanging
to the floor. You wrap a coupling loop (3-4in. diameter)
around a hand and twist-tie it together. Then you slip
it beret-style over the top side of the radio, and tune away.
Results were a fair boost at night, and a big gain in qty.
of stations in daytime. Going bigger gives major improvement
though. In order to do that, you need a loop "top frame" bigger
than a dining table. Two 4-ft dowels lashed helps. Going from
5 feet to 8 feet, and 13 feet total wire to 20 feet, really brings
the signal in. An excellent untuned loop would be an X-shape
with maybe 4-foot spokes stuck in a drilled block, and wire
taped or eye-hooked out at the ends.
The untuned loop is a little combersome, but I love not
having to fiddle and tune it.