Hello All,
Thanks for your replies. Here some reactions from my side:
I used an AN-1 in a concrete apartment for a year and it worked well
after I had made a change to it. Unmodified, it was quiet, didn't hurt
the signals but it didn't seem to have much gain. I added a thin
hustler 2 meter 5/8 whip to the end of the AN-1 whip (about 4 feet as I
recall) and that improved it consiserably. I think that Sony was
worried about generating spurious in high-signal areas like Europe and
used very a conservative amplifier. Adding a length to the whip in
weak-signal areas had no bad effects.
I did this as well, I do live in Europe (Holland) and it increased the
noise heavily, making it not really usefull for me.
Small active loop antennas are pricey but are most likely the best in
town choice.
Unfortunally, no money for that :\
To get an idea how this type of antenna will work in your location you
could build a passive loop at small cost using just coax cable.
This is what I am going to do. Aftre some digging around I will go for
copper tubing however, as on one site I found that on lower frequencies
thicker copper will do better then the thinner one advised in the
article I gave the URL for.
I'm looking forward to building somehting of my own though! And I'll
probably experiment afterwards to improve the results. Can't wait to
see wether it will outperform my AN-1 antenna.... The costs are, like
you said, minimal.
I'll post back when I have done some testing on my to-be magnetic loop