Groan, I've been there too.

Here's a wild idea that worked for me as well as anything did back in
my urban apartment days.

Assuming you have metallic window-screens (plastic screens do NOT work
at all), try wrapping one end of a length of wire around your radio's
whip (or push wire into center coax connector) and the other end hooked
around some part of your window-screen.

The window-sceen acts as a capacity hat and seems to allow decent
signal pickup.

That said, a tuned loop would work better but will cost you time or
money.

You might try the Sony AN-LP1 if you don't mind switching bands and
listen mainly to the standard SW broadcast frequencies. It doesn't
cover the utility bands.

Still, a length of hookup wire is cheap, so I recommend trying this
first to see if it improves things. It's certainly true that you can
spend any amount of money on radios and antennas, and even so there are
no hard guarantees of results.

Good luck.