Hi!

On many modern radios, the AM antenna is inside. It's a ferrite bar wrapped
with many turns of fine wire.

I would suggest looking for a radio that offers the ability to connect an
external antenna for AM, FM or even both bands. You can then hook up a long
wire antenna and this should improve the reception.

Also check for common sources of interference to AM broadcasts, such as
fluorescent lighting, motors and some switching power supplies.

William