Depending on where you are situated, a small loop antenna can really boost just about any portable you care to get. Tecsun AN200 loop is small, cheap, effective, and it's what I've used to snag some 3000+ mile catches with a Redsun 2100 & Degen 1103 receivers (both <$100 portables). Just sit the loop & portable next to one another, tune in a weak station, adjust the tuning control on the loop to really lift the station out of the mud - it can even make a station that's so weak that it just can't be heard to the point where it is decently listenable.