In article ,
says...
Also, who sells external ferrite antennas? Also, what is a Hi Q
antenna?

While it might be considered overkill for one of the radios you
mentioned, the Quantum QX (http://www.dxtools.com/QX.htm) would most
assuredly overcome the limitations of the internal antenna. Another
alternative would be the CCRane AM Antenna (formerly the Justice AM
Antenna) (http://www.ccrane.com).

If you're inclined to experiment, you can make a tuned ferrite antenna
fairly easily with about $20 worth of parts (probably less if you can
find an old tube radio at a garage sale). Do a search on Google and you
should find lots of places with detailed instructions.

-- Jay