You would be surprised at how far AM can propogate if there is nothing in its way to stop it. I presume you were using a U.S radio,, which would probably filter out the euopean frequencys on,, lets say 751,,,, it would be heard as squeal... I used to be able to DX spain on Outer Banks N.C on an analog car radio,,, I think it was on 1031,, but it played a mix of spanish and US pop music, and this was during the day,,, but would have been at night over there,, this was in the 80s,, Im sure the station is probably still there, but with dial congestion I doubt you would hear it over here now... Spain is only like 2000 miles from the south US Coast ya know.