Thanks to Doug Virden for this link to different stations' radiation patterns on 1090 kHz AM; too bad KAAY's isn't still "there":
I remember a story by one of The Greats mentioning that the lady who either programmed or owned the station in Nashville, TN called KAAY one early morning and DEMANDED that they change their night-time pattern immediately, because it was interfering with their station coverage locally. As the world turns (pun intended!), it would be several minutes before the station would automatically switch from the night-time to the day-time pattern, from daylight in Nashville to daylight in Little Rock. Whoever she talked to refused to change things just to suit her- KAAY was well within its legal limits.
Also, in my opinion, you can't fool with the nature of the atmosphere and how it affects radio waves. That's another subject entirely for another time....
Thank you, Doug!
Bud S. (email@example.com)