This rather unwieldy URL leads to a BIG list of MW broadcast stations. It
seems to be the entire Western Hemisphere; I'm sure someone will correct me
if I'm wrong. It's a big page. Here's a couple of sample lines:

WFLF AM 540 kHz DA2 Daytime B B LIC PINE HILLS
FL US BL-19921211AD 50.0 kW 51970 N 28 22 52.00 W 81 47
31.00 4 Eastern CLEAR CHANNEL BROADCASTING LICENSES, INC.

WFLF AM 540 kHz DA2 Nighttime B B LIC PINE HILLS
FL US BL-19921211AD 50.0 kW 51970 N 28 22 52.00 W 81 47
31.00 6 Eastern CLEAR CHANNEL BROADCASTING LICENSES, INC.

http://www.fcc.gov/fcc-bin/amq?state...2=&EW=W&size=9

"PM"