From: http://www.rnw.nl/realradio/html/medianews.html
United States/Worldwide
18 August 2000: There has been some uncertaintly concerning the transmitter
sites used for various recently-introduced AFRTS transmissions on shortwave.
National Public Radio, some of whose programmes are relayed by AFRTS, gives
the following information on its Website:
Key West, Florida: 6458.5 and 12689.5kHz
Puerto Rico: 6458.5 and 12689.5kHz
Sigonella, Sicily: 4993 and 10940kHz
Guam: 13362 and 5765kHz
Diego Garcia: 12579 & 4319kHz
Iceland: 10320 and 6350kHz