640 AM - The following radio stations broadcast on AM frequency 640 kHz:[1] 640 AM is a North American clear-channel frequency.[2]KFI in Los Angeles, California, KYUK in Bethel, Alaska, and CBN in St. John's, Newfoundland and Labrador, share Class A status of 640 AM.
Between 1951 and 1963, the frequency was also one of two used for the United States' CONELRAD emergency broadcasting system, the other frequency being 1240 AM.
2 Shortwave uses a combination of AM, VSB, USB and LSB, with some NBFM and CW/morse code (in the case of time signal stations) as well as numerous frequencies, depending on the time of day/night, season, and solar activity level. A reasonably full list from 16 kHz to 27MHz can be found at [1]
3 Regions 1 and 3 also use Region 2's frequencies as well, with 50 to 100 kHz spacing.