What can be done about the interference that HD radio causes to adjacent AM channels?
There are four classifications of potential interference: ground wave to ground wave, ground wave to sky wave, sky wave to ground wave, and sky wave to sky wave. A sampling of voiced concerns about potential interference (i.e. letters to Radio World, NAB sessions on the subject, and Internet list servers) shows that many are concerned with maintaining the ability to hear stations at a location other than the primary service area. It is likely (but by no means guaranteed) that the FCC will be most concerned with the potential for interference in the station’s PRIMARY (ground wave) service area, and less so with new interference in the secondary and intermittent service areas.
