So that's what I may have been hearing on WTOP, 1500 in Washington DC. It's sort of a rushing noise, a bit like older TV sets used to put out on the AM bands. If that is the source, I have never heard WTOP advertise that they are broadcasting digital and there wouldn't seem to be an advantage since they ar 24 hours news unless AM stabelizes reception for a given distance. Is there a listing of U.S. stations broadcasting digital? 73 Bob Martin KC3FI PS Hope this letter doesn't bounce due to format. Changed mail program and settings.