Go to this website-http://www.nws.noaa.gov/nwr/CntyCov/nwrAL.htm. If you know what county you live in, find it on there and all of the info you need is right beside the county name. If you live in a county that has more than one transmitter, you will have to try all the frequency channels that are affiliated with that county. Whichever channel transmits the best, is the one that you need.