I believe you're right. This must be the reason. Thanks for your help
I hope you get it figured out. Check out DFU's Post 38 - the Select-A-Tenna is marvelous for pulling weak stations out of the mud. I myself use a CC Crane radio for listening to one small town AM station that carries high school football games for which I have a special interest. The station is far away and their transmit power is miniscule, but the CC Crane radio pulls it right in.