Try unplugging and reinserting the KX3/KXPA100 interface cable., I seem to remember someone else having this problem and it was a bad connection at the radio end. -- View this message in context: http://elecraft.365791.n2.nabble.com/KXPA100-ATU-Issue-tp7584424p7584428.html Sent from the Elecraft mailing list archive at Nabble.com.