This happens on different brands of radios when I connect to an outdoor discone. I program 225-250 MHz into a search, but end up having to lockout most of the frequencies due to open carriers. I turned off my computer, cable modem and router but the interference persists. Some signals are strong, 3bars, others are 2 and 1 bars. Two years ago the electric company upgraded their lines running directly from a sub-station to the local pharmaceutical company. These lines run the length of my street. Also, I live across the street from a railroad line. Could any of this be the cause of my interference? I've only monitored the Public Service bands the last several years and never noticed it on them.