Rolls pm351 picking up radio
I’ve using a Rolls PM351 for vocal and bass in ear monitor for about a year now and it’s been great. Until….yesterday I played a party out in the country and the mic line picked up AM radio station so strong that I couldn’t use it. The instrument line was usable but the radio was there to, just much weaker. I had to unplug the mic entirely from our PA or it would broadcast into our PA
Is there thing I can do too fix this when it happens?
Thanks for any help!