I have MICS 6.1 with a single T7406e. Phone has been working fine. Now the recipient party will hear a buzz when speaking with the T7406e. The antenna is about 15 feet away from the cordless. this is a small office. I did not try that RF Scan procedure. Is it worthwhile? I changed the power supplies, and moved base to a different spot. No change. Is it a bad handset?