Just ran a cross a pretty strong very over modulated phone conversation in English on 4428.1 usb a EE OM holding a phone conversation. Sounded like It was possibly a real time conversation with the Mic near the phone. I could only hear one side of the conversation which was the OM. I didn't have enough time to grab a recording. It reminded me of having a recorder on a desk like you would have if you were sitting through a lecture at College. It was running S7 - S8 so i'm thinking it was local seeing as how conditions are in the toilet today for me at this time of the day and there was no interference or fading. I tried different modes and Its most definitely USB.