Howdy! This is probably a user interface error but I don't know what else to try. I follow the instructions coming up on the screen, Battery switch to "PWR", Inverter switch to "STBY", and UHF to "Main" or "Both" (I've tried each). I can't hear Biff. I did some research and read to fire up the APU and APU generator first so I did that. Still no luck. I've seen various things like make sure radios are set to "Man" and/or also set to "T/R". I've tried every combination I can think of and still no luck. I've also "RTFM". I need someone smarter than me to weigh in. I'm really excited to learn this but a tad frustrated at the moment. Thanks so much!