I've got a problem with radio frequency noise coming from my HR-20. I have an outdoor long wire AM antenna. The HR-20 emits a steady 60 cycle noise on the AM band that's really pronounced. The HR-20 is grounded properly to the electrical ground via the dish. I tried unplugging the two converters, no change. The noise is there as long as the unit is plugged in. If I unplug the power cord, all is quiet. As soon as I plug it back in the radio noise starts again. Has anyone run into this issue and if so how did you solve it? I unplug the unit when I want to listen to the radio then plug it back in when I'm done. It's rather annoying when I want to listen to the local high school football games and wife wants to watch tv. Seems like it could be a power supply noise. Should i contact DTV and see if I can swap it for another?