Have new HR54 along with Genie for my 4K TV. Installer told me I could NOT connect my old AM21 to the HR54 and said he was certain of that. However, I've been reading posts in various forums where folks have done just that. So if I CAN connect, my questions: will I be able to record the OTA programs? I assume so but need to be sure. Second, my OTA antenna has coax output cable though HR54 has USB input. Assuming there is such a thing as a "coax to usb connector, will it work when connected to the HR54's USB input? Where can I find such a connector? Thank you for any assistance.