I found an RCA DTC210 HD receiver.. Wondering if these are still supported by DirecTV. I heard they do not work with MPEG-4.. Not sure of all HD channels have switched over to MPEG-4 or just the locals.
You cannot get HD signal because they are made to run on the 101 and 119 and all of the most recent HD channels have migrated over to the 99 and the 103, but it will still work as a standard receiver.