I just bought a house with an HD DVR that is newer than mine that DTV apparently doesn't want back. Unfortunately, I don't have the model numbers handy. I also have an SD DVR. Both have shows I haven't had time to watch and won't be able to watch for some time. Consequently, I don't want to activate another DVR and pay the monthly fee. What I would like to do is sap the access card back and forth to record new shows on the newer unit and to watch old show on the older one. Preferably, I would like to swap between the SD and HD unit, which would eventually give me an all HD system. Alternately,, I can swap between the two HD units, ultimately giving me a newer unit. Is either possible?