Is it possible to remove the HDD from a 622, put in an enclosure, and then connect to a Hopper 3 via USB port, and use as an external HDD to access the recordings already on the drive? Anybody done this, or does it seem feasible / plausible?
In theory you could remove the drive, put in an enclosure, and use as an EHD on a Hopper 3, but you would not be able to view prior recordings from the 622. As soon as the H3 recognized the drive plugged in, first thing it will do is reformat the drive.
That all said, if you want to keep the recordings from the 622, you just need to get an EHD now, plug it in to the 622 and backup the recordings you want to keep to the EHD. Then you can plug the EHD into the new Hopper and transfer them or watch them from that EHD.