The OP and I, and probably many others, got little or no help from anyone in the RV business. I gave up on the factory satellite input and split to bdrm TV and ran cable from the Sat dish to the 612 receiver, split the signal and ran cable to the other TV. I feel certain that if I'd used the dual 622 instead, putting it in dual mode would have worked just fine. When the Tailgater and 211 came out, I switched to that system, adding an external ac powered HDD. That works and setup takes about five minutes, plus downloading time. However, the 211 remote is IR, and that's a pain.
BTW, about a month ago we switched the home system to the Hopper/Joey. It's visually unfriendly, difficult to locate DVR recordings, and the skip back, skip forward features are particularly frustrating. Skip back might go back 8 seconds as it's supposed to, or a few minutes. Skip forward has similar problem, and pause pauses, but when unpause is tapped, it may go to live.
Didn't mean to HJ.