Ron, the Home Distribution output on the 622/722 is analog not digital.
If you tried several different UHF channels (assuming you changed the receiver modulated output accordingly) and still didn't get a clear signal, I would guess you have a problem with your cable distribution in your house. Also, you need to determine if the signal is not "clear" because of week signal (snowy picture) or interference on the same frequency, usually "herring bone" type of interference with a strong signal.
If your house is wired for Cable TV you may have (usually at the cable entrance to the house) up to 8 way splitter which splits the signal (1/8) to all the locations in your house. I would trace each cable to each room and splice 2 cables (with a barrel connector) from the 622/722 Home Distribution output with a specific TV in one of your rooms. This way you can verify the quality and integrity of each of your cables. If you find out that all your cables are good then you can use a 2 way splitter to any two rooms, instead of the 8 way splitter which will increase the signal strength to these rooms.
