I'm replacing my now obsolete 522 receiver - I have no need for all of the features of the Hopper, so I chose to get a second 722 - Most of the connections are straightforward, but I couldn't help but notice that the 522 has separate coaxial connections for channels 21- 69 and 3-4 but the 722 has only one coax connection that's marked "Home Distribution 21-69 and 73-125 - Which cable that I will disconnect from the 522 should be connected to the 722? -
Presumably, the two cables you have now go to two different TVs. TV 2 can be connected as before. It appears (from googling up a picture of the 722 back panel) that for TV 1 you are expected to use a better connection: ie: HDMI, Component, S-video or Composite video. (The first two being the typical HD connections and the latter two being the old SD connections.) So replace the cable to the main TV with an HDMI if possible. Although if it's an SD TV, you'll need to use S-video or Composite Video. BTW, HDMI does it all with one cable, but with S-video or Composite video, you will also need left and right audio connections.