This is exactly what I want to do!!!! I already have the Roku, but I want to get a digital antenna and make sure it works before I let the cable go. Let me ask you. . . right now I use the cable company's remote to tell the TV to go to Roku. Once I get the antenna hooked up and disconnect cable how do I tell the TV if I want the antenna or Roku?
So - ROKU goes through your HDMI cable (and Internet), TV via your digital antenna is direct. So unless you use your remote and “select” HDMI you are usng your antenna.
Hope that makes sense.