I know this sounds counter intuitive, but what I am trying to do is use an Elgato tv tuner to hook my imac to my Fios set top dvr.I know the Elgato tv tuner will work with over the air digital signals. What I don't know is will it work with a regular cable box. I have lots of stuff that I have recored on various discovery channels, the smithsonian channel and so on. If I can get them on my imac I can burn them so I can make more room on my dvr.