Sorry, I took dvr to be receiver rather than recorder. Usually that is a pvr, or a personal video recorder. For that I use a HD Home Theater Computer and Windows 7 Media Center.
Try your omni directional antenna. I never have any success with them but like I said I am in a difficult reception area. You have broadcast towers arrayed around you like I do and you may need a rotor, (I don't like fooling with rotors so I use multiple antennas). If your omni directional antenna does not work see what your neighbors are using or search this forum with your zip code or neighborhood name and see what antenna others are using. If that doesn't help I would suggest you start simple with a sliver sensor or a channel master 4220 inside, (before running cable and setting up a mast), and experiment with positioning the antenna. Small changes in where you put the antenna and where you point it can make a big difference. Go to Frys and get your antenna, if you are not satisfied take it back and step up to a channel master 4221 or the monster 4228. However, I think reception is simple for most people and one small antenna does the trick. Getting reception is a much art as science. Start small and simple.