Over and over I read that you need a multi-satellite elliptical dish to get HDTV from DirecTV. However, I assume this requirement is for getting BOTH HDTV and regular service, as they come from two different satellites. Suppose I want ONLY HDTV. Can I do it with a single, round dish, pointed only to the HDTV satellite? My thinking is that instead of installing a multi-satellite dish now, in case I want HDTV later, it may be much cheaper to put in a round disk now (to take advantage of the cheap new-installation bargains), and add a second dish later should I ever want HDTV.