Is this right: If a tv has HDTV, it already has a HDTV tuner inside of it. If a tv is HDTV-ready, it needs an external tuner. What about other tvs? Can a non-HDTV-ready tv be turned into an HDTV with an outside tuner? Also, it would seem more advantageous to buy a tv w/o a built in tuner since there is no industry standard on the type of HDTV which will be used. Thanks for any responses.