Originally Posted by overlander63
As long as your HDTV has a digital receiver, nothing. At most, you would have to purchase a digital converter for your tv, if you were one of the unlucky ones to get an analog-equipped HDtv.
While technically correct, luck has less to do with it than when you got into HDTV and how much you spent. Until the FCC put their foot down and enforced a phase-in of digital (ATSC) tuners, the Consumer Electronics Association and their members delayed implementing them in TVs, including HDTVs, except for high-priced premium models, for which they were charging $1,000+ extra.
Most early-adopters of HDTV, in fact, have only the old analog (NTSC) tuner, and, as said, will need the same converter as those with standard-def (SDTV) televisions.