Joe,
That model Hitachi does not have a built-in ATSC tuner, so you will have to buy an STB. Considering how cheap you got the set, spending another 500+ to get HD will be well worth it.
------------------
Steve S.
I prefer not to push the subwoofers until they're properly run in.
If the set has a built in HD tuner, yes. Most sets on the market are HD-Ready, meaning they do not have a built in ATSC digital tv tuner, and you'll have to buy an stb to recieve ota HD.
The 38" RCA widescreen direct view, and their 61" widescreen rptv have built in ota and DirecTV HD tuners...