Digital cable TV tuner
While a QAM can be harder to find in more basic, smaller TVs like the kitchen set I was looking for, most of the larger sets now feature integrated QAM tuners. That said, if QAM is a feature you're interested in, always check the specs to make sure it's there. (Note that "ATSC" doesn't guarantee QAM compatibility-you want to make sure that QAM is specifically mentioned).
3. You probably won't get any premium cable channels.
There's no ESPN, CNN, MSNBC, CNBC, and assorted other "premium" channels. Depending on your provider and location, you may get some bonus channels such as TBS and WGN.
4. Channels have funky numbering and can move around at moment's notice.
When you start scanning for channels, you'll notice that some of the stations are labeled in ways you're not used to seeing, like 2-131. Also, you might have thought you lost a channel, but it's simple been moved and is labeled differently. Tip: Scan the channels in, then add the ones you think you'll watch most to a favorites list that you should be able to access from your TV's remote. It's the easiest way to jump between good channels without wading through the crappy ones. Typically, you'll have about 8 to 20 HD channels and the rest will be standard-definition channels that generally look pretty poor. Which leads us to...
5. HD channels look a lot better than SD channels.
The difference is night and day, even on a small set, because many of the unscrambled SD channels have limited bandwidth devoted to them and look grainy.Elgato USB QAM tuner. Sarah Tew/CNET
6. Some HD channels come in better than others.
Unfortunately, the signal of some of HD channels you get using a QAM tuner can be shaky. While the sound usually is fine, you can get little tears in the picture or the channel can go out altogether. In other words, it's not the most reliable way to watch TV (you can always switch to the SD version of an HD channel, but, as noted, the difference in picture quality is usually huge). How good your picture is will also depend on how strong a signal you have coming into that particular outlet. In some cases, your signal gets split (multiple times) and that's bound to lead to picture problems. If you don't feel you're getting a strong-enough signal, you'll have to call in a technician from your cable provider to see if anything can be done.
7. What channels you get will vary from cable provider to cable provider.
Different cable companies are piping out different unscrambled stations. Usually, all your local stations should be available, but it's possible for stations to disappear from time to time. To find out what's available at a given moment from your cable provider, the best advice is to use Google and troll the message boards of sites like AVS Forum.