With all the talk of 3D, plasma vs. LCD, LED TV backlighting schemes, 240Hz vs. 120Hz, and all other sorts highfalutin technical specs, there's one small but potentially important TV feature that doesn't get a whole lot of play: The QAM tuner.
Just what is a QAM tuner? Well, according to Wikipedia, QAM stands for "quadrature amplitude modulation, the format by which digital cable channels are encoded and transmitted via cable television providers."
More specifically, it allows you to pull in certain digital cable channels without the use of a set-top box. Or, as the Wikipedia entry puts it, "an integrated QAM tuner allows the free reception of unscrambled digital programming sent 'in the clear' by cable providers, usually local broadcast stations, cable radio channels, or in the case of providers which have transitioned to do so, public access channels."
Now that we have the definitions out the way, let's move on to the real world. I wanted to mount a small LCD TV on the wall in my kitchen--but I didn't want to deal with a set-top box. First off, the place where I wanted to put it (above a table that was attached to the wall), there was simply no place to put a set-top box and I couldn't build a shelf for it inside the wall. To get that nice, clean, wall-mounted TV look, I simply couldn't have a box. I also didn't feel like paying $6 a month to rent a box if I didn't have to.
I did a little research on QAM and started looking for a cheap 1080p LCD TV that looked decent aesthetically. It actually wasn't so easy to find an inexpensive set that fit my criteria and had an integrated QAM tuner. But I ended up with a refurbished 24-inch Viewsonic VT2430 that cost $180, which seemed to fit the bill (the set has received mixed reviews from users but so far has worked fine for me).
At the time I bought the TV, I had Time Warner Cable. Indeed, when I hooked the set up, I was able to pull in several stations and was content to receive all the locals and a few other random stations, most of which I assume you could get with an OTA (over-the-air) antenna. Some of the channels came in with a pretty sharp wide-screen picture. While it seemed to fall a bit short of true HD, it was close enough and for the type of stuff I had running (kids programs, a lot of PBS, some sports, and a sitcom or two), it was fine.
The situation changed dramatically when I switched to Verizon Fios a couple of weeks ago. Ironically, when I asked the installation technician about QAM, he said it wouldn't work and that I needed a box (he even made a call to ask). I said no, I'd read on the Internet that it did work. And indeed, when he finally got everything set up and I plugged the coaxial cable into the back of the TV, hit scan on the tuner, I immediately started pulling in stations, many in pristine HD. Again, most of the stuff was local, but there were a few nice bonuses like WGN from Chicago.
The technician seemed moderately surprised by my box-free demonstration.
"OK, then," he said. "Well, now I know QAM works with our system."
Somehow this guy had done hundreds of installs and never bothered to tell anybody about it. Which made me realize that there were probably thousands of cable subscribers out there who had unneeded set-top boxes attached to lightly used TVs.
Magical as this all sounds--and not in an Apple iPad way--some people will have some qualms with QAM, which is why I thought it would be a good idea to provide a few tips on the subject.
1. You need basic cable.
For starters, for the QAM scenario to work, you do need to have basic cable running in your home--and cable outlets around your house to tap into (you just run a coax cable to the back of your TV; no HDMI or component required--this is a direct feed). To get basic cable, you usually have to pay something, which is why I put "free" in quotation marks in the headline. Satellite systems Direct TV and Dish don't work with QAM.
2. Many, if not most, of the larger name-brand HDTVs have built-in QAM tuners.
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.
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.
8. QAM tuners are available in other products, not just TVs.
Many QAM computer accessories are available, such as Elgato EyeTV (for Macs) and Hauppauge's and AverMedia's tuner cards and USB dongles. They have built-in QAM tuners so you can watch TV from your cable provider on your laptop or desktop computer. Some of these accessories even allow you to record the video signal to your computer's hard drive.
9. Using a QAM tuner to get cable won't save you a lot of money, but it does add up.
Set-top boxes cost whatever they cost to rent a month. If you think you're really going to use a particular TV to watch all the channels, you're better off forking out the $6-$10 a month (or whatever your cable company charges a month to rent a box). But all you have to do is multiple by 12 to see what you save for the year. It could mean as much as $100. That's not a lot but it's $100 in your pocket rather than the cable company's.
10. Cable providers will most likely keep piping out "unscrambled" channels for a while, but that doesn't mean they won't cut them off someday.
We can't tell you what will happen in the future, but cable providers continue to broadcast unscrambled channels that can be decoded with a QAM tuner. We don't see that changing for a while, but there are no guarantees.
It's important to note that we haven't tested every cable provider out there for compatibility with QAM, so if you have any QAM experiences to share, please add them to the comments section.