By Danny Kumin

1) I know about MTV, CATV, and CCTV. What's DTV?
DTV stands for Digital Television. The FCC has gifted broadcasters with a few billion dollars worth of TV-band spectrum to commence the changeover from the analog "NTSC" system we all know and love to a powerful, flexible, and quite complex digital one. DTV's potential benefits are: far greater video and audio quality; a more robust signal---being digital, DTV is either there or it's not, there's no such thing as snow, ghosting, and the like; and a highly configurable transmission channel that eventually will empower a single station to send out one channel of high-quality, or two or three (or more) programs of lower image quality.

2) Okay... so then what's HDTV?
High-Definition Television. The short form is this: All U.S. HDTV is DTV, but not all DTV is necessarily high-def. The new standard encompasses 18 different video-image formats. Only three or four of these are important, at least just now. The most frequently employed high-def DTV flavor is 1080i, a format that delivers about triple the perceived resolution of "regular" NTSC TV images (though such comparative descriptions are notoriously subjective). Another currently employed high-def option, 720p encodes a bit less internal resolution but delivers twice as many fresh "fields" (frames, sort of) per second; a lot of video experts consider 720p better for sports and other motion-rich programming but prefer 1080i for typical TV and film programming. The 480i DTV format is pretty much a digital equivalent to today's analog (NTSC) TV---except that, digitally delivered, it's immune from video noise (snow), ghosting, banding, and the other visual flaws that weak-signal "POTV" suffers.

3) What else can DTV do?
Simultaneous data-casting and two-way interactive TV are two future possibilities. And as already mentioned, a single DTV broadcast channel might be used to transmit two, three, or even more 480i (standard-definition) or even lower-def---programs. Put another way, a single DTV channel can be applied to quantity instead of quality. Just think: Montel, Jenny, and Maury, all from the same "channel," all simultaneously. Is this a great country, or what?

4) How do I get my DTV?
Right now, just about every major U.S. market has at least one station actively broadcasting DTV over the air, and several big ones---New York, L.A., Washington D.C., Boston---have three or four or more. All of these to date are on previously unoccupied slots of the UHF band, and can be received via existing UHF antennas. (Eventually, DTV stations will crop up here and there on the VHF 2-13 band, too.) Signal-strength and freedom from multipath are both important---remember, DTV is an on/off proposition---so antenna placement, cabling, and in-line amplifiers can be key. Big-city or fringe-area dwellers may be well advised to seek the help of an antenna pro.

5) What about cable TV?
Technically, there's nothing much impeding cable companies from distributing DTV. As far as the actual wire is concerned, a DTV channel is indistinguishable from a regular UHF station---electrons is electrons. But the cable guys have been very slow to roll out DTV, partially because the "head-end" equipment and other capital start-up costs are steep, and partially because there are---so far---only about 37 customers in each market who care. Cable is a huge cash-cow industry, so why fix what ain't broke? What's more, unlike over-the-air broadcasting there is no FCC requirement mandating a cable changeover. Bottom line: Only a tiny handful of cable systems currently carry any DTV stations. But this will change, with increasing speed. By 2005, certainly, DTV-on cable should be widespread.

6) Okay then, what about small-dish satellite?
DirectTV already has two channels broadcasting movies in 1080i hi-def; Echostar's DISH network has one as well. In both cases, however, you need some new equipment: for DirecTV systems, a specialized antenna (that can "see" two satellites) and a combination DSS/DTV receiver that doubles as an over-the-air DTV tuner; DISH systems require a Model 5000 receiver with the addition of a hide-away Digital Modulator component, which connects both to the Model 5000 receiver and to the antenna input of an existing DTV tuner (or integrated HDTV set), which is required.

7) So all I need is a UHF antenna and a new DSS or DISH setup and I'm in business?
Uh, no---did I neglect to mention you also need a new TV? Actually, as you may have surmised by now, first you need a DTV tuner or "set-top box" (STB). This receives DTV signals from an antenna (or cable) and sends them in a format that the TV can handle. STBs also provide a digital-audio output, since DTV broadcasts carry sound in Dolby Digital format, either stereo or 5.1-channel surround, with all the same virtues found on DVDs. But as mentioned above, HDTV-capable DirecTV receivers also function as over-the-air/cable DTV STBs, making them the most economical solution by far if you also want to make that upgrade.

8) You said something about a new TV?
Well, err---yeah. While nearly all DTV STBs can deliver standard-def (480i) to today's TVs, this kind of defeats the purpose. (Though this gets clearer, noise-free images---more or less DSS-like in overall quality.) But to view the good stuff in high-definition 1080i and 720p formats, you need a far more capable television than what you probably have right now. Whether a direct-view "tube" type or a rear-projection model, this can be had in two basic forms. "DTV-ready" sets have the image quality and wide bandwidth to display DTV, but require an outboard DTV tuner---the set-top boxes already mentioned. "Integrated DTVs" have all the requisite electronics on board, with the STB built right in. Both types are available in two screen formats. 4:3 DTVs have the screen shape familiar to all from 50 years of television: just over-square, four units wide by three high. 16:9 models display widescreen shapes that better match the "anamorphic" aspect ratio of typical movies and produced-for-HDTV programming.

9) So which is better, 4:3 or 16:9?
One school favors 4:3 screens even for DTVs, on the theory that for years to come much programming, whether DTV or NTSC, will be conventionally formatted. The 16:9 school maintains that, regardless, displaying a widescreen movie (or other program) on a 4:3 set wastes about a quarter of the set's potential resolution, since the wider image necessarily leaves full-width black bars across the top and bottom edges---and since those screen elements (pixels) are not being used, the visible image can only be resolved by the remaining three-quarters. (Of course, when you watch 4:3 material on a widescreen set, the same is true in reverse.) For what it's worth, I myself favor 16:9 sets: Once you've seen a high-def movie shown full-screen in your own living room, it's awfully hard to go back.

10) Anything else?
A few items. Most DTVs/STBs also function as high-performance "regular" (analog NTSC) TVs/tuners, too. Unfortunately, not all STBs are compatible with all DTV-ready sets, due to non-compatible interconnect formats. VGA, the familiar 15-pin cabling system used between PC and monitor, is common, but "HD Component," a high-definition version of the three-wire interconnect (usually RCA jacks) between top-line DVD decks and high-end NTSC televisions, is quickly becoming the most prevalent. Fortunately, many recent DTV sets include both inputs, easing compatibility worries. (A minority of DTV-ready monitors, mainly high-end front-projectors, accept only RGB/HV connection, usually via four BNC jacks.)

Note: also that just as all DTV is not necessarily HDTV, not all DTV-ready sets (or integrated DTVs) assure full-resolution display of all hi-def formats. Most direct-view DTV sets present a 1080i image intact, but only the highest-end rear-projection big-screens can really make the same claim---but most that don't come very close, and still look dramatically superior to regular TV. (A class of less costly, "improved-definition" sets display DTV in 480p format, a sort of halfway point between POTV and hi-def.) A solid majority of DTV STBs and integrated sets perform line-doubling processing on incoming "regular" NTSC TV signals, improving image quality somewhat though the ultimate results vary widely from brand to brand and model to model.

11) Geez, this all sounds expensive.
That's a statement, not a question. Oh, all right: Yes, DTV is big-ticket stuff---for now. A DTV-ready set with reasonable hi-def compatibility currently runs anywhere from around $1100 for the smallest direct-view sets to $10,000-and-up for the top big-screen RP models. Set-top boxes start at $650, and integrated DTV televisions at $3500 for the most affordable, smaller-size direct-view models. These prices will come down, of course, over time, but precisely how rapidly is not entirely clear. On the one hand, DTV is not gathering momentum as rapidly as did DVD, which dramatically out-performed most initial expectations. On the other, with its hi-def allures and FTC mandate DTV is, quite simply, the future---when it starts rolling in earnest, it should quickly be become a juggernaut.

As always, the cost of being an early adopter is high. But so are the advantages---especially if you like company. Because once friends and family see hi-def movie and hi-def sports, their own OTV screens are going to seem pale things. Make them bring the pizzas.

Danny Kumin is technical editor of Stereo Review's Sound & Vision Magazine