Alphabet Soup — Buying a New TV

As I’ve written before, TV as we now know it in the United States is due for a change.

Since I wrote that last article, the end date of the transition from our current broadcasting standard has been set: February 17, 2009 is the date that your standard television set will go dark. Or, more appropriately, get nothing but “snow.”

Walking into the local electronics emporium can be daunting. There are a lot of new terms to learn: ATSC, DTV, SDTV, HDTV, 480i, 720p, 1080i, 4:3 and 16:9 to list but a few. And, the pimply-faced kids at most of the stores are truly ill-equipped to answer any real questions on the subject.

Follow along, and I’ll give you the skinny — what you really need to know to buy the right TV set to last you through the digital transition — and how to get a 27″ digital set for under $379!
Our current broadcasting system in the United States is something that has been around since pretty much the beginning of television. It’s called NTSC, and there are two flavors: black & white, and color. NTSC is an analog system, and defines such techie things as the scanning frequency, number of scan lines, number of frames of video per second, and interlacing options. You really don’t need to know all this — it’s all going away soon — but for those interested, the basic spec is 480 lines of vertical resolution, 30 frames per second, with video information interlaced in two fields (making 60 fields per second). The picture is not too bad, especially on smaller (sub-19-inch) tubes.

Our new broadcasting system is something called ATSC Digital Television, or, DTV for short. DTV comes in several flavors, all of which are color. Here’s where it gets tricky …

HDTV is what all the stores want you to buy. HDTV stands for High Definition Television. The pictures are awesome — assuming the source content was recorded in an HDTV format.

“Uh, what’s that, you say? AN HDTV format?”

That’s right, there’s more than one. HDTV, or HiDef, can be recorded four ways! It can be 16:9 (wide screen), 4:3 (standard screen) at either 1080i (1,080 lines interlaced) or 720p (720 lines progressively scanned).

I’d better describe the difference between interlaced and non-interlaced. In interlaced video, the picture is broken down into two fields. Field one contains all the odd-numberd lines, and field two contains the even-number lines. The two fields are displayed one after the other, and video looks good. The reason for interlaced video was that early picture tube systems could (a) not scan the entire screen fast enough to display the whole image and (b) the “persistence” of the phosphors was not long enough to display the image through the intire scanning cycle. So, interlacing was a way to scan the entire tube rapidly, while at the same time refreshing the adjacent phosphors. This gave the appearance of smoothly flowing video. However, in larger screens, the spacing between the lines can be clearly visible.

Here’s where “progressive” scanning comes in. Newer technology in tubes and support electronics allows for large screens to be scanned much faster, and better phosphors will glow longer. So, engineers figured they could scan the lines sequentially, or progressively, and cram more lines on the screen. The result is something called 720p, and the video looks like film! In fact, some digital camcorders call this mode “film” mode.

LCD, DLP and Plasma screens have always been able to “keep up” with this higher quality video.

Now, where were we. Oh, yes. What exactly is going to be on the air?

I mentioned that DTV comes in a few basic flavors: 16:9 at either 720p or 1080i and 4:3 at 480i, 720p and 1080i. If you look closely at that list, you should notice something familiar: 4:3 at 480i. That’s the same resolution, aspect ratio and scanning as our current NTSC analog, and it’s referred to as SDTV — Standard Definition Television — or, a digital version of our current standard.

A good 27″ 4:3 ratio SDTV set can be had at major retailers for less than $379, with the required digital tuner (ATSC) built-in! For only a couple hundred more, you can get the HDTV version of the same set.

So, to start your digital transition without breaking the bank, you can look for sets that are SDTV with an ATSC tuner, and know that you’ll have a set that will continue to work for years to come. The information will be clearly listed on the box. If it’s not, don’t ask the pimply-faced kid at the store (or, the fellow who looks like he failed as a used car salesman). Check the manufacturer’s web site for specifications, or heck, ask me.

Now, I’ll let you in on another little known fact. The US government will be rolling out a program to assist you in transitioning to digital. They realize that many folks will have a hard time affording a new TV. So, the government will issue up to two vouchers per household to assist in purchasing a set-top converter box to allow you to continue to use your existing televisions to view SDTV signals. The realize that, while they can mandate what goes out over the air, they can’t force you to by a new TV.

Stay tuned, so to speak, and I’ll tell you about ways to view those wonderful digital signals — again, without breaking the bank!