Digital TV Mythconceptions

No, I didn’t misspell that title.

Now that I have two TVs and a converter box and have had time to play around with them, now that two of our local TV stations have dropped their analog signals, I think I have a pretty good idea how well digital TV is going to work and it’s not a pretty picture.

The TV industry and the FCC are telling us how great it is and how easy it will be to receive local TV programming once analog TV is gone. Here’s my take on the Myths and misconceptions about digital TV, a subject I have written about before, but still is an issue.

1. Digital TV is High Definition. FALSE. It can be. But it probably won’t be. Most of what is on digital TV (DTV) is still in the same resolution they put on the analog signal and at the same old squareish 4:3 aspect ration. More and more content is coming out, though in the wide screen aspect ratios that you will like to see if you buy a new flat-screen TV. The networks have spent the money and will soon be nearly 100% wide screen, but it’s still far from HD. Of course, there are so many different levels of high definition TV, that it’s hard to decide which are true HD.

2. DTV is better. FALSE. A digital TV signal is beautiful to behold. If you can see it. The truth about digital TV is, it is all or nothing. While it comes in, a DTV signal is pure and clean, no snow, perfect color, perfect sound. But as soon as it gets a little weak, or some electrical noise comes along, what do you see? With analog TV, you might see a few white dots mixed in your picture. You might hear a buzz. With Digital TV, the screen goes blank. You get nothing until the signal gets back to perfect. One of my TVs doesn’t even recover, you have to change the channel and come back to get it to redisplay the channel.

3. The FCC brought you digital TV to make TV better for you to watch. WRONG! The main reason for DTV is to squeeze the TV stations into a smaller piece of the radio spectrum so the can reallocate some of it for other purposes. Most DTV signals are ending up being shifted to UHF channels. Remember, just because you see a DTV channel say it is 4-1 or 7-1 doesn’t mean it is on channel 4 or 7. The channel number is programmed on the data carried by the signal and could just as easily be A or B or X as a number. They call it 4-1 so you will associate it with it’s old analog channel 4.

4. I don’t need a special antenna, the one I have on my roof will work fine. YES and NO. Many of the new digital stations will be on UHF frequencies, although not all. You will need to do a little research and see where your local stations will end up. If you currently have a good VHF-UHF TV antenna, it will probably work okay, but if it’s a little weak on the UHF end, you might need an upgrade. The good news is, UHF antennas are smaller than the VHF or UHF/VHF combos. One problem I’ve found is using a rotator to aim the antenna can be a problem. With analog TV, you just watch the screen and turn until you get the best picture. With DTV, there is no picture until the signal reaches a point where it can be decoded, then there is no difference in picture as you swing through the signal’s peak. You almost have to know where to point the antenna in advance. The converter box I have has a menu option with a signal strength indicator, a nice idea that both TVs lack. You can get information about all this at Antennaweb.org. Here in Buffalo, we will be left with only one VHF station after the transition, WNGS in Springville, and they won’t go on-air until after June 12th because they have to wait for WKBW to vacate channel 7.

5. What do you mean UHF? It’s channel 2, 4, and 7. Aren’t they VHF channels? NO. The funny thing about the channel your TV displays is, it is encoded in the data sent along with the signal. Our channel 2 is on 33, 7 is on 38, 29 is 14, 17 is 43, 23 is 32, and they don’t even list channel 4’s new assignment.

6. I don’t need a new TV, mine will work just fine with a converter box. MAYBE. Unless you bought a rare flat-screen TV that doesn’t have a digital tuner built-in, your TV is only going to last so long anyway. Old style CRT televisions are not energy-efficient and let’s face it, it’s just not practical to have them repaired anymore. When it goes, it will be cheaper to replace it than fix it. Prices are dropping and by next Christmas, you’ll find a new set awfully attractive.

Posted in Rants, Tech Stuff, TV
3 comments on “Digital TV Mythconceptions
  1. Al Gritzmacher says:

    Craig Maser >grgeliz @ yahoo.com wrote, but it somehow didn’t get posted here, so I’m pasting from the email:

    I’ve had my converter box since December 2008 and it is connected to my tv. Since then, channel 7, 67,51, 5, & 11 don’t come in any more.
    With analog, my 1994 23″ screen picked up all of these stations. Once June 17, 2009 comes around, I don’t know if I’ll get any Channels.
    There is so much misinformation on every channel. They don’t tell the whole story. They don’t want to upset us because you have to buy a converter box, antenna, and/or a new tv when we used to get all of our stations for free. Please respond. Thank You.

    You’re right it is a dismal picture. The TV stations and the NAB are putting on a brave face and acting like they support this, but in reality, they didn’t ask for it. They didn’t want to be given a deadline by which they had to spend millions of dollars to buy new transmitters, antennas and upgrade studio equipment to support a move that is going to leave them with less coverage area and therefore fewer viewers and advertising dollars.

    What will happen after June 12, nobody knows. Will the stations be able to upgrade the present digital signals to acheive anything close to what they have with analog now? Will they be able to install satellite transmitters to restore some of the lost coverage? It may take years to do.

    WIVB, Channel 4 in Buffalo, which has always enjoyed coverage from Toronto to Central Pennsylvania is already adding language to their announcements to warn the outlying areas they may lose the station and to call the FCC for guidance.

    If Canadian TV reception here in the states is any indicator, the reverse path may be bleak as well. I have always enjoyed good reception of all the major Toronto and Hamilton stations and several weaker Southern Ontario stations that might have been snowy, but watchable. I had wondered what the Canadian DTV scheme was, because I had seen (until recently) no DTV channels out of Canada. It turns out, CITY TV in Toronto, was the first digital TV station in Canada and probably one of the first in North America and has been transmitting digitally since 2007.

    The Canadian TV industry will undergo the same switch by August 31, 2011. But the only Canadian station I can get digitally, even by turning the rotor, is CBLT, Channel 5 (digital 20, displays as 5.1)

    The only one that stands to benefit from this – unless you buy into the better picture quality argument – is the FCC, which stands to collect a bundle in spectrum auctions when they give the VHF space to data carriers who want it for wireless data and can’t get enough spectrum.

    So, when you can’t get TV over the air anymore, download it off the internet. That’s where the spectrum is going.

  2. Al Gritzmacher says:

    One more thing. The switch to Digital TV, once the bill has been paid by the TV stations, has one perk that benefits the existing stations, rather than encouraging new stations and the diversity of viewpoint and programming they might bring. That is additional “channels” carried on the same signal.

    Whether the stations view this as an opportunity to make up for the expenditures of the upgrade they were forced to make, or an opportunity to capture more advertising dollars, it further entrenches the existing media and makes it harder then ever for any new outlets to get established.

    The digital channels are 6 mHz wide, the same channel width as the old analog ones, but they can fit 3 or 4 channels on the signal. Couldn’t they have shrunk the channel size to 2.5 mHz and doubled the available channels, but only put one picture on each? That would have been fairer to all and encouraged new broadcasters, but the FCC threw the TV industry the bone of having the extra on-carrier channels to appease them.

  3. Al Gritzmacher says:

    http://www.popular-communications.com/23-AntennasWeb92708.pdf is an article on making a small Yagi antenna for DTV. It’s technical level and construction techniques are a bit better than the YouTube video variety of DIY projects.

    But the thing I found interesting, is the author makes some good comments about the digital TV signal’s actual makeup and shows some spectrum plots of typical signals.

    One more thing of interest is his observation that the digital transmitters are “running typically 14 to 17db less power.” To me, that says that if, after the transition, if the coverage sucks, and the viewers let the stations and FCC know, there is room to increase power to compensate.

    Another good antenna construction project can be found at http://www.digitalhome.ca/ota/superantenna/index.htm.

    Most of the web articles I’ve seen so far on DTV antennas are total crap. “Cut some wire from a coathanger and screw it into some wood with a washer” or “glue some tinfoil to a shoebox and hook a cable to some wire and tape it to the box.” just isn’t either specific enough to make a reproduceable design. The worst I saw was the one where they wrapped the “cocktail” cable around a nail and pounded it into a coffee can. They must have been joking.

    But the above article is quite good and supported by the hard work of a number of people who did the computer modeling work to support it.

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