Thursday, August 21, 2008

The basic rules of receiving digital television

I recently wrote to Maine Public Television (MBPN). They are one in a long list of organizations I have contacted in an attempt to gain support and/or guidance concerning the difficulties in receiving digital TV signals in certain areas of Maine. I was surprised that they actually responded and even more surprised that J. Maurice Doyon, Audience Services Representative, gave some very useful information. It's not all good news but I thought I would post the response in full as it does give some very good advice on the best way to try and receive digital signals (they were speaking receiving MPBN specifically but many of the tips apply to all digital reception).

"Thank you for contacting the Maine Public Broadcasting Network. The following text is a comprehensive response for viewers experiencing difficulty in obtaining a digital signal. The portion in bold print addresses the fact that some, regardless of what they do, may not receive a digital signal off air. As a non-profit entity, MPBN simply does not have the financial resources to consider building more towers. The initial conversion from analog to digital will present challenges for sure. In your area of expertise, I'm sure you can foresee many of the ramifications, problems, and challenges that this change in technology will offer.

MPBN is receiving a steadily increasing number of contacts from television viewers who have purchased digital converter boxes and hooked them up to their TV sets only to find they can’t pick up MPBN. These experiences stand in contrast to the generally upbeat articles about the upcoming DTV conversion touting mainly the benefits of digital TV – of which there are indeed many, provided you can pick up the signal. Now that people are actually buying the converter boxes and hooking them up, however, they’re finding that it’s not always as easy as those public service announcements make it seem.

Here at MPBN we’ve tried out converter boxes on sets here at the station and asked some employees to try them out at their homes, with mixed success. In so doing, we’ve come up with a few things to check or consider:

  • Unlike analog transmissions where the TV picture gets fuzzier as distance from the broadcast tower increases, with digital television you either get the signal or you don’t. You don’t get a snowy picture as the signal fades, it just cuts out completely.
  • If you can’t get any channels at all, check your connections to make sure they are good. Especially with an outside antenna, connections can loosen or corrode and may need to be tightened or fixed.
  • If you get other channels but can’t get MPBN, go to your TV’s menu and try entering the channel manually (follow the manufacturer’s instructions; most converter boxes have a signal level indicator) and adjusting the antenna.
    Keep in mind that MPBN’s digital channel number is not the same as its current analog channel number, and that the correct number depends on which of MPBN’s five TV stations in Maine you receive your signal from:

    o Bangor: analog channel 12, digital channel 9;
    o Portland/Augusta: analog channel 10, digital channel 17;
    o Biddeford: analog channel 26, digital channel 45;
    o Calais: analog channel 13, digital channel 10;
    o Presque Isle: analog channel 10, digital channel 20.
  • Also keep in mind that channels 1 – 13 are VHF (regular “rabbit ear” antenna),
    but channels 14 and above are UHF, and will require a UHF “rabbit ear” loop or dish-resembling antenna for best reception.
  • Try moving your rabbit ears near a window or try your converter on a TV upstairs, if you have one. If this works, a different set of rabbit ears might do the trick. In the Bangor area, MPBN shares a broadcast tower with WABI-TV Channel 5, so pointing your antenna in the same direction as you would to pick up WABI provides the best chance of receiving MPBN’s signal.
  • If you still can’t find MPBN, you probably need an external VHF/UHF antenna. Among those who watch our over-the-air signal (not cable or satellite), an outside antenna with coaxial cable provides the highest probability of reception – but we still can’t guarantee that it will help.
  • One last twist: in February, digital channels 17 (Augusta/Portland) and 20 (Presque Isle) will both switch to digital channel 10. All the other digital channels will stay where they are now. If you are in the coverage area of these stations, this change will most likely solve your issue, but there’s no way to be sure of that or even to test it before then.

Our Canadian friends are not facing a similar conversion to digital television in February 2009 in their country. They (and Americans along the border who can receive Canadian analog TV signals) will continue to be able to receive over-the-air analog TV emanating from Canadian TV stations. But if Canadians along the border want to continue to receive MPBN for free over the air, they will have to either purchase digital TV sets or the converter boxes, just like their American counterparts.

In addition to the materials produced by the Federal Communications Commission to explain the DTV conversion generally to a national audience, we are busily preparing similar materials specific to Maine and MPBN and what this transition will mean for you. We will announce the availability of these materials on TV and radio, on our web site and in our programming magazine as soon as they’re ready.

Finally, it does appear that it might be the case that regardless of what steps a person might take to receive MPBN for free over the air in the coming digital TV era – no matter which manufacturer’s converter box one uses, or what model digital TV one purchases, or how high one places the antenna on the roof, or which direction one contorts one’s body to receive the signal (“That’s it! Now stand just like that!”) – there will likely be a very small number of people who can pick up MPBN today who will not after February 19, 2009, converter boxes and new TVs notwithstanding. For those viewers, a cable or satellite subscription might be the only way to continue to receive public television broadcasts from MPBN. We wish it were not so, but that is reality.

Other resources include:

Maine Assoc. of Broadcasters - Conversion to Digital TV
http://www.mab.org/i4a/pages/index.cfm?pageid=3335

DVT for Maine - DTV News for Maine: http://www.dtvforme.com/

2 comments:

GreatOpportunites said...

Consumer Reports has rated some of the available converter boxes at:
http://www.consumerreports.org/cro/electronics-computers/televisions/digital-tv-converter/ratings/dtv-converter-boxes-ratings.htm

Some Off-Air viewers who buy a converter box have problems receiving the same stations digitally with the box installed as they did without it or get no broadcast stations at all (with converter boxes that don’t pass analogue signals). Excluding the possibility that they have a defective converter box or have installed it incorrectly, there are many more likely reasons why this happens:

There are many more likely reasons why this happens:
1. They have an old antenna that has corroded over the years
2. They have the wrong antenna (VHF only) for UHF reception where most of the digital broadcast signals are and will be located
3. They may have received an acceptable analogue picture for years, but a) the broadcast station analogue signal was not that powerful in the first place (signal power or distance) producing a little snow) and/or b) the old antenna is not powerful enough to receive and send a strong digital signal to the digital tuner in the converter box. Unlike analogue, no strong signal, no picture, just a blue screen
4. Many of the TV antenna designs now in use and on the market today such as the Yagi and rabbit ears have technology roots going back 30 years or more and may not work well with the digital chip sets in converter boxes.
5. The analogue signal passed through trees, but the digital signal passing through tress, especially through pine trees, will not be strong enough to be decoded by the digital tuner.
6. Their antenna is aimed at the old analogue tower location and the digital towers have been relocated or it was aimed wrong all these years, but received a marginal analogue picture.
7. The digital stations may be broadcasting in low power until the transition.
8. If you live less than 5 miles from the station, you might need an attenuator to reduce the signal strength and prevent overloading the tuner.
9. They may be dealing with multi-path. Multi-path (bounced signals) is caused by buildings, hills and any other hard object in the line-of-sight to the broadcast towers. They cause signals to reach the antenna out of phase, confusing the ATSC (Digital) chip set in the converter box (or digital TV set tuners.
10. They may have not performed the correct search procedure on their TV to find the digital stations. Many stations have changed channels, mostly to UHF (14-69)
11. The old incoming cable and/or connectors may be bad. These do not last forever.

And while cable and satellite program providers will continue to serve the great majority of homes as the primary signal source, missing HD local reception, compression issues, higher costs, billing add-ons, service outages, contact difficulties, in-home service waits and no shows have left many of these subscribers looking to OTA antennas as a good, alternative.

But TV reception starts with the right antenna.

Viewers should certainly try their old antenna first. It is true that any of these older antennas will pick up some signals, maybe all the broadcast signals a viewer wants to receive, depending on their location. If they are getting all the OTA channels they want and almost completely uncompressed DTV and HDTV, unlike cable or satellite, than they are good to go.

While it is correct that antennas cannot tell the difference between analog and digital signals, there are definitely certain models which have higher DTV batting averages than others. Not all antennas are equally suited for DTV. A percentage of viewers will require something a little more tailored for DTV reception.

With one of the newer and smaller OTA antennas, with greatly improved performance, power and aesthetics, viewers may also be able to receive out-of-town channels, carrying blacked out sports programs, several additional sub-channels or network broadcasts not originally available with analogue. And for those with an HDTV, almost completely uncompressed HD broadcasts.

OTA viewers can go to antennapoint.com to see quickly what stations are available to them, the distance, UHF or VHF and compose heading to help in choosing and aiming their antenna.

And if they decide to buy a newer antenna, they should buy it from a source that will completely refund their purchase price, no questions asked, if it does not do the job for them.

RSCME said...

Thanks for the extensive addition to my blog. I don't personally have digital reception issues; I get all 7 major networks in digital/high def. I am certainly lucky and I must admit I spent a lot of time up front finding just the right spot for my antenna (I use and recommend the TERK UHF/VHF antenna for about $73 at Best Buy.

But the information you provided is more great info and resources for visitors to this blog.