Bill Hayes has been Iowa Public Television's Engineering Director since 1999, and is responsible for Iowa Public Television's transition to digital television. In a little more than a year, analog television will be shut off, and we’ll all be watching television a little differently. Visit this page frequently to get answers to your digital television questions and to read about the industry and IPTV’s transition.
Thursday, August 11, 2011
What is the best tv for digital reception
"We live in Dubuque and need every advantage when it comes to reception. Our system now uses a large outdoor antenna with a pre amp and a convert box. We receive all the national networks most of the time. We are thinking about buying a new television and assume that not all tvs receive digital signals the same. Is there any way to know which tv will do the best job?"
Boy is that a tough question. There are minimum performance specifications that all DTV receivers are expected to meet. Take for example the existing converter box you are using. In order to qualify for the coupon program the model theoretically had to pass tests. Early on in the conversion I started to see issues with a couple of the units we had so I purchased about 50 different makes and models and set up a little test facility in my basement. My goal was not to uncover whether some of the units actually didn't meet the required minimum performance specifications. Although I suspect a few of the units I tested didn't, I did not have the necessary laboratory test equipment necessary to make that call and since I was testing one of each unit, it was always possible that I was seeing issues with that particular unit and not the overall brand or model. What I wanted to do was to figure out which units worked best and which didn't perform as well. I was not in the position to make a recommendation of the best unit, but I felt pretty comfortable steering people away from units that didn't seem to work as well as others.
Unfortunately, I don't have the where with all to pick up 50 or so of the most popular DTV sets and do the same kind of testing. I have suggested to a number of organizations including Consumer Reports, that this type of testing should be done on a regular basis. Unfortunately over the air reception doesn't seem to be one of the key features that they consider important enough to invest in on any kind of regular basis. I am hoping that one of the broadcast organizations like the National Association of Broadcasters will consider underwriting the project. Until then, it is really more a matter of believing the specifications and the reputation of the manufacturer.
One test that I have suggested to a number of retailers is to put an attenuator into their master antenna feed. An attenuator would allow them to slowly make the signal reaching the television sets weaker which replicates distance from the transmitting antenna or increased moisture in the air or signal blockage from foliage, all of which degrade reception. By doing this on their master antenna they could observe all of the televisions connected to the antenna at the same time and see which ones begin to have problems first. This would be an indicator of which receivers are performing better as the signal fades. It is not the most scientifically accurate way of doing it but it does provide some general guidance. I have found smaller, locally owned television shops much more willing to do something like this while the bigger stores will not.
I hope this helps a little and if I ever find a source of independent test evaluations, I'll let you know.
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