Saturday, May 16, 2009

Please Don't Send Them to AntennaWeb.Org

UPDATE 5/17/09
While checking out mom-in-law's converter, I discovered another cause of pixelation from digital converter boxes! See below in the bullet points for wind related problem!

I had a call from my mother-in-law this morning. She had been listening to "Old Folks Radio" here in the Twin Cities, WCCO. Used to be quite a station with over 50% market share - but that's a subject for another post.

Apparently, we in the Twin Cities have one of the largest percentages of non-participation in the cable/satellite television revolution. Probably over 25%! I can believe this. As resident technical guru for the family, friends and associates I am truly amazed at the number of people who receive their television signals Over The Air. (OTA)

The "Fix-It Guys" on the Saturday morning WCCO radio program (You see why I call it "Old Folks Radio"?) made another reference to AntennaWeb.Org on their show this morning. This site gets frequent reference in newspaper articles, on radio and TV shows and on websites purporting to tell you how to deal with the transition to DTV. (Digital TeleVision)

Now, I will personally guarantee you that if you are having trouble getting your converter box to work reliably there is nothing on AntennaWeb.Org that is going to help you! But let's try it. Go there and plug in an address in Fridley, Minnesota. You will get a screen that looks like this:

Now for people like me, it is actually interesting to know that digital channel 2 is broadcasting on UHF channel 34. For mom-in-law, I think, not so much! So the useful information being provided to her must be that she is going to pick up channel 2 at a compass heading of 85 degrees and channel 5 at a heading of 81 degrees. Do I get mom a compass? I have already suggested that "point it to the East - toward the Anderson house" would be the best bet.

Most converter boxes have a built-in signal strength meter that you can watch as you (or a helper if it's a rooftop antenna) adjust the position of your antenna. DO NOT CONSIDER BUYING A CONVERTER BOX THAT DOES NOT HAVE A SIGNAL STRENGTH METER! Now there is some useful advice.

In fact, here are several pieces of useful advice for making your converter box work well.
  • Many converter boxes are bad. Bad designs, bad quality, bad workmanship, bad bad bad. I know several people who returned them for different boxes of the same type and for different brands with much improvement in results! Read the reviews before you buy. Or after you buy and before you take it back to get a different one. And, o yes, DO NOT CONSIDER BUYING A CONVERTER BOX THAT DOES NOT HAVE A SIGNAL STRENGTH METER!
  • Many indoor antenna's are bad. You may need a good quality UHF antenna to make your box work. Warning: antenna manufacturers operate like fishing lure manufacturers. The objective is not to make lures that catch fish - it is to make lures that catch buyers! A good quality UHF antenna is quite simple in design. The indoor variety is a simple loop and the outdoor variety is a simple Yagi design. Don't know what I mean? Find someone to talk to who does - not someone who says "Terk." Both of these designs are strongly directional. That is why you need the antenna meter.
  • If you are very close to the TV station, you can overload your converter box with the signal. Try using an attenuator. Only about two bucks - worth a try. Buy a 12db version if you think this might be the problem.
  • The antenna designs I mentioned (loop and Yagi) are very direction sensitive. That was deliberate on my part. If you are visiting this site, chances are you are having pixelation problems - your image is breaking up into little boxes. Did you formerly suffer from "ghost images? The digital equivalent is pixelation. These phenomena come from the signal being reflected off an object, such as a building, hill or water tower and you having to deal with two signals arriving a tiny fraction of a second apart. You must change their relative strength to solve their problem. Solution? A directional antenna and a means to rotate it if you have signals coming from different angles. (this is what the site is actually useful for)
  • Digital signals are subject to pixelation drop-outs resulting from the wind! Mom-in-law had already consulted with her next-door-neighbor (Yes, in the Twin cities we even have clusters of non-cable-or-satellite participants) who had noticed that his drop-outs seem to correlate with windy days. I got the same correlation from another friend. It turns out that there is a thread on SatelliteGuys.US on this subject. SatelliteGuys.US is, in my opinion the best site for anything technical on digital TV. This specific post even explains a bit about the phenomenon:
    "What you are experiencing is a form of multi-path interference . You will likely see dropouts when the wind blows because the strong and weak spots of the UHF signal will move around as the tree deforms and the branches move about. The effect is called wave diffraction and overlapping fields. It is common on UHF on windy day and will be worsened by climate temperature inversions called ducting. Experienced yesterday on a service call. The levels on the meter were all over the place and could not perform the maintenance. had to schedule it for another day."
  • Final recommendation? Subscribe to satellite TV or cable. This is a temporary solution, just until you have fiber-optic service to your home. Then you will receive all of your Television via the Internet at your own choice of time. And how long is that going to be? Well, I attended a seminar in the late 1970s where Harry Newton was advocating just that change in U.S. telecommunications infrastructure. He noted that our 50 state public services commissions would stand in the way of that and so far they have managed to oppose it for well over thirty years.
And now, back to

If they don't have much useful information for the average consumer, why are they around? Well, look at the screen you used to get the antenna direction information? Hmmmmm, address, telephone number and "send me ..."

WCCO. Old folks radio. Bah, humbug!