Michigan Telephone, VoIP and Broadband blog

Believe it or not, there are still people in the United States that do not subscribe to Cable TV service, or to pay Satellite service.  There may be many reasons for this, from feeling that the cable and satellite companies charge too much, to not being heavy TV watchers, to having discovered that there’s a lot of free (and legal!) programming available via satellite if you have the right equipment and know how to use it (hint: The magic search phrase is “Free-To-Air“, and that is all you’re getting out of me on the subject).

The problem is that when Analog TV stations go off the air on February 17, 2009, there are going to be a lot of people who have problems receiving stations – particularly those in “fringe” areas where the signal strength isn’t that great.  The issue with digital TV is it’s an all-or-nothing proposition – you either get crystal clear picture and sound, or none at all, depending on the signal strength.  And with over the air TV, signal strength can vary, for example, when an airplane passes overhead.  This can case the picture and sound to freeze up at various intervals and for various lengths of time.

But there is another issue.  Often, people who live in a fringe area can receive signals from more than one direction that are of nearly equal strength.  For example, if you live at a certain point between Grand Rapids and Lansing in Michigan, you might receive stations from both communities nearly equally well, IF you have your antenna pointed toward their transmitter.  And therein lies the rub.  If you have a tall antenna (as is often required in fringe areas to avoid the aforementioned signal dropouts) you can put a rotor on it and change the antenna direction, but a) this takes time,  b) it may be difficult to get the antenna pointed in precisely the right direction each time it’s moved, and c) If you are feeding more than one TV set (or VCR or whatever) you may improve the signal on one set at the expense of losing a desired signal on another (whereupon the spouse and/or kids start yelling at you).

The way to avoid that is to have two antennas (either on the same or separate masts), each pointed in the respective correct direction for the signals you want to receive.  But even with analog signals, it has always been difficult to combine signals from two antennas.  With digital you have the added factor that you cannot try different configurations and actually see how much it is improving or degrading the signal (the all-or-nothing thing, remember?).  So what we will need in the coming months is a way to digitally combine the signals from two separate antennas.  Something like this (pdf file), in other words. What that device does is to take a digital channel and convert it to another channel, so it can be inserted into a different antenna or cable feed. It’s built for use by cable companies, and priced that way too (which is to say, way out of the range of many home users).

What we need now is a consumer-grade version of that device, one that may not meet cable company specs but would be good enough for home use.  If it could convert multiple channels, that would be a plus.  The idea is, you’d have your two antennas, one your “primary” and the other your “secondary”.  You’d feed both the primary and secondary antenna feeds into this box, and a single output would emerge with a combined feed.  However, rather than simply acting as a signal combiner (which would be bad), it would actually take one or more channels off the secondary antenna and convert them digitally to a totally different frequency, then insert those “clean” converted channel streams into the original (primary) feed.  My suggestion would be to convert the secondary channels down to channels 2,3,4, and/or 5 (which will be unused in many parts of the country) and then have a setting that switches in a high-pass filter, so no signal on those channels is passed from the primary antenna feed. But the point is, we need something in the (preferably) under-$100 range that can do this (at least for a single channel).  Given that digital TV converter boxes can be built for under $50, I suspect that a consumer grade unit could be built for not much more than that.

Granted that there would not be a huge market for these, yet the aforemention Free-To-Air receivers are built overseas and sold here for not much more than $100, and I have to think that what they do is probably at least as complicated as the device I’m suggesting. And while no self-respecting cable company would use one of those as their satellite receiver (for those few channels they need to receive that are not scrambled), they are nevertheless good enough for home use, so I see something of a parallel in this situation – we don’t need something that can be rack-mounted and that will feed 100,000 customers, just something that will feed a few TV sets or other devices in a home TV distribution system. Could someone – Channel Master or Winegard, perhaps – build and sell this thing, please?