OTA Coverage Map

[queonda]

I came across this today: http://blogs.pcworld.com/tipsandtwea...es/004517.html

Just thought some would be intrested.

[ClamsTheCat]

Pretty neat. I just got tired of messing with antennas, and my cell phone actually messes with the reception somehow when I send a text message. QAM is the way to go.

[Rich A]

I've found the way to really find stations is to use the FCC web site and look up the stations there. There is everything you need to determine if you can get a station and where it is on that site. The only problem is that it is in technical format and you have to know something about radio waves and such.

Since I've been putzing with radios since the late 50's that was right up my alley.

Just knowing where to point the antenna is sometimes not enough.

For example.

Some stations are actually beaming their signals to a certain geographic location. They actually use directional (sometimes phased) arrays. This is mostly prevalent when dealing with stations near country borders. A station in the northern mid-west near the Canadian boarder may be concentrating their signal to favor the US and not Canada. And that could effect your reception if you are too far to the north of it.

Public Broadcasting stations are also sometimes using directivity to keep from beaming signals into other PBS areas. Each station has it's own geographic audience. And the station you are trying to get might have most of it's signal going in the wrong direction.

Also a lot of the Digital stations are newer and are utilizing existing towers and have antennas mounted partway up the tower or on a side which also affects the signal pattern.

Then of course there is the power thing. One local station here (the analog one) is well over a few megawatts in effective radiated power. That's millions of watts. Their digital counterpart is only a few thousand watts.

Terrain makes a huge difference as well. I have a mountain blocking the NBC digital station almost completely. However I'm getting just a tad of the signal to one side of the mountain. If I move my antenna more than 2 degrees in either direction I loose it entirely. Just 2 degrees. I'm lucky that there is a trickle of signal getting past the west side of the mountain. If I was any closer to that mountain, I would be completely in it's shadow and not able to get it at all.

Yes, there is a lot to reception of VHF and UHF frequencies that depend on a LOT of factors other than just direction.

By the way. I too am now "QAM Equipped" and am loving it. However, in all honesty after carefully examining the OTA and QAM same broadcasts, I have to say that IF you can get the full OTA digital HD ... it's the best HD you can get. In my case the QAM digital I'm getting is pretty darn good. Actually good enough to make me want to take down my antennas. (need more room for my ham radio antennas anyway) Some other cable company QAM signals are not as good. And I CAN see the difference here. But to be honest again, if I had never seen a good OTA HD signal, I'd be perfectly happy with my cable Clear QAM channels.

I think the OTA is a viable alternative if you don't have any cable service. And down the road when ALL terrestrial Analog TV is taken off the air, THEN you will see all the technical attention being given to the digital stations. Their antenna environments will be upgraded and power out upgraded as well. At that time the megawatt analog stations will have to change over to megawatt digital stations. Although they shouldn't need as much power using digital as opposed to analog. But right now the digital stations are sorta the "other" ones and not the primaries.

Here is the data supplied to the FCC for WEDH-DT. This is a digital PBS OTA station in Central CT. If you look at the plot of the radiation pattern you will see that it is beaming most of it's power to the North, Northeast and South East. However you can see that it has a VERY weak signal to it's West and South West. This is most likely because there are other PBS stations to the West of this station and they try not to over-lap coverage. So a guy 20 miles north of the station may get it perfect. But another guy only 10 miles to the SouthWest might not get it at all. You'd think a guy 10 miles closer would get it better. That would be true if they were not beaming a directional antenna pattern.