# Trees and their effect on Digital OTA



## Stephen J (Mar 26, 2006)

Anyone know if trees have the same effect on Digital OTA as they do on DBS? I had to go out into the yard in order to get DBS, because of that will I need to get away form the house in order to get a decent Digital OTA signal as well. My house is surrounded by large, tall trees. Thanks.


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## BNUMM (Dec 24, 2006)

Stephen J said:


> Anyone know if trees have the same effect on Digital OTA as they do on DBS? I had to go out into the yard in order to get DBS, because of that will I need to get away form the house in order to get a decent Digital OTA signal as well. My house is surrounded by large, tall trees. Thanks.


No, because trees are a total block for satellite signals. With OTA trees may reduce the signal strength but they do not block it.


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## mw1597 (Jan 13, 2007)

From http://www.hdtvprimer.com/ANTENNAS/glossaryR.html
Trees as obstructions - A tree has very little effect on VHF-low, but a significant effect on VHF-high. But the big problem is UHF. A tree with leaves blocks about 90% of a UHF signal. The space behind the tree is an overlap of the signal going through the tree and the signal diffracting around the tree. Such overlapping fields have an alternating pattern of strong and weak spots separated by only a few feet. An antenna in a strong spot might work nicely until the wind blows, deforming the tree and moving the spots. Thus, for DTV stations, you are likely to see dropouts when the wind blows. Even in a good-signal neighborhood it is inadvisable to put a UHF antenna behind a tree.

If the tree loses its leaves in the fall, reception behind it will improve dramatically. Many people get a TV for Christmas, and erect an antenna for it in January, and then wonder why it quit working in May. It's the trees.

The farther away a tree is, the less of a problem it is. For far away trees, assume no signal penetrates the tree, and reception will be by diffraction around the tree. See Diffraction.

Trees block 100% of satellite signals.


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## whatchel1 (Jan 11, 2006)

The worst offender in attenuation are evergreens such as pine. the needles on these trees are close to the size of the wavelength of UHF. The get even worse when they get wet, then they not only are the right length but they clump together. When they clump together. Their absorption will almost completely eat the signal. For VHF the biggest problem isn't trees but multi-path. The bounce that gives more than one path confuses the receiver and starts blocking.


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## scooper (Apr 22, 2002)

I live in a forest. My experiance is much like said above - VHF works pretty good with a decent antenna, but UHF gets attenuated greatly.

I live about 22 miles @20 degrees from most of our towers. Low VHF stations come in great. Hi VHF stations are still fine. What I have to do for UHF will shock you - Antenna is a CM3021 4 bay - 19 dB Winegard AP4700 Pre-Amp. I have used a Radio Shack UHF75 antenna - the CM3021 is less directional and works better.


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## BNUMM (Dec 24, 2006)

I have a huge tree in the direction of Chicago which is 90 miles from me and I have no trouble receiving channel 5 and channel 7 digital. I also receive South Bend, Indiana stations which are blocked by pine trees and are 50 miles away.


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## hmcewin (Jun 30, 2006)

Stephen J said:


> Anyone know if trees have the same effect on Digital OTA as they do on DBS? I had to go out into the yard in order to get DBS, because of that will I need to get away form the house in order to get a decent Digital OTA signal as well. My house is surrounded by large, tall trees. Thanks.


I have a solid wall of oak trees about 20 ft from my Radio Shack antenna and the reception is excellent. Located about 45 miles from the stations on Cedar Hill near Dallas. In my case it seems the conventional wisdom does not apply and I am happy about that. The tuner in the VIP 622 is fantastic.


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