Hi,

I'm located in Bronx, NY 10465. About 10.7 miles from the Empire State Building transmitter.

Just put up a Winegard 7694P on the roof this weekend. Reception has been perfect on calm days. But the antenna is pointing straight into our neighbor's huge, ancient tree which is blocking a big portion of the field of view from our roof. On windy days it is unpredictable. Channel 4.1 WNBC (UHF 28) will usually be unusable, and there will often be problems with the other major networks, including some of the ones on VHF. But other channels will work fine.

Since this is obviously a challenging reception environment, I realize there may be nothing I can do. But since some channels continue to work fine, I'm tempted to try a pre-amp or a rotor. Is there a chance this will be worthwhile?

You may get a better response in your local OTA thread:

http://www.avsforum.com/avs-vb/showthread.php?t=275729

Thanks.

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How long is the coax feedline from the antenna to your tv set or converter box? The RG6 cable loss for a UHF signal is about 6 dB per 100 ft. A little stronger signal at the tv might lessen the signal problem caused by the wind in the tree; this is a case of dynamic multipath which is harder to overcome than static multipath. The digital error correction system (FEQ) is limited in its abliity to correct errors.

I have a similar dynamic multipath problem because my antenna is aimed across a well-traveled road that causes signal reflections from the moving cars, but it only affects my weakest signal.

There is a preamp that will makeup for the feedline loss without overload from your strong signals and might help:
http://www.winegard.com/kbase/upload/WC-809%20_HDP-269.pdf

Let's see, single story house, cable runs down from the roof, let's say that's 30 feet right there, then it runs horizontally to a grounding block, 30-40 feet, and then back that same distance to near where it came down from the roof in the first place - so let's say we've got 90 to 100 feet or more. I actually put another grounding rod in place, which would have eliminated the need for much of that cable run, but the installer didn't have the supplies he needed to connect the secondary grounding rod to the house's main ground; so we've got the coax running all the way over to the main ground.

Anyone else pointing an antenna thru let's say just one tree, but it's big and nearby, and getting decent results?

Since you have good reception on calm days, you've got enough signal, it's the multipath which is the problem. Aside from moving the antenna so the tree isn't in the way (which I assume isn't practical), the solution most likely to work would be a more directional antenna, like the largest one in the 76xx series.

...Anyone else pointing an antenna thru let's say just one tree, but it's big and nearby, and getting decent results?Yes, except for VHF, which is mostly a VHF/weather related problem around here. YMMV

Hi,....I'm located in Bronx, NY 10465. About 10.7 miles from the Empire State Building transmitter. Just put up a Winegard 7694P on the roof this weekend. Reception has been perfect on calm days. But the antenna is pointing straight into our neighbor's huge, ancient tree which is blocking a big portion of the field of view from our roof. On windy days it is unpredictable......., I'm tempted to try a pre-amp or a rotor. Is there a chance this will be worthwhile?

i could be wrong, but i cant believe one tree is going to cause any problems with signals from only 10 miles away.....no way....now if u were 50 miles away and it was a whole forest, then maybe......

and since youre so close an amp will almost for sure overload...especially in nyc....so forget amps...u have tons of signal....

i'm guessing its a multi-path/ghosting problem....in which case there may be no practical solution .....but moving the antenna to a different location might help....moving it up/down or sideways only a few feet could make a difference.....

also....since u mentioned wind related problems, it could be as simple as a loose connector....so double check everything....good luck!

Since you have good reception on calm days, you've got enough signal, it's the multipath which is the problem. Aside from moving the antenna so the tree isn't in the way (which I assume isn't practical), the solution most likely to work would be a more directional antenna, like the largest one in the 76xx series.

Actually I think a less directional antenna would be the solution, as he might get stable reflections off the side which would allow the tuner to reject the garbage coming through the wind driven tree leaves.

You might do better ditching that big antenna, (if its impractical to move it), and going with something smaller and more easily mounted in a sweet spot (free from that particular antenna positions affliction as much as possible) at another location.

Also the attic is always an option.

A chainsaw might help. :p

But the antenna is pointing straight into our neighbor's huge, ancient tree which is blocking a big portion of the field of view from our roof.

A chainsaw might help. :p

neighbor might object

[QUOTE=pm3839;16716619]i could be wrong, but i cant believe one tree is going to cause any problems with signals from only 10 miles away.....no way....now if u were 50 miles away and it was a whole forest, then maybe......

I have seen this happen many times with a large tree in the way, even at ten miles.

Since you have good reception on calm days, you've got enough signal, it's the multipath which is the problem. Aside from moving the antenna so the tree isn't in the way (which I assume isn't practical), the solution most likely to work would be a more directional antenna, like the largest one in the 76xx series.Agreed,

A more directional antenna is always best when trees, and or multipath are causing issues. A less diirectional antenna allows more of the unwanted ,reflected signals to reach the tuner.

[QUOTE=pm3839;16716619]i could be wrong, but i cant believe one tree is going to cause any problems with signals from only 10 miles away.....no way....now if u were 50 miles away and it was a whole forest, then maybe......

I have seen this happen many times with a large tree in the way, even at ten miles.Trees can cause issues even in a close in urban environment. Multipath is usually at it's worst the closer you are to the transmitter.

Yeah that is the solution to classic multipath (a tighter beamwidth antenna), but not pointing it through a 100,000 tree leaves fluttering in the wind. That kind of scintilating multipath cant be defeated by a tighter beamwidth.

At least that has been my experience here. Am I wrong?

Continued observation of my setup: looks like it might be dealing more with classical "fade" than "dynamic multipath". I've now had some CALM (but overcast) days where the leaves are not moving but the signal is weak. I'm talking just barely below threshold, with choppy audio coming in but no video. It seems like the audio part of the signal is often a little easier for my receiver to tune.

Pulled my VCR out of the loop (duh; that should recover 3.5db of loss) Now I'm getting Channel 58.1 a little bit better. Hopefully this will also improve channels 4.1, 5.1, and 9.1 which had been the worst offenders. Fingers crossed and so far so good. If this doesn't help enough, my next step is to get that loop out of my cable run.

[QUOTE=pm3839;16716619]i could be wrong, but i cant believe one tree is going to cause any problems with signals from only 10 miles away.....no way....now if u were 50 miles away and it was a whole forest, then maybe......

I have seen this happen many times with a large tree in the way, even at ten miles.

I believe it's contributing to some issues. Perhaps there are enough problems in my setup (long cable run, and VCR, described above) that the attenuation from the tree is the proverbial straw that broke the camel's back. Channel 50 seems to come in better and I think the path to that channel goes around the tree. Despite coming in a bit on the side of the antenna it does seem better.

FWIW, see this related thread: link (http://www.avsforum.com/avs-vb/showthread.php?t=1158433)

I had a Juniper tree 25' from my antenna directly in front of it. Since I had so so reception on several channels I went out and cut it down to 5' below the antenna. No difference.

I would look at cable connections. Make sure the antenna is mounted securely so it doesn't move in the wind too much. Make sure all outdoor cable connections are weatherproof.

Rick R

I recently celebrated the one year anniversary of giving up a PHDTV1, in favor of the classic single bowtie. The bowtie is best when aimed about 45 degrees off of the "correct" aim. I've since added the rabbit ears to the mix for an antenna that, for me, is better than a Terk HDTVi could ever be. The window where it's located does afford the ability to aim in the "correct" direction. However, the "correct" direction is straight into several trees. Reflected signals are my friends.