I've read that large trees can interfere with TV reception and that DTV may be more prone to this issue than NTSC. If one tall tree can be an issue, what about an evergreen windbreak? (http://cestanislaus.ucdavis.edu/newsletterfiles/Horticulture_News8421.pdf)
In locations exposed to cold north winds, a windbreak of one or two rows of closely spaced evergreen trees planted perpendicular to the direction of the prevailing winds can help reduce your winter heating costs.
This same article also states:
In many residential areas, where lot sizes are small, it's not always possible to plant large windbreaks or to plant them in ideal locations.
However, some homeowners may not be aware of such recommendations and over plant for the size of their lot.

1.) What solutions are there if your neighbor has a dense, tall, evergreen windbreak that is located directly between your home and the main TV transmitters for your area, which will eventually grow to 100'? :eek:

2.) As the windbreak becomes taller over time, is one eventually forced to:

Receive fringe or deep fringe broadcasts from another compass direction?
Give up and subscribe to overpriced cable or satellite TV?
Something else?
3.) Has the FCC given any consideration to the negative effects of trees (an inescapable reality of life) on DTV?

No. And they probably never did. :)

DTV reception remains a concern (http://broadcastengineering.com/news/dtv-reception-remains-concern-0615/)
Jun 15, 2009 11:22 AM, By Michael Grotticelli
Broadcast Engineering

Another dirty little secret about the DTV transition is that some viewers will completely lose a few channels — antenna or not. With analog signals, even viewers on the fringe of a station’s coverage area were able to receive an imperfect picture. Interference with the signals — tall trees or bad weather — would cause the screen to get noisier, but the picture would remain.

Digital signals, however, are different. They only extend about 40 miles from the station’s transmitting antenna and are more susceptible to multipath interference caused by tall trees or buildings. Even a small obstruction of the signal will cause a TV set’s picture to freeze, pixilate or disappear completely. For this reason, expect some familiar stations to disappear completely.

FCC acting chairman Michael Copps experienced this problem personally. When Copps upgraded his TV set for digital reception in February, he at first got an excellent picture. But now that the leaves have grown back on the trees surrounding his house, he is getting interference.

In the above example, the interference was caused by deciduous trees.

Imagine an evergreen windbreak.

A relative of mine only lives ~15 miles from our broadcast towers. Pre digital he had a medium sized UHF/VHF antenna and had decent reception, occasional ghosts but livable. Well enter DTV and with the same antenna his picture would break up constantly. I helped him upgrade his antenna to a Antennas Direct C4(their best UHF Hi VHF antenna). While the picture is better he still gets the occasional annoying dropout.
His problem? I'm convinced it's a large stand of Cottonwood trees between his house and the towers. His signal strength will go from 95% down to 10% within seconds(worse on windy days). I'm hoping when the leaves fall off the trees in the fall his signal will get better, he had no ghosts on analog during the winter. Of course with evergreen trees they never lose their needles so you'd be SOL:(
DTV is great for a large segment of the population but much worse for others, if you have a wind block of evergreen trees between you and the towers you'd be in the second group:(

Hi jjeff,

I agree with your analysis - exactly correct. How far are the Cottonwood trees from his house?

In our case:
Pre 6/12, DTV reception was pretty good with 2nd-story attic antenna & pre-amp.
Post 6/12, two of our most watched stations moved back to VHF. They are now much more prone picture break up &/or audio dropouts.

I spoke with Antennas Direct tech support yesterday. His initial recommendation for our area was a rooftop C4 (UHF) and C5 (VHF-hi). But as soon as I told him about the evergreens, he changed his recommendation to the 91XG plus a 10-element yagi for VHF-hi to "try & punch through."

What is the likelihood that this recommendation will solve the issue?

Since evergreen needles have a much smaller surface area than leaves, I wonder if the branches are more likely the issue with evergreens?


Fortunately, we have TV transmitters at several different compass directions. However, our favorite channels are on the the other side of this windbreak.

Why did the FCC adopt a new broadcast standard that is more susceptible to trees & weather (http://www.avsforum.com/avs-vb/showthread.php?p=16729667#post16729667) both of which are inescapable realities of life? :confused:

Is there a hidden agenda - Do they want everyone to subscribe to cable or satellite to increase tax revenues? Follow the money. - Deep Throat

The cottonwood stand is maybe 200? feet from the antenna and unfortunately some are close to 100 feet tall so raising the antenna is out of the question.
My friend has actually used the C word (cable) but he has used OTA all his life and would prefer to stay that route if at all possible. Installing a preamp did nothing if not make things worse. Personally I have no trees in the way of my antenna and I get great digital reception. Digital is really digital, that is it works great or it doesn't, very little middle ground(unless you consider occasional breakups middle ground). I'd prefer a few ghosts to breakups but luckily get neither at my location.

From another DTV tree thread:
A more directional antenna is always best when trees, and or multipath are causing issues. A less directional antenna allows more of the unwanted ,reflected signals to reach the tuner.

I would agree with that 100% although if you have a stand of evergreens directly between you and your TV station and those tree move of sway I just don't see how you're going to get reliable DTV reception. I don't think DTV likes changing conditions, hence the warnings on portable DTVs that say something to the effect "for stationary use only". I think they're working on a mobile DTV standard but I don't think it's live yet.
BTW just yesterday I pointed someone towards your 480i component thread at AVS. They were saying they'd never heard of a TV with component inputs that wasn't also 480p, you and I know that's not true;)

In 60 years... DTV will surpass what analog has provided over the same period of time. ;)

...if you have a stand of evergreens directly between you and your TV station and those tree move of sway I just don't see how you're going to get reliable DTV reception. I'm sure it's going to be a challenge. I'm open to ideas.

I don't think DTV likes changing conditions... How realistic! The world is constantly changing.

I think they're working on a mobile DTV standard...That's good! Some sort of improved bit stream dynamic error correction is obviously needed. Trees are a fact of life. How could they not plan for them? The world is not going to stand still for DTV. What good is a high quality picture if one can't receive a reliable signal?

BTW just yesterday I pointed someone towards your 480i component thread at AVS. They were saying they'd never heard of a TV with component inputs that wasn't also 480p, you and I know that's not true;) Good recall!

In 60 years... DTV will surpass what analog has provided over the same period of time. ;)
I'm sure you're right. But could they hurry up! Perhaps in our lifetimes.

From another DTV tree thread:

My experience here was that a wider beamwidth lower gain antenna was superior to the xg91 with trees.

Please tell me more about your experience.

In 60 years... DTV will surpass what analog has provided over the same period of time. ;)

If the DTV standard is around at all, (and it might be) I doubt that we will be using it the way we are now. The NTSC standard lasted about 55 years (for color, and almost 70 years for B&W.) That is a phenomenal run for any standard. How long do the latest computer disc standards stay around?

The xg91 was horrible at my location, wind and rain, fluttering and wet leaves, through the forest.

I have a gap off the side of the direct line of towers though, and the wider beamwidth antennas like the 4 bays seemed to do better, giving more stable reception through wind and rain.

That is my experience.

... Installing a preamp did nothing if not make things worse...Try an attenuator.

Stations urge patience with digital switch (http://www.daytondailynews.com/news/dayton-news/stations-urge-patience-with-digital-switch-161470.html)
By Jim DeBrosse, Staff Writer
1:28 AM Saturday, June 13, 2009
Dayton Daily News

Mike Petsch, who lives near Sugarcreek Reserve, said he knows all too well about “terrestrial blockage.” He has spent more than $160 on converter boxes and another $150 on DTV antennas “only to find out that my trees interfere with the signal.”

“This is a nice place to live, but I won’t get any TV reception until winter-time,” he said.

With all of the negative articles you dig up on the internet... your "handle" should be "Dr.OTA.Doom". ;)

Can't you find anything positive or is everyone SOL?

Point taken. That's not my goal. I just find it hard to believe that a new national broadcast standard has been selected that wasn't designed to function in a world that contains trees - a nearly ubiquitous landscape feature in many parts of the US.

If mobile DTV catches on, perhaps tuner makers will eventually add a feature to drop back to the more robust mobile signal in areas with dynamic multipath. Trying to be optimistic here...

FWIW, my antenna faces big oak trees in one direction and pines in another. I don't have a problem with wind. I do have a problem with two (highband) VHF stations and lightning. ARRRRGH!!

Search for the countries that use DVB-T as the "new" standard. I bet they have had their issues as they have trees in other countries also. ;)

Is there a national broadcast standard that would be better? ;)

FWIW, I have been using an attic antenna for 7 years for DTV. I have to shoot through a large stand of maple, locust and sycamore trees about 60' away. The analog cutoff did not cause me any major issues.

Thanks for telling me about your DTV reception experience - Sounds encouraging.
How far away are the transmitters from your location?
Are you using a highly directional antenna to minimize multi-path from the trees?

~18-20 miles.
4228 for UHF
cheap dipole for VHF (post transition only for RF channel 6).
No splitters, pre-amp, combiners, joiners, etc.
Home run of RG6 from attic to primary TV ~80'

BTW... trust me, these are 60+ year old trees. ;)

Ha-ha... as an added point to alleviate the "doom and gloom". My OTA receiver is 1st generation DTC-100. :)

Our nearest large city is 40 miles away.

I live in an older housing addition with full grown oaks and such. My antenna has to point right down the front yards (full of trees) of my street. I have a single story roof mounted antenna, with CM7777 pre-amp, on 20' of pole. The transmitters are about 40 miles away.

When I switched to HDTV, I had a "virtually omni-directional" powered antenna. At that time, it was the best for analog....but it sucked on digital because of multi-path. I just went to lowe's and bought the biggest combo antenna they had. Things improved to the point that I could live with it, but still had some drop-outs on some channels. After finding avsforum, I built a CM4228 clone (size tweeked for my situation) and put it up 2 weeks ago. It has a very narrow beam and has almost gotten rid of my multi-path problem. Almost, because I still have one problem channel that has always given me trouble (even when it was analog). The situation with that one channel has improved to the point where I can watch it now with just little hick-ups now and then where as before in was 2 seconds on, 2 seconds off. I now get mid to high 90's on all channels and the bad one only fluctuates down into the 80's.

Unfortunately, we haven't had any rainy or stormy weather lately, so I can't say for sure that I'm done. Still have to see how it performs under those conditions.

I think I remember reading something about tilting the antenna to point at the top of the blockage may help also.

I'm not trying to talk you into anything, just give you some hope. I had almost given up myself, but thru alot of searching, I found a solution for my crappy reception.

Shame...
Nothing you can do except but experiment as we all did years ago. ;)

It is what it is.

Just curious...
What have tried to get stable/reliable reception via OTA. What is your setup?

OTA:
19' high attic antenna: CM-1162A with CM-0100DSB pre-amp, 2-way splitter to:
2nd-floor: Samsung DTB-H260F ATSC HDTV tuner
1st floor: CM-7000 D2A

Added pre-amp 1 yr ago, shortly after purchasing DTB-H260F & CM-7000 = significant DTV improvement.
Post 6/12: Two of our most watched stations moved from UHF back to VHF and dropouts & cliff effect have been more frequent. However, last night was no problem.

Also, our nearest & strongest station creates adjacent channel interference for our weakest station.

Next step: rooftop separate antennas on a rotor 35' above ground. Thus, we will be able to receive the next closest cities (from other compass directions) as alternative to receiving through the neighbor's evergreen windbreak.

...FWIW, my antenna faces big oak trees in one direction and pines in another. I don't have a problem with wind. I do have a problem with two (highband) VHF stations and lightning. ARRRRGH!!Additional info:
Stations behind the oak trees are 70+ miles away.
Stations behind the pine trees are from 9 to 45 miles away.

Does anyone have a location where large mature evergreen trees are between your antenna and the local transmitters? If yes, how has your post 6/12/09 reception been?

I wonder if the small surface area of evergreen needles produces less multi-path interference than the much larger surface area of deciduous tree leaves?

...
3.) Has the FCC given any consideration to the negative effects of trees (an inescapable reality of life) on DTV?

It needs to be pointed out here that the recent move to VHF and lower UHF frequencies is totally beneficial in this connection. Attenuation due to foliage is much less at these lower frequencies.

Does anyone have a location where large mature evergreen trees are between your antenna and the local transmitters? If yes, how has your post 6/12/09 reception been?

I wonder if the small surface area of evergreen needles produces less multi-path interference than the much larger surface area of deciduous tree leaves?

Multipath is not an issue here, the problem is the attenuation of signals passing through the foliage. If the foliage is very dense, it will be more of a problem that otherwise.

Is a higher gain, higher F/B, more narrow beamwidth antenna the answer for the tree attenuation in your loaction?

Is a higher gain, higher F/B, more narrow beamwidth antenna the answer for the tree attenuation in your loaction?

It will certainly help; the attenuation will, of course, still be there, but you will be getting more signal, just as if the station had increased its power.