jktan99,

Good to know that you got your channel back. Actually, I wouldn't be able to restore mine until this weekend.

You said that you just angled a litte bit, how many degree? Is it backslash or forward-slash?

Thanks,

Neoyip,

I don't know how many degrees. I just angled it backslash (i.e. toward the sky) a little bit (may be 5 degree or less). I think this will help if there are some high rise building or big trees on the signal path.

It is important to have your antennas aimed "at the horizon". I have been told that this may mean aiming it at a treetop if that is the true horizon from your antenna location etc...

Simply aiming it more toward the sky would not be following this rule of thumb and could negatively impact your reception.

Is there a way to calculate the highet or a DTV channels tower relitive to my location.


for example if the antenna is 998 ft at x elevation.

is there a program / easy way to calculate how high i would need to be at my location to be in line with the tower. the reason i am asking is to figure out if I would benifit by poitning my antenna slightly up / down.

thanks for the help.

If tilting your antenna is the goal rather than finding the right height, my rule of thumb is to test with no tilt and then test again with tilts upwards between 1° and 10° to see if there is a benefit. That of course assumes you can reach the antenna safely! :eek:

From Post #21 in the OTA FAQ:
Should I tilt my antenna up or down? Most people can simply mount an antenna without tilting it, although in deep to deepest fringe areas it may sometimes be helpful to tilt the antenna upwards by 5 to 10 degrees if you can safely do some trial-and-error testing on distant, weaker stations. Pointing the antenna downwards is not an option. Sometimes there are situations in which the line-of-sight from an antenna to a broadcast antenna up on a mountain or tower is upwards, in which case tilting the antenna to match that line makes sense. If you need to figure out a tilt angle to set and forget the antenna once-and-for-all then with TVFool you can experiment with different antenna heights, and with Google Earth you can use the perspective tool to place your line of vision from behind your antenna through it to the horizon to see how various tilts would look.

One last note: recently several people in the GTA area have tried tilting their antennas only to find that reception was significantly lessened on key channels. My advice is to test, test, test and be prepared to put things back to the way they were. The easiest way to do that is to make some guide marks with a permanent marker that allow you to reset the antenna to its standard tilt.

Yea, your right stampeder. I've tried the tilting as well, and just when you think everything is ok you start searching other channels and while some will be fine,others are not so good and they may be the channels you really want.

All I can say is, do lots of experimenting and find out what works best in your particular situation.

Bob

My funny story is I installed a tripod on the roof peak, got at least one bolt on all 3 legs onto joists...however the mast appears to be slightly deviated to the left. The reception was still not up to where I want it (I want 100% LOL) but it could be tropo because when it is good it is good.

So instead of it being tilted a little sideway, I aimed it a little upwards so it looks nice and straight from the front. It is pulling in the channels just as good. Thank goodness for the adjustable tripod.

I use an Antennas Direct LacrosseA and it has an adjusting bracket for tilt on the antenna. I'm aimed at the new 49-1 which would be slightly east of the other south Buffalo towers and directly over Grand Island. I first adjusted the antenna for direction to maximize signal and then adjusted tilt. Improvement in South Buffalo signals was quite dramatic. I'm not quite sure of the affect this had with CN Tower or Hamilton channels. These come in strong enough anyway. I would expect less tilt to be better for closer tower. You need to find a happy compromise.

That's good info to have - nice that AD put a tilter on it so they must have been aware that the Lacrosse can/should be tweaked for tilt. From Mississauga what tilt angle did you find the sweet spot at, RustyHD?

I'm not sure what the configuration is inside the plastic, but it would appear to me that it is supposed to have some tilt for the design. When you look at pictures on the web site, it is always tilted. Without measuring, I'd say it would be around 20 degrees. 90 degrees to the face is certainly above the horizon. For effect, if vertical with the mast, 49-1 and 29-1 gone. Tilted for max. signal strength 75% signal on both these channels. Strength on Sharp Aquos signal meter.

What is the best elevation angle to set an antenna at for LOS receiption? I am pretty much in the highest spot in the immediate relatively flat neigbourhood and I have currently set my antenna to point pretty much horizontal. I know that if there is some obstruction nearby then one should aim for the top of this obstruction as the adjusted horison. However, as in my case, would there be a significant amount of receiption coming in at above zero elevation angles due to atmosperic "bending" of the electro magnetic propagation? I can imagine that for long distances this may be more important but what about the LOS case where the transmitting tower is about 20miles away?

The only thing you can do is experiment, it varies at each location and can vary over the course of a day.

The only thing you can do is experiment, it varies at each location and can vary over the course of a day.
I wonder about the SW model that the folks at TVfool uses. When I worked in the Infra red field a couple of decades ago we had an atmospheric model, called LOWTRAN, to predict the transmission of infra red through the atmosphere. This model took into account changes in atmospheric conditions and broke the atmosphere up into layers with characteristics of every layer defined. Standard libraries existed for say tropical, sub tropical etc conditions and the seasons of each of these areas which one could use and modify for the local condition of interest including atmospheric pressure, temperature, humidity, visibility etc. I am sure that something similar should exist for the UHF band. The optimal angle would probably also change for each frequency so it may not be a set angle and as you say it may change throughout the day and seasons.

I am sure that something similar should exist for the UHF band.
I think the guy who does the tropo ducting forecast would have that info. Try following back thru the site. http://www.dxinfocentre.com/tropo.html

Also, LOS infra red light wouldnt be affected like uhf is by ground conditions. So, not only do you have to look for the signal coming in at say plus 20 degrees, it could also be coming in at a minus 20 degrees angle. Its always a compromise and an experiment, heh.

I can imagine that for long distances this may be more important but what about the LOS case where the transmitting tower is about 20miles away?
I think youre right about that. At 20 miles, the bounce angle from the atmosphere would have to be extremely sharp.

RamKat I think you missed the original thread so I've merged yours into it - see the previous posts for more advice on tilt.

Large bodies of water between TV antennas and stations can also require tilting to try to get over the "Lake Effect" or as we now call it on Canada's west coast, the "Straight Effect".

I heard Lacrosse is basically a 'DB2' in disguise. So I can do the same for my CM4221HD bowtie given that I have to aim across the lake to Grand Island.

I have a satellite J pipe with tilt feature. Hmmm...I have to do some thinking how to retrofit it to my stacking bowties.

Large bodies of water between TV antennas and stations can also require tilting to try to get over the "Lake Effect" or as we now call it on Canada's west coast, the "Straight Effect". Would this be to get a multipath out of the sensitive part of the vertical gain in order to improve the LOS to reflected signal strength ratio?

I had similar issues with infra red transmission over a body of water - had to add a special blanking algorithm to get rid of that.

as a practical matter, I wonder how many people actually tilt, I imagine its more fringe areas, also doesnt that become a strain if a rotator is involved...

as a practical matter, I wonder how many people actually tilt, I imagine its more fringe areas, also doesnt that become a strain if a rotator is involved...
Tilting about the centre of gravity shouldn't affect the rotor at all.
That's how the (home built) manual tilt on our big array here does it.