: Is mounting an OTA antenna higher "always" better?
2009-09-25, 10:09 AM
Hi, I am pretty happy with the way my antenna is working currently about 15-20 feet off the ground on my deck. Pointed north, I get some ottawa stations and most of the watertown stations coming in from behind. My wife would ultimately like the antenna out of the way, on the roof. I am thinking of strapping it to the chimney, which will probably put the antenna at 30 - 40 feet.
Since it will be a big effort to get it installed up there, I want to investigate what my chances are of it actually having worse reception. Has anyone raised their antenna and found it worked worse?
2009-09-25, 12:37 PM
I have seen both improved, and degraded performance with additional height. Unfortunately, the only way to tell is to go ahead & try it. You can then experiment with minor height tweaks once you get the antenna on the chimney, and hopefully get better overall reception on most if not all channels.
2009-09-25, 12:53 PM
I have seen moving up a couple feet cause the signal to degrade, but I think a 15ft shift would give good benefits, and from there you may need to adjust up or down a couple of feet if you find you are in a dead zone.
2009-09-25, 07:01 PM
If you're happy with the performance of your setup, than going higher isn't necessary. Though in your case, I don't see you having a choice (who wants to argue with their wife!).
In certain circumstances, going higher up can negatively impact reception quality of some channels. This is often caused by signal artifacts from distant transmissions on the same channel. It would be especially noticeable during strong tropo conditions. A narrow beam antenna can usually work around these problems, by putting the distant station in a null of the reception pattern.
However, since you're not go up a significant height, I doubt you'll run into problems.
2009-09-25, 07:24 PM
Great, thanks for your comments. Since its getting colder here, might be able to get away with leaving it for the winter. Come spring, up she goes!
2009-09-25, 10:54 PM
After I moved the 4221 onto a tripod on the roof, my Toronto channels get a little weaker across the board (lowest is City with 4-5/10 on Samsung LCD), but still, I have yet to lose a minute on any Toronto channels.
See my other thread, as other variables are involved :
2009-09-26, 08:48 AM
No, sometimes it can cause problems. With microwave systems, the antennas are set at a height that just clears all obstacles (with consideration for Fresnel zones). Going much higher can create multipath problems as there may be a reflected signal, in addition to the line of sight one.
2009-09-26, 02:22 PM
Correct. Placing the antenna high enough to get line of sight to the broadcast antenna is usually the best solution. In cities with flat terrain and stations at a moderate distance, that means above the tree line or above the roof line of nearby buildings. For distant stations, that varies with the broadcaster's antenna height and distance (due to the earth's curvature.) According to Fresnel (http://en.wikipedia.org/wiki/Fresnel_zone), additional clearance must be provided but that is often not practical in an urban environment and not necessary to get 'acceptable' results. It's also well known that a few feet, either laterally or vertically, can make a big difference so higher is not always better. I would move it to the chimney, if only to get better results on the Watertown stations. Mounting it in a way that allows easy adjustment of height might be a good idea.
I would not be concerned about increased height causing interference. That happens at any height. The best way to avoid it is to obtain a strong, steady signal on the desired station. That usually means obtaining line of sight.
2009-09-30, 02:03 PM
And just to bring this to a close, the OTA FAQ Post #21 has this item:How High Should My Antenna Be?In layman's terms, raising the antenna shows real benefits to a point, at which the more time, money, and labour it takes to raise the antenna past that point, the lesser the benefit per dollar/hour/back spasm is achieved (the law of diminishing returns). For this reason I only recommend tall towers to people known to be in deepest fringe areas. For some rare occasions the local conditions of other folks might dictate a tower even if they are in a closer range. For the vast, vast majority of OTA users the point of diminishing returns will never be reached because reception will have already been found to be satisfactory well below that point. Having said that, in some unusual situations reception can be improved by lowering the antenna due to local issues. Deciding on whether to use a tower should be done after reading through the Reception Results thread for your area to understand local reception issues that might require one.So the answer is test and test again to get your best local reception, and of course look up all the tips accumulated in the OTA FAQ beforehand. :)