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How Obstructions Affect OTA Signals

We talk a lot about how to improve your antenna signal and maximize the number of channels that you receive. If you have a weak signal, the root cause of your problem is one of two things: obstructions, or distance from a broadcast tower.

There isn’t much you can do if you live far away from a broadcast tower. But if obstructions are affecting your signal, you may be able to fix the problem.

I’m going to cover some of the most common obstructions and give you some tips on how to address them.

But first, let’s talk a little bit about how signals work.

Over-the-air (OTA) signals are distributed via the line-of-sight concept. This means that you’ll get the best possible reception when your antenna is in close proximity to the broadcast tower and with few obstructions in between.

The concept is similar to your home’s Wi-Fi signal. The more space you put between your router and your device, the weaker your Wi-Fi signal will be. It’s the same idea with an indoor TV antenna. If you’re far away from the tower and you have a mountain in between your home and the tower, your signal will be weak if it exists at all.

Ideally, your antenna should be within 35 miles of local broadcast towers and have few obstructions in between.


Trees give you privacy, but they also obstruct your antenna’s signal. You don’t necessarily have to live in a heavily wooded area for trees to be a problem. If you have one or two trees directly in the path of the broadcast tower signal, that’s enough to interfere with your signal.

Things only get worse in the spring and summer when foliage and wind can obstruct the signal even further. Sometimes, the sudden explosion of foliage in the spring is bad enough to cause a total loss of OTA reception.

If trees are the problem and you’re serious about using an OTA antenna, you might consider cutting a few down that are in the way of your signal. But before you go that far, you may want to try using a booster first.

Mountainous Terrain

Signals can be tricky if you live in the mountains. Getting a clear signal is especially problematic if the broadcast tower is sitting behind a mountain or if you live really deep down in the valley.

If mountains are the problem, there’s little you can do to fix the problem. A booster may work. You can also try placing your antenna at the highest point inside of your home. Placing it on the second floor, for example, may help you overcome a line-of-sight issue.

Large Buildings

If you live in an urban area, large concrete buildings may be obstructing your signal, especially if the buildings are directly in the path of the nearest broadcast tower.

Mirrored buildings are also a problem. You’d think that they would help boost the signal, but in reality, they make things worse. Mirrored exteriors can cause multipath interference because signals are bounced off of the reflective surface.

A booster may fix the problem if the building is in the way. Positioning the antenna away from a mirrored building may also help fix the problem with bouncing signals.

Construction Materials

Your antenna’s signal is a lot like a cell phone signal. Have you ever noticed that you lose signal when you’re in a parking garage or buildings with thick concrete exteriors? The reason this happens is because the signal can’t penetrate those thick, heavy-duty construction materials.

Concrete, rebar construction and mesh stucco walls are problematic and can completely block OTA signals. For this reason, we never recommend placing your antenna in your home’s basement. You should also avoid placing your antenna in the attic if you have a radiant heat barrier.

If your home’s construction materials are causing the problem, your best bet may be to place your antenna on the closest window to a broadcast tower. This will put less building material in between your antenna and the tower.

Power Lines

Some signal obstructions are less obvious. Who would have thought that power lines could obstruct your signal?

The lines don’t even have to be directly in front of your antenna to cause a problem. If you have overhead lines or high-tension lines in your yard, there may be an issue with signal reflection from broadcast towers.

A power line issue can be tricky to deal with, especially if it’s related to overhead power lines. In this case, a booster may make the problem even worse. An outdoor antenna may be your best bet in this case, but I would try every placement possible indoors before going with an outdoor option.


Yes, weather can affect your OTA signal. Wind, fog, snow and heavy storms may interfere with the signal. Keep in mind that the signal bounces off moisture in the atmosphere, so you may wind up with a very weak signal when the weather is poor.

You can’t control the weather, but fortunately, it’s only temporary. You have to deal with a weak signal or signal at all until the weather improves.

LTE Cell Towers

Signals from LTE cell towers can be invisible obstructions. But here’s the good news: If you have a high-quality antenna, you shouldn’t have to worry about this too much. Many modern antennas have some LTE filtering. TV tuners have them, too.

If you’re still having issues with LTE signals, you can purchase accessories that can help mitigate this issue. It’s impossible to overcome this problem without some kind of filtering or special accessory.

LED Lightbulbs

Did you know that your home’s lighting can actually interfere with your OTA signal? Pay attention to when your signal is the weakest. Does it happen at night? If so, your lightbulbs may be to blame. Older LED bulbs can create enough radio frequency interference or block the signal entirely.

If your LED bulbs are the problem, you can purchase ones that are FCC certified. These will not cause interference with your OTA signal.

May 6, 2019 ,

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Jack here. I’m the admin behind Best HD Antenna – a site for hardcore cord cutters. I’ve been struggling to find a way to help friends and family cut the cord