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What is Antenna Gain?

People who have trouble receiving over-the-air broadcasts may benefit from a high gain antenna.
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  • Written By: R. Kayne
  • Edited By: O. Wallace
  • Last Modified Date: 21 October 2014
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In laymen’s terms, antenna gain refers to the ability of the antenna to focus scattered radio frequency (RF) waves into a narrower, useful plane, thereby increasing signal strength. Antenna gain is expressed in decibels (db), and an antenna with higher gain will be able to make use of weaker signals more efficiently than an antenna with lower gain, all else being equal. In more practical terms, a consumer living at the outer reaches of his or her local networks’ broadcast range, will get better reception using a high-gain antenna than a low-gain model.

Antenna design dictates how efficient an antenna is in gathering the wavelengths it is designed to receive. High gain antennas makes use of extra elements to pull in wayward RF waves, focusing the radiation into a stream along a “flattened” trajectory. In a rough analogy, consider a magnifying glass that focuses scattered sunlight into a beam, greatly strengthening the beam’s power. Elements play the same role, and the ability to focus scattered RF waves results in a gain in signal strength, or antenna gain.

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People who have trouble receiving over-the-air (OTA) broadcasts can possibly benefit from a high gain antenna, though it can’t work miracles. Regional topography can reduce broadcast range by blocking or scattering RF waves. Online tools such as those found at TVFool help consumers conduct research that can be useful when it comes to choosing the right antenna. An interactive map displays regional broadcasts, distance, and signal strength. Adjusting antenna height causes results to recalculate, enabling one to see if raising the antenna would result in better reception. Tools also indicate whether or not antenna gain will make a difference.

You might wonder, If antenna gain provides better reception, why not just buy a high gain antenna no matter what? The answer is twofold. A high gain antenna will generally be more expensive than a low gain model, so if you don’t need it, you can save some money. Also, the higher-the-gain, the more important it is to point the antenna exactly towards the station you want to receive. If it is a few degrees off, it might not pick up the signal at all. Therefore, if antenna gain isn’t required, it’s better to buy an antenna that can accommodate a broader angle of reception so that pointing it to an exact spot isn't so crucial.

Aside from height, gain and range, some antennas are made to withstand extreme weather; a good investment for those in harsh climates. Mounting masts are not always included but can be purchased separately along with cabling.

The claim is often made that free-to-air, local HDTV broadcasts come in clearer over roof antennas than through cable or satellite boxes, but your experience could vary. A roof antenna does provide a backup solution for receiving local channels if cable or satellite services are interrupted. Antennas range in price, starting at about $20 US Dollars (USD) for a basic model, extending to over $100 USD.

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highbill
Post 6

Here is my problem. I purchased a large UHF HDTV antenna with a range of 60 miles. Most of my stations are 41 miles away and the transmitting antennas are all in the same located at 53 degrees magnetic from my location.

I live on a hill and the transmitter antennas are on a mountain top. With this antenna, I only received four stations out of a possible 21. I purchased a LAVA 2605 and my reception improved 50 percent, but as the day went on, the reception started to fade with pixelation and complete fade.

I can get NBC and ABC, but not CBS, which has the same power output and location. PBS is located at 87degrees and I can get it sometimes. Should I raise the antenna up? It is two feet above the roof's ridge now.

anon350685
Post 4

I live in Florida where it rains a lot with thunder and lightning being very common, but neither of these have caused any interference for me on stronger signals. Some of the fringe signals are affected sometimes but they are weak even on clear days. With a basic antenna just slightly higher than my roof and being around 30 miles from the bulk of the stations in Orlando, I receive 43 stations total.

I kept a TV log for about six months and determined 70 percent of my viewing was on network or PBS. Another 15 percent was Discovery and the like. The rest were a show here and there on a cable channel or two. I hooked up a PC to my antenna and use Media Center as a channel guide and DVR. Between Netflix, free Hulu, and SecondRunTV, I haven't paid for cable in almost four years and saved thousands of dollars. I admit having ESPN would be nice, but the savings is a fair trade and if I'm that desperate I'll buy a six pack and go to friend's house.

reader888
Post 3

Isn't kind of funny that it might be possible to get a better picture with an antenna on your roof than with cable or satellite television? Everyone always seems to assume that cable and satellite are the best ways to go.

Imagine, you could pay a one time fee to get an antenna, instead of paying a cable bill month after month, and even get better quality!

Sure, you get more channels with cable or satellite, but does anyone really watch all those channels anyway?

claire24
Post 2

I've been thinking about getting an outdoor antenna for my home, but I've heard that if the weather is bad, you can completely lose your picture. I would be so irritated if that happened right in the middle of a good show.

Is there a difference with performance between high gain and low gain, when it comes to weather?

rosoph
Post 1

I'm thinking of getting an outdoor antenna because even though I have cable, my picture comes in all fuzzy. I can't stand it, and it seems the worst on my favorite station, which just happens to be a local one anyways.

I'm hoping an antenna will give me better results than cable service has. I'm thankful for the information provided here, because now I know that I want to be shopping specifically for a low gain antenna. I don't want to have to worry about pointing it in exactly the right direction!

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