If you go down to your local building supply or discount store you will see radios that say they have a range of 14 miles, 22 miles, or something like that. Yet when you take them home you find that they don’t even go a mile. Why is that?

One of the biggest factors to reducing range is the obstacles in the path of transmission. These obstacles absorb and reflect the radio waves so while a radio advertised to go 22 miles may actually do that if both users are standing on peaks of a mountain with nothing in between, the same radio can’t go a half mile through a forest. Two-way radios communicate “line of sight,” which means that if you can see between two points, the radio should be able to communicate between these two points (radio signals do bounce off objects so you don't really have to be able to see between two points, but to get maximum range you should). Consider that the radio the Apollo astronauts on the moon used to communicate only used one watt of power and you’ll get the picture on this.

If you consider that two points on land or water become invisible after about five miles between them because of the curvature of the Earth, you can understand that communicating more than five miles becomes difficult even if there are no obstacles between the radios. The key to getting more range is either to raise the height of the antenna, increase the power of the radio, or both.

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