With aviation radio manufacturers not listing the range of their models, this is something that every pilot wants to know. However, answering this question isn’t as simple as it sounds. There are several factors that can affect a radio’s range, and this is largely one of the reasons why manufacturers seem to omit this information.
A couple of the most important factors that can affect the range include how limited you are by the line of sight, as well as how high up you are due to the antenna height over ground. Where you are inside the plane will also have an effect.
So, while it may not be as straightforward as it sounds to answer this question, there is a rough answer that can be given.
First, let me ask you what you think the range of a typical portable aviation radio is? You probably said something in the vicinity of a few miles and probably no more than 5. This is an answer we get a lot from pilots, especially those without a whole lot of experience. However, even inexpensive radios comfortably work at 5 miles, and at ten miles transmissions are still readable. When you’re in an emergency situation this should be enough range and time to contact air traffic control and avert disaster.
While 5 miles may be all you need, you can be safe in the knowledge that the better portable radios out there, like the Yeasu FTA-750L and Icom-A25N, are still usable up to 20-25 miles. At 25 miles transmissions will start to become unreadable, so this seems to be the maximum range possible from a portable radio. When we say unreadable we mean completely garbled. So, while there might be a loss of clarity, some static and some garbling before reaching this distance, you should be able to communicate just fine.