The transmitting distance of a two way radio set is an important factor to consider when investing in one. The good news is that they can communicate over a multitude of different ranges depending on the type that is bought, so, with a little research, anyone will almost certainly find one that fits his or her needs.
The first thing to understand about two way radio range is that most of the commercially available ones operate on frequencies that travel exclusively in straight lines. This means that one will get different results depending on the area in which it is used. Large, metallic objects will block the radio’s signal, although other things like walls will not affect it. The frequency may also bounce off of things like trees or buildings, so maximum range is greatly influenced by its environment.
Now, assuming that the radios are operating in a wide, open space, the true maximum two-way radio range is calculated by factoring in the curvature of the earth. Because the radio’s signal travels in a straight line and the earth is curved, eventually the radio’s signal will travel off into the horizon, through the atmosphere, and right into space. The point at which this happens depends upon the height of the antenna. Raising the height of the antenna would extend the line of sight and thus the maximum range of the radios. If one could position his antenna on top of a mountain, he would greatly increase his transmitting distance. Of course, few people are capable of doing that.
Power output is another thing that can affect two way radio range. If a radio is not powerful enough, it will cut down on the maximum range determined from the information in the last paragraph. The more power (in watts) a radio has, the farther its transmitting distance. However if the radio is battery powered, those extra watts will run down the charge quickly, so be careful!
The last major factor in two way radio range is frequency. The two most popular frequencies for this application are VHF and UHF with neither being inherently better or worse. VHF has a very low frequency and can thus transmit radio waves over longer distances, however, UHF may be better in more crowded areas because it can pass through metal buildings more easily. With all of these thoughts in mind, it is easier to decide on the technology one needs to use two-way radio.