I’ve brought this up enough times already; let’s de-mystify this beast. Communications fall into one of two categories: Line of Sight(LOS) and Beyond Line of Sight.

LOS

If you can see it, in theory at least, you should be able to communicate with it. Low-band VHF(10M/11M/CB) and above(UHF, Microwave) works in this manner. VHF can have some characteristics of HF; but that’s beyond the scope of this article. Squad level communications work in this manner. This would be your mobile rigs and HTs. Keeping it simple, if there’s something big in between you and the person your talking to(like a mountain or a bunch of buildings) or long distance, you need a repeater to compensate. Line of Sight(plus repeater) looks like this:

Beyond Line of Sight

So what if you’re outside the range of repeaters? Eventually the energy from your radio or repeater will fizzle out. At some point…