RF communications equipment end users often ask, “How far will I be able to talk?” Unfortunately, the answer is, “it depends on a lot of factors, none of which are consistent from place to place or circumstance to circumstance.” Despite the numerous factors influencing achievable communication distances, means exist to extend that distance greatly, with one of the best options being the addition of a booster amplifier to the system. However, to effectively add an amplifier, communications equipment end users must understand the factors affecting communication links and how to improve them.
Amplifier-boosted signals have become increasingly critical as analog communications systems give way to more digital systems and the “waterfall effect” becomes a more prominent consideration. Specifically, a low signal-to-noise ratio in an analog system will lead to noisy static and/or communications cutting in and out, but the receiver operator still might be able to understand what is being said (i.e., the human brain provides “digital processing,” automatically filling in gaps and interpreting the full message). But modern digital systems afflicted by low signal-to-noise, receiving incomplete packages or degraded bits, can suffer complete loss of link — dropping off the waterfall, so to speak. Accordingly, it is more important than ever to maintain low signal-to-noise and a positive link margin.