Unlocking the secrets of walkie talkie and HT range testing with my latest video. Discover why these devices are mosttly reliable at under 500 metres, and how factors like a clear line of sight as well as elevation (say on a hilltop) can increase or degrade performance. Join us as we examine the science behind walkie talkie antenna gain, and see some real-time software modeling of range on a real map. Featuring (Retevis RB639) - here's Fred's video: https://youtu.be/jJCW5Y8XzgE Experience tells us that walkie talkies are mostly reliable at around 500 metres. However, sometimes you can get a greater range, for instance if you are in the clear or on top of a hill. We look at why this is, the software used to check the gain and we can even model the range over a live map. Tune in to understand.