Can I use the signal strength indication of a VR28 to estimate range to the transmitter?
First, it is important to realize that estimations of range based on signal strength cannot be precise. There are many factors which can cause the signal strength at a given range to differ from a theoretical value calculated from transmitter power and transmission losses due to spreading and absorption. It is also quite common to see significant fluctuations in signal strength even if range doesn’t change. So in using the suggested procedure below, you should, first, regard it as giving a very approximate estimate of range and second, you shouldn’t attach too much significance to short term variations in signal strength. The basis to estimating range is to note that the VR28 uses automatic gain control which increases the gain as the signal strength gets less – i.e. the larger the gain displayed the weaker the signal and therefore, the greater the range. You could do a rough calibration of this by conducting a range test with a typical transmitter and noting the value of the gain disp
