I just barely hear nashua/manchester and I'm next to Nashua. It depends on your elevation/how high your antenna is/what direction you're pointing at/what antenna you have. Obviously different factors will indicate if you can hear the system or not. Start by stopping on the control channel in search mode. For Manchester, hold the frequency on 859.4875 and see if you can get any sort of reading. Same goes to Nashua. Hold it on 853.4500 and see if your scanner can pick it up. If it falls on deaf ears, most likely you're too far to hear the system. The higher you are, the better chances you may pick it up.