Hi William, there's been a lot of discussion on pre-amps - they will only amplify the signal if there's one there in the first place - their best use is to boost a signal over a longer length of co-ax. I get up to 275nm (on irregular occasions), but regularly 230nm. This is with the basic standard antenna that comes with the RB. What I have going for me is my location, on top of 185' asl cliffs, AN twig at some 30' above that, so roughly 215' with a clear horizon to the west. If you're in a valley, or surrounded by high buildings, reception could be limited to 35 - 65nm, as I get to the east, restricted by the roof ridge which runs n - s and about 5' above the twig.