The city of Nashua is, if memory serves, on a trunked system. In addition, there are numerous conventional frequencies that are digital in nature (any frequency that has a 'NAC' in the tone field is digital). Neither of these can be heard on a 355. You will need a digital scanner for this purpose.
The first 2 links (anything that's blue) are links to our database, as well as the one at Scan New England. The third is our list of digital scanners (which can also handle analog signals)...
And of course there's the question of the antenna. A little indoor antenna is only good for a couple of miles tops (and that range will decrease as the frequency increases). A good outdoor antenna (such as a discone) will bring in many more sigs.