155.1750 is NH Med-4 or VEMS02. It is designated for Mutual Aid/Disaster Tactical use; but often used by EMS units, especially in that area for local use. Exeter used to use it alot for the Exeter ALS Units.
In theory, there is no PL used. But 156.7 is the common nationwide PL, 136.5 the common State PL and others may use their designated Hospital PL's.