Jersey City EMS is mostly run by Jersey City Medical Center ambulances (similar set up to UMDNJ in Newark). They operate on 155.235 (146.2), dispacher is "HUDCEN". Just be advised they also cover most of Hudson County for ALS so its a pretty busy frequency. Units identify as "MC-##". The Fire Dept will run first responder to many calls when it gets busy.
Also, there are a number of other ambulance companies, such as "AMB-U-CAR" but I don't know if they do emergency transports.
