Safecare Ambulance Services Inc (DBA Network Ambulance Service) is located in Philadelphia and licensed for 80 mobile units on 155.16, .175, .205, .22, .235, .28, .295, .325, .34, and .355 at 45 watts. The call sign is WQBK737. It's certainly possible they have multiple tones for these frequencies, and some of the hospitals they cooperate with are likely to be the location of the base stations that they talk back to, but being far from Philadelphia I don't really have the ability to find out much in the way of direct monitoring.