No guarantees, I don't even live in your state. However, Air Evac has been known to use their itinerant freq in certain areas (but usually don't do so when they have a licensed pair already in service).
ULS License - Industrial/Business Pool, Conventional License - WPYR891 - AIR EVAC LIFETEAM - Frequencies Summary
- 151.505 / 158.400
If they have a licensed frequency pair in your area, I'm surprised they wouldn't be using it. But it doesn't hurt to listen in on this and see if you hear em.
Might also want to check FCC records and look for other surrounding Air Evac bases since they might be using one of those freqs:
- go here:
http://wireless2.fcc.gov/UlsApp/UlsSearch/searchLicense.jsp - then click on Advanced Search, then type
AIR EVAC in for the name and set the # of records to 100 (instead of 10) and then do a search.
Also, maybe they are still using the frequency you are monitoring but are using a different tone - If you haven't done so already, I'd suggest removing any tone and setting it to search for a tone just in case they are using one different than what you have listed.
Mike