Having worked as a CMED dispatcher here's the process a little better explained:
- Ambulances can call in to CMED via a repeated channel (typically CMED 4) or call into CMED which rings on the radio console.
- CMED dispatcher assigns the unit a "patched" channel depending on their location/hospital location (the channels that the ambulances are assigned to are not repeated and you need to be in the line of sight to the ambulance to hear the report).
The "radio" that is located at the hospital is typically not on a frequency, but a hard line to the CMED board. So when listening to a CMED report on CMED 1, you'll only hear the hospital if you not in the line of site to the ambulance. So you will be able to hear all ambulance/CMED dispatch traffic on the call channel, but not on the assigned patched channel.
Also as someone said previously, there are different channels which units can call in on depending on the location throughout the state. In Western, MA some of the "hill towns" use 340 to call into Springfield CMED and in Worcestor some of the small towns use 280.. which are open EMS channels that are free for EMS agencies to use.
So if you live near a major hospital you should be able to hear most patches, as the ambulances usually give their report right down the road from the hospital.
Last edited by zappbravo; 03-20-2013 at 11:01 AM..