YC EMS
*ch1 155.175 Lancaster county EMS ch3
*ch2 155.340 is the hospital (only used on the way to the hospital)
*ch3 155.385 is dispatch (primary)
*ch4 155.265 is where they give patient reports and general chat (secondary)
*ch5 155.280 mutual aid with NC
*ch6 155.160 is used for rescue operations/searches (portable only)
*ch6 155.220 is used ems admin (mobile only)
*453.0375 is a control link to dispatch....no field units actually use this frequency as it links the dispatch center with the base station.
The other channels are used, but only when the situation warrants. ch2,3,4 are used daily...with 3 being dispatch. also, i am not sure you understand that the their is no repeater on the ems channels. communications between units is direct....from me to you and nothing to help extend the range of the communications. you are hearing dispatch from an antenna atop the hospital. you are hearing the units from the antenna atop their vehicle or hand held.
rock hill police, and all other law enforcement in the county use repeaters. that is why you can hear both sides of the conversation. when a officer is talking to dispatch or anyone else, he is actually talking to the repeater with antenna on top on a high tower. everyone, including you, is listening to the tall tower....not the antenna on top of the patrol car or hand held.
simplex/direct = good range for dispatch...very short range for portable
repeater = greater range for everybody
As for Rock Hill Police
*ch2 154.755 is now primary (repeater)
*ch1 155.610 is now secondary (repeater)
*ch3 154.890 actually belongs to the county but is used by all l/e agencies (simplex)
*tac 4 is a special events channel (simplex)
*tac 5 is a special events channel (simplex)
*tac 6 is a special events channel (portable repeater...not always on the air)
*mobile data is used for exactly that
*narcotics is used for exactly that, but is almost always encrypted so there is no reason to attempt to listen to it.
Okay, that should answer all of today's questions. and remember, if it is listed as simplex, then you may not be able to hear any unit traffic where you are located and all of YC EMS is simplex. tac 4, 5, 6 is are almost always used on portables only...so if you are more than a mile away, you probably won't hear anything!