I have searched and searched the net wide to help me figure this out and I have not found a description that lets me wrap my head completely around this (I have been searching for weeks).
System
Cobb County, GA - a Project 21, Phase I system using APCO-25
It is a multi site system with four control channels (two in county, two out of county). There are MANY trunk ID's on this system as the entirety of the Cobb County uses it as well as neighboring counties. I believe the system is a work in progress to get the metro Atlanta agencies to be able to interact using any officer's radio (at least that is what they told me at the Sheriff's Office). When the logistics of the 96 Olympics highlighted the need of inter departmental communication, a Metro wide initiative was launched to remedy the problem. Now 20 years later and many elections and administration changes with various departments, I don't know where it all wound up, but it is definitely not what was originally envisioned.
Now to my questions...
When I am at work in a building I scan my departments channels, the fire department, and all of the police departments in the county (total of 7 departments) I hear nothing from the police departments. This does not surprise me as there is a lot of metal around me to stop the signals. But, this is what I do not get. Here (the jail admin area - less metal) I can hear everything on the Sheriff's Office talk groups. About 60 percent of the time I can also hear all of the fire department traffic. Other days, I hear nothing from the fire department.
Not fully understanding how this system works and why this is happening is bugging me.
The four control sites (two of which SHOULD be heard where I am). The other two listed out of the county, I doubt.
Can someone point me to a description of how that traffic is actually handled through this system. I need to be able to visualize this in my mead as I am a visual learner. The old days were easy. Car to tower, tower to scanner. I do understand the basics as I have read everything that pops up on the first four pages of a google search for this topic. But I am just not there yet.
P.S. See post #4 for a better drill down of my questions.
Thanks!
System
Cobb County, GA - a Project 21, Phase I system using APCO-25
It is a multi site system with four control channels (two in county, two out of county). There are MANY trunk ID's on this system as the entirety of the Cobb County uses it as well as neighboring counties. I believe the system is a work in progress to get the metro Atlanta agencies to be able to interact using any officer's radio (at least that is what they told me at the Sheriff's Office). When the logistics of the 96 Olympics highlighted the need of inter departmental communication, a Metro wide initiative was launched to remedy the problem. Now 20 years later and many elections and administration changes with various departments, I don't know where it all wound up, but it is definitely not what was originally envisioned.
Now to my questions...
When I am at work in a building I scan my departments channels, the fire department, and all of the police departments in the county (total of 7 departments) I hear nothing from the police departments. This does not surprise me as there is a lot of metal around me to stop the signals. But, this is what I do not get. Here (the jail admin area - less metal) I can hear everything on the Sheriff's Office talk groups. About 60 percent of the time I can also hear all of the fire department traffic. Other days, I hear nothing from the fire department.
Not fully understanding how this system works and why this is happening is bugging me.
The four control sites (two of which SHOULD be heard where I am). The other two listed out of the county, I doubt.
Can someone point me to a description of how that traffic is actually handled through this system. I need to be able to visualize this in my mead as I am a visual learner. The old days were easy. Car to tower, tower to scanner. I do understand the basics as I have read everything that pops up on the first four pages of a google search for this topic. But I am just not there yet.
P.S. See post #4 for a better drill down of my questions.
Thanks!
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