A basic Trunking Question - newbie

[daren77]

I have a very limited understanding of trunking. Am I correct in that if you are within receiving range of one of the towers in your particular trunked system that you can hear all activity on that system....not just the activity in the town the tower is located in?

For Example.

I live near Spencer, IA which has several (5) frequencies listed for the RAYCOM trunking system that has many users all across the state of Iowa and then some on it. So if I put in the proper talk groups for Cedar Falls Police (on the same system) will I be able to monitor their communications even though they are 5 hours away from my location?

I know this is probably a basic question but thanks to anyone who takes the time to help out a newbie.

 

[wannabescannist]

From my (also limited) understanding....if you can receive from the tower, you can hear all activity.

 

[hankv]

I have a very limited understanding of trunking. Am I correct in that if you are within receiving range of one of the towers in your particular trunked system that you can hear all activity on that system....not just the activity in the town the tower is located in?

Not exactly. For you to hear a transmission, a unit on a particular Talk Group, it must be associated with (in range of) that particular tower.

You will hear all transmissions on TG's from your local area. If a TG on your local Tower is used Statewide, you will hear transmissions on that one TG from anywhere in the State.

If a unit from another area travels to your area, you will start hearing transmissions from his home area until he gets out of range of your tower.

 

[troymail]

Sorry to use the word 'depends' but .... it depends....

One of the greatest features of these systems is the ability for units across very large areas to talk to each other.

For example, in a statewide system, units could actually be able to talk from one end of the state to the other.

The primary system I listen to is a COUNTY system. The county has somewhere between 5-10 towers. For this system, ALL conversations hit ALL towers so ALL radios can hear the conversation regardless of where they are in the county. But that's the way the system is set up.

Other systems (particularly statewide systems) seem to break things down into "zones" (example: http://radioreference.com/modules.php?name=RR&sid=411&d=&opt=all_tg). In this example, the STATE decided to build a system that includes all counties into that one system. However, this is in fact multiple systems in ONE system since Site 001 is one county or area, Site 002 is another etc.

Going back to my local system I listen to - in order for units from my county to talk to units in another county, the user/unit in my county must "leave" the local system and switch to the system/frequencies that are used by the neighboring system. Fortunately, those surrounding systems are programmed into the local system radios (and vice-versa). The down side of this is that (a) units are sometimes "lost" because neither jurisdiction really knows where that user is unless they can get them on the radio and (b) every time neighrboring systems make a change to their system, the surrounding counties have to have programming done as well to keep up with the changes (job/financial security for the radio techs...)

Bottom line is "it depends"....