ARMER tower questions

wa8vzq · #1 (**permalink**) 07-29-2009, 04:40 PM

Is there any logic to the new tower numbering scheme?

It seems that over time, multiple towers have disappeared from previous matrix lists while new ones appear. Are they decommissioned, relocated, renamed or something else?

Exhibit F from the Radio Board website shows about 10 towers for Dakota County but only 2 are listed in the database. I understand that they may not all be built but are there really only two that are active or only two towers with control channels? What am I missing?

I don't see any unique Dakota County Sheriff groups. Are they behind on migrating or just using one of the common groups like 4300?

Dan

n9upc · #2 (**permalink**) 07-30-2009, 01:35 AM

Dakota and Wash Co run off some of the same towers/sub-sys. When we went on-line with 800 in Wash Co with just public works and a few other users that really only used mobiles we only had a few towers up and running.

However, when we went the full gambit we did some tower adding and re-zoning. If you look in the databse you will see Dakota has one tower set marked as Site ID 1-003 and also bounces off of Wash Co's Site ID 1-005.

Now even though you see only one Site ID it still has numerious towers under that ID. Example for Wash Co we have 14 towers that all run with the Site ID 1-005 and all towers run those channels listed next to the Site ID.

As for the number in front of the Site ID (i.e. 1 for Wash Co, Dakota, Anoka, and Carver) state what zone controller/router that these networks work on.

As stated in Wash Co we are on Zone 1 and when the consoles Tx on talkgroups the ID for the consooel will come up with: z1-wash-op3 So from that you can see it is a Zone 1 console from Wash Co and Operator position 3. (However the names for consoles and radios are ALL over the board.)

Hope this helps and does not hinder!

wa8vzq · #3 (**permalink**) 07-30-2009, 07:59 AM

John

Thanks - that helped a lot. I could see that most were somewhat grouped geographically. Initially I thought perhaps the numbers were related to install phase but quickly ruled that out.

I thought more about the towers that disappeared. I'm guessing that some may have been temporary installs to get the services running. Worked on a county system in the DC area that was just converting from 150 MHz to 490Mhz in mid-70's. We had a heck of a time getting good coverage for officers using HT's out of Convertacoms. Mobiles worked great, HTs worked Ok until the officer popped it out and stepped out of the squad - then the coverage issues started. That county was divided into several zones, each with a dedicated repeater and satellite receiver sites. Dakota County is just slightly larger so I'm curious about coverage with just two towers. Especially curious about west past county road 5 and north of 13. I'm guessing that some of the coverage comes from overlap coverage from other counties?

vf702 · #4 (**permalink**) 07-30-2009, 09:49 PM

The system uses digital simulcast. Each of those 14 towers in the Washington County subsystem are receive and transmit sites. They all transmit at the exact same time on the same frequencies creating a bit bubble of coverage. All of the metro is built out like this.

n9upc · #5 (**permalink**) 08-06-2009, 06:43 PM

Actually only the towers that have a radio affilated with that tower, ON that talkgroup will broadcast off of that tower. I know myself, especially at night tend to have some towers that have no affliation on some radios with talkgroups and you have a hard time hearing the traffic. (i.e. some city PD talkgroups)

But yes the whole system is built out this way. Which I think it is funny as it is using a Motorola patnet technology but with a P25 CAI voice format. I know many people think that this is what P25 trunking is, but in essence it is really not.