State DTRS for Dummies

[sargeek]

OK - Just want to make sure I understand the system:
A state trooper gets issued a pack set - The pack set is programed with the "talk groups" the trooper is supposed to use: Dispatch, tactical, Hazmat ect. The trooper accesses these talk groups by using the traditional channel selector on the top of the radio. I would make the assumption that they have 16 of these talkgroups and if they use other functions on the radio they can adjust the selector to access other groupings of 16 talkgroups. On average how many talk groups are intalled in a radio.

The radio is also programed with the information reguarding the repeater sites and the specific frequecies to use. Does the system hand off radio traffic from one repeater to the next similar to cell phones or does the user have to specifically choose the site? If the system detects a Thornton PD talk group in the area of the Trinidad site will it relay all the Thornton PD radio traffic over the Trinidad repeater?

Are their top end and bottom end radio? My guess is that a douglas county school bus drivers radio doesn't need to access all 26 repeater sites, and needs only 1 or 2 talkgroups installed is a low end unit, while the CSP Trooper get a higher end radio that has multiple talk groups and capability to function on all the repeater sites?

 

[Troop]

Our Radios have a common channel selector. A talk Group is what most would consider a "channel". Our radios have a certain amount of talk groups on 8 zones. The groups include all the state wide troop channels, TAC channels, specialty channels, the CSP simplex, all the MACs, ITACs, and anything local, ie S.Os P.D.s, and F.D.s....we also have the CDOT channels for our troop area.

My radios hand off to the tower much like a cell phone does. hope this helps, At one point I listed all the channels on each zone on my radio.

 

[k0pwo]

I will try an answer a few of your questions to the best of my knowledge.

As troop said above, the common radio, no matter who it is programmed for will have that agencies talk groups programmed into the radio in an order specified by the dept that person works for. It may also have neighboring agency talkgroups programmed into the radio. Most if not all the radios that you will see on the state system will be programmed so that the radio will have 16 or less talkgroups per zone. On protables the radio will almost always be programmed so that the channel selector is used to select talkgroups and the arrow keys on the keypad will be used to select the zone that is wanted. It can be programmed the other way around and more than 16 talkgroups can be put into one zone, however only 10 at a time can be scanned no matter how the radio is programmed. To clairify that last statement. Even if you programmed the radio so that the channel selector is used to select the talkgroups, you can programm more than 16 talkgroups into that zone, however, there will be no way to select that talkgroup via the radio.

When programming the radio for site ussage. Through the software one can program the raido to "perfer" certain tower sites. Such as, if the radio is a Arapahoe County SO radio it will be programmed to use the cheveron site, the smoky hill site, the littleton site and the bennett site along with a few others. The radio will check those tower sites first and if they are useable it will select those towers over the others. If none of those prefered sites are useable it will then search all apco 25 control channels that it hears and that have the proper system id and then will lock onto one of the sites for use. When it starts losing the selected site will scan control channels again and log onto the next useable site it finds. Keep in mind, when the radio affiliates with a site for use, the controller at that site downloads information to the radio telling it which sites are nearby that site so that if control channel is lost the radio will then check those sites recommended by the previous site. This saves time when the radio must find and new control channel nearby so that it may reaffiliate again.

All of this is a quick overview of how you can program the radios and how they work. The programming of these systems is quite involved and there are lots and lots of different things that must be set up right for the radio to work correctly with the system.

Hope this helps somewhat if you have more questions. Then ask away.

Dave

 

[firescannerbob]

Our radios are set up so that the a-b-c toggle switch sets the zones, and the selector knob sets the TG.
While the a and b zones vary based on the agency, the c zone is the same for all users in the system (police, fire, ems, utilites, parks and rec, etc).
My radio has several additional zones that are accessible via the keypad. Any of those trunked TG's can also be scanned (ICall, Simplex, etc cannot be scanned).

 

[RDCat]

thanks for the info--good heads up