Understanding CO DTRS

Status
Not open for further replies.

KE0KBE

Member
Joined
Jan 10, 2017
Messages
5
Hi,

Perhaps someone could help me understand the relationship to sites and talkgroups in the CO DTRS System. There are 217 "sites", and lots of talk groups assigned to a particular agency. If I want to listen to CO State Patrol, do I need to load all the 217 "sites" and the state patrol talkgroups, or is there a subset of sites that maybe only the state patrol utilizes? I understand the hierarchy, however just not sure how to correlate perhaps if sites are assigned to specific functions/talkgroups.

Also wondering if anyone has any tips for organizing systems in the scanner (BCD325P2). For example, dumping all the sites into single system, splitting them up, perhaps grouping them in some way?

Cheers and thanks in advance.
Tim

BCD325P2
 

k0aa

Member
Premium Subscriber
Joined
Nov 9, 2004
Messages
45
Location
Colorado Springs, CO
Hi,

Perhaps someone could help me understand the relationship to sites and talkgroups in the CO DTRS System. There are 217 "sites", and lots of talk groups assigned to a particular agency. If I want to listen to CO State Patrol, do I need to load all the 217 "sites" and the state patrol talkgroups, or is there a subset of sites that maybe only the state patrol utilizes? I understand the hierarchy, however just not sure how to correlate perhaps if sites are assigned to specific functions/talkgroups.

Also wondering if anyone has any tips for organizing systems in the scanner (BCD325P2). For example, dumping all the sites into single system, splitting them up, perhaps grouping them in some way?

Cheers and thanks in advance.
Tim

BCD325P2
Hi, Tim.

Your inquiry is a valid one. I'll give my thoughts, and you may receive different recommendations from others.

It's necessary to first select the sites near you that you wish to monitor. Since I live in Colorado Springs, I chose the El Paso County radio sites that provide the signal strength needed for my scanner to receive the signals at my home.

Then, I selected the talk groups I wanted to monitor. In the case of the CSP, I selected the talk groups for El Paso County CSP units.

I use software to program my scanners, and most of the transmitters I monitor are imported from the Radio Reference database.

In summary:

1st - Select nearby sites. You won't need a lot. Select those in the area. If you take your scanner to different locations, select the appropriate sites based on where you will be when you want to listen to your scanner.

2nd - Select the talk groups for your area.

Sites first, talk groups second.

I hope this is helpful.

Best regards.

Phil
 

natedawg1604

Member
Premium Subscriber
Joined
Jun 29, 2013
Messages
1,956
Location
Denver-Metro
Also, it's important to remember that certain sites only carry certain talkgroups (and "deny" others). Some people log nearby sites with Pro96Com (only compatible with certain scanners) or RTL SDR dongles and Unitrunker, to determine with certainty which sites carry which talkgroups. DTRS is a HUGE system, and it will take you a while to figure out (1) which sites you are able to monitor from a particular location, and (2) which talkgroups are allowed and/or in-use (technically 2 different things) on which sites.

Furthermore, DTRS uses the same control channel frequencies on different sites located in different counties. Therefore, it's important to confirm the Zone/RFSS and Site# on the scanner display of a site you're monitoring, to verify you are truly hearing the site you *think* you are hearing.
 

Spitfire8520

Completely Clueless =)
Premium Subscriber
Joined
Jun 29, 2009
Messages
1,810
Location
Colorado
The biggest concept that needs to be understood about DTRS and large networked trunked radio systems is affliation. Affiliation refers to a radio checking with a specific talkgroup it wants to use on a site. A site on DTRS will not transmit a talkgroup over the air unless it knows someone is listening through an affiliation. This is because sites on DTRS have a limited number of physical frequencies that can be used to transmit the information.

As a scanner user who wants to listen to specific radio traffic, it is extremely important to select sites that most likely have a radio affiliated to it with the talkgroup you are interested in. Many factors are involved with this, but a majority of the time it is the closest site to the location with a good coverage footprint. You may find the site map for DTRS to be helpful here.

Now listening trying to listen to CSP can be complicated, especially given that you are using a Uniden scanner. The Colorado State Patrol (CO) page on the wiki has some good information. CSP Denver Dispatch patches everything all the time, so you pretty much have to program all the CSP Denver Dispatch talkgroups in order to ensure that you will hear the troop you are looking for. A quick explanation for patching is that certain talkgroups are basically forwarded to a different talkgroup. Uniden scanners, for whatever reason, will not handle the special patch information.

As for organizing the scanner, unfortunately I have not used a Uniden scanner so I do not have personal experience. My understanding is that most people setup quick keys for sites to turn them on and off as needed as well as groups quick keys to focus in on departments. It is probably necessary to split off into multiple systems with the number of talkgroups, so maybe setting up systems by geography would be a good idea.
 

KE0KBE

Member
Joined
Jan 10, 2017
Messages
5
Thanks, this is extremely helpful! As a test, I loaded all sites and listened for the day. To my surprise, I've heard a lot of traffic on the "San Antonio Peak, NM" site. I'm quite sure this site is out of range of listening from my basement just outside Boulder :) So, as mentioned, I'll try to identify it further, and narrow down the sites that are closer to my location. There are several places throughout the state that I camp during the summer, so perhaps organizing systems into geographical location would be beneficial.

I'll continue to play with it and review the information here.

Cheers,
Tim
 

OregonScanner

Member
Premium Subscriber
Joined
Oct 30, 2009
Messages
692
Location
Sherwood, Oregon, USA
To see a map of all the sites go to the DTRS radioreference page and click "RR locations" at the top right of the site list. This will open a mini Google maps map of all the sites. Click on one of the location markers to see the site name. This can be done on any trunked system on radioreference so long as location info has been submitted to the DB.
 

Spitfire8520

Completely Clueless =)
Premium Subscriber
Joined
Jun 29, 2009
Messages
1,810
Location
Colorado
Thanks, this is extremely helpful! As a test, I loaded all sites and listened for the day. To my surprise, I've heard a lot of traffic on the "San Antonio Peak, NM" site. I'm quite sure this site is out of range of listening from my basement just outside Boulder :) So, as mentioned, I'll try to identify it further, and narrow down the sites that are closer to my location. There are several places throughout the state that I camp during the summer, so perhaps organizing systems into geographical location would be beneficial.

I'll continue to play with it and review the information here.

Cheers,
Tim
As Nate mentioned previously, many sites in Colorado reuse frequencies since they generally do not travel long distances. In the case of San Antonio Peak, one of the alternate control channels that would have been loaded is 853.775 MHz, which is control channel of Lookout Mountain and has some of the most varied amount of traffic in the Denver area.
 

csgaraglino

Member
Premium Subscriber
Joined
Jan 20, 2017
Messages
47
Location
Riverview, FL
I'm new to radios - been a photojournalists here in Colorado Springs for many years and feel that I am missing out on way too many opportunities. I have listed to the local scanners via the web or a while now and I think I am ready for a portable. I have seen the RadioShack PRO-651 (On sale now for $300) but I also see that Uniden has a couple of Digital Scanners under $100 on Amazon.

Bearcat 500 http://amzn.to/2jI6zZt
BC75XLT http://amzn.to/2jWcszY

Will either one of these work here in Colorado and pickup CSPD and Fountain PD?
 

Spitfire8520

Completely Clueless =)
Premium Subscriber
Joined
Jun 29, 2009
Messages
1,810
Location
Colorado
I'm new to radios - been a photojournalists here in Colorado Springs for many years and feel that I am missing out on way too many opportunities. I have listed to the local scanners via the web or a while now and I think I am ready for a portable. I have seen the RadioShack PRO-651 (On sale now for $300) but I also see that Uniden has a couple of Digital Scanners under $100 on Amazon.

Bearcat 500 http://amzn.to/2jI6zZt
BC75XLT http://amzn.to/2jWcszY

Will either one of these work here in Colorado and pickup CSPD and Fountain PD?
Unfortunately neither will work. A full list of scanner models that will support the system can be found at this link. You may consider taking a look at Mountain News Net, contact information can be found at Denver Radio - Resources. You may find that the Denver Radio page has a lot of good local information.
 

csgaraglino

Member
Premium Subscriber
Joined
Jan 20, 2017
Messages
47
Location
Riverview, FL
Unfortunately neither will work. A full list of scanner models that will support the system can be found at this link. You may consider taking a look at Mountain News Net, contact information can be found at Denver Radio - Resources. You may find that the Denver Radio page has a lot of good local information.

Thanks for the advice! I was able to pick up a RS Pro-651 on eBay for $150.
The mgr at my local RadioShack, said bring it in and he will program it for me.

My next question, suphould I buy a better entenia, and which one?
 

Spitfire8520

Completely Clueless =)
Premium Subscriber
Joined
Jun 29, 2009
Messages
1,810
Location
Colorado
Thanks for the advice! I was able to pick up a RS Pro-651 on eBay for $150.
The mgr at my local RadioShack, said bring it in and he will program it for me.

My next question, suphould I buy a better entenia, and which one?
Hopefully the guy programming actually uses their products so that he knows how to program for your location. The agencies you are looking for use the State of Colorado DTRS and will only be found on the RFSS/Zone 4 sites that are seen in the database. Programming a site like Cheyenne Mountain will leave you very confused on why it doesn't work. You also may need to reprogram it later this year depending on some changes that will be taking place.

A special note for Fountain PD is that they recently switched over to El Paso County Dispatch. They will therefore be heard on EPSO Channel 3 (South Dispatch) from roughly 7:30 AM to 1:00 AM and EPSO Channel 1 (North Dispatch) for the rest of the AM hours. They are the F (Frank) units over the air.

As for the antenna, it's more of a personal preference on if you want a better antenna. A majority of the time I end up with a good signal using the stock antenna from overlapping sites when outdoors. Scanning from a vehicle or indoors is where problems might come up. Most people end up getting a RadioShack 800 MHz Antenna. Something to keep in mind is that sometimes the scanner can get overloaded with nearby cell towers, which may require doing things like switching to a worse antenna and attenuating the signal.
 

csgaraglino

Member
Premium Subscriber
Joined
Jan 20, 2017
Messages
47
Location
Riverview, FL
Most of what I will be doing is at my desk in Fountain or in my truck. I don't really see myself carrying in the open outside.
 

KE0KBE

Member
Joined
Jan 10, 2017
Messages
5
The post by spitfire8520 included a link to a CO site map. I have searched extensively and have not figured out how to duplicate/find that page via menu pages or searchs. Typically all I can find is a listing for an area, then a site map for specific site (not an area such as a state). Anyone have suggestions, or perhaps a guided menu path?

Cheers,
Tim
 

Spitfire8520

Completely Clueless =)
Premium Subscriber
Joined
Jun 29, 2009
Messages
1,810
Location
Colorado
The site map can be found by going into a system's page and then looking right underneath the System Frequencies header, but above the actual list of sites next to where it says "Red (c) are primary control channels | Blue (a) are alternate control channels". It is link called "RR Locations" that you can pull up. There is also an option to plot a map based on the FCC Callsigns entered for a site.

Keep in mind that both site maps are based off the data submitted by users and entered by the database admins. The information in the database can sometimes be wrong.
 

KE0KBE

Member
Joined
Jan 10, 2017
Messages
5
Thanks Spitfire!

I knew I had stumbled on it in the past, but not very obvious.

Cheers,
Tim
 
Status
Not open for further replies.
Top