Programming Control Channels for Trunked Systems into Scanner

[TexTAC]

Hopefully someone can help answer some of the questions I have about trunked systems and how to efficiently scan them. I have several trunked systems in my area (Plano, Allen, Wylie, Murphy (PAWM) and Fort Worth Regional Radio System, for instance). Both of them contain multiple "sites" containing multiple frequencies (primary control channels, alternate control channels, and other channels). Here are some questions:

Do talkgroups belong to the individual sites or are talkgroups common and shared across all the various sites?

Do I need to program every site into the scanner to hear all the traffic?

Do I need to program all the frequencies for each site into the scanner (or only the control channels?)? Does it matter which order I enter the frequencies?

I currently have an SDS100 and am trying to figure out how to make it scan trunked systems faster. My old Pro-106 (only good for P25 Phase I not Phase II) had a "multi-site mode" setting which I could set to "off" (finds first usable control channel and then uses it until it is no longer useable), "Roam" (scanner attempts to find the best possible control channel and then ignores the others until the best one is no longer useable), or "Stationary" (scanner uses the first useable control channel). The SDS100 doesn't have these settings so I don't know how it actually decides which control channel to use.

 

[RaleighGuy]

Do talkgroups belong to the individual sites or are talkgroups common and shared across all the various sites?

Sometimes, in my area TGs are assigned the county they are in plus one surrounding county. It all depends how the system admin sets it up. That said they can affliate with other sites if in the area.

Do I need to program every site into the scanner to hear all the traffic?

If you are traveling yes, if you are stationary, or only staying local, just the sites around you is sufficient.

Do I need to program all the frequencies for each site into the scanner (or only the control channels?)? Does it matter which order I enter the frequencies?

Control Channels and alternates should be programmed as the control channel may change for whatever reason to one of the alts. You do not need other channels.

 

[TexTAC]

Thanks for the quick response. If I delete the other channels (i.e. not the primary control channels and not the alternates) and list the primary control channel first, do you think that will speed up the scanning speed? Sentinel automatically downloads all the channels for each site in the order they are listed on Radio Reference. Thanks again.

 

[RaleighGuy]

Thanks for the quick response. If I delete the other channels (i.e. not the primary control channels and not the alternates) and list the primary control channel first, do you think that will speed up the scanning speed? Sentinel automatically downloads all the channels for each site in the order they are listed on Radio Reference. Thanks again.

Less freqs mean faster scan time, so Yes

 

[hiegtx]

Thanks for the quick response. If I delete the other channels (i.e. not the primary control channels and not the alternates) and list the primary control channel first, do you think that will speed up the scanning speed? Sentinel automatically downloads all the channels for each site in the order they are listed on Radio Reference. Thanks again.

No. The scanner is only checking for control channels, so the other (voice) channels are not scanned. The scanner takes up to 1.5 seconds, per site, to acquire & decode the active control channel frequency. So, less sites would result in an improvement in speed.

Only program the sites that you can hear, in the areas that interest you. FWRRS has a number of sites. If you are interested primarily with FWFD, Tarrant County, and the smaller cities in Tarrant County, you would need the Layer 2 site. However, some do use Layer 1, so include both. To hear Euless, Bedford, & the other cities in the northeast part of the county, you need the Northeast Tarrant site. Depending on your location & antenna used, it's unlikely that you could hear all of the various FWRRS sites. Only include the ones in range.

The Denton County P25 system has three sites. One for the County & smaller cities, one for Lewisville, and the third for the City of Denton.

In Collin County, you have PAWM, with one site for the original cities, and a new site to be used by Collin County after they move off their current analog system. You also have the individual Frisco & McKinney systems.
In Dallas County, you have GMRS (used by Garland, Mesquite, and some smaller cities), Metrocrest (four cities), and Richardson. Irving & Grand Prairie are part of FWRRS. If either, or both, are of interest, & in range, you would need their respective sites.

 

[Ubbe]

If I delete the other channels (i.e. not the primary control channels and not the alternates) and list the primary control channel first, do you think that will speed up the scanning speed?

If you have voice channels first in the list, at the top, and they are active with calls then the scanner will stay some 50-100mS on each one until it has determined that it is not a control channel. If you have 10 voice channels first in the list and it is an extremly busy site it could take up to 1 second of wasted time until it finds the control channel.

/Ubbe

 

[TexTAC]

Thanks for the replies. Sounds like moving the primary and alternate control channels to the top of the list may help scanning speed somewhat.

I use range control, even when not mobile and at home, to help select which “municipal” sites are loaded. I’ve noticed that at 0 miles I only get a very few sites (PAWM, Collin Co, Dallas P25). At 2 miles I pick up all the conventional Dallas PD/FD (which are always very active and interesting). At 5 miles I start getting more surrounding cities (Denton, Richardson, McKinney, Rowlett, etc). At 10 miles a Fort Worth site (northeast Tarrant). At 25 miles all Fort Worth sites (although I think I only get the control channels for about 3/4 sites). At 50 miles, it starts including a lot more smaller cities, even Oklahoma sites, but I seldom hear anything that far away. Sometimes I scan at 50 miles just to see what I can actually hear and am sometimes surprised.

I appreciate the input!

 

[hiegtx]

Thanks for the replies. Sounds like moving the primary and alternate control channels to the top of the list may help scanning speed somewhat.

I use range control, even when not mobile and at home, to help select which “municipal” sites are loaded. I’ve noticed that at 0 miles I only get a very few sites (PAWM, Collin Co, Dallas P25). At 2 miles I pick up all the conventional Dallas PD/FD (which are always very active and interesting). At 5 miles I start getting more surrounding cities (Denton, Richardson, McKinney, Rowlett, etc). At 10 miles a Fort Worth site (northeast Tarrant). At 25 miles all Fort Worth sites (although I think I only get the control channels for about 3/4 sites). At 50 miles, it starts including a lot more smaller cities, even Oklahoma sites, but I seldom hear anything that far away. Sometimes I scan at 50 miles just to see what I can actually hear and am sometimes surprised.

I appreciate the input!

Remember that there are two components to the 'range setting' that you use. If a circle, representing the range you set on the scanner, intersects with the range circle of a given site or department, that will be enabled on the scanner if using range control. For a more complete answer on location, see this:
How it Works: Location, Location, Location