How many sites to include?

[fenderblue]

I have programmed 5 favorite lists w/P25 MOSWIN Patrol locations. Do I program just one site per every location that is closest to the location? Or do I program all of them to 1 or 2 of them that are close to me? I have 4 P25 systems that are at 35-60 miles and 5 towers that are in those locations. Maybe I need just one tower that is 15 miles from me for all of them.

 

[Voyager]

Any sites not in range will be skipped fast (within milliseconds). Any within range may carry traffic you might want to hear. So I would program any that serve areas you are likely to travel into.

I will add that any co-channel users could increase the time of the millisecond skip time. That's why you only want to program the primary and alternate control channel frequencies. The scanners never use the voice channels for P25 systems - they only use the control channel(s).

 

[ofd8001]

I'd be inclined to build my Favorites Lists by appending from the Sentinel database. Then I'd set the Favorites Lists to Location Control On, enter my current zip code and set the scanner's Range to about 30.0.

That would take a lot of guess work out and let the scanner function operate as designed. Additionally if you go outside of your normal location, just re-enter the zip code for the new location and you can contine scanning as the new locations will become "activated". If you kept the number of locations to a minimal, you are somewhat tying your hands on traveling.

Given the extremely large memory capacity of the x36 scanners, one can be very liberal with loading up sites and departments.

 

[RF23]

Any sites not in range will be skipped fast (within milliseconds). Any within range may carry traffic you might want to hear. So I would program any that serve areas you are likely to travel into.

I will add that any co-channel users could increase the time of the millisecond skip time. That's why you only want to program the primary and alternate control channel frequencies. The scanners never use the voice channels for P25 systems - they only use the control channel(s).

I agree that most of the time this appear to be the best way to program Trunked P25 sites, however, new sites will sometimes switch the control channel to one of the voice channels (perhaps for better propagation). If that happens then the site will go dead unless you also have the voice channels programed in too (so it can become the new control channel). I believe this may have happened at one of the MOSWIN sites in Southeast Missouri.

 

[ofd8001]

. . . however, new sites will sometimes switch the control channel to one of the voice channels (perhaps for better propagation). If that happens then the site will go dead unless you also have the voice channels programed in too (so it can become the new control channel). I believe this may have happened at one of the MOSWIN sites in Southeast Missouri.

If one builds their Favorites Lists using Sentinel (importing/appending data from the full Sentinel database) all frequencies are included for sites. That are those identified as primary Control Channel, alternate Control Channels and voice channels.

I too am in the "put all frequencies in the scanner" camp for trunked systems (unless doing so creates a problem memory limits).

 

[troymail]

If one builds their Favorites Lists using Sentinel (importing/appending data from the full Sentinel database) all frequencies are included for sites. That are those identified as primary Control Channel, alternate Control Channels and voice channels.

I too am in the "put all frequencies in the scanner" camp for trunked systems (unless doing so creates a problem memory limits).

I've gone both ways with programming for different reasons -- sometimes I only program the primary control channel frequency, other times primary and alternate, and still other times I just leave them all in there. There's reasons for doing so... The safe route is to leave them all in there. In fact, some systems (Harris) list ALL of their frequencies as either a primary or control frequency. My state P25 system sites almost never change control channels and I use that to my advantage since this one suffers heavily from simulcast problems. My county Motorola system changes control frequencies quite often for one reason or another to include (sometimes) a non-control channel frequency.

As far as sites -- again - you have options. One option is to include all sites, assign QKs to the sites, and only enable those sites you want to try to monitor. This might be your local site and may be one or two "adjacent" sites. Then, if you travel to the area covered by another site, you can just enable it on the fly with a QK.

Zip code programming -- I never use it other than in a situation where I didn't plan ahead and program a radio for my trip or I'm bored and the radio is quiet when I get there. Even with only a few services enable, I find the scan time to cycle through everything just takes far to long and tends to include things not even close to me.

 

[Voyager]

new sites will sometimes switch the control channel to one of the voice channels (perhaps for better propagation). If that happens then the site will go dead unless you also have the voice channels programed in too (so it can become the new control channel).

Technically, that is not true. The system will never switch the control channel to a voice-only channel unless all the system radios are reprogrammed.

What you are describing is an Alternate Control Channel which I said have to be programmed as well as the Primary Control Channel.

Some systems rotate the control channel among the primary and alternate(s), and some only use the primary unless there is a fault detected with that channel (low power, interference, co-channel user, etc.)

I will add that any channel that is not the current active control channel can carry voice or data traffic. That includes the Primary and Alternate control channels.

 

[darunimal]

Technically, that is not true a new system may change, unless: you 1: call it a reprogrammed one, or from the start when old ones were new, then, there, will never have been any new 1's, except the first ones were new and all the ones now are also new since they are just reprogrammed new ones from old new ones.

 

[Voyager]

Can you translate that into English?

There are three types of channels for most trunked system types:

1. Primary Control channels
2. Alternate Control channels
3. Voice-only channels

Once a system goes on the air with users, these rarely will change with the exception that additional voice-only channels may be added.

The way most radios are programmed is with only the Primary and Alternate control channels. That's why they don't change much - it requires reprogramming of the radio to add the new control channel frequency(-ies). Motorola radios use what the scanner industry calls "Control Channel Only trunking". In fact, I believe that is the P25 spec as well, and except for Implicit P25 systems they also use strictly CCO trunking.

Voice-only channels, on the other hand, are dynamically assigned and do not require any radio reprogramming.

Again, this does not apply to all system types, but applies to most P25 and Motorola systems.

 

[darunimal]

I agree

 

[fenderblue]

What would be a problem if a person just added control #'s of all sites together and added manually the 2 or 3 TGID's to a one i use all the time?

 

[ofd8001]

If you are talking about "merging" all control channels from several sites into just one site, it is a problem. The scanner stops on the first active control channel it "hears" and checks for channel grants (voice communications).

When all control channels are merged into one site for programming purposes, the scanner would disregard any other active control channels.

With regard to the other discussion, my reason for programming all frequencies associated with a site (primary CC, alternate CC and voice only) is completely non-technical. The RR database is information entered by humans and humans can make occasional mistakes. Its possible a voice frequency could be an alternate control channel, but hasn't been marked as such in the database. So just to be extra cautious and ensure all bases are covered, I program all frequenices for each site.