DMR Capacity+: Why...?

[rbuxton]

Here's something else,,,,,

When I ran a discovery session on the two channel trunked system during the day I got 40 hits. A few encrypted transmissions but for the most part all were received loud and clear.

Then, when I scanned the same system I hear nothing (while I hear DSD+ running on my computer blaring voice calls loud and clear.)

Can someone explain how Discovery works? Does it listen to the system as I programmed it (MotoTRBO) or is it listening to the frequencies as if I programmed them as conventional?

 

[lu81fitter]

To throw this in the mix, does this apply to the 996p2 also? I was just about ready to get the DMR upgrade for it.... I don't have DSD or any other program. There are 2 agencies that I would monitor, one on an 800 system (LaSalle County, IL), and one single freq in the 460 range (Marshall County).
Don't mean to hijack your thread, just wondering....

 

[DaveNF2G]

While using DSD+ is extremely informative, it can create confusion when transferring the information to a scanner.

What DSD+ reports as "LCN" is really the "LSN" which is not the same thing.

Here's a simulated example of a 3-repeater CAP+ system:

461.1000 Slot 1 LSN 01 LCN 01
461.1000 Slot 2 LSN 02 LCN 01
461.2000 Slot 1 LSN 03 LCN 02
461.2000 Slot 2 LSN 04 LCN 02
461.3000 Slot 1 LSN 05 LCN 03
461.3000 Slot 2 LSN 06 LCN 03

Hope this helps.

 

[ur20v]

Question for you guys who find these new trunked systems - do you submit them for inclusion in the RR database?

 

[rbuxton]

Question for you guys who find these new trunked systems - do you submit them for inclusion in the RR database?

Once I figure them out I do.

 

[dtscho]

Roger all of the above. Why does the Fredericksburg site not have a LCN3? Is that proper or is the freq just unknown?

001 (1)
FredericksburgSpotsylvania 01 451.9375 02 452.2375 04 452.100

They've apparently elected not to have an LCN 3. If you run DSD+, you'll see that none of the voice calls ever go to LCN 3 (which are LSNs 5-6). It's perfectly acceptable to set up a system like this.

But we're kind of getting off-topic here...

Dave

 

[rbuxton]

Problem solved

I have determined that my trouble in receiving a local Cap+ site is due to the poor reception by using the stock antenna. I replaced the stock antenna with a Diamond SRH77CA antenna.

To find the optimum digital settings I set up duplicate systems with the only difference being the threshold settings. With the Diamond antenna and using the system analyze function I found that Manual/5 thru 9 were the best, 12 and 13 received nothing.

Using the stock antenna and the same system analyze testing as above I received nothing.

FWIW, the freqs of this system are 461.800 and 463.4125.

Questions remain on whether the reception problem is due to the antenna or something else. And, when using the stock antenna why DMR trunked freqs programmed as conventional can be heard but when they're programmed as MotoTRBO they cannot.

 

[jonwienke]

The Diamond antenna is significantly better than the stock in that frequency range.

 

[INDY72]

CAP + ?

When initially setting up a Cap Plus in an 436, should one follow the adage of putting in placeholder LCNs? I have one I am working on here, 8 Freq UHF confirmed as Cap+. In conventional mode I hear the conversations, and get the color codes, and see slots as they are used. LCN finder does NOT show a dang thang, and found out hard way that with the LCNs all 0, you don't get nada. So, should I just punch in 1 thru 8 as placeholders until I get some valid traffic and the LCN finder work it out after?
And yes I am running FW .31

 

[UPMan]

Valid LCNs are required to scan CAP+ systems. Put in placeholders if you don't know the LCN, then use LCN finder.

The problem with identifying LCN on CAP+ is that CAP+ will only move to a new LCN if there are more than two simultaneous conversations on the system. With only one conversation, the voice appears on the Rest Channel's slot and the Rest Channel moves to the other slot (same frequency). On a slow system, it can take a loooong time to catch all the LCNs.

 

[INDY72]

Considering this system is for an convention center, and NFL football stadium (https://www.radioreference.com/apps/db/?sid=9454) , this will be an very busy system during the very big conventions, sporting events including Indianapolis Colts games, concerts, monster truck shows, motocross, DCI...... It is used by housekeeping for both sites, security/safety, HVAC, IT, Lighting/Sound, multiple food services, groundskeeping, full time maintenance staff, as well as special event staff from George E. Fern.

So should not be too hard to nail it all down fairly quickly. Especially as I will be pretty much living there for 4 days next month during GenCon which uses both facilities