SDS100/SDS200: Uniden SDS100 Monitoring Capacity Plus One Frequency Trunked System

[JASII]

I am monitoring a VHF high band system. There is only one RF frequency is use. My Uniden SDS100 displays the Color Code. The There is only one TGID that I have monitored in use. The Time Slots alternate between TS1 and TS2. This leads me to believe that it is a Single Frequency Capacity Plus System.

The SDS100 consistently shows it as DMR rather than CAP. I have monitored Single Frequency Capacity Plus Systems in the past. Does the SDS100 typically display these as DMR or CAP?

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[dave3825]

Maybe list the freq, county and state? Sometimes the license can offer some details.

 

[Whiskey3JMC]

Are you hearing periodic bursts of data on said frequency when there's no voice traffic? If truly Cap+ you'll see CAP+ flash up at the top of the screen during a scan every second or so to coincide with the data bursts of the rest channel. CAP+ indicator remains steady when there's voice traffic, slot carrying said traffic flashes. Otherwise it could be a DMR one-frequency system. Hard to say with no info on said system

 

[JASII]

Maybe list the freq, county and state? Sometimes the license can offer some details.

152.7800. This is in Minnesota, possibly Palmer Bus Service Shakopee on either no license or an expired license. Shakopee is in Scott County MN.

 

[Whiskey3JMC]

Mystery solved...

 

[JASII]

Mystery solved...

Partly solved. If it is pure DMR, like it logs as, why are TS 1 and TS 2 being used for TGID 10. Is it actually a one frequency Capacity Plus system? If so, it should log as CAP, not DMR. Perhaps voice is on TS 1 and digital data is on TS 2, but it is incorrectly logging it as voice.

Then there is the whole lack of license information. Was it licensed and expired? I do think it is Palmer Bus Service, but I don't see a license for this frequency at that location.

 

[dave3825]

I could not find any license for that freq, active or expired.

 

[Whiskey3JMC]

Partly solved. If it is pure DMR, like it logs as, why are TS 1 and TS 2 being used for TGID 10.

Looks to be a conventional DMR channel. Both timeslots can certainly be used by one talkgroup

Perhaps voice is on TS 1 and digital data is on TS 2, but it is incorrectly logging it as voice.

Well are you only hearing voice on slot 1 and not slot 2? DSDPlus would tell you for sure if only data is carried on slot 2

Is it actually a one frequency Capacity Plus system? If so, it should log as CAP, not DMR

Again, review what to look for in post #3. Screenshot I took IS a one-frequency CAP+ site

 

[CanesFan95]

It is possible the same TGID 10 could be used on slot 1 and 2 as 2 different channels the users have on their radios. This would still allow 2 simultaneous conversations like 2 separate channels on the radios they're using.

But if it was Cap+, then a you can't have 2 different TGs with the same TGID. It would all just be on that one TG (one channel) and 1 conversation. But the TG would rotate back-and-forth with the same TGID to slots 1 and 2 as the TG trunks around.

 

[Ubbe]

I've seen this done many times. A conventional analog channel, or two, are replaced by a DMR conventional channel and user radios are programmed exactly as their old radios to make their operation the same. Each slot are regarded as being their old analog channels and the TG that the program guy selected to use do not matter. Sometimes their rounded off old CTCSS tone frequency are used as the TG number.

The radio responsible person just collects radios and repeater from a radio shop that has done the programming and then simply do a quick 5 minute switch of the repeater basestation, with the same antenna and battery backup. They are not interested in texting and status calls and only need voice but using more modern hardware. High quality DMR equipment are much cheaper today than 20 year old analog that perhaps have expensive repair costs.

/Ubbe

 

[JASII]

Looks to be a conventional DMR channel. Both timeslots can certainly be used by one talkgroup


Well are you only hearing voice on slot 1 and not slot 2? DSDPlus would tell you for sure if only data is carried on slot 2


Again, review what to look for in post #3. Screenshot I took IS a one-frequency CAP+ site

I am starting to think more about this. It looks like it works with the SDRPlay devices. Which SDRPlay device should I consider?

 

[Starcom21]

Here is your license: ULS License - Part 22 VHF/UHF Paging (excluding 931MHz) License - WPXN905 - ALPHA WIRELESS COMMUNICATIONS CO