SDS100: False DMR Color Code Decodes

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JASII

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I have performing some searches lately, under Butel ARC536PRO, in the 451-454.9875 and 460-464.9875 areas to log what Color Codes are being used on those frequencies. In most cases, only one Color Code is being logged. However, in a few cases, more than one Color Code has been logged. While it is certainly possible that a given frequency is being used with more than one Color Code in my receiving area, I am inclined to think I am get false logs, somehow. For those familiar with this, do you have any idea of the best way(s) to reconcile these differences and determine the correct Color Codes being used?
 

kruser

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They are packing UHF users so close together here in my area that it's not uncommon to hear three (or more) different DMR signals from my home location.
They are all legit business users with different FCC licenses. Each user here will use a different Color Code so they don't hear the others on the frequency. It's really no different than using CTCSS or DPL tones on analog channels.
Some of the frequencies here with more than one DMR user also still have analog users!

If your signals are from base radios, you may be able to see the difference by one of the radios signal strength indicators. That can help figure out that you are hearing more than one licensee.

If they are using certain DMR types, you may be able to setup the frequencies as one freq trunk systems and watch for UIDs to display along with talkgroups. Different users will generally have different UID and TG ranges as well as different color codes.

As packed as the UHF band is here with DMR users, I've never found any of the DMR capable Uniden's I have to display false Color Code info. I suppose it's possible but I've not seen it. I'll often verify what the scanner tells me with DSD+ as well and they have always agreed.

I do use ProScan for logging but ARC536 should work just as well and without error. I still watch what the radio displays though.
 

Ubbe

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I see a lot of false color codes and also TG's in my logs and also live directly on my BCD536. That's why I suggest to not use color code filtering or NAC or RAN if it is not necessary, like if you actually have several systems within coverage that use the same frequencies. I've never seen false decodes on my TRX scanner so it is Unidens firmware code that seems to be at fault.

To verify a code I use DSDPlus or another scanner or perhaps guess that the code that comes most often with a Uniden scanner are the correct one.

/Ubbe
 

kruser

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I see a lot of false color codes and also TG's in my logs and also live directly on my BCD536.
/Ubbe
I don't see this with any of my Uniden models Ubbe.

Is it possibly a weak signal condition that makes false color code detection on your Uniden models more prominent?
I also compare against DSD+ and the two have always agreed but I do tend to work more with stronger or good signal levels when it comes to UHF DMR around here.
 

JASII

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I have an AnyTone AT-D878UV dual band DMR/analog portable transceiver. I might just use it to help verify the Color Codes being received.
 

kruser

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I have an AnyTone AT-D878UV dual band DMR/analog portable transceiver. I might just use it to help verify the Color Codes being received.
There ya go. You might also find some signals don't appear on the Anytone but do on the SDS which may indicate you are getting signals from multiple systems.
Can you use the same antenna for the AnyTone and your SDS at the same time? That may help if some have weak signal levels.
 

JASII

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One other thought I had is to select the Attenuator. I am using an outdoor antenna and if I am getting too much signal, perhaps selecting the Attenuator will reduce the possibility if getting false hits if that's what I am getting. I have sort of mixed thought on doing that, but I suppose I can try and see what my results are.
 

garys

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Especially on business frequencies. There is one frequency within my listening range that is used by three different companies. Three different Color Code as well as TGs and RIDs that don't conflict. Still, it can be confusing trying to figure out who is talking to who.

One if them is even part of a trunk system.

They are packing UHF users so close together here in my area that it's not uncommon to hear three (or more) different DMR signals from my home location.
They are all legit business users with different FCC licenses. Each user here will use a different Color Code so they don't hear the others on the frequency. It's really no different than using CTCSS or DPL tones on analog channels.
Some of the frequencies here with more than one DMR user also still have analog users!
 

kruser

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One if them is even part of a trunk system.
Same here. I think it's Monsanto (Bayer now) that has a Cap+ system. Actually about four or 5 different Cap+ systems in my area.
At least three of the freqs used by one or more of their Cap+ systems are used by other conventional DMR business users.
I think it's one of Bayer's Cap+ systems that also has the analog user I hear occasionally. I'm not sure how well this works out for the non Cap+ users with the Rest channels always sending out beacons.
 
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