SDS100 missing conversations on DMR Trunk

Melv7956

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Jul 31, 2005
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I didn't realise until today that my SDS100 is missing chunks of conversations. I put it next to my whistler TRX-1 sat them on the same talkgroup expecting to see the Uniden get the conversations first. Sometimes it does but when there is a delay in a reply the Whistler hears the conversation but the SDS doesn't and sometimes the whistler gets it first and the Uniden either joins in later or misses the conversation. I have set up the correct, frequencies LCN settings (Found by the scanner itself on LCN find), colour codes etc. Feeling a bit cheated as I've always been told the Uniden does a proper trunk track. Not to mention the fact the whistler came with DMR put I had to pay extra for the feature for the SDS.
 

Ubbe

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Feeling a bit cheated as I've always been told the Uniden does a proper trunk track.
It does do proper trunk tracking but the firmware code have been compromised since Uniden added RAS support a couple of years ago, that's anyhow how I experiance it. They reuse the exact same code in different scanners as they believe it's good enough to use.

Other problem are that the receiver in SDS100 must be the worse one that Uniden have ever used. The scanner logic is ok, it's identical to 436, but the radio receiver are terrible. Uniden said to only buy a SDS scanner if you have simulcast problems that cannot be solved with another scanner.

SDS100 cannot handle adjacent channel interferencies, it's bleeding over, and anything within 10Mhz range could be strong enough to desense the whole scanner and could drop communications completly. Using a SDS100 connected to a splitter with other scanners reveals how much it misses and how often it comes in late and drops communications in mid sentencies. But if you have severe simulcast problems then other options are few or complicated and non userfriendly.

/Ubbe
 

jonwienke

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Are you doing a site hold or system hold? Are there multiple sites in the system?
 

Melv7956

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It does do proper trunk tracking but the firmware code have been compromised since Uniden added RAS support a couple of years ago, that's anyhow how I experiance it. They reuse the exact same code in different scanners as they believe it's good enough to use.

Other problem are that the receiver in SDS100 must be the worse one that Uniden have ever used. The scanner logic is ok, it's identical to 436, but the radio receiver are terrible. Uniden said to only buy a SDS scanner if you have simulcast problems that cannot be solved with another scanner.

SDS100 cannot handle adjacent channel interferencies, it's bleeding over, and anything within 10Mhz range could be strong enough to desense the whole scanner and could drop communications completly. Using a SDS100 connected to a splitter with other scanners reveals how much it misses and how often it comes in late and drops communications in mid sentencies. But if you have severe simulcast problems then other options are few or complicated and non userfriendly.

/Ubbe
Wish I knew all that before I shelled out the best part of £600.
 

Kaleier1

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Dec 27, 2019
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I have the same problem on my SDS200. Even just holding on a single talk group.

I also have a problem where the wrong talk group comes through. I use the Uniden Wav File Player and when the wrong talk group comes through it shows the talkgroup I am listening to and correct color code but no UID and no DMR time slot number. It usually happens once or twice every 50 to 100 transmissions. Have even had it where it is 4 transmissions in a row and you can tell by the conversation it is the wrong talk group. No one in the correct talk group ever says someone is on the wrong channel so that's not the issue.

Tried filters and attenuation but didn't help either issue.
 

Ubbe

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I also have a problem where the wrong talk group comes through.
It's the same with the 536. When Uniden came out with the DMR option for the 536 it worked fine for a while then a later firmware version ruined it and then some functionality in discovery mode, and probably some other functions, where also broken as well. The firmware are far from a finished product and it's getting reused in newer models that inherits the same bugs and problems.

/Ubbe
 

Kaleier1

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Thank you Ubbe. I half way considered getting a 536 because of this and the missed transmissions but you saved me the money. Sad that firmware updates usually mean making things worse.
 

gabrielddc

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Jul 15, 2009
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it happens to me too, i'm using a BCD436hp, misses a lot of conversations on DMR Tier 3 with RAS enabled, compared to DSDPlus. It also loses transmissions listening to DMR direct (without repeater), I compared it side by side with an Anytone 878 and the BCD436hp loses some conversations and in others it starts to listen after having already started the conversation. I thought the SDS100 or SDS200 would solve this problem, but I already realized that they don't. luckily I found this conversation telling about your experience with these scanners. I would like to thank you for that, you saved my money. I will think about Whistler TRX1.
 

Ubbe

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I will think about Whistler TRX1.
For systems with few active simultaneus calls a TRX will handle DMR with a 100% accuracy. With a high intensity call rate it could have a delay until it finds an ongoing conversation among the active channels. It has to spend something like 200mS on each active voice channel that carries a conversation to be able to tell if it is the TG you have selected to monitor.

If it is 5 conversations active on a site it will in a worst case scenario be a 1 sec delay until you hear your TG again and you have missed the first couple of words in a conversation. The systems I monitor have only had up to 3 simultanious calls on a site so TRX works perfect with that kind of activity. And as it scans the voice channels it will also always catch the private calls radio to radio, that are only transmitted briefly on the control channel at the setup time. So Uniden scanners misses a lot of private calls in trunked DMR systems.

/Ubbe
 

werinshades

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And as it scans the voice channels it will also always catch the private calls radio to radio, that are only transmitted briefly on the control channel at the setup time. So Uniden scanners misses a lot of private calls in trunked DMR systems.

/Ubbe
I monitor a few busy DMR trunked/MotoTRBO systems and program a talk group i0 and label it Private Calls. Scanners are not skipping the these calls.
 

W1KNE

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while then a later firmware version ruined it and then some functionality in discovery mode, and probably some other functions, where also broken as well. The firmware are far from a finished product and it's getting reused in newer models that inherits the same bugs and problems.
Hopefully Uniden is actually working on new firmware to fix the issues listed! Or after Paul's passing, has Uniden pretty much abandoned the scanner market?
 

OldRabbit

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Hopefully Uniden is actually working on new firmware to fix the issues listed! Or after Paul's passing, has Uniden pretty much abandoned the scanner market?
Hope not - but many of their scanners show 'sold out' on the Uniden of America homepage - indicating a possible stop of production
 

buddrousa

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For the Uniden SDS Scanner to track DMR or NXDN Trunking Systems you have to put in the proper LCN's for each frequency.
The reason the Whistler hears better it does not TRUNK TRACK it SCANS VOICE CHANNELS. I have proved this many times on local
DMR and NXDN TRUNKED SYSTEMS backed up by SUBSCRIBER RADIOS.
 

jonwienke

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Hope not - but many of their scanners show 'sold out' on the Uniden of America homepage - indicating a possible stop of production
No. They are sold out often, as Uniden prefers to sell through dealers rather than factory direct.
 

R0am3r

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For the Uniden SDS Scanner to track DMR or NXDN Trunking Systems you have to put in the proper LCN's for each frequency.
The reason the Whistler hears better it does not TRUNK TRACK it SCANS VOICE CHANNELS. I have proved this many times on local
DMR and NXDN TRUNKED SYSTEMS backed up by SUBSCRIBER RADIOS.
A point of clarification and a bit off topic - Direct Frequency Access NXDN trunked systems do not require the user to put in the proper LCN for each frequency. Both of my SDS scanners seem to follow these NXDN systems without any noticeable issues.
 

twotoejoe

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I didn't realise until today that my SDS100 is missing chunks of conversations. I put it next to my whistler TRX-1 sat them on the same talkgroup expecting to see the Uniden get the conversations first. Sometimes it does but when there is a delay in a reply the Whistler hears the conversation but the SDS doesn't and sometimes the whistler gets it first and the Uniden either joins in later or misses the conversation. I have set up the correct, frequencies LCN settings (Found by the scanner itself on LCN find), colour codes etc. Feeling a bit cheated as I've always been told the Uniden does a proper trunk track. Not to mention the fact the whistler came with DMR put I had to pay extra for the feature for the SDS.
I'm having the same problem with my SDS 200. I've set my 536 right beside the 536 with identical programming and the 200 is missing some transmissions, chopping others, just like you have posted.
 

jonwienke

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Sounds like there are multiple sites programmed, and the Uniden is resuming scanning.
 
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