Uniden UBC125AT + DSDplus, searching for suggestions

Frasso

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Jul 29, 2022
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Hi Mates! I'm a radio scanner enthusiast from Italy.
I have recently modified my UBC125XLT (the european version of the 125at) with a discriminator Tap.
The discriminator tap works, i can see on DSDplus, when tuning on a dmr frequency, that the software can read the colour codes etc..., but i'm not able to listen to the audio, sometimes i hear somenthing, but is unclear audio. The signals are strong and im cheking them with sdrsharp. I've followed this procedure to set VBcable and the audio input:
maybe im missing something, someone can help me?

Im using the free version of dsdplus, but i have also dsdplus fast lane
 

LimaZulu

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Jul 7, 2011
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You mentioned unclear audio - is there any possibility to be encrypted? If yes, then you cannot do anything.
Could you please provide some examples of what you see and hear? Some audio samples directly from the discriminator output, some video of your screen....something like that will help us to be able to help you :)
 
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Fredo68

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Jun 7, 2020
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I notice you are maxing out the bars on the cable output. Maybe reduce the audio volume (a lot)? DSD can be quite sensitive to the 'right' audio level. I see a lot of errors in DSD. What bandwidth are you using?
 

Frasso

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Jul 29, 2022
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You mentioned unclear audio - is there any possibility to be encrypted? If yes, then you cannot do anything.
Could you please provide some examples of what you see and hear? Some audio samples directly from the discriminator output, some video of your screen....something like that will help us to be able to help you :)
Hi, no it's not encrypted is a clear frequency
As Fredo68 said i think it's a problem of audio volume:
Im using an audio volume from the scanner of 8, if i go under dsd cant recive well
I attach an image. I know there are lots of error, but in all the videos i saw when using dsd with a discriminator its always like that
 

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Frasso

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Jul 29, 2022
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I notice you are maxing out the bars on the cable output. Maybe reduce the audio volume (a lot)? DSD can be quite sensitive to the 'right' audio level. I see a lot of errors in DSD. What bandwidth are you using?
I have seen that the microphone input was amplified from the computer of 20db, with 0db i have no signal on dsd, now i try to use 10db. I think that the problem is with the audio input in my case or its low or its high, maybe there is a pice of software that can help me
 

LimaZulu

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Jul 7, 2011
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Amplification by fixed values does not allow you to tune things smoothly. Set it to 10 dB if that's what works for you and start to play with the sliders. Also, check "advanced" and "spatial sound" tabs under input properties. There shouldn't be any audio improvements turned on and should look like that
1688108812831.png 1688108837813.png

Some other things to consider are signal strength and bandwidth that's set by the scanner.
Your scanner is your entry point so start by setting it up first, then work your way up.
 
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Fredo68

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Jun 7, 2020
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Perhaps you could also test your setup separate to the scanner. You could download SDR# and use one the online receivers to test your cable input/DSD end of the chain?

I previously mentioned bandwidth; I use an Airspy so this may not be relevant - for DMR, I find 8kHz gives a better SNR than 6.25kHz.
 

Frasso

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Jul 29, 2022
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Amplification by fixed values does not allow you to tune things smoothly. Set it to 10 dB if that's what works for you and start to play with the sliders. Also, check "advanced" and "spatial sound" tabs under input properties. There shouldn't be any audio improvements turned on and should look like that
View attachment 144681 View attachment 144682

Some other things to consider are signal strength and bandwidth that's set by the scanner.
Your scanner is your entry point so start by setting it up first, then work your way up.
Ok i checked and the cable input setting are ok.
the scanner bandwidth is setted to 12,5khz

Perhaps you could also test your setup separate to the scanner. You could download SDR# and use one the online receivers to test your cable input/DSD end of the chain?

I previously mentioned bandwidth; I use an Airspy so this may not be relevant - for DMR, I find 8kHz gives a better SNR than 6.25kHz.
the setup separate works fine, i use it everyday with sdr#, dsd, Tetra Trunk Tracker, acarsdeco2...and more it's all good. The signal is very strong it's not a problem. I can try to change the bandwith
 

dave3825

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I notice you are maxing out the bars on the cable output. Maybe reduce the audio volume (a lot)?

Pretty sure the video posted is not from the OP as it is 4 years old.



Im using the free version of dsdplus, but i have also dsdplus fast lane


@Frasso , from the DSDPlus FastLane notes file,
Using DSD+ with external signal sources

DSD+ can be used with external signal sources such as a properly discriminator-tapped receiver
or SDR software such as SDR#. To use DSD+ with these sources, use the menus in DSD+ to
select Passive Digital Monitor mode and then to select the audio input device that carries
the digital audio signal. When running in this mode, DSD+ can be used to monitor conventional
analog and supported digital signals; DSD+ will not directly support trunk tracking.

What is it you are trying to decode? Conventional or trunked?
 

Frasso

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Jul 29, 2022
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Pretty sure the video posted is not from the OP as it is 4 years old.






@Frasso , from the DSDPlus FastLane notes file,


What is it you are trying to decode? Conventional or trunked?
That note file is very interesting many thanks! I must try when i come back home. Now im in Bulguary (Nothing interesting for scanners enthusiast)
You know, who reads instructions!?😂
Im trying to decode conventional dmr

I think that at the end of the month i will buy an udniden UBCD36000XLT the european version of the BCD436HP.

I Saw many videos on youtube about discriminator tapping uniden scanners and it seems be that older scanners like the 69xlt or the 92xlt are better to do that
 

racingfan360

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Dec 19, 2005
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1,158
Hi, no it's not encrypted is a clear frequency
As Fredo68 said i think it's a problem of audio volume:
Im using an audio volume from the scanner of 8, if i go under dsd cant recive well
I attach an image. I know there are lots of error, but in all the videos i saw when using dsd with a discriminator its always like that
So problem #1 to solve is getting the discriminator tap on your uniden working correctly. A functioning disriminator tap will bypass the audio filters on the scanner, and that includes those elements that control volume. So the volume control shouldn't work. The fact that you can alter the 'discriminator' output using volume controls tells me the tap isn't right. Note it is sometimes possible to get some very poor DSD+ decodes using the standard scanner audio output, that could be what you're seeing here.

Also if its working right, with a good signal you should see some occassional errors. Lots of errors isn;t the norm, reardless of what others might have posted. Conventional or Trunked will be irrelevant to the issues you are seeing/explaining.
 
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