SDR Unitrunker DSD+ Help

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firebal

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Hello all
I am new to the SDR world and have run into a bit of a problem. I am trying to listen to Baltimore Counties P25 P1 system https://www.radioreference.com/apps/db/?sid=7117 using 1 cheap sdr (as the voice) and 1 rtl-sdr (as the control/signal). VB cable is installed and is set as the default. I am the most recent versions of both Unitrunker and DSD+. Am am currently only receiving garble. I have attached all relevent photos that have been asked for with other questions regarding Unitrunker and DSD+. Any help would be greatly appreciated.

-firebal
 

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mtindor

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If that is a simulcast system, then good luck -- you can expect issues in that case. Unitrunker and an SDR dongle won't magically fix simulcast distortion, if that's the problem.

Mike
 

SCPD

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The image shows a health of 22%. Work on getting the control channel decode rate close to 100% before attacking voice quality.
 

firebal

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The image shows a health of 22%. Work on getting the control channel decode rate close to 100% before attacking voice quality.
Ok, thanks Unitrunker! And especially for making such a great program. Any suggestions on how to improve my signal health? Or control channel health?
 

SCPD

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The usual suspects are:

1. warp correction.
2. gain setting - too high or low
3. noise from nearby electronics
4. better antenna.

Adjust the warp correction to keep the window value low. A single digit window value (positive or negative) is good.

For gain setting - start with baseband AGC ON, tuner AGC off, and start with a gain of 300. Maximum is 485.

Use a USB extension cable to move the SDRs away from the PC host.
 

firebal

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Ok, I was curious to try to see if SDRtrunk works and it does. I am able to for the most part receive audio clearly. However, I would still like to get Unitrunker working. So now that we know that I can decode it with SDRtrunk. What should I try for Unitrunker?
 

mtindor

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Ok, I was curious to try to see if SDRtrunk works and it does. I am able to for the most part receive audio clearly. However, I would still like to get Unitrunker working. So now that we know that I can decode it with SDRtrunk. What should I try for Unitrunker?
You shouldn't bother using unitrunker.

SDRTRunk supports LSM systems

DSDPLus (using FMP as the receiver, not SDR#) and DSDPLus to decode supports LSM

DSDPLus (using SDRSharp as the receiver) does not support LSM

Unitrunker does not support LSM -- at least never has on any system i've tried.

Mike
 

dave3825

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Ok, I was curious to try to see if SDRtrunk works and it does. I am able to for the most part receive audio clearly. However, I would still like to get Unitrunker working. So now that we know that I can decode it with SDRtrunk. What should I try for Unitrunker?
If you're using the same dongle and the same antenna and it works in sdrtrunk, then to me it sounds like the gain is set higher in sdrtrunk than in unitrunker or your ppm could be off in unitrunker.

What antenna are you using and how far from a transmitter are you?
 

dave3825

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Looking at your pic on a different monitor, it looks like you do not have a ppm set set on the signal vco. You do have 11 set in the voice. The signal vco you said is a rtl-sdr . Is it dead on ?


Also, if I am not mistaken, I believe the gain will go past 100. Try 3 or 500 and see what that does.
 
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