DSD+ On DMR Simplex

[Aaron_B]

Hello, I have been transmitting on my Mototrbo radio (without any encryption) and I have been trying to get DSD+ and SDR# to decode the signal, however, no matter what I try, I have not been able to do it. This made me wonder, am I just doing something wrong or is it not possible for DSD+ to decode Mototrbo simplex. If it turns out that I am doing something wrong then I will provide more info for you guys so that I can hopefully solve this. Also, I was able to decode P25 so I know that this is not a problem with my equipment.

 

[thewraith2008]

You need to provide more info so we can decide if your doing something wrong.

Have you piped the audio from SDR# to DSD+ and configured DSD+ to process the signal from the SDR# selected audio pipe. Why not just use FMP24 to DSD+ via TCP.
What versions are you using.

Cheers.

 

[slicerwizard]

For DMR simplex, DSD+ seems to decode better if -fr is used in the command line.

 

[Aaron_B]

For DMR simplex, DSD+ seems to decode better if -fr is used in the command line.

Ok, I used -FR in the command line and I was able to get data to appear In the DSD+ window, however, it does not seem to be decoding properly and I still do not get any audio. Here are some images of how I have it set up.

 

[Aaron_B]

You need to provide more info so we can decide if your doing something wrong.

Have you piped the audio from SDR# to DSD+ and configured DSD+ to process the signal from the SDR# selected audio pipe. Why not just use FMP24 to DSD+ via TCP.
What versions are you using.

Cheers.

Yes audio is being piped from sdr# to DSD+ with a virtual cable. As for DSD+ I think I have it setup correctly, I have included some screen shots in a previous post which show the way I have it configured. And I do not see FMP24 in my dsd+ file.

 

[buddrousa]

Correct me if I am wrong but in the command line I see -i1 for input 1 but I do not see -o1 for out put to the speakers.

 

[dubs0980]

Just as a "throw this out there" have to tried changing the polarity? For some reason those errors just said polarity to me. Just another quick thing to try.

 

[elraval]

Maybe this helps: disable all audio filtering/noise reduction in SDR# so you're piping clean audio to DSD+

Sent from my Xylophone using Tapatalk...

 

[racingfan360]

I can't offer much help on configuring SDR#, but the other bit of advice I would give about DMR Simplex decoding is that good DSD+ relies on the tuner being PRECISELY on the correct frequency. I often use a tapped scanner with DSD+ and given the very wide coverage and tuning range you need to realize that the scanners can be slightly off frequency across different bands. Being off-frequency by even 1 or 2 khz can make night or day difference in the quality of DMR simplex decoding. You might find the same issue with SDR# perhaps?

 

[ak716]

i decode mine using the sample rate of .900???, and turn the squelch off, also looking at your PPM settings in SDR#, is 0 correct for you? Mine is 75 normally.

 

[Aaron_B]

Thank you to all, who helped I was able to fix the problem by turning off the squelch and removing the audio filters. I am still getting a high amount of errors on systems that are far away, but I believe that is because I am using the cheap antenna that came with my rtl-sdr. I will be getting a better antenna soon and hopefully that will fix my problem.

 

[ak716]

I'm in the same boat... got a telescopic scanner antenna attach right now, waiting for the weather to warm up and the snow to melt to climb my roof and put up an antenna on my chimney, going from the little one it came with to a telescopic hanging in my curtains did wonders, I can't wait to see what I get from the antenna on the chimney