DSDCC DMR repeater input

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DMRdude

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Jun 26, 2017
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I am trying to use RTL-SDR with DSDCC to decode DMR on a raspberry pi. When I listen to a repeater output, the audio sounds as good as if it was coming out of my HT; however, when I attempt to listen to the repeater input, the voice is not discernible and DSDCC throws a lot of errors. Does anybody have any suggestions or ideas on how to improve decoding of repeater inputs/DMR simplex?

My command line is :
rtl_udp -f 447.6375M -g 500 -s 70k -r 48k |dsdccx -i - -o speech

I have also tried with "-U 0", "-x" "-fr" "-T 1" "-T 2" "-T 3" options on the dsdccx command and varying gains/sample rates on the rtl_udp command. I know that it all has to be resampled to 48kHz for dsdcc. I use the rtl-udp fork so I can tune on the fly.
"speech" is a named pipe for the output.
 

DMRdude

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Joined
Jun 26, 2017
Messages
10
Solution

Is the input strong enough for you to hear? You would have to be in range of the unit to hear and decode it.
BB

Thanks for the quick response!!
I think that it was the other way around.

It is working now, I had been trying to run the device at varying distances from my HT from inside the same room as the receiver, to inside the refrigerator in the same room as the receiver, to a building over from the receiver with no luck (500 ft through concrete and other walls). I finally got it working in my apartment by taking the antenna off the RTL dongle and turning the gain down to ~5 db. it was mostly discernible, so I went to the next room over, set my HT on low power and it worked nearly perfectly.
 
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