Trying to decode DMR

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Padsdad
Posts: 2
Joined: Tue Feb 05, 2019 10:47 pm

Trying to decode DMR

Post by Padsdad » Sun Mar 03, 2019 4:39 pm

Hello, I wonder if anyone can offer any help?. I am using an RSP1A and dsdplus to try and decode DMR on a local repeater. I think I am nearly there, as in the main dsdplus window I get the raw data scrolling up, although it appears to show lots of error codes. When the resolved audio come through I get about 40-50% of the conversation, very broken up. This happens in both SDRUNO and in SDRconsole v3. The audio signal fron the repeater sounds strong enough, would say fully quieting about s9 on the meter. I'm using wide fm with de emphasis turned off. Any other ideas?. PC is a Dell i3 laptop about 2 Ghz, has been OK decoding other digital modes like Psk31, rtty, sstv etc.

Regards
Nigel, G0CQZ.
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Martien
Posts: 9
Joined: Wed Mar 06, 2019 1:48 am

Re: Trying to decode DMR

Post by Martien » Wed Mar 06, 2019 2:22 am

Hello,

These settings give the best results for me decoding DMR with DSD+ and SDRuno:

- SDRuno RX control

MODE: FM

FM MODE: NFM

FILTER: 10K

All other filters off

VOLUME: about 1/4 to 1/3

- SDRuno EX control

DEEM: OFF

50uS and 75uS: OFF

Best regards,

Martien, PD1G
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g1hbe
Posts: 493
Joined: Sat Jan 17, 2015 3:28 pm
Location: Cheshire, UK

Re: Trying to decode DMR

Post by g1hbe » Wed Mar 06, 2019 11:02 am

Wide FM is too wide for these PMR digital modes. A narrower setting of NFM 12 KHz or so should do the trick. WFM will let through adjacent channel signals which will corrupt the one you want.

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Andy

Padsdad
Posts: 2
Joined: Tue Feb 05, 2019 10:47 pm

Re: Trying to decode DMR

Post by Padsdad » Wed Mar 06, 2019 11:29 pm

Hi
Thanks for the replies guys. I got it sorted now and all working OK. Turned out I got my virtual cables mixed up. Answer was staring me in the face when I realised what was going wrong. Thanks again for the pointers though regarding filter widths etc. I found that nfm and 12 kHz works pretty good.
What a fantastic bit of kit this Sdrplay Rsp1a is, it's got me back into the hobby after a 15 year layoff.

73, Nigel, G0CQZ
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