Clarification on DMR decoding with DSDPlus 1.51 with SDR#

[SCPD]

Okay so there are a million posts on this topic but things have changed with DSDPlus 1.51 and it's hard to know what's what...

Can someone please clarify what settings must be used to get SDR# to work with DSDPlus consistently?

Example:

1. Uniden BCT-15 d-tap with DSDPlus 1.51 using Line In Jack == 100% decode of DMR

2. R820T with SDR# with filter off using NFM mode (11khz bandwidth) == 25% decode of DMR

I've noticed the polarity is DMR+ with the BCT-15 and with SDR# it's DMR- polarity. Is there a setting I've got backwards with SDR# ?

PS. With DSDPlus I just use the -V4 switch...

 

[brentab]

.[/QUOTE]
Can someone please clarify what settings must be used to get SDR# to work with DSDPlus consistently?

Example:

1. Uniden BCT-15 d-tap with DSDPlus 1.51 using Line In Jack == 100% decode of DMR

2. R820T with SDR# with filter off using NFM mode (11khz bandwidth) == 25% decode of DMR

I've noticed the polarity is DMR+ with the BCT-15 and with SDR# it's DMR- polarity. Is there a setting I've got backwards with SDR# ?

PS. With DSDPlus I just use the -V4 switch...[/QUOTE]



With R820T with SDR# I use WFM with a 12500 bandwidth be cause that is the bandwdth of the Trunking Frequencies

Do not use any FILTERING what so ever.

From that point I have experienced in getting a good decode rate in DSDPlus is keeping SDR# on perfect frequency and your volume control in SDR# going out to DSDPLUS At a certain level I use 29db work great for me. 28db or 30db I get all kind of errors.

With the setting above I get a 99% decode rate.

 

[SCPD]

With R820T with SDR# I use WFM with a 12500 bandwidth be cause that is the bandwdth of the Trunking Frequencies

I think you mean NFM. WFM is 180khz.

 

[brentab]

Hi nickcarr!

I am decoding P25, I am sure mine will be different than yours.

I was right on WFM and I as sure you can use NFM as well. I have tried both and for some reason I get
better decode rate with WFM.

You posted (I think you mean NFM. WFM is 180khz.).

You can set the bandwidth on WFM up to 250000 with is the max if you want.
The way i do it is, I watch the water falls and drag the bandwidth just to encompass the demodulated signal.
Here is a screen shot of my setup.

 

[woodpecker]

Okay so there are a million posts on this topic but things have changed with DSDPlus 1.51 and it's hard to know what's what...

Can someone please clarify what settings must be used to get SDR# to work with DSDPlus consistently?

Example:

1. Uniden BCT-15 d-tap with DSDPlus 1.51 using Line In Jack == 100% decode of DMR

2. R820T with SDR# with filter off using NFM mode (11khz bandwidth) == 25% decode of DMR

I've noticed the polarity is DMR+ with the BCT-15 and with SDR# it's DMR- polarity. Is there a setting I've got backwards with SDR# ?

PS. With DSDPlus I just use the -V4 switch...

11kHz is far too wide, 6.5kHz is plenty for DMR.

Try backing off the gain of the R820T, turn off the AGC and set the gain manually, if you overload the dongle digital decoding performance will degrade significantly.

 

[SCPD]

11kHz is far too wide, 6.5kHz is plenty for DMR.

Try backing off the gain of the R820T, turn off the AGC and set the gain manually, if you overload the dongle digital decoding performance will degrade significantly.

I never use AGC on the RTL and always set gain manually. I didn't change anything and it decode was better today. I did notice that DSDPlus can get confused rather easily by switching systems rather fast -- to the point where it stops accepting input. A restart will cure this problem.

I still have no luck with X2-TDMA on these newer versions. DSD thinks it's a P25 signal and when I force X2 it will decode some information but no audio comes through when voice headers are detected.

DSDPlus seems more stable with d-tap scanner.

 

[Voyager]

11kHz is far too wide, 6.5kHz is plenty for DMR.

Try backing off the gain of the R820T, turn off the AGC and set the gain manually, if you overload the dongle digital decoding performance will degrade significantly.

MotoTRBO spec is 7.6 kHz. 11.0 kHz is not "far too wide". It's a little too wide.

 

[SCPD]

MotoTRBO spec is 7.6 kHz. 11.0 kHz is not "far too wide". It's a little too wide.

Just for the record, I had no issues using 11khz. I might play with tighter settings at some point.

PS. One thing that I started to play with later on is the VOL CTL feature in VAC. I was able to just adjust the output VAC signal and I seem more output spew from DSD+ with a setting of only 25% versus anything higher.

 

[Voyager]

Just for the record, I had no issues using 11khz. I might play with tighter settings at some point.

PS. One thing that I started to play with later on is the VOL CTL feature in VAC. I was able to just adjust the output VAC signal and I seem more output spew from DSD+ with a setting of only 25% versus anything higher.

I had problems with the virtual cable programs with cumulative delay resulting in 24-hour runs being delayed by 5 minutes.

My solution was to simply run a jumper between the line out and line in on the PC. Now, no delay issues and much better decode rate. Of course, this won't work if you want to hear the decoded audio. BTW, there should be a solution within Windows that does not require a virtual cable, but I haven't found one yet. Not really looking too hard at this point since I don't need voice decode.