DSD plus P25 question

[WX4JCW]

I have something I’m stumped on , I run DSD plus, it is decoding DMR and NXDN flawless with no errors, but I can’t even get 0 err messages on a P25 control channel for some reason


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Jason WX4JCW
Unication G4, BCD536HP

 

[slicerwizard]

You need to provide more information.

What version of DSD+?

How are you feeding signals to DSD+?

What P25 system/site?

 

[WX4JCW]

You need to provide more information.

What version of DSD+?

How are you feeding signals to DSD+?

What P25 system/site?

RTL-SDR V3 and an Airspy Mini

The Latest Fastlane edition

I have VB-Audio Virtual Cable,have tried with VAC as well

happens on all P25 systems across the country i monitor as i work

 

[mtindor]

RTL-SDR V3 and an Airspy Mini

The Latest Fastlane edition

I have VB-Audio Virtual Cable,have tried with VAC as well

happens on all P25 systems across the country i monitor as i work

What SDR software are you running? You have to be running SDR software if you are using VAC / VB-Cable.

If you are using SDR#, make sure "Filter Audio" is unchecked and that bandwidth is set to at least 9500. Make sure the audio level getting to DSDPlus from the SDR software is reasonable (not too low, not to high).

And make sure you aren't using a specific switch in DSDPlus that forces a particular protocol (like -fr for DMR or -fN or -fn for NXDN). Just do something simple like:

dsdplus -i# -o# -v4, where the #s are your input and output devices as seen by DSDPlus.

DSD+ decides P25 very easily.

Mike

 

[DRL-XM43]

I have something I’m stumped on , I run DSD plus, it is decoding DMR and NXDN flawless with no errors, but I can’t even get 0 err messages on a P25 control channel for some reason


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Jason WX4JCW
Unication G4, BCD536HP

You are using a trunking software, you did not mention any?

P25 Control channels don't decode to voice so feeding DSD+ with a control channel won't do anything..

 

[WX4JCW]

Ok I have tried SDR# as well as FMP

DSD will read a P25 CC as well as read a DMR CC same thing, i get that

what i am having an issue is the quality of the decode,

dsd does decode DMR and NXDN just fine with 0 err messages and clean audio,

P25 usually shows ERR 1-16

the only issue is with P25, for some reason i cannot get it tuned properly, i can tune it all day long for DMR and NXDN it is just P25

if i run OP25 on my linux side P25 is fine with P25 as is SDRTrunk

this is not just one system, i travel the country, this happens to all the ones i listen to

 

[cg]

If it is every P25 system, I would suspect your settings. Post your FMP24 and DSDPlus batch files you use to start the P25.

chris

 

[DRL-XM43]

Ok I have tried SDR# as well as FMP

DSD will read a P25 CC as well as read a DMR CC same thing, i get that

what i am having an issue is the quality of the decode,

dsd does decode DMR and NXDN just fine with 0 err messages and clean audio,

P25 usually shows ERR 1-16

the only issue is with P25, for some reason i cannot get it tuned properly, i can tune it all day long for DMR and NXDN it is just P25

if i run OP25 on my linux side P25 is fine with P25 as is SDRTrunk

this is not just one system, i travel the country, this happens to all the ones i listen to

Just to confirm your setup for trunking P25 with DSD+/FMP

Do you have 2 dongles, 2 instances of FMP and DSD+. One for control channel the other for voice?

 

[slicerwizard]

RTL-SDR V3 and an Airspy Mini

The Latest Fastlane edition

I have VB-Audio Virtual Cable,have tried with VAC as well

happens on all P25 systems across the country i monitor as i work

Issues only on P25 systems points to simulcast/PSK issues.

The only way to monitor simulcast systems with DSD+ that works for me is FMPA or FMP24 TCP linked to DSD+. Using FMPA, FMP24 or some other SDR software with VAC or VB-Cable patching the audio ain't gonna cut it.

Here's a brief tour of the simulcast systems around these parts. Not much to listen to, but you can judge the decoding levels easily enough by looking at the console windows. If I did the same thing with virtual audio cables, it would be a cluster...

https://youtu.be/okogHlsU5xE

 

[WX4JCW]

Issues only on P25 systems points to simulcast/PSK issues.

The only way to monitor simulcast systems with DSD+ that works for me is FMPA or FMP24 TCP linked to DSD+. Using FMPA, FMP24 or some other SDR software with VAC or VB-Cable patching the audio ain't gonna cut it.

Here's a brief tour of the simulcast systems around these parts. Not much to listen to, but you can judge the decoding levels easily enough by looking at the console windows. If I did the same thing with virtual audio cables, it would be a cluster...

https://youtu.be/okogHlsU5xE

That’s exactly what I was looking for thank you


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Jason WX4JCW
Unication G4, BCD536HP

 

[relicwr]

I had DSD FL fixed for me when I couldn't pick up TG 1 on a P25 P1. I sent them a sample file and they fixed it for me since it seemed to be a local issue. They never said what it was.

Also, I don't depend on software audio routes anymore. I used TCP for everything and it's so much easier than having to hassle with audio routes.

 

[mtindor]

That’s exactly what I was looking for thank you


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Jason WX4JCW
Unication G4, BCD536HP

You claim that the issue you are having occurs for all P25 sites/systems that you listen to around the country. So every P25 site you listen to is simulcast? Hmm. Had you mentioned that you were monitoring simulcast, I would have given the same answer. Would be nice to not have to beat the information out of everyone looking for assistance!

mike

 

[WX4JCW]

Not everyone is as enlightened I guess, I’ve narrowed it down to that and tuning, and the fact that DSD is way more finicky than other software, on non simulcast systems it’s not as bad but P25 decode is nowhere near as easy on DSD as the other protocols are


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Jason WX4JCW
Unication G4, BCD536HP

 

[WX4JCW]

You claim that the issue you are having occurs for all P25 sites/systems that you listen to around the country. So every P25 site you listen to is simulcast? Hmm. Had you mentioned that you were monitoring simulcast, I would have given the same answer. Would be nice to not have to beat the information out of everyone looking for assistance!



mike

yeah its hard making people happy i guess

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Jason WX4JCW
Unication G4, BCD536HP

 

[slicerwizard]

You claim that the issue you are having occurs for all P25 sites/systems that you listen to around the country. So every P25 site you listen to is simulcast?

I suspect that many non-simulcast P25 systems, especially those that support Phase II, use PSK these days, so plenty of opportunities to run into this.

 

[WX4JCW]

thanks slicerwizard it helped greatly, using TCP does greatly help and yes PSK is showing up more and more

currently running the MSWIN Desoto County Simulcast nice and clean, working on setting up for following with my 2nd SDR

 

[slicerwizard]

Hm, looks like you have some text editing to do...

http://home.ica.net/~phoenix/wap/MSWIN.txt

 

[WX4JCW]

yes a whole bunch on many systems lol, this one i will not mess with too much as it is ENC 90%
but it was the strongest