Only Getting Noise From Tuned Voice Channels via DSD+

[rkillins]

I am trying to trunktrack the OnQue NEXEDGE48 system here (System 202-16) with DSD+. I have DSD+ getting the control channel signal from my tapped Pro97 (cc.bat). It is decoding no problem. I am using DSD+ fmp-vc.bat to to tune the voice frequencies through the use of a RTL-SDR dongle.

When it tunes a voice channel, all I get is noise. I get the same as if I was monitoring that frequency raw from a scanner. I was under the impresssion that DSD+ would decode the data to legible voice to my speakers. Is than an incorrect assumption? I don't think its encrypted ... If not, what have I done wrong?

Also ... after a transmission has been sent to my speakers, I get a noticeable and annoying squelch tail. Is there a way to eliminate that?

 

[slicerwizard]

You have to route the audio from FMP to DSD+, not to your speakers.

 

[rkillins]

I am so new to this, I'm not sure I know what you mean,

my FMP-VC.bat is ...
FMP -i1 -o1 -P0.0 -rv

my cc.bat is ...
DSDPlus -rc -i1 -v3 -v3 -ws1400.2 -wss100.200 -we10.1 -wc10.445 -wes400.520 >>CC.log

I haven't had any activity to test, but I changed my FMP-VC.bat is ...
FMP -i1 -o20001 -P0.0 -rv
Is this what you would recommend?

But I'm concerned as to how the decoded audio gets to my speakers.

 

[slicerwizard]

I am so new to this, I'm not sure I know what you mean,

my FMP-VC.bat is ...
FMP -i1 -o1 -P0.0 -rv

Audio output device number 1 is likely your speakers, so -o1 would send FMP's demodulated audio to your speakers. That's fine for listening to analog traffic, but definitely not what you want for digital signals.

my cc.bat is ...
DSDPlus -rc -i1 -v3 -v3 -ws1400.2 -wss100.200 -we10.1 -wc10.445 -wes400.520 >>CC.log

Audio input device number 1 is likely your mic or line in, so you're telling CC DSD+ to listen to your control channel scanner, which is correct.

I haven't had any activity to test, but I changed my FMP-VC.bat is ...
FMP -i1 -o20001 -P0.0 -rv
Is this what you would recommend?

Yes, you're telling FMP to send its demodulated audio out via TCP port 20001.

But I'm concerned as to how the decoded audio gets to my speakers.

You tell VC DSD+ to get its input from TCP port 20001 (DSDPlus -rv -i20001)

If your speakers are audio output device number 1, DSD+ will default to sending synthesized voice to the speakers. Otherwise, use the appropriate -o<num> specification for your speakers. You need to look at the list of audio output devices DSD+ displays at startup.

 

[rkillins]

Hi SlicerWizard ... thank you so much for your support and patience.

I'm not getting any audio out of my speakers ...

If your speakers are audio output device number 1, DSD+ will default to sending synthesized voice to the speakers. Otherwise, use the appropriate -o<num> specification for your speakers.

My speakers are audio output device 1 ... I used -o1 initially when I was getting the noise to the speakers. In what .bat would I put the -o1 parameter?

 

[morfis]

...... In what .bat would I put the -o1 parameter?

The batch file that runs your voice channel instance of DSD+

 

[rkillins]

So my fma-vc.bat?

FMP -i1 -020001 -o1 -P0.0 -rv

 

[morfis]

So my fma-vc.bat?

FMP -i1 -020001 -o1 -P0.0 -rv

That is running FMP.exe

You need to output the voice instance of DSD+ to your speakers.

 

[rkillins]

I never thought myself to be one that struggled with relatively simple concepts, but this for some reason has me flat on the ground.

My original FMP-VC.bat file was sending audio to the speakers ...

FMP -i1 -o1 -P0.0 -rv

with the -o1 parameter.

But it was sending non-decoded noise to them, no intelligible conversation. So, I understood from post #4 that "That's fine for listening to analog traffic, but definitely not what you want for digital signals." I then changed my FMP-VC.bat file to ...

 FMP -i1 -020001 -P0.0 -rv

This I assume sends the signal to be decoded, but I am finding its not being sent to the speaker after being decoded.

So each version has a deficiency. If I send to the audio device, I get no decoding. Changing it to a TCP port I assume allows decoding, but I am getting no audio. My last attempt I assume is wrong ... it's unlikely you can have two instances of -o parameters.

So not sure how to port to the speakers when FMA voice control is already being ported to a TCP port.
SlicerWizards states "If your speakers are audio output device number 1, DSD+ will default to sending synthesized voice to the speakers. Otherwise, use the appropriate -o<num> specification for your speakers. You need to look at the list of audio output devices DSD+ displays at startup." From my experience sending sound to my speakers initially (with my use of -o1), why would DSD+ not be defaulting the sound output there?

 

[morfis]

You don't want FMP sending anything to the speakers.

DSD+ is the software that outputs to your speakers.

In your first post you even say:

"I was under the impresssion that DSD+ would decode the data to legible voice to my speakers."

That is correct.

 

[M105]

Maybe this will help... This is the sequence of events to decode trunked NXDN.
(1.) Tapped Scanner audio to DSD+ CC decodes control channel and writes tuning files to disk.
(2.) FMP reads tuning files, tunes the SDR, and outputs audio on port 20001.
(3.) DSD+ VC receives audio on port 20001 then outputs decoded voice to speakers.
So you need.
DSD_CC.bat set to receive audio from your scanner.
FMP_VC.bat set to output audio to port 20001.
DSD_VC.bat set to receive audio on port 20001 and output audio to your speakers.
--------------
To decode trunked NXDN you will also need to have the DSDPlus.frequencies file loaded with the system channels. See example below. Ch58 = 453.075 Ch100 = 453.3375 etc.
NEXEDGE48, 69, 1, 058, 453.07500, 0, 0
NEXEDGE48, 69, 1, 100, 453.33750, 0, 0
NEXEDGE48, 69, 1, 140, 453.58750, 0, 0
---------------

 

[rkillins]

So, without having a chance to test right now, I think I might have a better understanding. Thank you all for your explanations. M105, your contribution was of great help.

Adding -o1 to my cc.bat I believe is what I am lacking. I'm exciting to see it all come together.

 

[M105]

I had CC instead of VC on the 2nd copy of DSD+. See edit.
---
Anyhow, that is what you are trying to accomplish. I have been decoding a NXDN48 system for over a year and the software works great. I started out with a tapped scanner as you are using but later purchased a second dongle. Once you get the flow of information in your head it isn't really very complicated. Enjoy!

 

[rkillins]

Looks like I may have finally found success.
I didn't realize I needed to execute 3 different applications working together to get the final result.
Slowly starting to figure this out. Thank you all!