New user of SDR & DSD

[Jphila20]

I've got DSDPlus installed and checked its operation on a vhf channel that uses P25 and it works. Trying to get Unitrunker up and operational. I have two SDR's running one on signal and the other on voice. (Info.png) The signal SDR shows 50 in the RSSI window and Window goes from -4 to 4.
I included a picture of both VCO also. I don't see anything about entering a freq for the voice SDR. (VCO.jpg)
I also included the DSDPlus screen shot. (DSD.jpg)
I updated the FMP-CC.bat to 770.0000mhz.
This may be second nature to some of you but I'm new at this.

Thanks in Advance.

John

 

[pinkfish457]

Change the Audio Output in the first VCO to Unspecified, let the software decide how to handle it. Under Audio Output in the second VCO do the same thing. Under Digital Output, you have it going into the Digital Output, it should be going into #1 Cable Output, VB_Audio Cable. DSD+ is setup to listen to VB Audio cable. The audio output in DSD+ looks okay. In a P25 system the PARK frequency should not be all 0's. Enter 771.5000 or close to the control channel frequency. I have some P25 unitrunker screen grabs if that would help.

 

[Jphila20]

I appreciate the quick responds.

I made your suggested changes. I now get hash noise with de-emphasis off. I set the squelch to 55 and the "Voice" park frequency to 771.5000. I show activity on the site

I have a RS Pro-106 and can hear traffic. When I look at the screen locked on Wildcard the 106 will display "DG" on the left with one frequency then switch "CCO5" with a different frequency. It can be in the 770's or 800's. Its weird.

I attached screen shot from Pro96 and site from Untrunker.

RSSI is 48 and Window is -4 to 3.

If it's easier you can send direct to my e-mail jp216@ncwcom.com.

Thanks again.

 

[natedawg1604]

On the signal and voice receivers, try selecting only P-25. Also, can you post a screenshot of the main Unitrunker site window (Call History tab), assuming the site's coming up and displaying data? A RSSI of 50 indicates a pretty weak signal, you may want to move your antenna around to increase your RSSI level.

 

[BM82557]

The CORRECTION is set to zero. You need to adjust this to whatever your dongle PPM correction is.

 

[pinkfish457]

One more step, I saw you have entered 771.60625 as the control frequency. In the SITE 002-007 the control frequency is 770.60625. Change this.

 

[Jphila20]

Corrected the voice frequency to 769.20625 which is one of the other channels within this system.

As for frequency correction I checked both dongles using SDR# and they are dead on. I included a screen shot of one of them.

On my RS Pro-106 without an antenna I get 99% signal strength. I have an all band ground plane antenna in an attic. I'm about 7 miles from the tower. On the site page the antenna signal is full.

I've got the hobbyists book, following the steps, but still lost?

Is the split between 700 and 800 the problem? 4 channels are in 800 and 6 in 700.


On a side note has anyone tried using an HDTV Yagi antenna for scanning by changing it to a vertical rather than a horizontal antenna. Looks to have the same characteristics.

Thanks again.

I appreciate the help.

 

[pinkfish457]

You almost got it. Change the voice PARK frequency to 770.500. The frequency you now have entered is causing unitrunker to lock onto that frequency and not scanning the rest of them.

 

[Jphila20]

Ok. I am starting to get some sounds, choppy voices.

Voice SDR shows RSSI 66, Window 21. Signal RSSI 66, Window 20.
The site window is solid green.

What should the numbers be for quality sound?

Your help really fix my mistakes.

Suggestions on how to increase signal strength? I pulled out an old scanner antenna booster. Covers 100mhz to 1ghz. When I us it the numbers increase a few points.

Also, some of the frequencies that show up on the Voice SDR are the 850's. Would I need a third SDR to pick those up?

Again, can't say enough for the help.

 

[natedawg1604]

Ok. I am starting to get some sounds, choppy voices.

Voice SDR shows RSSI 66, Window 21. Signal RSSI 66, Window 20.
The site window is solid green.

What should the numbers be for quality sound?
....

Those numbers suggest great reception. It's possible you have a simulcast system, so try starting DSD+ with -mp (PSK modulation) and see if that helps any.

 

[pinkfish457]

Here are the screen grabs from a P25 system here in Slidell, LA. In this case I used two dongles one was white and the other black so I could tell the difference. If you can match the "settings" you should have no problem with good decoding.

I have an antenna splitter feeding both dongles. You need a signal to both dongles as one is receiving the control channel and the other, voice. You could use the multi-VCO feature and use only one antenna for both.

The reason both audio & digital outputs are going to speaker is because this system had both analog and digital channels.

Keep going

 

[Jphila20]

DSD+ with -mp (PSK modulation)

I don't see a batch file for DSD+. How do I add the -mp?

 

[dave3825]

Just curious,and I know you are new, but why not just use Unitrunker and run dsdplus.exe itself and skip the batch files? I listen to a few systems with unitrunker. I set my voice digital output to virtual cable and I launch dsdplus.exe That's it. I get analog and digital. I don't use dsd batch files at all for that stuff. What I use dsd batch files for is dmr and nexedge.

 

[pinkfish457]

Just curious,and I know you are new, but why not just use Unitrunker and run dsdplus.exe itself and skip the batch files? I listen to a few systems with unitrunker. I set my voice digital output to virtual cable and I launch dsdplus.exe That's it. I get analog and digital. I don't use dsd batch files at all for that stuff. What I use dsd batch files for is dmr and nexedge.

I agree with you. I never used batch files, just ran it as is.

 

[natedawg1604]

DSD+ with -mp (PSK modulation)

I don't see a batch file for DSD+. How do I add the -mp?

Well how do you start DSD+, exactly?

 

[dave3825]

Well how do you start DSD+, exactly?

After my Unitrunker is up and running( or sdrsharp, ), I go into the dsd folder and click on dsdplus.exe. Its default state will be in autodetect mode and will start decoding whatever comes its way as long as it's a supported mode. Very easy and a lot less headaches..

 

[Jphila20]

Double click DSDPlus.exe in the folder.

 

[natedawg1604]

Double click DSDPlus.exe in the folder.

Well you can also start it with a batch file, or directly from a command window. Just open a terminal window, CD (change directory) into the DSD+ program folder and enter the appropriate start-up command string as per the DSD+ documentation. For example, here's how I often start DSD+ for P-25 systems:

DSDPlus -T -Pmp3 -i6 -E -e -T -f1 -v4 -O NUL -g25 -F1​

 

[VancouverScan]

Very useful info, thank you

I was pleased to see this thread as I will be receiving 2 SDR dongles soon, mostly in thanks to natedawg1604. I would not have even given it a 2nd though about SDR's with all the scanners I have but I will now, clearly the way to go with all the new technology flooding our hobby.

I will retain this thread as it will be vital info as I move forward and no doubt many others as well.

Thank you for sharing here on RR.

 

[N2ICV]

Have you tried New SDR# Plugin: GUI Interface for DSD+ - rtl-sdr.com