Help with DSDplus , Discriminator and SDR

[GrimChild24]

Im using a Uniden BCT15x with a discriminator tap, and a V4 SDR.
I can get DSD to listen to the tap and control channel. how do i make it load the SDRv4 and follow channels ?

 

[mtindor]

Im using a Uniden BCT15x with a discriminator tap, and a V4 SDR.
I can get DSD to listen to the tap and control channel. how do i make it load the SDRv4 and follow channels ?

You will need to download / run an application called Zadig, which will install the proper drivers for the dongle (if you do it right).

zadig

Read first, read again. Follow the instructions and do not be in a hurry. You'll need to run Zadig to use your V4 SDR dongle with any application on Windows.

Are you actually using DSD / DSD-FME / DSD-NEO, or are you using DSDPlus? If you are using DSDPlus, are you using the paid Fast Lane version or the free version from the site? If you are using the free version of the site, make sure you are running the most recent version from December 2025 on DSDPlus – Digital Decoder

 

[GrimChild24]

SDRv4 is running fine . just need to know how to get DSDplus to control and follow the frequencies.
CC.bat >>
DSDPlus -rc -T -E -Pwav -i20001 >>CC.log

FMP24.bat >>
FMP24 -rv -i1 -o20002 -P0.0 -v3

 

[mtindor]

You should run the defaults of:

FMP24-CC.bat
1R.bat

Until you have verified everything is working properly, don't mess with editing batch files or changing menu options. Just fire up FMP24-CC.bat and 1R.bat

 

[mtindor]

As for following frequencies, it will only do that automatically on P25 systems and the rare DFA (direct frequency assignment) systems.

Otherwise, for DMR and NXDN you are going to have to set up entries in your DSDPlus.networks, DSDPlus.Sites and DSDPlus.frequencies files for any DMR or NXDN or IDAS trunked system before it will follow voice.

Copy the info to the appropriate file (the files already exist):

DSDPLus.Networks
---------------------
; SaiaNet
CON+,171,"SaiaNet"


DSDPlus.Sites
---------------
;SaiaNet
CON+,171,23,"UB Cooke Hall"


DSDPlus.Frequencies
-----------------------
; SaiaNet
CON+,171,23,5,462.100,0.0,0
CON+,171,23,13,461.525,0.0,0
CON+,171,23,15,461.600,0.0,0
CON+,171,23,21,461.85,0.0,0


and I can't remember if you need L157 below or just 157 below

DSDPLus.Networks
---------------------
; FM Communications
NEXEDGE96,157,"FM Communications"

DSDPlus.Sites
---------------
; FM Communications
NEXEDGE96,157,2,"Tonawanda"

DSDPlus.Frequencies
-----------------------
; FM Communications
NEXEDGE96,157,2,4,424.700,0.0,0
NEXEDGE96,157,2,5,451.9375,0.0,0
NEXEDGE96,157,2,6,461.95,0.0,0
NEXEDGE96,157,2,7,463.725,0.0,0
NEXEDGE96,157,2,12,452.800,0.0,0
NEXEDGE96,157,2,13,463.45,0.0,0
NEXEDGE96,157,2,14,464.45,0.0,0

 

[mtindor]

If you want to program in any other sites, you are going to need to look at those systems/sites in the RRDB and get the information for those sites. And read NOTES.TXT and the top of the DSDPlus.Networks, DSDPlus.Sites and DSDPlus.Frequencies files for information on how to enter in the information for the various types (CON+, CAP+, P25, NEXEDGE96, NEXEDGE48, etc).

 

[GrimChild24]

Well that got me closer i think. once i changed the event window Control from passive to CC the SDR tuned to 0.000000
Unfortunately my times run out for the day , I do very much appreciate the help so thank you very much.

 

[mtindor]

Well that got me closer i think. once i changed the event window Control from passive to CC the SDR tuned to 0.000000
Unfortunately my times run out for the day , I do very much appreciate the help so thank you very much.


View attachment 196863

That’s why I mentioned for you to run FMP24-CC.bat and 1R.bat since they default of starting in trunking mode

But yes, you figured it out combined VC monitoring. That along with editing the files that I mentioned you should be able to trunk at least those two site sites.

Have fun!

 

[VK5DT]

Hi GrimChild,
If you are using a discriminator tapped scanner you would need to control the scanners frequency not the dongles frequency.
DSD only controls the dongles frequency via FMP24, but you are suppling a baseband signal from the tapped scanner.
I believe due to this you won't be able to trunk track, but you could program the networks voice channels into the scanner and scan.
If the network is not too busy you might catch the full conversation.

 

[mtindor]

Hi GrimChild,
If you are using a discriminator tapped scanner you would need to control the scanners frequency not the dongles frequency.
DSD only controls the dongles frequency via FMP24, but you are suppling a baseband signal from the tapped scanner.
I believe due to this you won't be able to trunk track, but you could program the networks voice channels into the scanner and scan.
If the network is not too busy you might catch the full conversation.

He started off with a discriminator tap, but then wanted to graduate to using a dongle. He’s using the dongle now and it is voice following. He ran out of time, but we will edit his files at a later date so that he will properly voice follow

M

 

[VK5DT]

Thanks M, Understood, my bad. I had missed that the scanner was discarded and now moved exclusively to dongle usage.
Definately easier to use DSD for everything.
Good luck with the setup, sounds like you are very close with getting it sorted.

 

[GrimChild24]

Alright guys Progress...

So yes . I am using the scanners discriminator tap as a control channel. dsdplus now tunes the SDR to the channels.
But.. Theres no Audible output.. here are my 2 batch files

....FMP24-Custom.bat (Loads the tuner)
FMP24 -rv -i1 -o1 -o20002 -f400.00

CC-Custom.bat (Loads Discriminator from mic input)
call dsdplus -i4 -o1 -T -i20002 -e -E -Pwav

heres what it looks like

 

[mtindor]

Alright guys Progress...

So yes . I am using the scanners discriminator tap as a control channel. dsdplus now tunes the SDR to the channels.
But.. Theres no Audible output.. here are my 2 batch files

....FMP24-Custom.bat (Loads the tuner)
FMP24 -rv -i1 -o1 -o20002 -f400.00

CC-Custom.bat (Loads Discriminator from mic input)
call dsdplus -i4 -o1 -T -i20002 -e -E -Pwav

heres what it looks like

Can I ask you why you would do that? Is it because you want to be able to sit on the CC 24/7 without it moving away from it? I mean FMP*-CC.bat and 1R.bat will do the same thing (trunk) but would divert from the control channel when a voice call comes in. Of course you could also get an additional dongle and run one dongle for CC and one for VC traffic.

But hey, whatever works for you. I'm glad you got it going. It really is most efficient just to use the dongle itself though.

BTW, you might want to turn down that gain a little bit on the voice channel FMP (you can do that by focusing on FMP24 ad then pressing G or g to raise/lower gain.. Noise level is pretty high, and you might be able to lower it a bit without actually lowering the signal strength of the signal itself.

And do keep in mind that if you ever want to monitor a simulcast trunked system, the discriminator audio is not going to perform as well as audio from a dongle with FMP24.

 

[GrimChild24]

Yes i do have it working with just 1 SDR Dongle. need to learn some audio tweaks as the robo voice is usually warbly but thats another issue.
i wanted to see if this would be more stable and just convenient, switching control with the bearcat scanner and less stress on the sdr.

 

[VK5DT]

Re no audio,
Just a guess and someone more knowledgeable with dsd can advise, but maybe contention with multiple outputs directed to -o1.

Your config has two "-o1" outputs, one for discriminator output and one for tuner output.
Maybe drop the additional output in FMP24 as FMP24 is pumping tuner output to dsd.exe to decode via -o20002, so the additional -o1 output seems pointless and could possibly be causing contention on the -o1 interface?

....FMP24-Custom.bat (Loads the tuner)
FMP24 -rv -i1 -o1 -o20002 -f400.00

CC-Custom.bat (Loads Discriminator from mic input)
call dsdplus -i4 -o1 -T -i20002 -e -E -Pwav

Good luck!