DSDPlus Fastlane-Trouble with simplex

[dlwtrunked]

I have current DSDPlus Fastlane working on several trunked radio systems using an AirSpy II and FMPA. I cannot get it to decode a simplex DMR frequency that I am interested in monitoring. I am able to decode that using an older version and feeding DSDPlus via VCable from HDSDR running the AirSpy II but have been unable to figure out how to do it using never versions and FMPA. (I can see that FMPA is tuning AirSpy but I get no audio or data decodes from DSDPlus. I have tried all sorts of things as parameters in batch files with no sucess. I am interested to know how anyone is receiving simplex DMR with DSDPlus Fastlane. What parameters are you using if any?

 

[slicerwizard]

In DSD+, I enable only DMR decoding. If the signal is local and very strong, I turn down the Airspy gain levels and may even remove the RX antenna.

 

[dlwtrunked]

In DSD+, I enable only DMR decoding. If the signal is local and very strong, I turn down the Airspy gain levels and may even remove the RX antenna.

I have one of the HTs with me. I do have the gain set low. What bugs me as it decodes on earlier version but will not decode the DMR on this version (2.347) but working fine for the county P25 tower 0.8 miles away and another system 30 miles away. What is the instruction in the batch files you are running and are you using FMP, FMPA or similar to control the SDR?

 

[slicerwizard]

I use FMPA or FMP24. When I'm decoding DMR simplex, I only have noise filter, shaping filter and decode DMR checked in the DSD+ decoder menu.

 

[dlwtrunked]

I use FMPA or FMP24. When I'm decoding DMR simplex, I only have noise filter, shaping filter and decode DMR checked in the DSD+ decoder menu.

I will have to try again tomorrow (oops, it already is). I cannot figure out why it just will not work and the old version does. But DSD+ does behave odd at times. I could not get 2.357 to run. In trying to figure out why, I replacde DSDPlus.exe 2.357 with 2.347 in the folder (not changing anything else). That would run fine (for P25). When I undid that and put DSDPlus 2.357 back (not changing anything else in the folder), 2.357 now runs...ending a week of trying to debug and I still do not know why other than running 2.347 fixed something. DSDPlus really has some issue including a good manual (yes, I have read the one someone put together). (I used to direct the writing and manuals of computer software for the government as part of my job before I retired.) Also, I do not find the independent UI to make anything better. Never had issues with UniTrunker or SDR Trunk. Thanks for your information.

 

[AM909]

... Also, I do not find the independent UI to make anything better. ...

That points me to suggest deleting DSDPlus.bin, which stores some of the settings from that new(ish) UI. I think it's been mentioned somewhere that it can get into a state that causes DSD+ to mis-behave. You'll probably have to reset some things afterwards. Maybe save a copy of the file first, so you can send it to them if that turns out to be it.

I'm guessing you probably tried this, but did you transmit with very low power and/or from another room – just something to reduce the RF level coming in through the AirSpy and computer case and cables?

What do you hear with the different source audio monitoring choices on the Input menu (or command line -m[1-4])? What does the source audio window (scope) show?

 

[slicerwizard]

Well, I just tried it now with a DMR portable (5 watts), FMPA and an Airspy Mini. No RX antenna, gains set to 10 10 5, 7.6 kHz channel bandwidth. Up to date copies of FMPA and DSD+. Direct linking between FMPA and DSD+. All protocols enabled in the DSD+ decoder menu and it's working fine. Not a single decoding error.

I know that I had to disable other protocols in the distant past to get good DMR simplex decodes, but I do recall making a previous post here where that was no longer the case. So I'd say that requirement hasn't existed for a while, at least with strong signals. If a weak DMR simplex signal wasn't decoding, I'd try disabling all of the other protocols.

Make a raw audio recording with DSD+. It might reveal something.

 

[dlwtrunked]

That points me to suggest deleting DSDPlus.bin, which stores some of the settings from that new(ish) UI. I think it's been mentioned somewhere that it can get into a state that causes DSD+ to mis-behave. You'll probably have to reset some things afterwards. Maybe save a copy of the file first, so you can send it to them if that turns out to be it.

I'm guessing you probably tried this, but did you transmit with very low power and/or from another room – just something to reduce the RF level coming in through the AirSpy and computer case and cables?

What do you hear with the different source audio monitoring choices on the Input menu (or command line -m[1-4])? What does the source audio window (scope) show?

Before I read the above I found that it was the HT RF getting into not the AirSpy but into the PC itself (I heard noices from the HP Desktop with the AirSpy not even running). I moved it farther away and things were then OK. Working now but not as good audio as I hear with P25 but having to key the HT in the same room as the PC/AirSpy of course causes issues in really checking that. I was hoping LRRP would work with this HT (not mine, I am looking into it for for a licensed entity); but it does not. However, it definitely is send its position as I can decode it in HEX data showing in DSD+....I had to walk around the neighborhood and spend some time starring at the DSD+ data to figure out the bits to lat/lon (which DSD+ does not recognize) protocol which is apparently not the LRRP standard. May be I can document this for this other protocol to be added. (To answer your question, before fixing the problem, I do not recall what was in the audio window.)