Put together a new box for this on 14.04, but had some issues unrelated to op25 so got it working on 16.04 instead.
All it took was installing wx 2.8 in parallel with 3.0 and updating scope.py to import 2.8 instead of 3.0. All other apps will pickup 3.0 by default so there should be no harm doing that.
I had to do a bunch of other stuff to get the SDRPlay working nicely via SoapySDR, but now thats its all together its working well at 8MHz.
Here's the details, think I captured all of them: https://gist.github.com/mattfielder/b328e68246d71e245980343a1a2544e7 https://gist.github.com/mattfielder/b328e68246d71e245980343a1a2544e7
I'm not able to get the Phase2/tdma voice decoding yet, every time scope.py reports a tdma slot in use a few seconds later I just get a timeout message, but the other voice traffic is fine. The phase 2 problem happened in 14.04 and a rtl-sdr as well, so something I'll have to keep looking at.
thanks - yeah unfortunately support for wx2.8 will be getting dropped from gnuradio.
Just to follow up on one point re: the gist, if you're having to click C4FM to get any decode that suggests you may not have sorted the QPSK decoding yet. That demod is selected when you go to the constellation tab. On that tab select "standard, mono, differential" for the options and advise if you get the 4-point constellation. You may need to fine tune the receiver. Please post copies of the exact command line you're running and the trunking TSV file (not the talkgroup). Reason for all this is phase II likely will work well only when using the PSK demod, not the FM one...
Max
Looks like I'm getting a clean looking 4 points on the primary control channel, I removed the alternates for now: https://s3.amazonaws.com/uploads.hipchat.com/30316/198758/Ic6e2NSjQqXHEAr/Sc... https://s3.amazonaws.com/uploads.hipchat.com/30316/198758/Ic6e2NSjQqXHEAr/Sc...
https://s3.amazonaws.com/uploads.hipchat.com/30316/198758/Ic6e2NSjQqXHEAr/Sc...
https://s3.amazonaws.com/uploads.hipchat.com/30316/19875... https://s3.amazonaws.com/uploads.hipchat.com/30316/198758/Ic6e2NSjQqXHEAr/Sc...
View on s3.amazonaws.com https://s3.amazonaws.com/uploads.hipchat.com/30316/198758/Ic6e2NSjQqXHEAr/Sc... Preview by Yahoo
The C4FM tab/demod works and I'll see constant traffic there and hear voice when no tdma slot is indicated, no voice when tdma is shown, but when I go to the constellation tab I stop seeing all traffic and just the tuning error/process timeouts.
Attached the trunk tsv and command line.
ok yes this is a common issue, it would be nice to have the coarse tuning working, but at present the tuning will happily lock on a signal that's pi/4 offset from the desired one (that's 1,200 Hz at a 4,800 baud rate). The C4FM demod is broad as a barn door but doesn't work well with simulcast, which is what you're probably using there. Suggest adding a "-q -1" or "-q 1" parameter to adjust the tuning - what you want is to get rid of the "tuning error" messages. The Datascope and C4FM tabs can also help show you whether the tuning is off, but for general reception you should stick with the constellation display...
Max
Yes its a simulcast system I'm monitoring: http://www.radioreference.com/apps/db/?siteId=18678 http://www.radioreference.com/apps/db/?siteId=18678
-q1 and some fine tuning and qpsk works great. Audio so far sounds better than the edacs narrowband that was deprecated. Also changed the -f to the same center as the trunk, not sure if that mattered.
./scope.py --args 'soapy=0,driver=sdrplay' -f 771.98750 -v0 -V -S 8000000 -T njics_center_singlecontrol.tsv -N "IFGR:20" -O "pulse" -2 -q 1
Thanks for the help, really appreciate op25!
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ikj1234i＠yahoo.com [op25-dev] -
mattfielder＠gmail.com [op25-dev]