• Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

    We've noticed a huge increase in rants and negative posts that revolve around agencies going to encryption due to the broadcasting of scanner audio on the internet. It's now worn out and continues to be the same recycled rants. These rants hijack the threads and derail the conversation. They no longer have a place anywhere on this forum other than in the designated threads in the Rants forum in the Tavern.

    If you violate these guidelines your post will be deleted without notice and an infraction will be issued. We are not against discussion of this issue. You just need to do it in the right place. For example:
    https://forums.radioreference.com/rants/224104-official-thread-live-audio-feeds-scanners-wait-encryption.html

op25 (boatbod) update

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boatbod

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#23
Making this mobile - Using console (no-gui) login on RaspberryPi

Is there something in the command line arguments I can do to up the volume?
Thanks
Yes, there is an audio gain parameter (-x 1.0) that you can increase to boost the volume if you've already maxed out your alsa mixer. The caveat is if you set it too high you can clip the audio and it'll sound distorted.

Code:
  -x AUDIO_GAIN, --audio-gain=AUDIO_GAIN
                        audio gain (default = 1.0)
 

chksmithcis

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#24
I usually recommend to keep fine tuning +/- 350 or less. Higher values usually indicate that you should increment/decrement -q 1 (ppm) instead. In the plot you posted you have a fine tune correction of 900, which is already a lot, yet the mixer hump could still move left a little so you might actually be closer to 1200 or more before you get it centered.

Reset fine tune (-d) to 0 and adjust -q iteratively until you get it close, then finish it up with fine tune. You'll know when it's correct because the tsbk counter (top right of terminal) will start incrementing.

Note: after adjusting fine tune using "," or "." you need to wait a second or so for things to settle down. Using "<" and ">" makes coarse 1200 adjustments whereas the "," and "." only change by 100 each time.
Boatbod,

So I took the drastic step of starting over on one of my Macs running Linux Mint 19 by reformatting the partition and installing Ubuntu 18.04.1 LTS. After installing development tools and Gqrx, I performed the github clone. Made sure I was still seeing control channels from the Radio Reference pages via Gqrx and ran rx.py with various values of -q from -2 to +2. While trying to fine tune with '<', '>', ',' or '.', I did not experience any of the crashes that were seen the previous evening. I was able to center the waveform and sure enough, I received the NAC and the tsbk counters incremented along with seeing active talkgroups. I can now proceed to try and finish the installation.

On my other machine running Linux Mint, I will try just re-installing Gqrx and op25 as a control. Very strange that the installation would work on one and not the other. The Mint installations were identical except for the different drivers for the Mac variants (iMac vs. Mac Mini)

Btw, the same errors that 'Dseven' reported in the 'rpi3-rtl-sdr-op25' thread are the exact same crashes I see when either the tuning is way off or when the tuning approaches '0' on gnuplot. Not sure if you pushed any changes yesterday, but as of 10 PM PST, your op25 fork was working for me.

Thanks for your assistance in getting this going for me.

Chuck
 

boatbod

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#25
Boatbod,

So I took the drastic step of starting over on one of my Macs running Linux Mint 19 by reformatting the partition and installing Ubuntu 18.04.1 LTS. After installing development tools and Gqrx, I performed the github clone. Made sure I was still seeing control channels from the Radio Reference pages via Gqrx and ran rx.py with various values of -q from -2 to +2. While trying to fine tune with '<', '>', ',' or '.', I did not experience any of the crashes that were seen the previous evening. I was able to center the waveform and sure enough, I received the NAC and the tsbk counters incremented along with seeing active talkgroups. I can now proceed to try and finish the installation.

On my other machine running Linux Mint, I will try just re-installing Gqrx and op25 as a control. Very strange that the installation would work on one and not the other. The Mint installations were identical except for the different drivers for the Mac variants (iMac vs. Mac Mini)

Btw, the same errors that 'Dseven' reported in the 'rpi3-rtl-sdr-op25' thread are the exact same crashes I see when either the tuning is way off or when the tuning approaches '0' on gnuplot. Not sure if you pushed any changes yesterday, but as of 10 PM PST, your op25 fork was working for me.

Thanks for your assistance in getting this going for me.

Chuck
I pushed dseven's patch and some other error checking of my own at 8:57pm last night.
 

chksmithcis

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#28
I pushed dseven's patch and some other error checking of my own at 8:57pm last night.
Works fantastically on all my Macs running Linux. The pi is next up.

Thank You! I can put off shelling out $350.00 or more for a new scanner to decode P25 and operate in the 700 MHz band.

Regards,

Chuck
 

boatbod

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#29
Works fantastically on all my Macs running Linux. The pi is next up.

Thank You! I can put off shelling out $350.00 or more for a new scanner to decode P25 and operate in the 700 MHz band.

Regards,

Chuck
Sure does, but I'd be surprised if you can buy a p25 ph2 capable scanner for $350 - last I looked they were north of $550!
 

maus92

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#30
Works fantastically on all my Macs running Linux. The pi is next up.

Thank You! I can put off shelling out $350.00 or more for a new scanner to decode P25 and operate in the 700 MHz band.

Regards,

Chuck
Try $650 for one that can satisfactorily track and decode a P25 simulcast system.
 
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Jefferson, Maryland
#33
I recently pulled the latest op25. In looking through the change log I notice that blacklist/whitelist can be specified in the trunk file and a separate blacklist/whitelist file. I also noticed a 3rd column is read from the tsig file for priority. Could I suggest that there is the ability to specific blacklist (such as encrypted channels) in the tsig file. I was thinking either precede the talkgroup number with a '-' to indicate it should be added to the blacklist. Or maybe multipurpose that new 3rd column and if the priority is -99 (or something like that) it indicates blacklist.

This would make it easier than having to maintain additional files and keeps things in one place. One could look through the radioreference database and simply add the indicator to the tsig file.
 
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