RTL-SDR and OP25 on Linux Mint 64-bit
Hello everyone, First of all: Thank you to the admins for granting me access to this group! :) I am a musician and IT professional living in southern California, but I have little experience with radio. I recently bought an RTL-SDR dongle (the silver one) and I successfully got it working on Win10 with HDSDR and DSDplus, so I can decode DSD and P25 phase I, mainly. I also have an installation of Linux Mint, 64-bit. I'm running everything on a gaming PC that I built, so it's got a lot of speed and RAM. Before I gained access to this group, I followed this PDF to setup the dongle on Linux Mint: https://ranous.files.wordpress.com/2018/02/rtl-sdr4linux_quickstartv2-18.pdf https://ranous.files.wordpress.com/2018/02/rtl-sdr4linux_quickstartv2-18.pdf I then managed to get OP25 installed. Once I gained access to this group and started to skim over the various tips and tutorials, I took a few days to decide what options I wanted to try: Raspi+OP25? Ubuntu 14.04 32-bit in a VM? Or stick with Linux Mint? I decided to try the Ubuntu 14.04 32-bit tutorial yesterday. I spent the entire day trying to get Ubuntu 32-bit installed in a VM before I realized it didn't like that I was trying to give it 16GB of RAM. 8GB did the trick. But after following the tutorial found here from 2017, OP25 generated a lot of errors and decided to put it down and go back to Mint for a while. Through the tutorials and RadioReference.com, I managed to find a local p25 control channel for the police. So I setup a trunk.tsv file and trunkk.tsv with the groups I wanted to listen to. As of this morning, I was able to run OP25 in a terminal window in Mint, tuned to 470.025, using rx.py. The command I am running is: python rx.py --args 'rtl' -g 65 -f 470.025e6 -N 'LNA:49' -2 -V -v 0 -S 1000000 -q 2 -T trunk.tsv The problem is, I'm not sure if it is working because: 1. I hear no audio (using an external sound module, alsamixer is working properly to route audio to this device) 2. When I run the script with the above command, my terminal window fills up with the error "tuning error +1200". The frequency displays in the lower left corner as 470.025000. Pretty sure I'm doing something wrong, lol. Any help would be greatly appreciated. Thanks, MP
On Tue, May 15, 2018 at 9:31 AM, mpuppet@yahoo.com [op25-dev] <op25-dev@yahoogroups.com> wrote:
Hello everyone,
First of all: Thank you to the admins for granting me access to this group! :)
I am a musician and IT professional living in southern California, but I have little experience with radio. I recently bought an RTL-SDR dongle (the silver one) and I successfully got it working on Win10 with HDSDR and DSDplus, so I can decode DSD and P25 phase I, mainly. I also have an installation of Linux Mint, 64-bit. I'm running everything on a gaming PC that I built, so it's got a lot of speed and RAM.
Before I gained access to this group, I followed this PDF to setup the dongle on Linux Mint:
https://ranous.files.wordpress.com/2018/02/rtl-sdr4linux_quickstartv2-18.pdf
I then managed to get OP25 installed. Once I gained access to this group and started to skim over the various tips and tutorials, I took a few days to decide what options I wanted to try: Raspi+OP25? Ubuntu 14.04 32-bit in a VM? Or stick with Linux Mint?
I decided to try the Ubuntu 14.04 32-bit tutorial yesterday. I spent the entire day trying to get Ubuntu 32-bit installed in a VM before I realized it didn't like that I was trying to give it 16GB of RAM. 8GB did the trick. But after following the tutorial found here from 2017, OP25 generated a lot of errors and decided to put it down and go back to Mint for a while.
I've had success with boadbot's fork on both Ubuntu 18.04 and Mint 18.3 (both 64-bit) within the last few days - see the last couple of pages of https://forums.radioreference.com/software-defined-radio/301459-virtualbox-p... 14.04 is pretty old at this point - I wouldn't use it as a starting point.
Through the tutorials and RadioReference.com, I managed to find a local p25 control channel for the police. So I setup a trunk.tsv file and trunkk.tsv with the groups I wanted to listen to.
As of this morning, I was able to run OP25 in a terminal window in Mint, tuned to 470.025, using rx.py.
The command I am running is:
python rx.py --args 'rtl' -g 65 -f 470.025e6 -N 'LNA:49' -2 -V -v 0 -S 1000000 -q 2 -T trunk.tsv
The problem is, I'm not sure if it is working because:
1. I hear no audio (using an external sound module, alsamixer is working properly to route audio to this device)
2. When I run the script with the above command, my terminal window fills up with the error "tuning error +1200". The frequency displays in the lower left corner as 470.025000.
You should redirect stderr to a file to avoid interfering with the curses interface - append "2>stderr.log" to your command line. "tuning error" generally means that you need to do some fine-tuning. If you have gnuplot-x11 installed, you should be able to bring up spectrum or mixer plots, and use that to see if your control channel is centered. If not, adjust your PPM (-q) and fine tune (-d) to fix it. When you get the control channel, you should see the "tsbks" count continually increase in the top bar of the UI. ~iain
Thanks Iain, I installed boatbod's op25 and gnuplot-x11. I also added the error log code at the end of my line. I copied my tsv files into the new installation and changed my script so it points there. Now, I can run op25 with the commands showing up at the bottom of the screen. I hit '1' to open a spectrum graph showing that I am tuned to the control channel on 470.025 but it's a little off, so I used the tune buttons (<>) to line it up(+400). My ppm is 0. I also opened the '5' mixer graph and the number is fluctuating between 0 and just over 100. But, I'm still seeing "tsbks 0" at the top. The entire line looks like this: NAC 0x734 WACN 0x-1 SYSID 0x-1 0.000000/0.000000 tsbks 0 Am I missing something from the command line?? python rx.py --args 'rtl' -g 65 -f 470.025e6 -N 'LNA:49' -2 -V -v 0 -S 1000000 -q 0 -T trunk.tsv 2>stderr.log Thanks again! MP
On Tue, May 15, 2018 at 12:55 PM, mpuppet@yahoo.com [op25-dev] <op25-dev@yahoogroups.com> wrote:
Thanks Iain,
I installed boatbod's op25 and gnuplot-x11. I also added the error log code at the end of my line.
I copied my tsv files into the new installation and changed my script so it points there.
Now, I can run op25 with the commands showing up at the bottom of the screen. I hit '1' to open a spectrum graph showing that I am tuned to the control channel on 470.025 but it's a little off, so I used the tune buttons (<>) to line it up(+400). My ppm is 0. I also opened the '5' mixer graph and the number is fluctuating between 0 and just over 100. But, I'm still seeing "tsbks 0" at the top. The entire line looks like this:
You could add '-d 400' to your rx.py command so you don't have to do that next time.
NAC 0x734 WACN 0x-1 SYSID 0x-1 0.000000/0.000000 tsbks 0
Am I missing something from the command line??
python rx.py --args 'rtl' -g 65 -f 470.025e6 -N 'LNA:49' -2 -V -v 0 -S 1000000 -q 0 -T trunk.tsv 2>stderr.log
What's in Trunk.tsv? Is this the site you're trying to get? https://www.radioreference.com/apps/db/?siteId=22010 If so, it appears that the NAC should be 0x370, but you have 0x734. boatbod's code allows you to specify 0 (zero) for the NAC, and it'll take the first one it decodes on the control channel. You could also use '-v 3' (or higher, instead of 0), and see what you get in stderr.log.... ~iain
Ah, you were right, I needed to adjust the NAC in my trunk.tsv file. I also changed -v to 3. After I made those adjustments, I was able to get data/audio on the control channel, albeit garbled
If you’re getting garbled audio and are running op25 on Ubuntu 14.04, then you can apply the following change that should address the stutter.. However, this step is not necessary when running Unbutu 16.04 or newer. sudo cp /etc/pulse/client.conf /etc/pulse/client.confbackup sudo nano /etc/pulse/client.conf Edit the following line: From: ; autospawn = yes To: autospawn = no Restart! Bill, WA8WG From: op25-dev@yahoogroups.com [mailto:op25-dev@yahoogroups.com] Sent: Tuesday, May 15, 2018 4:43 PM To: op25-dev@yahoogroups.com Subject: Re: [op25-dev] RTL-SDR and OP25 on Linux Mint 64-bit Ah, you were right, I needed to adjust the NAC in my trunk.tsv file. I also changed -v to 3. After I made those adjustments, I was able to get data/audio on the control channel, albeit garbled
If you've tuned the control channel correctly your "tsbks" counter should be continuously incrementing and your stderr.2 log should not contain any "tuning error" or "timeout" messages. With that done, audio should decode cleanly (provided you have specified the -T and -U options) unless your virtual machine is cpu starved due to too many background processes or insufficient memory. If that happens, try reducing the -S sample size (minimum of approx 274000) so there is less data to transfer and decode. Logs are a good way to troubleshoot most issues. Are you seeing lots of "PCM underrun" messages? Graham
I think I got something... The control channel seems silent but there are a couple of p25 streams on some nearby frequencies. I used the -d offset to lock into one of them and heard someone speaking English on it for a second. I'd call that a success for now. From what I read on this group, choosing a specific group to listen to is not yet possible, but hopefully I'm wrong. Thanks again, you got me the last steps I needed. MP
The whitelist and blacklist fields of the trunk.tsv file allow you to specify any number of talkgroups to be received or disregarded and is very powerful if used correctly. The fields are mutually exclusive, though. Use one or the other. On Tue, May 15, 2018 at 4:37 PM, mpuppet@yahoo.com [op25-dev] < op25-dev@yahoogroups.com> wrote:
I think I got something... The control channel seems silent but there are a couple of p25 streams on some nearby frequencies. I used the -d offset to lock into one of them and heard someone speaking English on it for a second.
I'd call that a success for now. From what I read on this group, choosing a specific group to listen to is not yet possible, but hopefully I'm wrong.
Thanks again, you got me the last steps I needed.
MP
participants (5)
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'William Becks' wa8wg＠centurytel.net [op25-dev] -
Brett Friermood brett.friermood＠gmail.com [op25-dev]
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gnorbury＠bondcar.com [op25-dev]
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iain macdonnell - N6ML n6ml＠dseven.org [op25-dev]
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mpuppet＠yahoo.com [op25-dev]