OP25 Underruns

[csharp2a]

I have OP25 running and its incredible. I am having an issue though with underuns. Has anyone else experienced this and what can be done to fix it?

Oddly enough, I can listen to one site with no issues. If I change to a different site, I get the underruns.

Any help would be greatly appreciated.

Craig

 

[boatbod]

I have OP25 running and its incredible. I am having an issue though with underuns. Has anyone else experienced this and what can be done to fix it?

Oddly enough, I can listen to one site with no issues. If I change to a different site, I get the underruns.

Any help would be greatly appreciated.

Craig

Going to need more info please.
- hardware & OS you're running on
- repository/version of code being run (osmocom vs boatbod)
- system(s) being monitored (link to RRDB reference)
- command line options you're using to start op25

May have more questions later, but this should be enough to get pointed in the right direction.

 

[csharp2a]

Hi and thank you for the reply. Here is the information you requested. I appreciate your help!

Computer: Dell E6400 Laptop
OS: Ubuntu 18.04.1 LTS Server with GUI
OP25: Boatbod - cloned from github. I assume its the latest version
System: https://www.radioreference.com/apps/db/?sid=100
Listening to Northville. Very strong singal.
Command: rx.py —args ‘rtl’ -N ‘LNA:47’ -S 2400000 -f 853.9625e6 -o 20000 -q -.9 -T trunk.tsv -V -2 -U

Note that the — args is actually two dashes. My ipad prints it as a single bar.

Most of the time the signals are clean but I am getting the underruns. I have found out that it may be PCM underruns. Just not sure. My constellations look great as well. Pretty tight pattern.

 

[csharp2a]

Here is a snap of it working correctly. When there are underruns, it prints across the top line PCM Underrun and some other things that mix with the existing line. Makes for a mess to read.

 

[boatbod]

Hi and thank you for the reply. Here is the information you requested. I appreciate your help!

Computer: Dell E6400 Laptop
OS: Ubuntu 18.04.1 LTS Server with GUI
OP25: Boatbod - cloned from github. I assume its the latest version
System: https://www.radioreference.com/apps/db/?sid=100
Listening to Northville. Very strong singal.
Command: rx.py —args ‘rtl’ -N ‘LNA:47’ -S 2400000 -f 853.9625e6 -o 20000 -q -.9 -T trunk.tsv -V -2 -U

Note that the — args is actually two dashes. My ipad prints it as a single bar.

Most of the time the signals are clean but I am getting the underruns. I have found out that it may be PCM underruns. Just not sure. My constellations look great as well. Pretty tight pattern.

The occasional "PCM underrun" is unavoidable due to missed/badly decoded frames. Mostly they can be ignored unless they happen so much that audio becomes distorted.

Try reducing the sample size to -S 960000 as it will free up some cpu cycles.
Also, redirect your stderr to a file so that it doesn't interfere with the curses terminal.

./rx.py ..... 2> stderr.2

Lastly, check the tuning is optimally centered by using the mixer plot (#5).