Looking for some help, I have 3 machines running Ubuntu 14.04 LTS and OP-25 and all are experiencing the same issues.
Machine 1 is a HP ProBook 6570b with 8GB ram and Core i5-3230M cpu
Machine 2 is a HP ProBook 6570b with 8GB ram and Core i5-3210M cpu
Machine 3 is a HP ProBook 4530s with 4GB ram and Core i3-2350M cpu
We are using RTL-SDR.com Blog sticks (the ones with the TXCO) and monitoring 2 different P25 systems, 1 is a mostly phase 1 and the second is all phase 2. All sites we monitor are LSM sites.
Machine 1 will run for several hours normally and then begin the aUaUaU on what appears to be every other packet. Most of the time closing scope and relaunching it fixes the issue.
Machine 2 will begin this after 20-30 minutes and machine 3 will begin after 10 or so minutes.
No adjustment of antenna location, gain, ppm, fine tune makes a difference once it starts the underrun. Location or proximity to the site also doesn't effect it.
Machine 1 was setup a few weeks before 2 and 3 so I'm not sure if there were any changes to op25 during the last few weeks.
Also I noticed that the op25.osmocom.org site is down. Is there another place to get current information?
Thanks to anyone who can offer any tips on how to make these machines reliable.
You didn't specify whether you're just seeing "aU" in the terminal, or if you're having audio playback issues. I'm going to assume it's the later.
This will help with the audio playback
create this file if it does not exist, otherwise edit the file: ~/.gnuradio/config.conf
Add this section to the file if your configuration uses ALSA. It's Ubuntu, it probably does...
[audio_alsa]
period_time = 0.100 nperiods = 5
I don't know what the hell is up with the OP25 repository/wiki. This place seems just as dead...
There are a few forks on github:
mmhhpp/op25 https://github.com/mmhhpp/op25 balint256/op25 https://github.com/balint256/op25 bitmunch/op25 https://github.com/bitmunch/op25 << this has a performance update thanks to Luke, and a few other minor tweaks and stuff
Yes, audio was cutting out as well. I created that .conf file and added that section. I have them running now and will update after they have ran for a while. Thanks for the quick response!
This did fix the problem, thank you! Does anyone know the feasibility of running two RTL sticks to get access to a larger chunk of spectrum?