SDRTrunk Audio Glitch with Random Tones

[air-scan]

I have asked about this. I have shown this to SDRTrunk developer the first video. He doesn't know what it could be. Maybe someone here might be able to help determine whats the deal with this annoying glitch.

I had this set to unlisted on YouTube so I listed it because it was hard to get an answer This is the second one showing worse symptoms. You see it start happening 28 seconds in and is intermittent. Everytime this tones come up the audio glitches.

 

[air-scan]

found the issue. video removed because issue found. It was up for troubleshooting only.

 

[air-scan]

The issue was 2 fold.

The Radom tones Cure:
First was a bug in JMBE that @DSheirer has updated to the JMBE Github to v1.60. The bug was JMBE was miss-classifying high amount errors as tones. That's fixed. You should update if the random tones appear on your setup.

The audio glitch cure:
Second was I was running with 1 dongle at 2.40 msps. I was wrong. I figured out by trial and error it sounds better and with no sync loss running 2 dongles. The system I monitor is 2.67mhz wide. So with each dongle running 1.44msps I assumed it's combined width is 2.88msps which covers it enough to work properly. Now their is no sync loss and no audio glitches.

I also would like to say sometimes running RTL-SDR dongles at 2.44msps is good on some SDR apps but with SDRTrunk, your mileage may vary, A safe move would be to reduce each dongle's msps setting the same as the other. This reduces the overhead on the USB bus data stream as well therefore reducing the overall work load. That only works if your system isn't greater than 2.88mhz wide. Some computers will need to work harder on larger systems. HIgher msps places a higher load on the machine and that in itself will cause sync errors and audio frames not processing right.

This is purely my experience. I am enjoying SDRTrunk for APCO P25 PII. Learning along the way. I have learned alot and I hope others can benefit from my experience.