OpenGD77

I've been troubleshooting an issue with my GD77 running OpenGD77 (all recent versions of firmware) where occasionally I hear a repeating digital noise in place of audio. If I change the channel (up and down), the radio begins decoding the audio correctly. If I do nothing, the repeating digital sound remains for the length of the transmission. I've attempted adjusting DMRTXLevel (up and down from 50 until i have other RX issues), setting TX and RX offsets, etc. Is there something else I should be adjusting on my hotspot to resolve this issue on my radio? Has anyone else experienced this?

I've made a recording of this issue: https://drive.google.com/file/d/1I3EuIT ... OkRkWJSMOP

Hi,

Are you running the latest beta ?
From what I see in this short video, if seems you get some audio at the end of the transmission (I see the QSO data disappearing).
Also, there are some problem with user transmission, so it's not unusual to have such effects (and I don't even talk about the loops on TG91 that did happened one or two weeks back).

Cheers.
---
Daniel

I'm currently using the 10/2/2021 firmware but have had this issue with all firmwares since I originally got the radio in June (R2021052901). In this case I only caught the tail end of the transmission. This happens to about 1% of received transmissions and seems to be more common, if not completely isolated, to my hotspot; although local repeaters don't have enough traffic for me to really test this. The fact that I can fix the problem just by changing away and back to the channel makes me think the problem is with the radio and not the hotspot. I have this issue with other TGs on Brandmeister as well as TGIF, so not sure there's anything network specific that might be related.

Also - re: the sound at the end of the video - I think that was my dog whining in the background. The only audio coming from the radio is the noise at the start. Sorry for the confusion. I will try to get a better video of this happening (with the channel change fix) asap.

I was able to get another video where I resolve the receive issue by changing away and then back to the channel: https://drive.google.com/file/d/1KWmo-Q ... jmkvUgrvTa

K5FYI wrote: ↑

Wed Oct 06, 2021 10:43 pm

I was able to get another video where I resolve the receive issue by changing away and then back to the channel: https://drive.google.com/file/d/1KWmo-Q ... jmkvUgrvTa

You have to show in the video how to make this happen. Otherwise its very hard to replicate the problem.

Simply changing channels does not normally cause this to happen for most people, otherwise we would have already had a flood of bug reports.

VK3KYY wrote: ↑

Thu Oct 07, 2021 12:55 am

K5FYI wrote: ↑

Wed Oct 06, 2021 10:43 pm

I was able to get another video where I resolve the receive issue by changing away and then back to the channel: https://drive.google.com/file/d/1KWmo-Q ... jmkvUgrvTa

You have to show in the video how to make this happen. Otherwise its very hard to replicate the problem.

Simply changing channels does not normally cause this to happen for most people, otherwise we would have already had a flood of bug reports.

As described in my previous posts, this happens on RX occasionally. I'd say between 1%-5% of transmissions received. I don't do anything to make this happen. It's not particularly predictable either (hence why my videos are of me reacting to and trying to capture the issue). The rest of the time I have clear RX and flawless TX. To clarify, changing the channels resolves the issue, it does not cause it. This is why I think the issue may be on the radio/firmware side of things. I very much appreciate the work everyone's put into this project. If there is any more information I can provide, please let me know.

FYI - Here's the factory calibration of my radio (captured before touching the firmware):

I've only uploaded the UHF calibration since that's what I'm using for my hotspot.

Hi,

I never had that kind of audio artefact, and I'm used to have a bad internet connection.
How is your hotspot frequency alignment ? Have you already tried to check with mmdvmcal ?


Cheers.
---
Daniel

F1RMB wrote: ↑

Thu Oct 07, 2021 3:31 am

Hi,

I never had that kind of audio artefact, and I'm used to have a bad internet connection.
How is your hotspot frequency alignment ? Have you already tried to check with mmdvmcal ?


Cheers.
---
Daniel

Hi Daniel,

I have calibrated the TX and RX offset with mmdvmcal and this still happens. My offsets were relatively small (under 250) and my BER when transmitting is regularly under 0.3%. I hear this kind of artifact with or without offsets configured.

Thanks,
Jason