Choppy DMR Receive Please Help!

[KO4ZNE]

Hello all!

So far I am really liking opengd77 but lately I have developed an issue. I am listening to a local DMR repeater and the audio is choppy. It is persistent.The signal is strong, from s8 to s9+20 or more. I searched the forum and found a bunch of post on how to tune a hotspot but nothing much on what to do if an actual repeater is choppy. It did not seem to do this when I first flashed the radio but the last week it has happened a lot. I am running no dmr filtering as I want to grab any cc/tg/ts. Should I reflash? I am unsure on how to resolve the issue. If this has been answered before, I could not find it. Maybe my google fu is lacking.

Thank you in advance!

[VK3KYY]

Hello all!

So far I am really liking opengd77 but lately I have developed an issue. I am listening to a local DMR repeater and the audio is choppy. It is persistent.The signal is strong, from s8 to s9+20 or more. I searched the forum and found a bunch of post on how to tune a hotspot but nothing much on what to do if an actual repeater is choppy. It did not seem to do this when I first flashed the radio but the last week it has happened a lot. I am running no dmr filtering as I want to grab any cc/tg/ts. Should I reflash? I am unsure on how to resolve the issue. If this has been answered before, I could not find it. Maybe my google fu is lacking.

Thank you in advance!

Frequency calibration ?

[KO4ZNE]

I am not sure how to do this. I have a Tiny SA and a NanoVNA.

[VK3KYY]

I am not sure how to do this. I have a Tiny SA and a NanoVNA.

Neither device can accurately measure the frequency

Try manually tuning to plus or minus a few hundred Hz using the VFO

[KB8YKF]

I had questions about my only DMR local repeater sounding pretty bad, when the analog repeaters around me sound phenomenal. So I got a MMDVM board from Aliexpress and setup WPSD on an old Raspberry Pi 3B+ to settle if it was the repeater or my radio. And the hotspot sounds sooo much better than my local repeater, despite my close proximity to it. I'm taking that to mean my radio (RT3S) is fine.

I got this hat from this specific seller: https://www.aliexpress.us/item/32568060 ... pt=glo2usa

I followed this video to set it up with WPSD software - this is successor/fork of pi-star: https://www.youtube.com/watch?v=ZsTKUE0W6l0

The only gotchas I had were related to duplex hat I purchased - I had to select "MMDVM_HS_Hat_Dual Hat (VR2VYE) for Pi (GPIO)" as the hat type I had. In the video, the author is configuring a Simplex hat. I also wasn't able to log into BrandMeister network until I had sane TX/RX frequencies selected. I used this chart to help me pick: https://www.michiganonedmr.net/2021/04/ ... r-dmr.html

I was literally up and running and listening to and talking on talkgroups in about 30-40 minutes! It was nowhere as challenging as I'd thought it would be to setup my hotspot because I found that great video. The board was only ~$24 shipped since I already had a Pi to try it on.

[KO4ZNE]

I am not sure that a hotspot would help. The repeater in question is public service using unencrypted DMR. I have a cheapish hotspot... I guess I could set it to promiscuous mode and rebroadcast it I guess. Maybe a larger outdoor antenna would help.. TBH I dont care for Ham dmr. It seems like voice chat with extra steps to me. However I do like listing to public services and opengd77/RT3S works for the most part. My local ham repeater is so choppy it is unusable. That lead me to think it was the radio. How do you have a 20 over s9 and sound bad. Lol.

I will try tuning a sdr to the channel in question and use the vfo to compare receive. Does firmware offer a freq offset? I am new and tbh I have not RTFM. Hahah. Be gentle please.