New to DSTAR - Links to Reflector but BER 13%

Help with D-Star related issues
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KN6CXC
Posts: 2
Joined: Sat Jul 06, 2019 4:42 pm

New to DSTAR - Links to Reflector but BER 13%

Post by KN6CXC » Sat Jul 13, 2019 4:59 pm

Hello,

I'm new to HAM radio in general but I had no issues setting up DMR and getting it to work flawless. I got a new HT and the next challenge is DSTAR.
I have a pi3+MMDVM module, I repurposed it to use it from DMR to DSTAR (since I could not figure it out how to make both work at the same time) - it's a duplex MMDVM module.

I can connect to the DSTAR network, usually I connect on the DSC030 default reflector. I can hear other people, not problem, but when I select to use the reflector (CQCQCQ) I can send my transmission but my BER is 13-15%.
Sometimes when transmitting with this high BER, the radio makes weird noises (like interference) and will not stop until I reboot the pi3.

Any ideas how to solve this? I tried different Reflectors and no success. I'm in the US West coast.

Thank you.
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G4AON
Posts: 53
Joined: Tue Apr 24, 2018 5:34 pm

Re: New to DSTAR - Links to Reflector but BER 13%

Post by G4AON » Sun Jul 14, 2019 6:42 am

Could it be that your DMR or your D-Star radio is off frequency relative to your MMDVM?

Make sure both radios are on frequency, then adjust the MMDVM for minimum BER.

73 Dave
ID51E plus 2
ID5100E
TYT MD-UV380
Chinese MMDVM on a Pi Zero W
DVAP on a Pi 3B
Shark OpenSPOT 2

KN6CXC
Posts: 2
Joined: Sat Jul 06, 2019 4:42 pm

Re: New to DSTAR - Links to Reflector but BER 13%

Post by KN6CXC » Sun Jul 14, 2019 4:21 pm

I got it to work.
I was using a MMDVM duplex on Simplex mode. For some reason that did not go well.
A lot of guides that you can find that talks about duplex MMDVMs are for DMR only. And almost all of the guides that I found for DSTAR uses Simplex MMDVMs.

Changed it back to Duplex, set the TX and RX frequencies.
Configured my D74 with the same TX frequency as my MMDVM and a plus offset frequency the same as the RX on the MMDVM.
Other thing that I did, I set Gateway = 1 on the Expert configuration on the pi-star.

Now everything works perfectly with both DMR and DSTAR on the same MMDVM. DSTAR in my case sounds much better than DMR.

73
Filipe
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G4AON
Posts: 53
Joined: Tue Apr 24, 2018 5:34 pm

Re: New to DSTAR - Links to Reflector but BER 13%

Post by G4AON » Sun Jul 14, 2019 5:03 pm

Glad you got it sorted Filipe. I find the audio on D-Star sounds better on the small speaker of my ID-51, than on the larger speaker on my ID-5100.

73 Dave
ID51E plus 2
ID5100E
TYT MD-UV380
Chinese MMDVM on a Pi Zero W
DVAP on a Pi 3B
Shark OpenSPOT 2

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