Anyone running GMSK node adapter Star*Board (DUTCH*Star fw)?

Help with D-Star related issues
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iz4efn
Posts: 2
Joined: Mon Apr 13, 2020 1:43 pm

Anyone running GMSK node adapter Star*Board (DUTCH*Star fw)?

Post by iz4efn »

Hi folks

I have one of these from my early Dstar days: https://www.k6jm.com/mc/catalog/index.php?cPath=23

It's a USB-based GMSK modem for DStar only. I managed to get it mostly working with pi-star by using DStarRepeater. TX works fine. I can't RX anything despite playing with the audio levels: nothing comes up in RF heard list. The same radio works fine with MMDVM on STM32 board.

Can anyone suggest any configuration trick that might be preventing RX to work? I also tried to set different invertRX parameters as suggested on this forum but no luck.

Thanks in advance!

Alessio IZ4EFN
M1DNS
Pi-Star Team
Posts: 1394
Joined: Thu Apr 05, 2018 5:30 am

Re: Anyone running GMSK node adapter Star*Board (DUTCH*Star fw)?

Post by M1DNS »

Stick with the dstarrepeater setup the board doesn't have compatibility with Mmdvmhost.

First look at the FAQ section. It has an entry 'using DSTAR mode with pistar' read through that, if the dstar radio is setup correctly then...

Look in the expert pages ...
admin/expert/edit_dstarrepeater.php
Look at inverting the rx audio entry.

Sent from my SM-G935F using Tapatalk



Andrew M1DNS.
Pi-star Admin Team.
iz4efn
Posts: 2
Joined: Mon Apr 13, 2020 1:43 pm

Re: Anyone running GMSK node adapter Star*Board (DUTCH*Star fw)?

Post by iz4efn »

Andrew

I was indeed using all correct settings. I just figured out the Kendwood TM-v7 has very different behaviors over different VFO's.

I'll document here for other folks. I am using the DIN connector and setting DATA ON with 9600 baud ON.

On the same frequency (I am using 145.337,5 for my tests)
  • when running DATA on the right VFO, audio levels can be adjusted well for TX audio, but no proper signal will get to the board hence no decoing from radio to pi-star (this was my original problem)
  • when running DATA on the left VFO, audio levels can be adjusted well for RX audio, meaning I can see my handheld transmissions being received by pi-star, but the TX audio from the modem to the radio is just awful - sounds completely saturated and unable to lower enough via R36 (TX level)
Bottom line, be careful if you are using a TM-v7 for your tests. Other than that, the GMSK board from MoennComm works great in DStarRepeater mode on pi-star with these settings:

pttInvert 0
dvrptr1RXInvert 1
dvrptr1TXInvert 0
dvmegaRXInvert 0
dvmegaTXInvert 1

Not sure which of the above is really important for the combination I am testing, however I am pretty sure with a different radio and maybe a little resistor on TX audio the board is perfectly usable.

Thank you.
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