GD-77S unable to access hotspot

Help with DMR issues
Post Reply
AC8OB
Posts: 40
Joined: Thu Nov 01, 2018 2:28 am

GD-77S unable to access hotspot

Post by AC8OB »

I have an issue with a Radioddity GD-77S that will not access my duplex hotspot.
The hotspot is working with other radios (including a GD-77).
The GD-77S is working with a local repeater.

Nothing appears in MMDVM log apart from the occasional

Code: Select all

M: 2022-01-27 15:50:21.608 Downlink Activate received from G4IRX
Modem firmware

Code: Select all

Selected Modem:     MMDVM_HS_Hat_Dual Hat (VR2VYE) for Pi (GPIO)
Connected Hardware: MMDVM_HS_Dual_Hat-v1.5.2 20201108 14.7456MHz dual ADF7021 FW by CA6JAU GitID #89daa20
TCXO Value:         14.7456MHz
Checking the CPS settings between the the GD-77 and the 77S, I can't see any differences in the channel settings. Is there anything else I should be checking with the 77S or any way to get more debug information from Pi-Star/MMDVM?

Thanks.
Nick - G4IRX - AC8OB
IO92JV - EN70VN
AC8OB
Posts: 40
Joined: Thu Nov 01, 2018 2:28 am

Re: GD-77S unable to access hotspot

Post by AC8OB »

KE7FNS wrote: Thu Jan 27, 2022 5:13 pm
And what DMR ID do you have programmed into the radio? According to the database you have multiple DMR ID's and by default Pi-Star is set to block all but the one that matches whatever you entered into the DMR ID field on the main configuration page.

You can either leave it on private, and use only one of your DMR ID's in all of your radios, or you can set it on public but on public I'm not sure if some of the private call forwarding will still function due to the hotspot having a different DMR ID as the next to last hop.
I have it set to public and I have 2341099,2343531 (both registered to G4IRX) in the DMR access list. The hotspot is configured as 2343531 This is working with other radios.
KE7FNS wrote: Thu Jan 27, 2022 5:13 pm If you use MMDVMCal, you can eliminate the DMR ID public private issue. It could be that radio is far enough out of spec that it isn't recognized. Try seeing if the hat responds to the radio and tune for lowest BER. Google MMDVMCal if you need instructions.
Thanks, that appears to be the issue. The initial MMDVMcal BER was showing around 10%. After some F/f tuning I've established a correction factor of -350 which I applied to the modem RXOffset. It now works with a BER of 0.2%.

Now I'll go and check GD-77S and other radios to see what the error spread is.
Nick - G4IRX - AC8OB
IO92JV - EN70VN
Post Reply