OpenGD77

Hello all.

I have a Pofung DM5R, the GD77 firmware has really made this HT user friendly.

I have access to a local repeater, however I want to use a pistar hotspot.

I have the pistar, it's all setup and working, to a point. The HT hears the pistar on the chosen freq tg colour etc, no problem, however the pistar does NOT hear the HT. I have followed the procedures for working out the hotspot offset, and have that set.

Is there something I am missing?

Hotspot mode is when the GD77 is the Hotspot

Its not a mode specifically for use with hotspots

If your hotspot can't hear your radio its because you probably did not calibrate your hotspot. Hardly any MMDVM_HS type hotspots work straight out of the box.

Its outside the scope of this forum, to explain how to commission and setup a MMVM_HS etc hotspot, try the PiStar forum

https://www.pistar.uk/

Hi,

Also, you have to pay attention about the DMRId you entered in the PiStar configuration page, it has to be identical to the one you defined in your transceiver, as the PiStar by default is set as private, hence it will handle only your own transmissions.


Cheers.
---
Daniel

VK3KYY wrote: ↑

Tue Jan 25, 2022 10:36 pm

Hotspot mode is when the GD77 is the Hotspot

Its not a mode specifically for use with hotspots

If your hotspot can't hear your radio its because you probably did not calibrate your hotspot. Hardly any MMDVM_HS type hotspots work straight out of the box.

Its outside the scope of this forum, to explain how to commission and setup a MMVM_HS etc hotspot, try the PiStar forum

https://www.pistar.uk/

If you read my post fully you would have read that I have calibrated the hotspot.
My question was about the Hotspot mode and did I need to use it.
Thanks for the clarification of what I thought was the case, but was not sure.

G4WXN wrote: ↑

Wed Jan 26, 2022 9:24 am

If you read my post fully you would have read that I have calibrated the hotspot.

Have you calibrated the hotspot to exactly match your particular radio? It means nothing if you calibrated the hotspot with another radio. ADF7021-based hotspots have no RX AFC, so even 100-200hz uncompensated offset increases BER significantly, and about 500hz offset makes the hotspot unusable - while the radio still hears it perfectly.

Also with my RD-5r the problem was not in the hotspot, but in the radio itself. It worked OK with the original firmware - but I had to re-calibrate the frequency when switched to openGD77.

G4WXN wrote: ↑

Wed Jan 26, 2022 9:24 am

My question was about the Hotspot mode and did I need to use it.
Thanks for the clarification of what I thought was the case, but was not sure.

The short answer is no.
This option is needs to be enabled on another gd77 or dm1801 (but not rd-5r) to use it as a hotspot instead of adf7021-based board - but i's clearly not your case.

UA0LMC wrote: ↑

Wed Jan 26, 2022 11:01 am

Have you calibrated the hotspot to exactly match your particular radio? It means nothing if you calibrated the hotspot with another radio. ADF7021-based hotspots have no RX AFC, so even 100-200hz uncompensated offset increases BER significantly, and about 500hz offset makes the hotspot unusable - while the radio still hears it perfectly.

Yes I calibrated the offset with the same transceiver.

So it appears you are saying that the GD77 firmware shifts the calibration of the transceiver?

I would be interested in what calibration changes you had to make?

G4WXN wrote: ↑

Wed Jan 26, 2022 12:48 pm

So it appears you are saying that the GD77 firmware shifts the calibration of the transceiver?

I would be interested in what calibration changes you had to make?

I had to re-calibrate "Reference oscillator tuning" parameter. In my case it was -15 before, and now it's -63. Other parameters are left intact.
It's highly recommended to use some kind of a test equipment, or at least an RTL-SDR and a known signal source to compare the frequency.
Don't forget to save a calibration file before changing anything.