OpenGD77

Well I guess I will just have to mark it off on my receive because of my duplex hot spot I guess. A lot of incoming transmissions are robotic sounding or quiet. I either have to do a channel up and down or have my talking party repeat themselves. Does anyone know a work around for this? I have tested with filters on and off and it is no different.

Thanks to all ham working for this new stable release.
73 de Uli

linkford wrote: ↑

Mon Mar 07, 2022 7:46 pm

Well I guess I will just have to mark it off on my receive because of my duplex hot spot I guess. A lot of incoming transmissions are robotic sounding or quiet. I either have to do a channel up and down or have my talking party repeat themselves. Does anyone know a work around for this? I have tested with filters on and off and it is no different.

Lots of people have duplex hotspots, perhaps you just need to calibrate your hotspot and/or the GD77. Have you done that yet?

What tools do you use. Give me some ideas please! My other Radioddity GD-77 receives same conversation just fine.

linkford wrote: ↑

Wed Mar 09, 2022 5:28 am

What tools do you use. Give me some ideas please! My other Radioddity GD-77 receives same conversation just fine.

Did the radio with OpenGD77 also work fine on the hotspot before? If so maybe you've lost calibration in it itself or just need to tweak it.

Reference oscillator tuning in OpenGD77 is what you'd want to adjust.

You should also calibrate your Hotspot as well, as they are rarely exactly on frequency. This page explains how to do it: http://www.k9npx.com/2019/02/hotspot-of ... ation.html

Just try to keep in mind that you want correct calibration, not "matching" calibration. In other words try to make it output on the right frequency not just tweak it until it works on one radio. Start with the OpenGD77 radio and the Reference Oscillator.

Do I need to run my duplex hotspot in simplex mode to fix these issues? I have run those test before and still nothing. When you ask I was wondering if there was another test that may be different. When you suggested calibration, I thought you were referring to something different that I hadn't run. I have a BER around 0.4%.

linkford wrote: ↑

Wed Mar 09, 2022 1:29 pm

Do I need to run my duplex hotspot in simplex mode to fix these issues? I have run those test before and still nothing. When you ask I was wondering if there was another test that may be different. When you suggested calibration, I thought you were referring to something different that I hadn't run. I have a BER around 0.4%.

No, duplex hotspots work just fine. BER is only one side of the transmission.

Wonder what I have set wrong on the duplex side if the simplex side works perfectly.

Hi,

Does you hotspot is well calibrated (using MMDVMCal, pistar-mmdvmcal on PiStar) ?
Have you defined a large enough shift between RX and TX frenquencies ?
What is your output power (GD side), and the mean distance to your hotspot ?

Cheers.
---
Daniel

Thank you.

Good job ! I just installed it on my two GD-77 and DM-1801 devices without any problems.