I wasn't able to do a firmware update. I got an instant message saying the update was complete (no processing time) but the firmware wasnt updated. I used the usual setup method on the radio (hold P1 while switching on). The firmware file was 'Retevis_RT73_FW 20210329.bin'
Ian
Firmware Update
Re: Firmware Update
The latest version download should fix the issue, as there is a space in the filename it would not process correctly. It should work successfully now 
However the code for updating the firmware isn't really optimized yet, while it can successfully write the firmware there are no checks to see if it was successful or not.
This means the radio does not turn off after the update is complete, like it does when using the IAP software but so long as it has shown the process of writing the firmware and you have the message saying it was complete. It is safe to turn off the radio and turn it on as normal.
However the code for updating the firmware isn't really optimized yet, while it can successfully write the firmware there are no checks to see if it was successful or not.
This means the radio does not turn off after the update is complete, like it does when using the IAP software but so long as it has shown the process of writing the firmware and you have the message saying it was complete. It is safe to turn off the radio and turn it on as normal.
-73 de MM7DBT