Hi Oscar, Jose EA5HVK author of VARA modem, tells me that the version of the Vara modem we've tested is 2.2.1 which covers a delay of up to 1.2 seconds, not enough to work via satellite, it asks me to try again with the 3.0.2 beta version which covers delays up to 1.7 seconds with which it should work:
I have also requested both Jose and to the author of Winmor and Ardop the possibility of operating in full-duplex which would probably be the solution to the problem, considering that the audio sources are different, uhf radio in TX and SDR or analog receiver in RX and this would make it possible to reduce delays and with the possibility of decreasing the delay, even an increase in normal performance.
If you have the possibility to install v.3.0.2 i would be grateful, i have already installed it and this evening we can carry out further tests with VARA.
Rick KN6KB, Winmor and Ardop author suggest to use Ardop where is possible to increase the 'leader lenght' parameter, it can accept up to 2500ms, we can try with 2000ms and if not work to calculate exatly all the delay via SAT, in order to modify the software.
If someone else wants to try, they can communicate it is welcome
My server listen on 10489635 dial