Hi All,
Today I’ve installed the FA dark blue 1090 filter and that strange issue/phenomena has disappeared!!! Eureka!!
All connections has well done, no any unscrew to the “magic point”.
Msg/rate improved alot, range increased too.
I’ll buy a second filter to install it in the second radar setup, having the same problem.
So… it seems I was suffering of a severe RF problem managed by filter, or this filter added a new electrical “situation” going to solve my strange issue. I don’t know, but I can declare “SOLVED”