Hello,
I just made some test because since I restarted to play the mirage 2000c in multiplayer I can't get any contact with my radar or very few. (I've played it since the release and didn't played it a lot since 1-2 years.)
So I made a test in the editor, I've put an F16 right in front of me (same altitude, 20k ft) starting 80nm away from each other.
And what I found is very strange, the F16 can start launching its missiles even before I can see it in my radar. I finally detected it at 23nm. This is normal? The F16 is as stealthy as that?