Thanks for your interests and concern about the radar performance
in our sim, we actually implemented KLJ7v1.
the radar screen max range 80nm doesn't mean it can detect contact as far as 80nm. Any contact beyond 40nm needs to scale the screen to 80nm
AFAIK, KLJ7v1 is almost the newest radar which was developed in mid-late 2000s. the perf of radar not only relies on the power, but also the post process (signal process). newer radar normally has better post process (in algorithm as well as circuit design), that with a good signal filter, even some weaker contact echo can be identified.
compared to all public info (from CETC), as well as what we know, current radar perf is reasonable
if you have other questions, you can ask @L0op8ack