"Lynn Coffelt" wrote in
:

"Sealed up" being a theoretical state in the marine environment, of
course. Do the Raytheon open array antennas still have drain tubes to
sling water "in case" there should be any "condensation"? Hmmmmm?
Got about 12 liters of water out of an 8 foot Krupp Atlas one
time. The
beautiful, almost new, 64 mile radar would only get echos from about
half a mile.
A good "TR down" installation had one or more mica "dams" in the
waveguide to keep from having wet feet in the pilot house (or the
"void").
Old Chief Lynn



The drain tube is where the water intrusion enters the 2D case at
dusk...exactly like an empty fuel tank...as the case cools to condense it.
The water can't drain out because of the many plastic stringers in the
bottom of it, and it being flat, not sloped to channel water to the drain
tube.

How stupid it is. Open any SEALED Icom AT-130 antenna tuner that's been to
sea for years and you'll find it looks just like the day it was installed
inside unless the lightning blew it apart. Of course, the Icom's plastic
box ISN'T held together with 4 little screws around a 3' diameter o-ring,
either.

From the look of Raymarine's picture of the RD-424 new dome, it also has 4
screws instead of a proper seal.

If they'd left the whole bottom open with a big hole so the air could blow
out the humidity inside the dome...it would probably be fine that high up
on the mast.