Also ... in case you started doing the math of how much power you will
need and possible upgrades of your electrical system, and are
attempting to convert that 2kw or 4kw into amp hour draw on your
battery, hold up.

A 4kw radomes such as Raymarine's only uses 38 watts of battery power
while active, and 10 watts in standby (per the documentation). That is
a lot less than the 4000 watts you might be thinking 4kw implies. The
transmitter is in the "off" cycle of each pulse, for most of each
second, giving the electronics some type to store up those 38 watts and
release them in a powerful pulse. Since all the electronics in the
radome are on all the entire time, the chartplotter of course is on all
the time, the total power consumption between a 2kw and 4kw system is
negligable.

Dan