View Single Post
  #25   Report Post  
Larry W4CSC
 
Posts: n/a
Default

Jeff Morris wrote in
:

I've had minor second thoughts on this after checking the specs. In the
"old days" more powerful domes were heavier and used more power - that
is not the case now - the 4kW Raymarine dome only weighs a few pounds
more and uses 1 or 2 Watts more juice.


Pot metal and plastic is much lighter, which is what the Raymarine is made
from. They'll replace it when the pot metal consumes itself from the
condensation of breathing in and out through the drain tube makes it rain
inside the dome, though. We're on our third...(sigh)

The communications on the RL70CRC also failed, which explains why we
couldn't get the Seatalk Gyro/Compass to ever calibrate properly, no matter
how many times we turned it slowly. They fixed that, too, but I don't
think it was ever working right in the first place.

Isn't it amazing how 2,000 watts of peak RF power just appears from thin
air for only 1-2 watts more DC? Magic? Divine intervention? Maybe its
the printer stepper motor that turns the rubber band that drives the PC
board antenna array...??


I'm still not sure of the value for long distance viewing, but the high
power dome will have finer resolution, so that a pair of channel buoys
will be resolved as two targets further away with the more powerful
unit. Navigation is easier, since coastlines will more closely resemble
the chart. However, this takes a lot of practice and you're better off
relying on a good gps.


Ah, but you have another problem in the fog. The higher the antenna, the
further away the target will disappear as the target approaches the boat!
You won't see the bouy 8 miles away with the antenna down low, but you WILL
see the bouy in the fog a LOT closer to the boat as you, hopefully, pass
it.

Traveling at Mach 1, I'd understand having more range. But, traveling at 6
knots I'd rather see that target two boatlengths off the port bow with a
lower-down antenna....wouldn't you?


The downsides of the large unit is almost double the cost (a $1000
premium on the RayMarine list) and a much larger dome (an issue for
those trying to hide the dome from the jib).


I'm tired of changing out pot metal Raymarine antenna pods. There's gotta
be a way to build a $2000 radar transceiver that isn't made out of the same
materials as the window winder in a '97 Ford pickup. The damned chassis
it's all mounted in is made of ZINC!! Idiots.... Look inside for
yourselves! Don't trust me. Unscrew the 4 little flathead screws and take
the top of the dome off. Do it on that boat down the dock and see if it's
wet inside!

Furuno? Anyone had water destroy a Furuno radar dome??