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From: (no name) (no email)
Date: Sun Jan 02 2005 - 19:31:58 EST
Chet asked:
What opinions does the list have of the appropriate size and power radar for
a 49 foot boat that will be used offshore? What experience exist in seeing
the small boat or other target as the radar power and antenna size
increases? At what point is it a waste of money to purchase higher power
and or larger antenna?
I assume you are looking at a stand alone radar installation, not integrated
nor networked electronics nor PC display.
I'd look at test results for antenna sizes and powers you are considering,
but I don't have them myself. Empirically, an open array generally gives the
narrowest beamwidth and hence the best discrimination. For offshore, do you
expect to see many small boats? Will you run in restricted visibility
much...at
night?? I'd be personally much more worried about big ships and huge radars
aren't as necessary for that.
More power and higher antenna add to long range but I doubt a 49 foot boat
will get your antenna high enough to see any small targerts very far away.
Height and range tables are given in Eldridge...No radar can see a typical
cruising boat, as I recall, even close to 36 miles based on the antenna
heights of
most of our boats...Return depends on height of transmit antenna and height
and
cross section of target..In my subjective opinion anythying more than 3 or 4
feet of antenna and 4 or 6 kW is unnecessarily expensive.
"...In the past, Furuno has received the "highest marks" by the list members.
I have noted that JRC, Simrad, and others also make "high end" radars. Is
Furuno still the preferred choice?"
As I've posted before, radar preference seems to vary by location on the East
Coast. Commercial boats in Maine have Furuno more than all others combined,
Raymarine was predominant in Nova Scotia. I would go with Furuno since
Raymarine is a newly independent company and its longevity unknown.
I have a 1989 Raytheon 40XX 2 ft dome antenna and a 1999 Furuno 2 ft open
array and both work fine. The newer Furuno has better dial interfaces. One
antenna is on my roof, the other on a radar arch about 12 feet away for
diversity.
On rare occasions I have visually seen a small outboard boat and not seen it
on
radar, most of the time I see the radar image first and then look for the
boat. Sometimes apparently huge targets like a tug and empty steel barge do
not
appear as relatively large on scrren as you would expect...But I have spotted
piper cubs on the radar and looked and looked for a boat before realizing what
was reflecting. I'm not interested in targets more than five or so miles
distant and posts from other listees lead me to conclude that is a common
preference...
Unless a given antenna size for Raymarine has narrower beamwidth than the
same size Furuno, I'd favor the Furuno but it's a subjective decision based on
my
trust in Maine Lobsterman...they don't spend money unless they have to.
Here is a comment on JRC from a recent TT post:
b b&I recently installed a JRC 1500 Mk II - it seems to work well, and is
fairly easy to use. I would like an easier way to switch between
range selection and gain setting - as it is, one knob is used for these
functions, sea clutter, tune and rain suppression - you press the knob
to step through the functions, so you have to press the knob half a
dozen times to switch from range to gain and back..b
This is NOT an arrangement Ibd like to have during tense navigation in poor
visibility.
Rob Brueckner
Hatteras Yachtfisherman
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