I have a Furuno 1621 MkII radar that I've never been happy with. At this
point I believe that the radome has basically failed and I'm planning on
replacing the entire system.

I think that I'm going to replace it with RayMarine C70 system which
provides a radar and chartplotter. This will be compatible with my
Autohelm autopilot and this will provide a redundant chartplotter.

I've been pondering the differences between a 2KW radome and a 4 KW radome.
Based upon the litature the 2 KW unit provides 24 nm range vs 48 nm range.
This doesn't seem to really matter as the radar is only mounted about 10-12
feet above the water on a radar mast and the radar horizon to a 50' high
target is only 14+ miles. I've been told that the 4KW is very helpful in
dense fog (not applicable to the Caribbean where I spend most of my time,
but would be useful when I return to New England) or heavy rain and that it
also provides better separation of targets.

My typical use of radar is at night where I have the range set to about 8
nm or to watch for squalls, where the extended range would be useful.

There's a huge difference in cost between the two. The 2KW unit runs
around $900 and the 4KW unit runs about $1600. Based upon my usage and
setup, is the additional cost worth it? Are there other things that I
should be thinking of?

Thanks, Geoff

On Wed, 29 Sep 2004 14:38:26 GMT, "Geoffrey W. Schultz"
wrote:

There's a huge difference in cost between the two. The 2KW unit runs
around $900 and the 4KW unit runs about $1600. Based upon my usage and
setup, is the additional cost worth it? Are there other things that I
should be thinking of?

=================================================

I'm going through the same decision process at the moment and am
tilting towards the 4 KW unit. To me the most important issue is
being able to pickup small targets in poor weather and poor
visibility. Anything that helps with that is a plus as far as I'm
concerned. In the grand scheme of things, the $700 difference is not
all that much, especially if it saves even one close call.

it also provides better separation of targets.

I think this is only true if the 4kw antenna is larger, say 24" vs the usual
18". If the radomes are the same size I think the principle advantages
would be the extra power to punch through rain and fog. I imagine with more
power you get a stronger signal reflected back so this might also help with
small targets? You might also get more sea clutter though?

"Geoffrey W. Schultz" wrote in message
7...
I have a Furuno 1621 MkII radar that I've never been happy with. At this
point I believe that the radome has basically failed and I'm planning on
replacing the entire system.

I think that I'm going to replace it with RayMarine C70 system which
provides a radar and chartplotter. This will be compatible with my
Autohelm autopilot and this will provide a redundant chartplotter.

I've been pondering the differences between a 2KW radome and a 4 KW
radome.
Based upon the litature the 2 KW unit provides 24 nm range vs 48 nm range.
This doesn't seem to really matter as the radar is only mounted about
10-12
feet above the water on a radar mast and the radar horizon to a 50' high
target is only 14+ miles. I've been told that the 4KW is very helpful in
dense fog (not applicable to the Caribbean where I spend most of my time,
but would be useful when I return to New England) or heavy rain and that
it
also provides better separation of targets.

My typical use of radar is at night where I have the range set to about 8
nm or to watch for squalls, where the extended range would be useful.

There's a huge difference in cost between the two. The 2KW unit runs
around $900 and the 4KW unit runs about $1600. Based upon my usage and
setup, is the additional cost worth it? Are there other things that I
should be thinking of?

Thanks, Geoff

See Below:
"Geoffrey W. Schultz" wrote in message
7...
I have a Furuno 1621 MkII radar that I've never been happy with. At this
point I believe that the radome has basically failed and I'm planning on
replacing the entire system.

I think that I'm going to replace it with RayMarine C70 system which
provides a radar and chartplotter. This will be compatible with my
Autohelm autopilot and this will provide a redundant chartplotter.

I've been pondering the differences between a 2KW radome and a 4 KW
radome.
Based upon the litature the 2 KW unit provides 24 nm range vs 48 nm range.
This doesn't seem to really matter as the radar is only mounted about
10-12
feet above the water on a radar mast and the radar horizon to a 50' high
target is only 14+ miles. I've been told that the 4KW is very helpful in
dense fog (not applicable to the Caribbean where I spend most of my time,
but would be useful when I return to New England) or heavy rain and that
it
also provides better separation of targets.

My typical use of radar is at night where I have the range set to about 8
nm or to watch for squalls, where the extended range would be useful.

There's a huge difference in cost between the two. The 2KW unit runs
around $900 and the 4KW unit runs about $1600. Based upon my usage and
setup, is the additional cost worth it? Are there other things that I
should be thinking of?

Thanks, Geoff

Definitely go with the higher power/larger dome if it is available. Not
only more power too burn thru rain/fog but better target discrimination with
larger dome. Is that a single blip or a tug/barge? Without gong into great
detail I ma running a 10 KW on my yacht because I can afford it both
economically and from a power draw and mounting standpoint because I was
once in a situation where the rain was so heavy that I couldn't attenuate
the rain echoes without losing all targets and I was in the Straits of
Mackinaw where there were 1000 foot freighters within 1 mile of me (I knew
because I was giving security broadcasts and they were responding on the
VHF).

In article ,
"Geoffrey W. Schultz" wrote:

I have a Furuno 1621 MkII radar that I've never been happy with. At this
point I believe that the radome has basically failed and I'm planning on
replacing the entire system.

snipped for brevity

My typical use of radar is at night where I have the range set to about 8
nm or to watch for squalls, where the extended range would be useful.

There's a huge difference in cost between the two. The 2KW unit runs
around $900 and the 4KW unit runs about $1600. Based upon my usage and
setup, is the additional cost worth it? Are there other things that I
should be thinking of?

Thanks, Geoff

The basic difference is that the 4Kw T/R Unit will have a better modulaor
and pulse forming network than the 2kw T/R. If it has a larger antenna,
then it will have a correspondingly smaller Horozontal Beamwidth, which
means it will discriminate between two closely spaced targets at a
greater range. It will also tend to show returns from smaller targets,
like logs and floating debris. The receivers will be very similar in
Noise Figure and Sensitivity, but the bigger Transmitter Pulse and
Antenna Gain (If a bigger antenna) will make it a much better radar.
Also bigger T/R's usually have the PPR (Pulse Repetition Rate) split
into more ranges so you have a much nicer Target Definition, than the
standard two on the small T/R's. If you can afford it, Bigger is Better.


Bruce in alaska
--
add a 2 before @

First, you might think about Furuno.

I purchased a Raymarine radar with the 4KW dome a couple of years ago. It
worked well for about 9 months, then just quit on a trip. Got it home, the
tech worked and worked on it, and said he'd have to send the whole thing to
the factory for warranty repair. I got it back TWO MONTHS later, still
didn't work. Turned out the cable between the unit and the dome had "gone
bad". No damage, just was bad.

Now I don't know if the backlog at Raymarine is due to understaffing or TONS
of units coming back for repair, but either is ominous, especially if you
really NEED your radar. Luckily at the time I was not traveling full time or
out of the country.

OTOH, I've heard nothing but good about Furuno equipment. If I had it to do
over, that's the way I'd go.

As to the 2 vs. 4 KW dome, I'd get the best you can afford and be done with
it. If you can't afford the 4, got with the 2. Any radar is better than
none! If you're just looking for very basic radar though, you probably need
to look at JRC. Good, solid basic systems at a great price.

--


Keith
__
"How soon a ship can age and die for want of the love of a human being."
--Peter Gerard--
"Geoffrey W. Schultz" wrote in message
7...
I have a Furuno 1621 MkII radar that I've never been happy with. At this
point I believe that the radome has basically failed and I'm planning on
replacing the entire system.

I think that I'm going to replace it with RayMarine C70 system which
provides a radar and chartplotter. This will be compatible with my
Autohelm autopilot and this will provide a redundant chartplotter.

I've been pondering the differences between a 2KW radome and a 4 KW
radome.
Based upon the litature the 2 KW unit provides 24 nm range vs 48 nm range.
This doesn't seem to really matter as the radar is only mounted about
10-12
feet above the water on a radar mast and the radar horizon to a 50' high
target is only 14+ miles. I've been told that the 4KW is very helpful in
dense fog (not applicable to the Caribbean where I spend most of my time,
but would be useful when I return to New England) or heavy rain and that
it
also provides better separation of targets.

My typical use of radar is at night where I have the range set to about 8
nm or to watch for squalls, where the extended range would be useful.

There's a huge difference in cost between the two. The 2KW unit runs
around $900 and the 4KW unit runs about $1600. Based upon my usage and
setup, is the additional cost worth it? Are there other things that I
should be thinking of?

Thanks, Geoff

I agree. Go with the 4KW unit if you plan on spending time actually using it
for navigation. 2KW is more or less a toy in my opinion. Like the previous
post said. Furuno is traditionally a better product but is usually more
expensive. Raymarine has come a long way, and their product has been pretty
solid for a few years now. JRC is very good also. They are much cheaper than
Furuno and Raymarine with about the same reliability as the Raymarine (All of
this is my opinion of course). Good luck and Safe sailing


Brian

Ft. Lauderdale
Remove NOJUNK from Email for responses via email.

OJUNK (NIFFOCBT) wrote in message ...
I agree. Go with the 4KW unit if you plan on spending time actually using it
for navigation. 2KW is more or less a toy in my opinion. Like the previous
post said. Furuno is traditionally a better product but is usually more
expensive. Raymarine has come a long way, and their product has been pretty
solid for a few years now. JRC is very good also. They are much cheaper than
Furuno and Raymarine with about the same reliability as the Raymarine (All of
this is my opinion of course). Good luck and Safe sailing


Brian

Ft. Lauderdale
Remove NOJUNK from Email for responses via email.

Thank you every body for the clear information.
Now can we have the same level of information on color vs monochrome?
Is color merely the same information on a prettier display?

In article ,
(Rolf) wrote:

OJUNK (NIFFOCBT) wrote in message
...
I agree. Go with the 4KW unit if you plan on spending time actually using
it
for navigation. 2KW is more or less a toy in my opinion. Like the previous
post said. Furuno is traditionally a better product but is usually more
expensive. Raymarine has come a long way, and their product has been
pretty
solid for a few years now. JRC is very good also. They are much cheaper
than
Furuno and Raymarine with about the same reliability as the Raymarine (All
of
this is my opinion of course). Good luck and Safe sailing


Brian

Ft. Lauderdale
Remove NOJUNK from Email for responses via email.

Thank you every body for the clear information.
Now can we have the same level of information on color vs monochrome?
Is color merely the same information on a prettier display?

Depends on what the color indicates. If it is like furuno, where target
strength is indicated by color then there is some usefull information
there, but for my money color is an expensive option. I would rather
put my money into a bigger antenna, and a bit more Tx Power. That buys
more sensitivity and better target resolution, which is why you have a
radar in the first place. In the old days, (before Loran and GPS) radars
had a dual purpose. We used them for naviagation, and position fixing.
(navigation=not running into things that move around position fixing=
not running into things that don't move) In todays world, radars are
used more for navigation, and much less for position fixing, as GPS does
a much better job of position fixing. Better to see moving stuff
farther away, than after it is under the bow.


Bruce in alaska who can remember before loran and GPS
--
add a 2 before @

(Rolf) wrote in
om:

OJUNK (NIFFOCBT) wrote in message
...
I agree. Go with the 4KW unit if you plan on spending time actually
using it for navigation. 2KW is more or less a toy in my opinion.
Like the previous post said. Furuno is traditionally a better
product but is usually more expensive. Raymarine has come a long
way, and their product has been pretty solid for a few years now.
JRC is very good also. They are much cheaper than Furuno and
Raymarine with about the same reliability as the Raymarine (All of
this is my opinion of course). Good luck and Safe sailing


Brian

Ft. Lauderdale
Remove NOJUNK from Email for responses via email.

Thank you every body for the clear information.
Now can we have the same level of information on color vs monochrome?
Is color merely the same information on a prettier display?

One thing that you need to consider is whether or not you're going to
get a unit with chart plotter capabilities. If you're going with a
straight radar, then B&W is fine.

From what I saw at the Newport boat show, the majority of manufactures
are combining chartplotter capability into their radar systems. Or is it
visa versa? The additional cost of doing this is fairly minor, and the
cost of daylight viewable displays seems to have dropped precipitously
over the past year.

I find that color does a much better job of quickly separating types of
data than does B&W. When stuff is hitting the fan I want to be able to
quickly glance at the display and know that the radar returns are in
magenta, land is yellow, etc, etc and not have to parse shades of grey.

-- Geoff