Opinions on Radars
 

I had a JRC 1000 on my first boat and now I am restoring a 43 Endeavour
ketch and it is time to think about radars. The JRC was a nice unit but
woefully underpowered. I would like to see out 8 to 10 miles with the
radome mounted 20-30' up the mizzen. I know that the 4kw will give more
power out and thus burn thru in foggy conditions but most of the 4kw units
have the big displays. Everyone on this group knows the drill...what will
give me the biggest bang for the buck with the best reliability amd a thin
small display.
Thanks
Bruce

--
Shield Finishes and Nauticoat Marine Finish Systems
www.shieldfinishes.com

Bruce on horizon wrote:
I had a JRC 1000 on my first boat and now I am restoring a 43 Endeavour
ketch and it is time to think about radars. The JRC was a nice unit but
woefully underpowered. I would like to see out 8 to 10 miles with the
radome mounted 20-30' up the mizzen. I know that the 4kw will give more
power out and thus burn thru in foggy conditions but most of the 4kw units
have the big displays. Everyone on this group knows the drill...what will
give me the biggest bang for the buck with the best reliability amd a thin
small display.

The RayMarine equipment lets you mix and match the displays and the
domes so you get what you need now, and upgrade later. BTW, the radar
horizon is about 7 miles from a transmitter 30 feet up. Large targets
will of course be seen at a larger distance, but I can't say that I've
had any problem with my low power Raytheon, and I cruise in Maine and
Cape Cod.

I would like to see out 8 to 10 miles with the
radome mounted 20-30' up the mizzen.

Hi Bruce,

As Jeff says, your radar will not be able to pick up small targets past
your visible horizon (about 6.3 nm according to Bowditch). You will be
able to pick up big, tall contacts further out, but that's about it.

I'd stick to a 1.5 to 2 kw radar if I were you. Higher power doesn't
"burn" through anything, including fog, and I think 4 kw is over kill
for what you'll be doing. In fact at the short ranges you'll be
operating at, the higher power will probably be a disadvantage. The
RayMarine stuff looks pretty nice and has alot of nice features (like
color and MARPA (their adaptation of ARPA)). But I'd go with a small
Furuno if you can afford it or another JRC if you're on the cheap. Just
my biased opinion though. Walk around the docks and see what the
smaller commercial fisherman in your area use. They tend to only get
stuff that works, why not do the same?

Just remember, if you get too fancy a radar, chances are your attention
will be fixated on that fancy screen and not your main navigation tool:
your "Mark I Mod II Eyeballs" ;-)

Hope this helps,

Paul

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On Sun, 13 Feb 2005 17:20:53 -0500, "Bruce on horizon"
wrote:

I would like to see out 8 to 10 miles with the
radome mounted 20-30' up the mizzen. I

Sidebar question: Am I woefully ignorant on radar implementation or am
I correct in assuming that a target heading directly for one's bow
would be invisible to a mizzen mounted radar due to the three-to-four
degree "screen" of the main mast directly ahead?

Or am I missing something? Why the mizzen (aside from its convenience
and the fact few people use a mizzen stays'l, so nothing to hook the
radome or mount).

R.

rhys wrote:
On Sun, 13 Feb 2005 17:20:53 -0500, "Bruce on horizon"
wrote:

I would like to see out 8 to 10 miles with the

radome mounted 20-30' up the mizzen. I


Sidebar question: Am I woefully ignorant on radar implementation or am
I correct in assuming that a target heading directly for one's bow
would be invisible to a mizzen mounted radar due to the three-to-four
degree "screen" of the main mast directly ahead?

Or am I missing something? Why the mizzen (aside from its convenience
and the fact few people use a mizzen stays'l, so nothing to hook the
radome or mount).

R.

Quite possibly, IF you where an expert helmsman at all times.

otn

BTW I hate small displays. I'd get the biggest one possible.
Also, don't get hung up on the "height of eye" distance capabilities of
your radar ..... your "HE" may only say 6ish miles, but you'll be able
to see a whole bunch of stuff beyond that.

otn

rhys wrote:
Sidebar question: Am I woefully ignorant on radar implementation or am
I correct in assuming that a target heading directly for one's bow
would be invisible to a mizzen mounted radar due to the three-to-four
degree "screen" of the main mast directly ahead?

A common misconception. If you think about it, you will realize that
the radio energy of flowing off of and being received along the entire
width of the antenna which is much wider than your mast. A healthy
percentage of it is reflected back and to the sides, but most of the
energy just flows right on past the mast. It works the same in reverse
for the reflected energy coming back from a target. Thus, the strength
of the reteurn is reduced, but you are still able to see it. Othereise,
all those boats with mast mounted radars would have a fairly wide cone
to their rear where they pick up nothing.

In answer to Bruce's original question, overall, I like the Raymarine
units. The one I put on my last boat worked so well for me, I put one
on this boat too and like it just as well. I find the JVC screens
harder to see and focus on than the others, but this may just be a
personal thing. Whatever you do, mount the display so that it can be
seen at the helm, not just at the nav station. A friend of mine's radar
is just visible at the nav station and having played radar operator
calling instructions up to him at the helm while dodging freighters in
dense fog on SF Bay, I'm here to say that this arrangement sucks.

Fair winds - Dan

I am not a schill for Practical Sailor (subscription newsletter), nor
do I play one on TV, but I do find their articles generally useful,
educational and informative. They did a piece on 'Entry Level LCD
Radar' in September '04, the preamble to which you can see he

http://www.practical-sailor.com/pub/...es/5003-1.html

MW

I ditto your comment about the radar in the cockpit. That is the reason I
want a smaller LCD at the helm. I will be right on top of the display, not
trying to look at it from 10' away.
Bruce

--
Shield Finishes and Nauticoat Marine Finish Systems
www.shieldfinishes.com
"Dan Best" wrote in message
...
rhys wrote:
Sidebar question: Am I woefully ignorant on radar implementation or am
I correct in assuming that a target heading directly for one's bow
would be invisible to a mizzen mounted radar due to the three-to-four
degree "screen" of the main mast directly ahead?

A common misconception. If you think about it, you will realize that the
radio energy of flowing off of and being received along the entire width
of the antenna which is much wider than your mast. A healthy percentage
of it is reflected back and to the sides, but most of the energy just
flows right on past the mast. It works the same in reverse for the
reflected energy coming back from a target. Thus, the strength of the
reteurn is reduced, but you are still able to see it. Othereise, all
those boats with mast mounted radars would have a fairly wide cone to
their rear where they pick up nothing.

In answer to Bruce's original question, overall, I like the Raymarine
units. The one I put on my last boat worked so well for me, I put one on
this boat too and like it just as well. I find the JVC screens harder to
see and focus on than the others, but this may just be a personal thing.
Whatever you do, mount the display so that it can be seen at the helm, not
just at the nav station. A friend of mine's radar is just visible at the
nav station and having played radar operator calling instructions up to
him at the helm while dodging freighters in dense fog on SF Bay, I'm here
to say that this arrangement sucks.

Fair winds - Dan

Jeff Morris wrote:
Bruce on horizon wrote:

I had a JRC 1000 on my first boat and now I am restoring a 43
Endeavour ketch and it is time to think about radars. The JRC was a
nice unit but woefully underpowered. I would like to see out 8 to 10
miles with the radome mounted 20-30' up the mizzen. I know that the
4kw will give more power out and thus burn thru in foggy conditions
but most of the 4kw units have the big displays. Everyone on this
group knows the drill...what will give me the biggest bang for the
buck with the best reliability amd a thin small display.


The RayMarine equipment lets you mix and match the displays and the
domes so you get what you need now, and upgrade later. BTW, the radar
horizon is about 7 miles from a transmitter 30 feet up. Large targets
will of course be seen at a larger distance, but I can't say that I've
had any problem with my low power Raytheon, and I cruise in Maine and
Cape Cod.

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.

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.

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).

Stay away from Raymarine! Since they separated from Raytheon, they're
turning into cheap junk. Stick with Furuno.

--


Keith
__
"Usually, terrible things that are done with the excuse that progress
requires them are not really progress at all, but just terrible things." -
Russell Baker
"Bruce on horizon" wrote in message
...
I had a JRC 1000 on my first boat and now I am restoring a 43 Endeavour
ketch and it is time to think about radars. The JRC was a nice unit but
woefully underpowered. I would like to see out 8 to 10 miles with the
radome mounted 20-30' up the mizzen. I know that the 4kw will give more
power out and thus burn thru in foggy conditions but most of the 4kw units
have the big displays. Everyone on this group knows the drill...what will
give me the biggest bang for the buck with the best reliability amd a thin
small display.
Thanks
Bruce

--
Shield Finishes and Nauticoat Marine Finish Systems
www.shieldfinishes.com