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-   -   Radar reflector location (http://www.trawlerforum.com/forums/s4/radar-reflector-location-21954.html)

Arcticspud 08-28-2015 12:17 PM

Radar reflector location
 
I did a search on the subject already. I have done a lot of reading on radar reflectors and realize the debate of their usefulness is like the anchor debate. I view it as a can't hurt item.

My question is...

Has anyone located a radar reflector in the forward area of the flybridge? I have quite a bit of space that isn't being used. I don't want to put any weight up there for the obvious reasons. It seems like it would be a good location.

The follow on question for anyone that has one up there, do you get any return or interference from your own radar?

Marin 08-28-2015 12:33 PM

If the radar transmission beam doesn't hit the reflector it shouldn't cause any problems no matter where it is. They are typically mounted high so they can be seen by radar units farther away from the boat.

Arcticspud 08-28-2015 01:05 PM

Quote:

Originally Posted by Marin (Post 363413)
If the radar transmission beam doesn't hit the reflector it shouldn't cause any problems no matter where it is. They are typically mounted high so they can be seen by radar units farther away from the boat.

Thanks for the answer.

I understand all that. I was hoping to hear from someone who has the installation in the flybridge.

Marin 08-28-2015 01:17 PM

Radar beams do a pretty good job of seing through fiberglass. That's why on many powerboats their best radar reflector is the engine(s) if at least part of it /them is above them waterline. From your avatar your radar antenna is a long ways above the flying bridge structure. Bif you don't get any interference from your power controls, instrumentation, flying bridge enclosure framng, etc you wont from a radar reflector mounted under the console somewhere. It's just another passive piece of metal.

As a single data point a friend has a lobsterboat with the radome mounted on the mast. He has a reflector on one of the mast stays. It used to be attached so it was just below the radome where it caused no interference to the radar display. Over time the clamps have loosened and the reflector has slid down the stay to be just off the cabin roof. He hasn't bothered to raise it back up, and in that lower position it still causes no interference to the radar returns.

Arcticspud 08-28-2015 01:22 PM

alright...that makes sense. My mast is full of gear and was looking at other locations to place a reflector. Has anyone place a Morbi type reflector directly on top of the radome?

FlyWright 08-28-2015 01:34 PM

Patrick,

I would think as high as possible but out of the radar beam would be best. How about suspended below the radar on your radar mast? No chance of catching the bottom of a radar beam there like you might forward on the FB.

Your vessel probably already has a pretty good radar signature. Have you asked a boating buddy to take a picture of his radar for you to see the radar return yourself? I was surprised at how well power vessels typically appear compared to sailboats. Maybe it's the engines or the large profile, but they are prominent on my radar.

psneeld 08-28-2015 01:54 PM

Up under the flybridge fairing is fine...make sure it is in the catch rain position for best reflection....that is more important than a few feet higher...


and remember most radar scanners are behind some thin fiberglass that they are encased in.

Capt.Bill11 08-28-2015 02:32 PM

This is about the only one worth buying:

EchoMaster by Davis

Just be sure to mount it as high as possible and in the correct "catch rain" position.

Of course just having your radar on increases your radar signature to other vessels. So you may be wasting your money on a reflector.

FlyWright 08-28-2015 02:35 PM

Paint it black and it'll double as an anchor ball.

markpierce 08-28-2015 02:42 PM

Quote:

Originally Posted by FlyWright (Post 363453)
Paint it black and it'll double as an anchor ball.

But what about when one is underway? You don't fly your anchor ball underway, do ya?

Trust this vessel displays its day shape in the vertical position when fishing:

http://www.trawlerforum.com/attachme...ffa5132fb8.jpg

psneeld 08-28-2015 02:45 PM

Hide it under a fairing like I suggested...for metal boats like yours...not needed to be out in the open anyway.

markpierce 08-28-2015 03:03 PM

Metal boat? Don't see the need for installing a radar reflector. My metal boat shows up good without one.

FlyWright 08-28-2015 03:30 PM

Quote:

Originally Posted by markpierce (Post 363457)
But what about when one is underway? You don't fly your anchor ball underway, do ya?

Simple! When underway, it's a radar reflector. When anchored, it's an anchor ball.

JDCAVE 08-28-2015 05:32 PM

Radar reflector location
 
Here is an interesting study...

http://www.ussailing.org/wp-content/...tor%20Test.pdf

In my opinion, the hull and superstructure shape, size and height as well as vessel orientation are more influential on the intensity of a radar return than a radar reflector. Sail boats with their sails down produce a poor return for the size of the vessel--much better when abeam of you and the sails up.

One of the better radar returns I've seen from a "trawler type vessel" for the size is the American Tug--there's a lot of flat superstructure returning a radar signal.

The best position for a radar reflector is high on the mast.


Jim
Sent from my iPad using Trawler Forum

JDCAVE 08-28-2015 05:42 PM

Quote:

Originally Posted by Capt.Bill11 (Post 363451)
This is about the only one worth buying:

EchoMaster by Davis

Just be sure to mount it as high as possible and in the correct "catch rain" position.

Of course just having your radar on increases your radar signature to other vessels. So you may be wasting your money on a reflector.


Not according to this study:

http://www.ussailing.org/wp-content/...tor%20Test.pdf

"The Davis Echomaster has a reasonable peak and average RCS but is too small to meet the performance requirements of ISO 8729[1]."


Jim
Sent from my iPad using Trawler Forum

stubones99 08-28-2015 09:59 PM

I don't recall albin making metal boats...

FF 08-29-2015 06:42 AM

Size counts , having flown SAR the best radar reflector seems to be the WWII Navy surplus units that unfold.

Sure you toss it after a season , but the coat is minor.

IF I ever put out a May Day , I would break out 3 or 4 and mount them and save one or two for the raft.

GFC 08-29-2015 01:19 PM

OK, I'm going to ask a question that should stir things up a bit. You all are suggesting mounting it in a location that's not in line with the radar beam. That makes sense because you don't want it to interfere with the transmitted beam.


But what about if you mount it in a position where it might distort the minute portion of the transmitted beam that is reflected back to the receiver portion of the antenna. Could that reflected beam be distorted enough by the position of the ball that it could throw off your radar display?


Just curious.

psneeld 08-29-2015 01:35 PM

It explains interference in the owners manual pretty well...but a good mounting location of the radar should avoid this issue otherwise radar would be useless on metal vessels.

So it would be pretty hard to mount it someplace to cause that interference unless you tried...turn on you radar and move the reflector around till satisfied.

Arcticspud 08-29-2015 05:10 PM

What about mounting a Morbi M3 or M4 on top of your radome?


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