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Wannabe Sailing Bum
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142 Posts
I opted for a mast mount (RayM 4kw installed in '08). Personally, I don't like the stern mounts for several reasons (most personal). Having it up on the mast is a set it and forget proposition. Radar technology is not that great as it is, especially so on sailboats. I wanted height to help maximise target acquisition, and I don't regret the decision at all. I certainly, and most importantly, wanted to avoid contact with the radar beam. Case in point, our baby monitor goes schizo when the (home) microwave is on, and it's 10 feet away, and not 4kw. Yikes! The suggestion of simply putting it in standby mode is not an option. Turning them on/off is bad for the microwave device, and will shorten its lifespan. And, crew is not likely to do that anyway.

As for climbing the mast. Well, can't comment as I had my mast taken down for the installation. I would say that I think mounting it from a bosuns chair would be very difficult.

Lastly, the genoa does not get stuck unless poor technique is applied. Most people when tacking will blow the jib as they start the tack, which is terrible technique (and bad for the sail). If you wait until almost in irons to blow the jib sheet, 1) the jib will still be driving the boat forward and 2) less sheeting in on the other board, which means the jib will flog a lot less (if at all).
 

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Senior Mumble
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320 Posts
I hope this isn't considered a hijack, but what is the potential for "damage" from the radome's radiation? Is this real, or akin to the concerns about cellphones causing brain cancer? If real, then it should factor into placement (and since I went backstay mount, means I wasted $s, but it won't be the first time). If not, it's just a distraction.
 

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I hope this isn't considered a hijack, but what is the potential for "damage" from the radome's radiation? Is this real, or akin to the concerns about cellphones causing brain cancer? If real, then it should factor into placement (and since I went backstay mount, means I wasted $s, but it won't be the first time). If not, it's just a distraction.
I do not think it is a hijack as it directly relates to the placement of the dome.

I honestly do not believe anyone knows whether it is harmful or not. I think there are a lot of guesses, but that is it. I tell you that it does bother me - real or imaginary. I have always heard that it is good practice to turn your radar off before entering a marina and to never look at a dome/array while it is running. Now, is there scientific proof that it will hurt you?? I doubt anyone has done a study of it. The cost of doing such a study would be extraordinary and you can be certain that a manufacturer of Radars sure won't support it. So, you are stuck with making your decision based on folklore and old wives tales, I guess.

Just my opinions... unless someone definitively knows better.

Brian
 

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Courtney the Dancer
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3,970 Posts
I have always had mast mounted radar on the sailboats I've owned and have never had a problem with the genoa getting hung up on them. I have a power boat that has a 4KW radome at about 10' above waterline and I really can't see a lot of difference between the sailboat 4KW which is app. 25' and the lower one. Coming into our marina is a very narrow channel and I get about the same detail on both boats on 1/4NM range (maybe a little better in the power boat, but it's also a brand new radar), and when on the higher ranges (I rarely use much above 8NM here) they both seem to pick up targets equally well. I'm sure that the mast mounted would be more effective in picking up a target at the maximum ranges. The mast mounted gets it out of the cockpit and gives you more room for a wind gen, solar, etc. As far as servicing and installation goes, I built my own ss mast mount and installed it from the chair, not a big deal on the last boat but keel stepped you would probably have to pull the stick to run the cable. Based on my experience I don't have a strong opinion either way based on performance, but if I was planning on putting a wind gen and solar panels and antennas on the stern I'd probably opt for the mast just to declutter. It seems to me that MaineSail had a thread about this and he strongly favored mast mount, and he probably uses radar as much, or more, than I do.
 

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Wannabe Sailing Bum
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142 Posts
I honestly do not believe anyone knows whether it is harmful or not. I think there are a lot of guesses, but that is it.
When I see something like this in the front of the Raymarine users guide, I would err on the safe side and heed their advice. I imagine the engineers have seen some pretty freaky stuff while testing these products. Ultimately, radomes emit a signal at a 25 degree angle, so 12.5 degrees below horizontal centerline. If you have that from stern to bow plus factoring the height of a tall person, than all is well.

From Raymarine User Guide, Page 5:
Radio Frequency Radiation Hazard
The radar antenna emits electromagnetic radio frequency
(RF) energy which can be harmful particularly to your eyes.
DO NOT look at the antenna at close range.
It is important that the radar is turned off whenever
personnel are required to come close to the scanner
assembly or associated equipment. It is recommended that
the radar scanner is mounted out of range of personnel
(above head height).
Distances from the face of the radar at which RF radiation
 

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Senior Mumble
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320 Posts
When I see something like this in the front of the Raymarine users guide, I would err on the safe side and heed their advice.
I had not noticed that in the manual. I agree with you re erring on the side of caution. Although I can't help but wonder if it doesn't fall into the category of the warning on the side of the McDonald's coffee cups that the coffee is hot. (Maybe that's not a good example, it IS hot.) Anyway, radar is not a new technology. Is the danger real? Or is it a theoretical danger? With all the boats in a busy marina with their arrays spinning and all of us looking at them admiringly... Are we risking our vision?

I went with the stern mount but will plan on moving it to the mast. I don't want to be responsible for frying my family.
 

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old guy :)
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1,061 Posts
When I see something like this in the front of the Raymarine users guide,
Please - I am not in favour of turning on your radar and sitting on the raydome or anything of the sort.

But, the warning in the manual has about as much weight with me as the warning on the take-out cup of coffee that says

"Danger - may contain hot liquids!"

Duh!

Too many lawyers, not enough somethings. :)

I helped my buddy bring his first power boat from where he bought it to where he lives. The first time I stood at the helm to bring it into the dock for him, and the radar was on, it made my hearing aide beep. I looked around and there was the radome on the arch - about eye level and about ten inches from my head.

I quickly sat down and let my buddy take it into the harbor. I figured it was about time he learned to dock his own darn boat!

Rik
 

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Wannabe Sailing Bum
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142 Posts
With all the boats in a busy marina with their arrays spinning and all of us looking at them admiringly... Are we risking our vision?
No boat owner should have his/her radar on in a marina. It's bad for the seagulls, and equally bad for the equipment to run with all that clutter around. Atleast that's what my technician said.

I just thought it was odd that the manual specifically stated damage to the eyes. That means they noted something specific during testing and qualification. Probably using rats or pigs as subjects.
 

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Old Fart
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514 Posts
I have a stern mount pole you can have for next to nothing but the shipping may be prohibitive and you most assuredly will have to modify the lower end to fit your boat. If you want it I can send photos.

I use a self leveling system that attaches to a small pole run up next to my rear stay. It works well for me.
 

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5,491 Posts
I do not think it is a hijack as it directly relates to the placement of the dome.

I honestly do not believe anyone knows whether it is harmful or not. I think there are a lot of guesses, but that is it. I tell you that it does bother me - real or imaginary. I have always heard that it is good practice to turn your radar off before entering a marina and to never look at a dome/array while it is running. Now, is there scientific proof that it will hurt you?? I doubt anyone has done a study of it. The cost of doing such a study would be extraordinary and you can be certain that a manufacturer of Radars sure won't support it. So, you are stuck with making your decision based on folklore and old wives tales, I guess.

Just my opinions... unless someone definitively knows better.

Brian
I do not definitely know better, but I recall a scene from the Jerzy Kosinski novel "Cockpit", where the sadistic main character convinces a woman he is photographing to stand in front of a fighter jet's running radar in order to give her a cancer-inducing dose of radiation...

I later found out that was implausible, but have always resisted the idea of voluntarily putting my body in front of a running radome!;)
 

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A 4 kw radar puts out about the same or less average power as your 25w vhf on low power. They pose no hazard at all in normal circumstances. Don't tempt fate however, and avoid long exposure if beam is at eye or gonad level. A 60 kw radar is another matter altogether. The multi megawatt military radars can do serious damage.
Howard Keiper
Berkeley
 

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old guy :)
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1,061 Posts
Sounds like a case for "Myth Busters" .
Too funny! I thought the exact same thing!

Watching them I now know:
  • not to try and clean a cement truck with dynamite
  • cell phones do not affect navigation systems on planes
  • you can't shoot a lock off a door with a pistol
  • and cell phones can not cause gasoline to blow up.
Your post made me smile! :)

Rik
 

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134 Posts
Radar hazards

When I was in the Navy this came under the heading of HERP (Hazards of Electromagnetic Radiation to Personnel) and along with HERO (Ordanance) and HERF (Fuel) made for some very complicated and boring reading. If you want to know what damage radar can do find and watch the video of the disaster on USS Forrestal. Radar can damage people mostly in the areas of the eyes and the testicles. Its' danger changes however based on dwell time, output power, beam width, distance from the antenna, frequency and a whole host of other factors. While it's not a good idea to sit on the radome to keep warm on a chilly day in most cases the radar for our boats does not pose a health risk due primarily to their low power. As long as you are not going to be at eye level with it at a distance of six feet or so during normal operation you should be fine. BTW the warning from Raytheon is accurate though on the conservative side of things.
 
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