Radar
- Thread starter giolic
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True and False are not the only answers to the question...
The correct answer is that microwave energy, if powerful enough, for long enough hits you, then you could be hurt. Recreational marine radars, even the more powerful ones, ( ie 4kw or even 8kw ) use an extremely short pulse. The total energy transfer is way below that which might hurt you.
Now, there ARE ( rare. really, really rare ) situations that are more likely to give you an very slight "overdose" though it would require a failure of some sort to produce those conditions. Therefore, it is wise to avoid those situations.
If you follow the safety guidelines in the manual, you will be avoiding those situations, and the answer would be "True".
The correct answer is that microwave energy, if powerful enough, for long enough hits you, then you could be hurt. Recreational marine radars, even the more powerful ones, ( ie 4kw or even 8kw ) use an extremely short pulse. The total energy transfer is way below that which might hurt you.
Now, there ARE ( rare. really, really rare ) situations that are more likely to give you an very slight "overdose" though it would require a failure of some sort to produce those conditions. Therefore, it is wise to avoid those situations.
If you follow the safety guidelines in the manual, you will be avoiding those situations, and the answer would be "True".
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The Furuno manual had a note on this. I think the "safe distance" for a four kW antenna was one meter, maybe two.
It will depend on the range being used. The bigger power units throttle down when you go to shorter ranges.
In the early sixties, my wife process paperwork for guys working on the DEW line. On a couple occasions the process involved DOAs from Alaska who were warming up in front of the antenna. They got cooked. So there is some potential for injury however it is small.
It will depend on the range being used. The bigger power units throttle down when you go to shorter ranges.
In the early sixties, my wife process paperwork for guys working on the DEW line. On a couple occasions the process involved DOAs from Alaska who were warming up in front of the antenna. They got cooked. So there is some potential for injury however it is small.
Francodoesboat2
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RF radiation is not something you want to mess with. I agree that the potential for immediate injury are very very very low, but long term effects are something else. Look at it this way, if folks have health concerns with the radiation from your cell phone, do you really want to be the Lab Rat for a RADAR test?
KKKKFL
KKKKFL
It's not a good idea to be that close and line of sight to your radar antenna. Get it above your head and high it will work better above you and you will be under the main lobe of the antenna. The power density on the minor lobes (antenna pattern) power are greatly reduced from being in the main lobe of the radar.
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blouderback
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Sounds like a cheap method of birth control.
Grady Wahoo
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Might wanna test it out on the cat first......
I see a couple of flybridge charter fishermen where I live with radar units mounted in front of the helms at just about the level of their units if you get my drift. I've wondered if the energy makes it through the fiberglass to where they sit. Anyone know the answer to that one? I've also seen radars mounted on the pulpits. Seems like an eye issue in the making.
I've seen the same setup. And as a radiologist, I would find it a little unsettling. Even though the fiberglass would, no doubt, protect your jewels and even though radar has very low energy (compared to xray), I would prefer to avoid it.
BTW, some of my now retired partners used to treat acne with xray. They stopped doing that decades ago when there was a bump in thyroid cancer.
As far as industry saying it's ok? Do any of you remember standing on a xray machine when you were a kid to get your shoes sized? That was an unregulated xray beam directly smacking your corneas. Makes you wonder how many shoe salesman were inexplicably impotent in those days.
BTW, some of my now retired partners used to treat acne with xray. They stopped doing that decades ago when there was a bump in thyroid cancer.
As far as industry saying it's ok? Do any of you remember standing on a xray machine when you were a kid to get your shoes sized? That was an unregulated xray beam directly smacking your corneas. Makes you wonder how many shoe salesman were inexplicably impotent in those days.
As another MD, I agree 100% with Papillon. Although with low dose there is probably no effect, I certainly never allowed my children or grand children to be directly in the radar beam. There are no valid studies with low does chronic micro wave radiation of the nature which comes from recreational boat radar.
As for mounting the radar on the front of the flying bridge--I would not do it. People do all sorts of strange things--and I consder this one of them.
Fiberglass will give you virtually no portection--what is the dome on the radar made of?--Fiberglass!
As for mounting the radar on the front of the flying bridge--I would not do it. People do all sorts of strange things--and I consder this one of them.
Fiberglass will give you virtually no portection--what is the dome on the radar made of?--Fiberglass!
Those vessels with the radar in front of the helm at "person" level are not a problem IF THEY ARE CONFIGURED PROPERLY. Most, if not all, radars have a feature in set-up to turn off the transmitter in portions of the arc. You can tell if it is set up properly if that arc of the display is blank.
Beyond that, it's not a good idea to absorb RF energy if it can be avoided. Those 25Watts from the VHF are nothing to mess with. That energy gets dissipated in your body and can ionize cells and DNA. The result could be cancer. That's one reason I moved the original install location of my VHF antenna from adjacent to the helm to the radar arch on our flybridge (and it looks better, too).
Beyond that, it's not a good idea to absorb RF energy if it can be avoided. Those 25Watts from the VHF are nothing to mess with. That energy gets dissipated in your body and can ionize cells and DNA. The result could be cancer. That's one reason I moved the original install location of my VHF antenna from adjacent to the helm to the radar arch on our flybridge (and it looks better, too).
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The fiberglas is virtually radar transparent. No protection at all.
As I covered above, you should follow the safety standards, which include not placing persons in the beam path of the radar. In most commonly seen radars this is a horizontal line from the dome outward, about +/- 15 deg ( ie: a 30 deg vertical beamwidth ). Those vessels with the radar mounted in front of the upper steering station do not follow this ( imho, excellent ) advice. Further, it is at the very least polite to turn off the radar when docked, so that you do not cook your neighbors. On my boat, this includes dropping the radar scanner to "standby" when someone is on the bow, tending the anchor ( they are in the beam path, at about 2 or 3 meters ).
Properly used, there should be very little risk. But, as with most things, improper use may significantly increase the risk.
( Note: at best my response should be considered an amateur opinion. )
--edit--
Just noticed dauntless post...
I have not done the radiation safety worksheet on the VHF radio, but I would expect that the risk from that to be greater than that of the radar. You definitely want the vertical radiating element ( antenna ) to be above the heads of any/all aboard. Placing the "broadside" of the antenna at the same level as persons is rough on people ( and for that matter, all of your other electronics! Compass, too! )
As I covered above, you should follow the safety standards, which include not placing persons in the beam path of the radar. In most commonly seen radars this is a horizontal line from the dome outward, about +/- 15 deg ( ie: a 30 deg vertical beamwidth ). Those vessels with the radar mounted in front of the upper steering station do not follow this ( imho, excellent ) advice. Further, it is at the very least polite to turn off the radar when docked, so that you do not cook your neighbors. On my boat, this includes dropping the radar scanner to "standby" when someone is on the bow, tending the anchor ( they are in the beam path, at about 2 or 3 meters ).
Properly used, there should be very little risk. But, as with most things, improper use may significantly increase the risk.
( Note: at best my response should be considered an amateur opinion. )
--edit--
Just noticed dauntless post...
I have not done the radiation safety worksheet on the VHF radio, but I would expect that the risk from that to be greater than that of the radar. You definitely want the vertical radiating element ( antenna ) to be above the heads of any/all aboard. Placing the "broadside" of the antenna at the same level as persons is rough on people ( and for that matter, all of your other electronics! Compass, too! )
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blouderback
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If that's the case, then wouldn't fiberglass boats be "invisible" to radar?
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Yes. It is.
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I was overly brief. Radar does not see the fiberglas in your boat, it sees the metal. ( as abalmuth indicates )
Think about those radar reflectors. True, they are tuned to reflect as much energy as possible, but they are typically only about 1.5 ft in diameter, yet they often double the radar image of your boat. For that matter, think about your Nice VHF antenna. It is a thin copper wire in a fiberglas tube. The glass provides physical support, but does not impede the radio signal radiating from the copper wire.
Think about those radar reflectors. True, they are tuned to reflect as much energy as possible, but they are typically only about 1.5 ft in diameter, yet they often double the radar image of your boat. For that matter, think about your Nice VHF antenna. It is a thin copper wire in a fiberglas tube. The glass provides physical support, but does not impede the radio signal radiating from the copper wire.
very interesting read.
my understanding is the way microwaves were discovered was from radars cooking people from the inside out. for this reason i make a strong habit of turning my radar off when entering my marina.then i saw an episode of the TV show Mythbusters.they actully took a chicken and placed it in front of the radar in the sun for hours only to find the chicken never even warmed up.after reading this post i am starting to wonder if there test failed to max out the power of the radar.
regardless i will not stand at the same height as a radar...ever.
my understanding is the way microwaves were discovered was from radars cooking people from the inside out. for this reason i make a strong habit of turning my radar off when entering my marina.then i saw an episode of the TV show Mythbusters.they actully took a chicken and placed it in front of the radar in the sun for hours only to find the chicken never even warmed up.after reading this post i am starting to wonder if there test failed to max out the power of the radar.
regardless i will not stand at the same height as a radar...ever.