Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 25-08-2017, 09:19   #16
Registered User

Join Date: Sep 2010
Location: Boat in Turkey, Beach cat in Israel
Boat: Lagoon 400 & Nacra 6.0 beach cat
Posts: 607
Re: Radar waves safe for humans?

Our radars send out pulses that have defined width and height and defined angle of radiating these pulses. When the unit is in a normal mounted height on the mast all of the radiation goes above your head.
When on cabin top you will be in the line of fire so to speak, loosing effectively info from the area your body obstruct. Range of radar will be much lower and clutter higher.
My advice - discard the idea.
__________________

__________________
Mark, S/Y Bat-Yam
meirriba is offline   Reply With Quote
Old 25-08-2017, 10:14   #17
Registered User

Join Date: Feb 2016
Location: Vilamoura - Portugal
Posts: 20
Re: Radar waves safe for humans?

From Raymarine Radar Installation Manual

Radio Frequency Radiation Hazard
The radar antenna emits electromagnetic energy at microwave
radio frequencies 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. It is
recommended that the radar scanner is mounted out of range
of personnel (above head height).
The maximum power density level which is considered safe for
general public exposure is 10 W/m2, and for occupational exposure
it is 100 W/m2. The distances from the radar scanner
within which these levels may be exceeded are given below:
Model Distance to 100 W/m2
point
Distance to 10 W/m2
point
RD418D
Max power density at any
distance is <100 W/m2 1.0m (worst case)
RD424D
Max power density at any
distance is <100 W/m2
1.0m (worst case)
__________________

__________________
dietervoegeli is offline   Reply With Quote
Old 25-08-2017, 10:29   #18
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 12,837
Re: Radar waves safe for humans?

" Are there health issues by being on the same level as the radar?"

Radar is microwave radiation. Exactly the same as your microwave oven.

So, if you think it is safe to sit IN your microwave oven...by all means then, sit within a foot or two of your radar dish.

Ah, really...someone should have explained all this to you before installing a radar. And I'm betting it is all covered in the OWNER'S MANUAL for that radar.

Even if your radar is mounted on the usual stern pole, crew standing up on the foredeck can still be within the beamspread of the radar. You really need to find and run the numbers. On the bright side, standing by the radar will also help dry out your clothes on rainy days. :-)
__________________
hellosailor is offline   Reply With Quote
Old 25-08-2017, 10:35   #19
Registered User
 
thomm225's Avatar

Join Date: Aug 2011
Location: Hampton Roads
Boat: 1974 Bristol 27
Posts: 3,343
Re: Radar waves safe for humans?

Quote:
Originally Posted by Tkeeth View Post
Wouldn't it be better to use real info than just ask a bunch of people you don't know?

WHO | Electromagnetic fields and public health: radars and human health

Marine radars can be found on small pleasure boats to large ocean going vessels. Peak powers of these systems can reach up to 30 kW, with average powers ranging from 1 to 25 W. Under normal operating conditions, with the antenna rotating, the average power density of the higher power systems within a metre of the antenna is usually less than 10 W/m2. In accessible areas on most watercraft, these levels would fall to a few percent of present public RF exposure standards.
Yeah, the marine radar on sailboats are very weak as compared to say air traffic control radar or surveillance radar.

The ones I'm most familiar with had a peak power of 1 megawatt and I have been in from of those many times with no ill effects so far

We were told as techs just make sure you don't get between the feedhorn and the antenna with the transmitter on

The new ATC Radars have less power these days because they are more efficient, but back in the day the transmitter would have maybe an 8500 volt power supply and that got boosted

We had these old UPS-1 radars that still had tubes and the thyratron tube was almost a foot tall by maybe 3 inches wide

Radar type UPS-1

(sketch from JSP 6 via Richard Vernon)

The UPS-1 is a lightweight assault radar which can be lifted and positioned by Wessex type helicopters. It has a limited early warning performance but no height finding capability. It is fitted with Moving Target Indication (MTI). It has a limited fighter control capability. (from JSP 6)

Frequency : 1250 - 1350 Mhz
Wave length : L-band
Aerial rotation : 15 r.p.m.
Air transportable : Yes
Aerial : Parabolic slatted reflector
Vertical beam width : 10o
Horizontal beam width : 3.5o
Peak power : 1000 kW
PRF : 267 (800 on MTI)
Pulse length : 4.2 uS (1.4 uS on MTI)
RX amplifier : Lin, bandwidth 145
Range accuracy : 2 nm on 275 nm range scale
Range resolution : 0.5 nm at 20 nm
Bearing accuracy : 1o
Bearing resolution : 4o at 50 nm
Height accuracy : N/A
Range on "Canberra" at 20,000 feet : 150 nm
Range on "Canberra" at 40,000 feet : 150 nm

Editors note: I am indebted to Richard Vernon for providing the sketches and the technical details of British operated versions of the UPS-1 tactical radar.

https://www.google.com/search?q=mari...IFj7Nrj-7qjNM:
__________________
thomm225 is online now   Reply With Quote
Old 25-08-2017, 11:28   #20
Registered User
 
alaskaflyfish's Avatar

Join Date: Jan 2016
Location: AK
Boat: Albin Vega 27
Posts: 111
Re: Radar waves safe for humans?

In the aviation world the smaller radar units utilized in general aviation aircraft had warning stickers plastered under the domes stating "do not stand in front of the radar while activated". The associated picture was of the typical stick figure man being pelted with radiation waves. Whatever that is worth. This was in the late 1990's.
__________________
Tim M
alaskaflyfish is offline   Reply With Quote
Old 25-08-2017, 12:00   #21
Registered User
 
transmitterdan's Avatar

Join Date: Oct 2011
Boat: Valiant 42
Posts: 3,903
Re: Radar waves safe for humans?

Quote:
Originally Posted by thomm225 View Post
The ones I'm most familiar with had a peak power of 1 megawatt and I have been in from of those many times with no ill effects so far

We were told as techs just make sure you don't get between the feedhorn and the antenna with the transmitter on

This is very bad advice. I am aware of people dying whilst sitting in front of high power microwave antennas. They were not between the feed horn and the reflector.

For many reasons the answer to the OP's question is "find a better place to put the radar consistent with the installation manual's specifications".
__________________
transmitterdan is offline   Reply With Quote
Old 25-08-2017, 12:06   #22
Registered User
 
thomm225's Avatar

Join Date: Aug 2011
Location: Hampton Roads
Boat: 1974 Bristol 27
Posts: 3,343
Re: Radar waves safe for humans?

Quote:
Originally Posted by transmitterdan View Post
This is very bad advice. I am aware of people dying whilst sitting in front of high power microwave antennas. They were not between the feed horn and the reflector.

For many reasons the answer to the OP's question is "find a better place to put the radar consistent with the installation manual's specifications".
The only way you might be able to die sitting in front of a radar like that was if you had a pacemaker or something (and I doubt it even then), but since this was a military radar installation and the old guys were around 30 years old, no one died

It's just the way it was done back in the day.

The radar we used for air traffic control was also the one used by other detachments for surveillance since it's range was 275nm

Our radar was mounted on a van which only stood about 9'-10' off the ground and was transmitting it's peak power pulse at 1 megawatt

The control tower was about 40' tall and maybe 50' in front of the radar.

https://www.google.com/search?q=mari...SaU7-w17gky9M:

We also had PAR radars mounted on tripods that had to be leveled daily (for the proper glide slope) out by the runway for final approach

https://www.google.com/search?biw=12...OriaeDYBeN6uM:

By the late 70's we had the ASR's . First was the ASR-8 then it went from there. It's the type you usually see at major airports today
https://www.google.com/search?q=asr-...eLz-3-vss4SeM:
__________________
thomm225 is online now   Reply With Quote
Old 25-08-2017, 12:10   #23
Registered User

Join Date: Apr 2011
Location: Cambridge MD
Boat: Carter offshore 35
Posts: 328
Re: Radar waves safe for humans?

Before they were called micro-wave ovens they were called radar ranges. If you want kids don't soft boil the eggs.
__________________
DeborahLee is offline   Reply With Quote
Old 25-08-2017, 12:12   #24
Senior Cruiser
 
witzgall's Avatar

Cruisers Forum Supporter

Join Date: Oct 2006
Location: Wintering in Annapolis
Boat: Camper Nicholson 44 Ketch
Posts: 1,769
Re: Radar waves safe for humans?

There is some very bad advice given here. Any radar with a magnatron (and yes, there are even "New" radars with them) poses a heath risk if you get in the path of the radiation.

There are some new radars that are solid state, that do not pose a radiation risk. So the answer is that you need to research the specific make and model you are considering.


Chris
__________________
witzgall is offline   Reply With Quote
Old 25-08-2017, 12:27   #25
Registered User
 
Cadence's Avatar

Join Date: Dec 2008
Location: SC
Boat: None,build the one shown of glass, had many from 6' to 48'.
Posts: 5,891
Re: Radar waves safe for humans?

Quote:
Originally Posted by DeborahLee View Post
Before they were called micro-wave ovens they were called radar ranges. If you want kids don't soft boil the eggs.
Nor the nuts.
__________________
Cadence is offline   Reply With Quote
Old 25-08-2017, 13:35   #26
Registered User

Join Date: Sep 2013
Location: Alert Bay, Vancouver Island
Boat: 35ft classic ketch/yawl.
Posts: 917
Images: 4
Send a message via Skype™ to roland stockham
Re: Radar waves safe for humans?

Quote:
Originally Posted by Cadence View Post
They say the new radars are safe. If yours is old you night as well crawl in your microwave oven.
It depends totally on output 4kw is still 4kw would stick to the principal of aligning the beam clear of crew stations with any radar
__________________
roland stockham is offline   Reply With Quote
Old 25-08-2017, 14:00   #27
Registered User
 
Cadence's Avatar

Join Date: Dec 2008
Location: SC
Boat: None,build the one shown of glass, had many from 6' to 48'.
Posts: 5,891
Re: Radar waves safe for humans?

Quote:
Originally Posted by roland stockham View Post
It depends totally on output 4kw is still 4kw would stick to the principal of aligning the beam clear of crew stations with any radar
I wouldn't want to be in front of any of them, even that the new ones are not suppose to be a problem. 2kw, 4kw or 20, If you want to have children?
__________________
Cadence is offline   Reply With Quote
Old 25-08-2017, 14:16   #28
Registered User

Join Date: Mar 2015
Location: New Zealand
Boat: Moana 33
Posts: 580
Re: Radar waves safe for humans?

Quote:
Originally Posted by mrybas View Post
Hi,
My radar used to be mounted on a tall pole well above deck, but I would like to mount it on top of the cabin. I sometimes sit on the cabin top while underway to keep watch. Are there health issues by being on the same level as the radar?
Years ago, crewman on fishing vessel was painting the roof of the wheelhouse while radar scanner was left on. Eventually he fell over as if drunk and was rushed to hospital. No idea of long-term effects but those microwaves are definitely unsafe - avoid at all costs.
__________________
NevisDog is offline   Reply With Quote
Old 25-08-2017, 14:40   #29
Registered User
 
thomm225's Avatar

Join Date: Aug 2011
Location: Hampton Roads
Boat: 1974 Bristol 27
Posts: 3,343
Re: Radar waves safe for humans?

Quote:
Originally Posted by witzgall View Post
There is some very bad advice given here. Any radar with a magnatron (and yes, there are even "New" radars with them) poses a heath risk if you get in the path of the radiation.
Two of the radars I mentioned above have magnetrons. The new ASR series had a klystron in the transmitter.

Another radar we maintained was the FPN Series PAR Radar and sometimes we'd be standing directly in front of the transmitting reflector and some jackass would turn on the transmitter and yell....."you are now sterile!"

We were late teens early 20's in those days

I'm simply giving you "real world" experience.

Another ATC PAR would be this one.

Here's an early version and if I remember correctly this one had a magnetron but used SCR's instead of a thyratron to discharge the PFN for the final pulse output

https://www.google.com/search?q=fpn+...=1503697114256


Here is a video of part of a Klystron they use in the transmitter of the ASR Series Radars. These are the radars with the red reflectors you see at airports today

The klystron is red and the metal part below is the oil tank for cooling. It's one of the new low voltage systems since it only uses 3,000 volts




Here's the reflector you see at the various airports for the radar in the video above. It's a bit stronger than your sailboat radar system:

__________________
thomm225 is online now   Reply With Quote
Old 25-08-2017, 15:03   #30
Registered User

Join Date: Dec 2015
Posts: 267
Re: Radar waves safe for humans?

I have a 3G with a range of 23 NM and the picture on the box is of a 7 year old youngster hugging the dome demonstrating how safe it is and that it uses less power than a cell phone that is pressed against you temple for long periods of time. They insist its safe to mount it anywhere you too.
__________________

__________________
Rorzech is offline   Reply With Quote
Reply

Tags
radar

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Two dogs, two humans, cruising to Mexico! SV Maclas Meets & Greets 2 08-11-2012 14:11
Humans, +3 / Mother Nature, Zero ozskipper Off Topic Forum 10 03-02-2011 11:36
Rogue Waves and Seiche Waves Seaworthy Great Lakes 18 27-11-2007 11:22
Deadly viruses mutating to infect humans at rate never seen before CaptainK Health, Safety & Related Gear 10 23-02-2006 19:04
Rogue Waves GordMay General Sailing Forum 8 27-09-2004 11:56



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 04:25.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.