Radar Head Elevation On Mast

MikeHoncho

MikeHoncho

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Dec 28, 2015
1,890
Laser, Hunter H30 Cherubini Tacoma
Rick D said:
I have had two mounted on poles FWIW. I can see a freighter out 16 miles easily and Catalina at 24 miles. I am SO glad it was stern pole mounted since I had to service the radome three times before I mounted a new B&G radar, which was also a whole lot easier. There are pros and cons of all; your money, your boat, your choice. Good luck!
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The poles I was looking at were in the $700-$800 range. I could cut the costs by 2/3rds by fab'ing one myself but my stern is cluttered enough. I'm going with a Furuno DRS4W which is a WIFI model using my IPAD. radar and mount shipped from IMarine for a little over $1k
 
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MikeHoncho

MikeHoncho

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Dec 28, 2015
1,890
Laser, Hunter H30 Cherubini Tacoma
sailme88 said:
It is very costly when you go with Seaview or Edson. BUT, a 96x3" section of stainless tube can be had for about $160.00.
What this says is find a good machine shop and have them make up a mounting plate with hinge that will support that 3" tube. Couple of struts and you'd probably be out of it for $5-600.00.
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I'd done this in a heart beat if I was set up (welding wise) to fab aluminum or stainless. I think your a little light in the fab side for added materials and shop hours.
 
sailme88

sailme88

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Jan 19, 2010
1,254
Catalina 34 Casco Bay
MikeHoncho said:
I'd done this in a heart beat if I was set up (welding wise) to fab aluminum or stainless. I think your a little light in the fab side for added materials and shop hours.
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I priced out the tube before the post. Took the first price. Could be less and stainless not aluminum was quoted. The machine shop I use is $95.00 per hr. Shouldn't be more than 3 hrs..$$$$
 
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dlochner

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Jan 11, 2014
12,398
Sabre 362 113 Fair Haven, NY
shemandr said:
Why the difference with digital radar? Doesn't it still transmit EMR?
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The big difference is the amount of energy the modern radars use. Gone are the big magnetrons. My B&G radar uses 27 watts when transmitting, roughly equivalent to a VHF, that includes energy used for the motor to rotate the antenna and the computer to analyze the data. I think there are also differences in the frequencies used to transmit, but I"m not certain of that.

With that said, I wouldn't stick my head in front of the antenna when transmitting, but the concern about EMR are very low. Keep the antenna above your head and you're good.
 
FastOlson

FastOlson

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Apr 8, 2010
2,062
Ericson Yachts Olson 34 28400 Portland OR
Speaking of radar poles, I now changing from a 1988 aluminum stern pole to a new carbon fiber pole. The new pole was around $700. but shipping across the country added another 150. or so.
The weight difference is astounding.
BTW, we love the closeup target differentiation with the Lowrance digital technology. (Same electronics under the Simrad and B&G name).

Our antenna is well over my head, I should note. Not a real concern with these newer units, but it's good to also use less power.
The radar antenna and post is visible in a picture in my "album" here, FWIW.
It does take a three step little folding ladder in order to reach and unbolt the radar unit to remove or install it.
 
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dlochner

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Jan 11, 2014
12,398
Sabre 362 113 Fair Haven, NY
MikeHoncho said:
that's not what the manual says
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Not sure what manual you are reading. Here's what the B&G (also Simrad and Lawrence) manual says:

Page 2
Radar Transmit Emissions
Note: Broadband 3GTM and 4GTM Radar are the second generation marine recreational radar from Navico that has Human Exposure Level RF Radiation of the Radar Transmitter outside the Radome well below the general public safety emission level of 1 mW/cm2 . This means the radar can be mounted safely in locations impossible with other pulse radars.

Note: If a pulse radar and Broadband Radar are mounted on the same vessel, do not transmit simultaneously as excessive interference is possible.
Page 5

Additional benefits of FMCW radar are:

Safety

low energy emissions. 1/5th of a mobile phone safe operation in anchorages and marinas instant power up. No warm up required
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Link to the installation manual:

ftp://software.simrad-yachting.com/prodocuments/RADAR_3G_4G_IG_988-10113-003_EN_W.pdf
 
Richard19068

Richard19068

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Jun 11, 2004
1,704
Oday 31 Redondo Beach
I am far from what I wouId consider electronically savy but I think there may be some differing or confusing terms here. Digital is not the same as newer solid state broadband or pulse compression radars. I think Digital still uses a magnatron and I assume emits more energy that could be potentially harmful.

What is Pulse Compression or Broadband radar? | West Marine

West Marine is committed to outfitting your life on the water. With over 250 store locations, 100,000 products in stock, and knowledgeable Associates, trust West Marine for your boating, sailing, fishing, or paddling needs. Shop with confidence - get free shipping to home or stores + price match...
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"Modern pulse radars, often tagged with “HD” or “Digital” as part of the product name, use high-definition digital processing to clean up the signal, but the problems with old, analog magnetron technology remain."
 
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dlochner

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Jan 11, 2014
12,398
Sabre 362 113 Fair Haven, NY
[QUOTE="Richard19068, post: 1666326, member: 62037"
"Modern pulse radars, often tagged with “HD” or “Digital” as part of the product name, use high-definition digital processing to clean up the signal, but the problems with old, analog magnetron technology remain."
[/QUOTE]

This is a terrible sentence that conflates two different concepts and implies that high power magnetron radars are still being sold in the recreational market. Crap like this is one reason I ignore WM's advice on most everything.

The current crop of digital/HD/modern radars from Raymarine, Navico, and Garmin do not use magnetrons. They use low power digital signals, which are different from high power pulse analog signals. These transmit at very low power levels and as the B&G manual I quoted above says, it is less than the power from a cell phone.

@Richard19068 this is not intended to be critical of you, just critical of the crap that WM produces.
 
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MikeHoncho

MikeHoncho

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Dec 28, 2015
1,890
Laser, Hunter H30 Cherubini Tacoma
What's in the manual. I'm not a radio frequency guy so I'm open to interpretation.
Untitled.jpg
 
FastOlson

FastOlson

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Apr 8, 2010
2,062
Ericson Yachts Olson 34 28400 Portland OR
For some reason, reading some of these well-intended replies reminds of trying to enumerate the number of angels dancing on the head of a pin.... :)
 
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dlochner

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Jan 11, 2014
12,398
Sabre 362 113 Fair Haven, NY
FastOlson said:
For some reason, reading some of these well-intended replies reminds of trying to enumerate the number of angels dancing on the head of a pin.... :)
Click to expand
Well, it did inspire Phil to add a pole to this weeks email blast. :)

If I'm reading @MikeHoncho's chart correctly, at 0 meters away from the radar antenna, there is less than 10 watts of RF per square meter.
 
uncledom

uncledom

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Jun 11, 2011
1,243
Hunter 41 Lewes
I took the poll this morning which was about mounting height and the only thing I can't figure out is where is my stReaming light?:laugh:
 
MikeHoncho

MikeHoncho

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Dec 28, 2015
1,890
Laser, Hunter H30 Cherubini Tacoma
I see the link for the poll on the home page but it takes me to a old thread about inviting people to go sailing .
 
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Richard19068

Richard19068

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Jun 11, 2004
1,704
Oday 31 Redondo Beach
dlochner said:
@Richard19068 this is not intended to be critical of you, just critical of the crap that WM produces.
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No offense taken. I appreciate the comments. As I said I am not that savvy about this type of thing and do get confused when people are talking about radar and seemingly using the same terms for differing technology.
 
FastOlson

FastOlson

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Apr 8, 2010
2,062
Ericson Yachts Olson 34 28400 Portland OR
A minor bit of thread drift, if I may... we moved our stern light off of the pulpit (where some light loom would fall on the top/edge of the transom) up to the back side of the pole, just under where the wiring opening is for the radar.
No more light reflecting onto cockpit surfaces and the height makes it more visible to other vessels.
...One of our nicer little upgrades, if I do say so.

The added light also lets you better appreciate the curling white wave tops tumbling over just short of the transom, at night, as we sail away from them! ;)
 
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FastOlson

FastOlson

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Apr 8, 2010
2,062
Ericson Yachts Olson 34 28400 Portland OR
MikeHoncho said:
On a completely different subject.....I just received my CPT autohelm today whoop, whoop!
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Please consider starting a new thread with install notes, pix, and of course commentary on operation.
Thanks!! :)
 
sailme88

sailme88

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Jan 19, 2010
1,254
Catalina 34 Casco Bay
I must confess that I'd never heard of CPT. Researched it...

Not my cup of tea....
 
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