Radar Reflector Position ??

[Planty]

Posted on a thread on PBO, about whether mounting a "French tube" Radar Reflector close to the Scanner was a reasonable idea?

JFM was only replyee thus far and suggested mounting it inside a locker, actually I had thought of fixing it inside the "tower " leading to the "Whales tail" upon which the scanner, vhf aerial, gps dome, annonometer are all mounted?? 'cos they are bl**dy ugly aren't they. The one I have purchased is approx 120mm Diameter, 450mm tall which I am advised is the one for our size boat??

Can one mount them inside GRP, does this negate performance, is it OK next to scanner, as no where else to put it up high?? No mention of not putting a reflector close to, in Scanner manual or installation manual. Any advice appreciated. Paul

 

[rickp]

Absolutely fine inside GRP which is pretty much radar transparent. Inside the strut up to the radar arch on an F43 would be a pretty good place to put one, I reckon. That or the locker on the flybridge, though higher is best - so go with your first suggestion.

Rick

 

[rogp]

Hi to all

I was hoping to hide it away in the radar arch but this doesn't seem wise after reading the article in the link below (if it works) which states "Any casing material should be as near radar transparent as possible (avoid GRP, for example, only 3mm of which will absorb some 50% of the radar fired at it). "

http://www.cruising.org.uk/z_radarref.htm

From my research todate the best postion still seems to be as high as possible, above the radar to avoid interference and in the open with rain-catchers favoured over the tubes.......safer but unsightly /forums/images/graemlins/confused.gif

 

[Wiggo]

FWIW, I think you'll find if you tip the bomber arch back, it's all closed up at the bottom with just a small cable entry hole anyway... And the reflector would be tipped forward at 60*, so next to useless.

 

[pissativlypossed]

We installed ours on the flybridge arch next to the Radar dome and we have no shadow, it isn't that unsightly and gives the best target pattern, according to the instructions.

 

[jfm]

The Emporer\'s New Radar Reflector

That article was written by a bloke who makes money out of sellign radar relfectors, and basically it says you need a reflector.

Fact is, on our leisure standard radar, (a Raymarine) we can see everything. Pot marker buoys, tiny inflatables, everything. Anything like a 25foot+ boat shows up very clearly, you couldn't possibly miss it. Even in a chop, we see small tenders and 3m RIBs on the radar long before we see them with our eyes. Not all these targets have refelctors. So whatver that article says about boats not returning a good radar rflection back to the transmitter, it must be bollox imho.

So imho a reflector isn't much use. It can only help if the radar looking for you is very poor quality, and needs the help of the reflector. Anyone with anything better than our £2000 leisure standard Raymarine (which must include all ships?) will see you clearly with or without a reflector.

I have put our reflector in a GRP locker. I'm pretty sure that all the metal handrails on the flybr, the nav screens and hydraulic steering gear on the flybr, the fridge, icemaker and electric grill on the flybr, the engines, the aluminium 4inch tube space frame holding the flybridge and superstructure, together, the glass windows, etc etc etc give a much better reflection that the poxy kitchen roll sized rip off radar reflector

In your case Panty it would have to be a pretty crap radar not to see a 40foot plus flybridge boat, so I wouldn't lose any sleep.

 

[jfm]

Also paul, you say "120mm Diameter, 450mm tall which I am advised is the one for our size boat"

Surely that proves these things are a con. Why should the size of the reflector have anything to do with the size of your boat? I wonder if they recommend larger reflectors for smaller boats - that would be logical. So, a 500mm diameter and 1500mm tall for a 3m inflatable tender then?