ID my radar reflector ... please.

JackFrobisher

JackFrobisher

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Can anyone ID this radar reflector?

one.jpg


two.jpg


I didn't have a measuring stick with me when I took the photo so there's a credit card next to it as a size guide.

It's been suggested that it "doesn't provide a good radar image and whilst the mast is down it should be replaced". I have no evidence either way and since the mast is unlikely to come down for another five years it's now or (relatively) never.

I have no plans to remove it since the tricolour/anchor light sits on top of it and would to some extent be masked by other kit if it was lower.

I'm not against fitting another reflector, an Echomax has been recommended, but at the moment I don't know if there's sufficient justification to add another one.

{|:o)#
 
IMHO its not worth changing a fixed passive reflector with another fixed passive reflector, its throwning quite a lot of good money at device that wont work very well, however that said you may consider carrying a plastimo £10 octohedral to hoist up a signal halyard if its foggy. See the Ouzo Quintec report on reflectors, the octohedral is not bad and when hoisted from a halyard it wont suffer losses from heeling in the way the others do.
 
Marsupial said:
IMHO its not worth changing a fixed passive reflector with another fixed passive reflector, its throwning quite a lot of good money at device that wont work very well, however that said you may consider carrying a plastimo £10 octohedral to hoist up a signal halyard if its foggy. See the Ouzo Quintec report on reflectors, the octohedral is not bad and when hoisted from a halyard it wont suffer losses from heeling in the way the others do.
Click to expand...

I had a Visiball on the old boat, and we couldn't see it on the radar from Jimi's boat, when we were anchored about a 100m apart. So either the reflector or Jimi's radar is carp (anag).

Left it there coz it's quite pretty, and it had the tri/anchor light mounted on top of it.

Still available new

Makes me wonder if really you need two, one mounted at 90º to t'other.
 
From memory, many years ago the Visiball was tested along with others and was pretty useless as were the 'tubular' type. The Echomax comes out pretty good on recent tests.
 
I have one. It came with the boat.
I have kept it over the years mainly because it is there, rather than any expectation that it will do any good. They are pretty heavy so if I can ever afford a 'lectric one, I will replace it. (the Mk 2 was much lighter, I think)
The design won a Queen's Award for Industry.
Its only advantages are that it needs no hoisting and is in a high place. In tests it was panned by one yachting mag but as they only had it in a rib on a broomstick I thought it was a swiz.
 
Twister_Ken said:
I had a Visiball on the old boat, and we couldn't see it on the radar from Jimi's boat, when we were anchored about a 100m apart. So either the reflector or Jimi's radar is carp (anag).

Left it there coz it's quite pretty, and it had the tri/anchor light mounted on top of it.

Still available new

Makes me wonder if really you need two, one mounted at 90º to t'other.
Click to expand...

I ve had radar on lots of boats over to many years to mention and none of them have been guilty of seeing a passive relector before our eyeballs saw the boat. :-)
 
Kemp Visiball. In the various tests it showed a very good polar diagram, i.e visible all around the horizon with few nulls - but however good the polar diagram it is a reflector that cannot return a signal strongly enough to be of any use.

And no, I wouldn't tolerate that weight at the masthead, even if I believed in the efficacy of the Visball, which I don't.
 
The weight at the masthead makes me cringe too.

Painting the upper masthead dayglo was trendy on blue water boats in the 1970' -80's, to my mind still has a salty look and still can only help people see the boat, as well as the aforementioned aid to self as in 'remember where we parked' !

How about replacing the visiball with something like one of those vertical axis shiny spinning ventilators one sometimes sees on the vents of buildings ?

I'd think it would make a good visual alert to the boat's presence flashing in the sun; OK it won't work in cloud or at night, but better than nothing and light weight.

I'd fit a tubular type passive radar reflector on each upper cap shroud, to allow for heeling / give a bit more chance of returning a signal, while saving up for a transponder and / or AIS.
 
Most of these things fulfill the legal/SI need to have a radar reflector.
If you want to reflect radar, an octohedral is probably most cost effective, but too much windage to fit permanently.

Having some knowledge of radar and antennas etc, I would say that visiball is not being given a fair chance due to the proximity of the metal mast head crane etc. It might well work a lot better in splendid isolation. Which may be of limited use practically.
 
I seam to remember that the only 2 worth buying are the big echomax or the seame type all the rest where useless in the test.
 
Seajet said:
I'd fit a tubular type passive radar reflector on each upper cap shroud, to allow for heeling / give a bit more chance of returning a signal, while saving up for a transponder and / or AIS.
Click to expand...

I believe the Quinetic report described the tubular reflectors as impossible to see - so ineffective that if out of phase they could make a visible boat disappear! Just bite the bullet and buy a dual band RTE!

Rob.
 
We have an Echomax on current boat and Firdell on last one. With both boats, I called Stenna Explorer fast ferry to check our visibility, was told we could be seen clearly at 8nm but I don't know on which of his radars.
 
GrahamM376 said:
We have an Echomax on current boat and Firdell on last one. With both boats, I called Stenna Explorer fast ferry to check our visibility, was told we could be seen clearly at 8nm but I don't know on which of his radars.
Click to expand...

...or whether he'd have seen you just as well without the reflectors :)

Pete
 
rob2 said:
I believe the Quinetic report described the tubular reflectors as impossible to see - so ineffective that if out of phase they could make a visible boat disappear! Just bite the bullet and buy a dual band RTE!

Rob.
Click to expand...

That statement is amusingly self contradictory.
To make the yacht disappear, the reflector would need an RCS the same as the yacht.

While RTE's are a good thing, there is a certain attraction to something that does the job with no complex electronics, power requirement etc.
 
prv said:
...or whether he'd have seen you just as well without the reflectors :)

Pete
Click to expand...

Maybe, who knows?

We all have to have one anyway under SOLAS regs and I was interested to see what our reflection was like. On the last occasion we called him, we were crossing Holyhead approaches around 2am and saw a fast ferry approaching on our radar. Comforting to know he'd seen us. Can't remember the exact details but he said he would pass half a mile ahead of us in ??mins,??secs. In the event, he was something like 20 seconds out - pretty good estimate!
 
lw395 said:
....While RTE's are a good thing, there is a certain attraction to something that does the job with no complex electronics, power requirement etc.
Click to expand...
What do you have in mind? Four leafed clover? Lucky rabbit's foot? Sprig of white heather from a romany?
 
timbartlett said:
What do you have in mind? Four leafed clover? Lucky rabbit's foot? Sprig of white heather from a romany?
Click to expand...

Big enough alloy mast! :-)

In the radar industry, we tend to use corner reflectors, a section of an octahedral.
But we tend to make them bigger in relation to the wavelength.
In reality, I think a big enough octahedral is the way to go, the problem is more with the standard than with the reflectors I think.

Some years ago I was involved in running a regatta, we managed to get a bit of sponsorship from a certain local company.
One of the competitors was heard to say 'If I win I want a set of chaff rockets!'
 
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