Fitting Radar

[Guest]

Ok.. everyone says first time out in fog you come back and buy radar..
I am looking..
See the review in PBO on the JRC 1000/1500 vs Foruno..
Does mention thick cable..
If I have to drill a hole in the mast to feed the cable.. and at the bottom
to get the cable out.. thin cable would seem better..
Have to remove plug to get through mast and cabin roof.. does this mean the
JRC is easier to fit??

Also doesn't seem to much difference between the JRC 1000 or 1500 display but
the 1000 Radome is lighter and less likely to foul the Genoa??

Leaning toward the JRC 1000 or possibly the 1500?? any feedback fom fit
yourself types??
Bob
Dehler 34
Largs

 

[charles_reed]

You put the thin end of the cable thro' to the radome. Not the screw connector thro' to the display unit.
A <12mm will be adequate.

Think about radome siting.
High = maximum range.
Low = Maximum accuracy.

I've found the most useful range to be 0.125M, on which I can pick up lobster markers.

Go for CRT rather than LCD and the biggest screen you can afford.

Mine is the Raytheon 10X, mad by JRC and probably the best of its type.

The bigger the transmitter the better the picture - look for small beam angles.
Lastly, if you have a sailing vessel, mount the array so that it is gimballed to allow for being on one or another tack.

 

[tonydyer]

I fitted a JRC1000 myself and it is excellent. Cannot give any advice regarding leading the cable through the mast, because the previous owner of my boat left an old cable fitted. The JRC cable was much thinner, so followed through without any problems.

I have fitted my display in the cockpit under the spray hood, so that I can see it from the conning position. I highly recommend this as it takes a lot of practice to uderstand what you are seeing on a radar, and when being used in real fog, it is the time when you do not want to be dashing below every few seconds.

I have only used the radar once in thick fog, and it made me feel much more comfortable that had I been without it. Otherwise I switch it on fairly regularly for practice - whenever there is no wind and I am motoring home in the Solent I have it on to keep familiarising myself as to what I am seeing on the screen. There is a constant need to alter settings (range and gain) to get the best picture, and to track targets as they approach and pass.

Tony

 

[vyv_cox]

Tony,

Do you disconnect the display when leaving the boat? Is the plug arrangement OK to be used frequently, and will it corrode if left unattached to the display monitor?

Vyv

 

[pwfl]

I fitted a furuno 1622 last year , & in general, I'm very happy with it. I have seen a JRC1000 working very briefly, & I thought my set had significantly better picture quality. But I'm sure it does much the same thing, & it's significantly cheaper.

The JRC's dome is also that much smaller, which could be an issue if your boat is small.

On the subject of cabling, (for the furuno) the end that goes on the radome doesn't have a connector on it - you have to open up the radome & connect up the wires (not that difficult, if you can wire a plug).

Nonetheless, it's still a fairly chunky cable. If you don't want to drill that size hole in your mast, you can (as I did) use an external cable conduit (available from Scanstrut, the people who make the mast brackets for radomes).

You can either (a) run the cable through from the display, then out through the coachroof & up to the radome, or (b) connect the cable to the radome before you put it up, & then have to drill extra large holes to run the other end through, because of the whopping great connector on it, or (c) as either/both, but then split the cable & join it up again at a convenient place using a junction box (fairly common practice).

If doing this you will need a junction box meant for electronics, rather than electrical stuff (ie Index Marine ones, common at chandlers), as the screws in these push down on plates which grip the wire, rather than screwing directly onto the wire (one of the wires is a coaxial with a very fine inner wire which will break otherwise).

I also have my display outside against the bulkhead , still protected by the sprayhood (which you couldn't really do with a CRT unit). I was advised by the suppliers that the level of waterproofness was not to be considered as 100%, the weak point being round the back where the cables connect. They suggested getting a sail/sprayhood maker to knock me up a little cover out of sprayhood material, with a clear front, which cost 15 quid & works fine. I also put some self amalganating tape around the connectors.

I cannot understand how anyone can have a radar inside, unless they have spare crew who can be sent in to watch. I sail with my wife - ie we're singlehanding most of the time, & when there's a close quarters situation developing, you need to be watching that screen constantly. To have to keep nipping inside to see what's going on seems a bit of a waste really.

On the subject of mounting it outside - if you wanted to do that, you may have to consider the type of bracket that comes with your unit - ie would it allow you to mount it to a vertical, as well as a horizontal surface.

hope that helps.

 

[tonydyer]

Vyv,

I leave my display connected all the time as I do not like the idea of regular connections / disconnections of the socket (for obvious reasons). I have a canvas cover and swivel the display as far as possible horizontally. I then cover the display with rope so that it is totally disguised.

When I first fitted the display I did disconnect it on each occasion. I then covered the socket with a WD40 inpregnated food bag and sealed it with a strong elastic band! I also used this method with my GPS, which I fitted on the steering pedestal. Now I have a large pedestal cover, so that too is disguised!

Tony

 

[Guest]

Thanks for all the comments..
I must admit to being concerned about drilling large holes into the mast for the cable.. also as the bottom is fairly well sealed I would need to drill and fish for a draw wire..

On the issue of inside or out..
I can see advantages of both..
If at the chart table you can see whats happening around you while down below..
Handy on the bulhead whilst at the helm..
Is there a wauy to put a plug and soccket at each location and move the display I wonder??

I have a CRT plotter at the chart table.. the display quality is very good..
The LCD radar would probably be ok for collision avoidance though as a blob is something to avoid.. dont know if the crt screens are as compact as my Robertson dataline plotter...

Not sure about the gimbal reference.. surely not the radome??

Regards

 

[yachtbits]

the gimballing comment refers to the radome. There are some mounting systems available that alllow the radome to remain horizontal when heeled over.

whilst this is a good idea in theory, most radomes have a reasonablly wide vertical beam angle that will compensate for heeling anyway.

based on the fact that scanstrut mast mounts are by far the most popular method of mounting, (non-gimballed) I personally don't think it is necessary.

All the items mentioned in the previous threads available from us (except Furuno)

happy sailing

kev

www.yachtbits.co.uk
sales@yachtbits.co.uk
marine electrical/electronics specialists

 

[Guest]

Would it be true to say that in very thick fog theres not likely to be much wind anyway and therefore not
much angle ?

I have a motor cruiser dont yet have a radar but have been in thick fog twice (Brighton to Ramsgate once hell
with no radar) and on each occasion no wind.
One more question I have an old radar not fitted which came with the boat and the manual says it runs on 3kw ?
sounds like a lot of juice, how do sail boats cope with that do they start the engine ?

"The Med is calling me"

 

[Strathglass]

The 3Kw quoted will be the peak output power transmitted by the radar and as on/off ratio of the transmitted pulse is very low then the average DC power consumed will only be a small percentage of this. The handbook should be able to tell you the average DC power required.
Iain

 

[Guest]

Hi Ian So sail boats just use the battery power then ? What about the point re fog and no wind? am I right

"The Med is calling me"

 

[Strathglass]

Been caught once in fog and no wind off Peterhead in an Impalla with lots of fishing boats around and no radar. Fog horns everywhere and we couldn't even see our own bow.
We were quite glad that we had an engine and even happier when we returned to port.
I used to day sail a very old 25 ft yacht which had neither engine, battery or lights.

 

[johnsomerhausen]

I've put my Furuno 1621 on a 7 foot post at the stern. The post is a section of a trashed aluminium spinnaker pole (2.5 in diameter) with a U shaped fitting sitting athwart the pole so that I can incline the radome to counteract the heeling angle. Having it at that height gives me less sea clutter and allows me to see targets nearby (useful when navigating a channel in fog). I may lose a little bit of "reach" for my radar, but I've seen ships going away from me disappear near the 16 miles range. The other advantage is that I can easily take the radome down (the cable runs outside the pole, held by cable ties) and bring the whole lot to a service shop
John

 

[johnsomerhausen]

Hadn't readd all the replies when I posted my first message.... My 1.5 KW Furuno 1621 has a 5 amps fuse, so the maximum DC current needed by the set is lower than that... I beg to disagree with friend Kev: the vertical range of a radar is usually 25 degrees, i.e., 12.5 degrees above horizontal and 12.5 degrees below it and it is not at all unusual for a boat on the wind to be heeled at more than 15 degrees, which is why I adopted the manual control. The solution I adopted for the display is to put it on a hinged wooden beam; hinged twice in fact, the first hinge is on the starboard cabin side, near the after cabin bulkhead and the second hinge is in the middle of the beam. That way, I can look at the display from the forward end of the cockpit (the boat is tiller steered) when the beam is fully extended or from the inside of the cabin when it is folded When it is extended but placed along the starboard cabin side, I can see it from the nav table which is on the port side. The cable hasn't as yet shown any sign of suffering from the repeatred bendings in four years of use. Slight correction on the shap of the support, it is more in the form of the greek letter "pi" than of a "U".
john

 

[heerenleed]

Re: fog and wind?

About your question re. fog, no wind: this is not necessarliy the case. In our climate, I think that mostly, there will be very little wind when there's fog. But this summer, we had fog AND F6 off the Belgian coast. So it does happen. The NW-Atlantic is infamous for its fog combined with strong winds.

Also, when you ask whether sailing yachts would use their engine when the radar is in use, many sailing yachts switch on the radar during nicht passages. We certainly would not run the engine in any decent wind. But then again, we do keep a keen eye on the batteries on passages, also when the autopilot is in use.

Happy sailing

Peter a/b SV Heerenleed, Steenbergen, Netherlands

 

[Guest]

havent had time to read all the replies you have received, so apologies if I write what someone has already done.

fitted a jrc 1000 2 years ago. initially had probs with the tuning but it now works excellently, detecting fishing boats up to 9 miles away.

installed it up the mast since I didnt see any reason for exposing myself to radiation when I didnt have to. very much doubt that there is any risk with scanners on poles at the rear of the boat, but why take any risk at all?

solved the cable problem by fastering the cable to the outside surface of the mast. it is unobtrusive, and has given no problem whatsoever.

fitted the display under my wheelhouse shelter and would strongly second the views of the poster who recommended this. when approaching the spanish coast single handed at night amongst a huge fishing fleet, I was very grateful to have the set where I could see it.

I had to shorten the cable and JRC advised me to use a chocolate block connector in a moisture sealed box. again, this has worked well.

pm me if you have any specific queries.