radar placement

[chesapeake albin]

one more question,

If I was going to put a simrad 4g radar on the boat, will I have big blind spots if this is placed on the radar arch,

I see some of you cool guys got a mast and I am sure that is better,

but how high would I have to go above the radar arch to get that 25/50 degree angle that the broadband needs to work well?

Thanks again
Travis

[Jeremyvmd]

My plan is to mount it flat to the arch for now. If I have blind spots I'll get a 6-12" riser and try again;)

[chesapeake albin]

thanks,

ugh, I might go ahead and get a mast and mount on the front,

its the best solution but this is getting really expensive,
I bought the wrong boat

[chesapeake albin]

just to be clear, I printed a profile of my boat on paper, took the 25/50 angle that is needed
there is no way it going to work ok on that radar arch, and the risers generally to look better rack backwards which even thought yur going up you go back too. There is a long way to clear the roof.

Anymore opinions of people that actually use their radar, does it work on the arch?
Does the broad band work less well back there than a pulse radar?

Thanks
Travis

[Tree]

My Raymarine works fine - I can trim the setting from the screen anyway but I agree, the radar arch isn't perfect.

RobS has posted some photos with his previous 28 underway that will give you an idea of how much you will need to wedge the rear of the dome up to achieve the best results.

With regards to things getting expensive - you bought a BOAT

Bust
Out
Another
Thousand

[Jeremyvmd]

It was never an issue with my old radar as it couldn't see that close to the boat. When you draw the line how far off the how does it hit the water? How close to the boat do you want to see?

[Jeremyvmd]

Quick search shows that seavee makes an 18" zero rake riser for 204 bux from defender.

[djpeewee]

Since radar is line of sight, it stands to reason that higher is better.

We changed out our electronics, and then ended up changing out the radar mount shortly after. So, we do have some experience pre and post factory arch with the same electronics package. We changed out the arch not just for radar performance, but also so the 10' inflatable dinghy would fit on the roof. The radar mount is just about 3' above the hard top. We use the radar every time we go out and have seen improvement in radar performance over the factory arch - particularly directly in front of the boat.

Shilshole.jpg

As mentioned in a previous post, you can test different shim angles with washers or a strip of Starboard under the rear of the radar. I found that my factory arch tilted back by about 3 degrees, so I ended up shimming the radar about 8 degrees forward using Starboard. The radar on the new arch is still shimmed forward, but only about 4 degrees. The added height is really what makes the difference though.


The previous post referred to is here:
viewtopic.php?f=27&t=5275&p=31136

[chesapeake albin]

IMG_3216.JPG

this is me right now,

notice the pretty ornament

[Jeremyvmd]

Off topic a little but can you post some more pics/specs on that little sunshade on the back of your hardtop?

Also your radome seems to be higher than mine? Might be an optical illusion but def seems higher.

[chesapeake albin]

IMG_2868.JPG

IMG_2847.JPG

the PO did the little roof, its great,

the radar is higher it was on a 2" block and another 2" hinge so it would fit under a boathouse

[Jeremyvmd]

I love that little roof! Me and the wife were trying to decide how to make a removable sunshade for the back. I think we might steal that idea. One last question and I'll stop derailing the thread, does it fold up?

[Pitou]

I would think that a 6 inch ScanStrut would get you where you want to be. The 10 inch would certainly do it. You can rake it back or forward / your choice. Add a wedge and you should be good to go. A wedge can be as simple as a piece of starboard running from rear bolt on the radar / side to side or a stack of washers.

Here is a link to a previous discussion:

viewtopic.php?f=27&t=5275&p=31787&hilit=radar#p31787