Raymarine 18" vs 24" Radomes ?

[Boo2]

I know one is obviously a bit bigger but can anyone here give me the executive precis of the performance differences between Raymarines 18" and 24" HD Radomes ? How important is it to have a gimballed mount for mounting on a sailing boat's main mast ?

Thanks,

Boo2

 

[pvb]

I know one is obviously a bit bigger but can anyone here give me the executive precis of the performance differences between Raymarines 18" and 24" HD Radomes ? How important is it to have a gimballed mount for mounting on a sailing boat's main mast ?

The only difference is the horizontal beam width - the 18" is 4.9 degrees, the 24" is 3.9 degrees. The narrower the beam width, the better the resolution.

I don't think a gimballed mount gives a significant improvement for most people, certainly in relation to its cost.

 

[Boo2]

The only difference is the horizontal beam width - the 18" is 4.9 degrees, the 24" is 3.9 degrees. The narrower the beam width, the better the resolution.

I don't think a gimballed mount gives a significant improvement for most people, certainly in relation to its cost.

Hi Pvb,

Is the difference in resolution significant in normal use ? I would only be using it for collision avoidance in fog and night conditions, nothing else. The tilting mounts are expensive, as you say...

Boo2

 

[Monique]

I chose a 4 foot scanner for my new 12 KW SHD Raymarine radar... for better definition. For our purpose, it is a better solution albeit at a sharp price point. We also have forward and sidescan sonar... we are setting off for many poorly explored areas...

My choices are not vg value for most sailors.

 

[prv]

Another minus-one for tilting mounts.

William and Stavros have manually-adjustable mounts for their radars, and the generally ex-merchant-ship officers use radar constantly. They generally also have half a dozen spare folk within speaking distance who would be more than happy to go and adjust the radar angle if asked. Yet I have never seen it done.

Pete

 

[macd]

I looked into gimbal radar mounts a few months ago.The overwhelming majority of posts I encountered on this and several other forums was that it wasn't worth the bother and expense. Most posters reported not being able to tell the difference in practice.

 

[pvb]

Hi Pvb,

Is the difference in resolution significant in normal use ? I would only be using it for collision avoidance in fog and night conditions, nothing else.

No, the difference won't be major for that sort of use. Depending on your boat size, a 24" radome can also look a bit big.

 

[sailorman]

No, the difference won't be major for that sort of use. Depending on your boat size, a 24" radome can also look a bit big.

UFO 34 & i would have HD was a tad over kill

 

[Ric]

Another minus-one for tilting mounts.

William and Stavros have manually-adjustable mounts for their radars, and the generally ex-merchant-ship officers use radar constantly. They generally also have half a dozen spare folk within speaking distance who would be more than happy to go and adjust the radar angle if asked. Yet I have never seen it done.

Pete

I have a gimballed mount on my mast and on my boat in my experience it definitely makes a difference when single-handing with a radar alarm set. Previously, without the gimballed mount, under sail sea clutter was unsymmetrical either side of the boat, making it difficult to tune out the clutter. I could thus have a virtual blind spot on one side of the boat, yet constant false alarms from sea clutter on the other side. Now I can tune out sea-clutter symmetrically and am far more confident in the performance of my radar look-out.

On a crewed boat, such as the ST vessels you mention, the radar alarm is probably rarely used so it is less of an advantage to have a gimballed mount.

 

[johnalison]

If you mount the radome low, as at the stern, you get very little sea clutter, if you are prepared to put up with a slight reduction in range. For my coastal and short offshore passages, almost all my radar use is in fairly calm conditions and gimballing would be of little benefit.

 

[charles_reed]

Another minus-one for tilting mounts.

William and Stavros have manually-adjustable mounts for their radars, and the generally ex-merchant-ship officers use radar constantly. They generally also have half a dozen spare folk within speaking distance who would be more than happy to go and adjust the radar angle if asked. Yet I have never seen it done.

Pete

Your comments re adjustable mounts probably appropriate for non-sailing vessels - however I must beg to differ with your opinion regarding sailing vessels - I've tried both and can assure you that, under sail, a tiltable unit is very much better than a fixed one.

 

[macd]

If you mount the radome low, as at the stern, you get very little sea clutter...

+1. Equally, 'broadband' radar suffers from scarcely any sea clutter at all. I can't speak from personal experience for Rayamarine radar, although they claim their HD kit suffers much reduced clutter.