DRS25A-NXT/6 and SCX20

[Bayhouse]

Continuing to plan my install and I don't see any reference in either manual about mounting the SCX20 in the radar sweep zone (come to think of it, hard for the SCX20 to NOT be in the sweep zone).

Both will be mounted on the hard top of my sport fish, radar in the center and the SCX on one side, close to a wire chase and not underneath the antenna sweep.

2nd question - the hard top is chamfered and the SCX20 would be mounted on a slight angle. Is this an issue or can it be compensated for in the setup? if not, assume I'll need an adjustable antenna base to level it off.

Friend of mine has the same, new 6' magnetron array with another companies digital compass mounted similarly. If he's running the radar, the compass becomes unstable.

 

[Johnny Electron]

Hi Bayhouse

Page 1-1 from the manual says...
How to select the installation site
The installation site must satisfy the conditions described in the antenna installation
procedure at the back of this manual. The drawing is found on page D-1 and shows placement outside the radar beam and other withdraw distances.

NMEA 0400 installation standards also speaks to placement of electronics and any trained installer should know that book well. It sounds like your buddy didn't research his install like you are doing. Kudos to you.

If you have photos of the boat with the subject location; I might be able offer more/better advice. Ideally you want to mount it flat but there are ways to setup offsets if needed. While slight angle won't do much to hurt the heading or GPS functions it will cause the pitch/roll sensor to be off.

 

[Bayhouse]

Let me dig deeper into those manual references Johnny, thanks for the direction.

I'll also find/snap some pics of the hardtop.

 

[Quitsa]

Continuing to plan my install and I don't see any reference in either manual about mounting the SCX20 in the radar sweep zone (come to think of it, hard for the SCX20 to NOT be in the sweep zone).

Both will be mounted on the hard top of my sport fish, radar in the center and the SCX on one side, close to a wire chase and not underneath the antenna sweep.

2nd question - the hard top is chamfered and the SCX20 would be mounted on a slight angle. Is this an issue or can it be compensated for in the setup? if not, assume I'll need an adjustable antenna base to level it off.

Friend of mine has the same, new 6' magnetron array with another companies digital compass mounted similarly. If he's running the radar, the compass becomes unstable.

If you have a tower, you may want to consider putting the SCX-20 on the sunshade for the upper helm. It's pretty light and the cable is a regular NMEA 2000 cabe that isn't too hard to fish through pipework. It may not need to go too far if you have a NMEA 2000 drop at your tower helm. That location will give the SCX-20 a completely clear sky view and get it away from the radar beam.

Mine doesn't seem to have any problem with the somewhat greater motion up there and stays locked on and outputting good data.

 

[Bayhouse]

Good suggestion to separate the components, but I don't have a tower on this boat.

 

[Magnetron]

You just don't want it in the beam of a radar, over time it'll degrade the performance of the GPS sensors. If it can't be helped, you should strongly consider setting up a small sector blanking zone for the SCX20.

Hope this helps, :sail

-Maggy

 

[Bayhouse]

I found the Radar Antenna Location drawing in the manual and am glad I asked the question.

The drawing shows the antenna must be above the radar based on certain distances, never below as was my original plan. I'll need a pretty tall extension tube now to get it above the radar, which is already elevated - pics attached.

 

[Quitsa]

If you put the SCX-20 near the center of the aft edge of the hardtop, would the radar antenna pass over it? Otherwise as magnetron suggests, perhaps you can install it there and blank the radar transmission for a slice that isn't too critical.

The DRS25A-NXT with a six foot array is a massive upgrade from that little Garmin dome!

 

[Johnny Electron]

I am totally tracking with Quitsa. Even with the dome it should be possible to have it close in and have the radar overshoot the SCX20. The manual showing it above the beam is the "ideal" location but below the beam would work very well for you. There is no doubt if changing the radar for an Furuno open array, you have more leeway because the antenna of the radar will be higher making it easier to get below the radar beam and move the SCX20 even more forward. I would be mounting it center, in front, as far forward as possible, without hitting the downward beam of the radar.

 

[Quitsa]

I am totally tracking with Quitsa. Even with the dome it should be possible to have it close in and have the radar overshoot the SCX20. The manual showing it above the beam is the "ideal" location but below the beam would work very well for you. There is no doubt if changing the radar for an Furuno open array, you have more leeway because the antenna of the radar will be higher making it easier to get below the radar beam and move the SCX20 even more forward. I would be mounting it center, in front, as far forward as possible, without hitting the downward beam of the radar.

High praise. Maybe I can work remotely part-time as a Furuno tech support person.

But don't you think it would be better to mount it aft of the radar? Normally there is a small downward mounting angle so the beam aft will be a little higher and farther from the SCX-20 on the hardtop. The SCX-20 won't care whether its forward or aft of the radar although the aft position has the further benefit of slightly less pitching and yawing being closer to the boat's axis of rotation.

 

[Johnny Electron]

It is always great to have your input/assistance. We can't pay but I would hire you. :respect

Yes I agree but it all depend on what else will be mounted on the boat. Because you don't want to block the forward motion view of the radar, most extra "Stuff" goes aft of the radar then the SCX has to contend with more blockage and possible other RF sources from that "Stuff". I normally recommend forward for that reason on a small platform like this. Every install is diffrent but if no other items are going aft, yes I totally agree.

 

[Quitsa]

Good point about other hardware. There isn't any in the photo but more may be coming.

Having one of the earliest TZT3 and DRS25A-NXT installations (the order went in during the first hour it was possible and we got some of the first batch shipped to customers), we needed extra help and you were great in working through the early issues.

I have been a Furuno MFD customer since the days of the VX1 and had an FCV-582 sounder before that. I strayed a couple of times and outfitted boats with hardware from other manufacturers, The old Simrad stuff was pretty good in its day with radar and sounder performance comparable to Furuno -- but that was before the Simrad recreational product business was sold off.

More recently, twice in the past 10 years I have installed other systems and after a couple of years ripped them out and replaced with Furuno equipment. You'd think I would have learned.

 

[Johnny Electron]

We appreciate you buying Furuno and we work hard to provide value and the long lasting products you desire. Our support department constantly gets calls from customers connecting their "other brand" units up to ours. When you have two items from two manufacturers, it is clear which company they get the fastest and best answers from. They call us. We are lucky to have a loyal base of customers (like yourself and many here) who appreciate the support, quality and ability to repair long term. Not to blow smoke, but you are not a typical user. You use the tools (yes tools, not toys) to a very high level and your input has been a great value to us and this forum. :capt

 

[Bayhouse]

The DRS25A-NXT with a six foot array is a massive upgrade from that little Garmin dome!

I still can't believe the previous owner put that tiny radar dome on the boat and I'm really looking forward to that upgrade!

2 new 19" TZT3, DFF3D, 2 xducers, Autopilot, XM weather - an almost complete refit with the best products supported by the best support team :furuno

 

[Bayhouse]

Adding a profile pic of the hard top. As Quitsa suggested, I believe the platform is slightly angled forward (the horn may be deceiving) and I think aft/center of the radar is probably safer. I believe that circular antenna currently after/center is some kind of a cell phone booster that is no longer in use - that's my target location, but I'll confirm when the install starts.

I expect (hope) the antenna array and SCX20 will be the last devices I need to mount on the hardtop, but may need to move the forward AIS antenna if it's in the 20* sweep.

 

[Johnny Electron]

If going with the open array you can safely place it where the yellow highlight is on the centerline and it should look very good there. The open array will sit higher and it will work well. Thanks for the support comment. We always put our best efforts forward.

 

[Quitsa]

Is it the angle of the photo or is the hardtop really angled that much? In the photo, it appears that the down angle of the radar mount pod is just about enough to create a level surface. If the boat runs bow up 3-5 degrees as is fairly typical of planing hulls, you may want a wedge under the radar pedestal to aim it a bit more down.

I'm with you on the aft location. Not sure I am following Johnny's argument for mounting the SCX-20 forward. That might just be a thick skull issue on my part. The distances aren't easy to guess from the photo but it looks as though there is more space aft, in which case the SCX-20 might be past the tip of the radar antenna. That would seem better than having the antenna passing over it 24 or 48 times per minute -- or actually double that.

 

[Johnny Electron]

AFT is fine too for the SCX as long as the VHF/AIS and other items are meeting distances by NMEA 0400 standards and out of the radar beam. I have no idea if you have plans to mount other items back there or not, but placement is important in relation to planned items.