SCX20 - Radar Dome Mounting

[Peter Parker]

I am taking some measurements for an aluminum plate and wanted to make sure the SCX can be mounted close to the antenna as long as its not in the beam width. Yes, snowing and a damp garage on Long Island today so the kitchen it is.

Thanks, Pete

 

[Poseidon]

How close are wanting to mount it?

 

[Peter Parker]

Just like the picture, the plate size I have in mind is 12x22 in. I have seen these mounted opposite of being on the bottom side of dome but mounted above the domes at about the same distance. Not knowing these people and the results is why I ask. The only reference to spacing distance is on page 1-1 of manual and it states 3 meters for Inmarsat antennas. I have seen nothing about any distance, only wave transmission.

Thanks, Pete

 

[Poseidon]

We would not recommend having them that close. The dome is blocking the GPS like an umbrella so it would not get some of the satellite transmission. I would recommend depending on the boat size, maybe moving it away from the radar a little bit so its not being covered by the dome.

 

[Peter Parker]

The angle makes it look deep, maybe 1 inch tops. The cover is just plastic. GPS signals go through a car roof. I see no mention of distance..this is all I am asking. Where is it published the recommended distance ?

 

[Poseidon]

According to NMEA the recommended distance is 2 -3 ft. The radar has a lot of RF coming from it, so its super noisy for the SCX that is listening for satellites to "hear" them.

 

[gtstang462002]

The angle makes it look deep, maybe 1 inch tops. The cover is just plastic. GPS signals go through a car roof. I see no mention of distance..this is all I am asking. Where is it published the recommended distance ?

Also need to keep in mind that the signals that the GPS is listening to from the satellites in the sky are not always coming straight down from the sky, more often than not they would be approaching the antennas from multiple angles. By giving the NMEA recommended spacing you would be allowing the antenna proper visibility to do it's job accurately. I would possibly suggest/recommend setting up a small blanking zone behind you to that the radar is not screaming into the "ears" of the GPS antenna given the proximity of the SCX20 to the radar.

 

[Johnny Electron]

There is a chart diagram about spacing distance and placement in the back that the manual. We also have some good post on the forum where others have discussed and mounted these. You are going to love it. Both are great units.

 

[Peter Parker]

Maybe a separate plate further behind the radome and blank from 175ish185 would make sense. My heavy questioning the spacing/placement is so it does not get fried. Its a 21 ft boat as mentioned in a transducer post, so not much room, but going to be making it all work. There is a little shelf area below the deck access at the bilge deck door, I was thinking about down there too. Really looking forward to getting this system installed than up and running.

I attached a pic of my boat plus 2 pictures of scx20 mountings I was mentioning.

I am always open for ideas and look for them too.

Thanks, Pete

 

[Johnny Electron]

Yes, those mounts rock. The one up higher would work best.

 

[Peter Parker]

Those arms are nice but I trailer my boat so would have to purchase the fold over mounting bracket also. Would folding it over during trailer transport damage the unit? The antenna on that bracket is less than 2 ft away (looks less than 1 ft) from the transmit antenna so I am not sure how noise does not affect in this position but mounting it flatly behind it seems contradicting. I guess I can install everything leaving this for last and than see in real life how it receives signals in my back yard and go from there. Thanks everyone for the suggestions.

 

[Johnny Electron]

You can use a hinged mast but if the radar is laying over, it needs to have a slight modification or it will get water intrusion. Take a look at this mod. https://www.furunousa.com/en/products/dom-wtr-plg

I think if you install the mod to the dome and used a hinged mast, you would be great for transporting but whenever you park it or have it on the water the mast should be raised. The design of these items are protected the most when in the operational position. I assure you that you don't want to hinge that dome without the mod.

 

[Peter Parker]

Johnny, only the mast and SCX20 would tip over and that should be already sealed up before mounting. So if it can be tilted for transport/storage.

https://www.boemarine.com/seaview-ltb-9 ... tb-13.html

What also is still not clear to me is the distance. This noise...why will it affect it below and not above? I want to mount it below.

 

[Johnny Electron]

It isn't about RF noise because you are out of the beam. It is about physical blockage. Put yourself as the SCX20. If lying below the radar, there are times that there will be GPS sats near the horizon or behind that dome which the SCX20 can't see, because it is being physically blocked. It doesn't have x-ray vision. While the lower position will still work well because there are other sats that it will catch, an unblocked view and more sats typically provide tighter information. Basically your current plan is deciding between Great and Excellent locations. I wouldn't be that concerned if you want the lower mounting type.