Does an arch mounted GPS need to be level?

dtfeld

dtfeld

Water Contrails
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Jun 5, 2016
5,572
Milton, GA
Boat Info
410 Sundancer
2001
12" Axiom and 9" Axiom+ MFD
Engines
Cat 3126 V-Drives
I was able to get a new Raymarine RS150 GPS (active GPS) module installed on the top of my arch. It was installed on a short 1"-14 mount where the previous passive GPS antenna for the RN300 used to reside (see pic). Manual sys it needs to be level. Obviously this is not level. However, best I can tell this improved reception 1000% over the stock Axiom in the fiberglass pod.

Anybody have any idea if this will affect GPS reception/performance?

Anybody have any idea on how to level the mount? I was looking for a 2 axis swivel that would screw in between but I can t find any such item. Does somebody make a wedge? Trying to keep the same 3 screw mounting holes, not have to drill a new screw pattern.

InkedResizeDCS_9195_LI.jpg
 
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dtfeld said:
I was able to get a new Raymarine RS150 GPS (active GPS) module installed on the top of my arch. It was installed on a short 1"-14 mount where the previous passive GPS antenna for the RN300 used to reside (see pic). Manual sys it needs to be level. Obviously this is not level. However, best I can tell this improved reception 1000% over the stock Axiom in the fiberglass pod.

Anybody have any idea if this will affect GPS reception/performance?

Anybody have any idea on how to level the mount? I was looking for a 2 axis swivel that would screw in between but I can t find any such item. Does somebody make a wedge? Trying to keep the same 3 screw mounting holes, not have to drill a new screw pattern.

View attachment 98079
Click to expand...

Can you make one of these work? https://www.westmarine.com/buy/west...avy-duty-stainless-steel--1986868?recordNum=1
 
dtfeld said:
Wedge? Is it something commercial or DIY?
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My PO had the old RM C80 installed w/GPS on the arch. When I replaced it 3 years ago w/a127 I uninstalled the GPS antenna, found the wedge, and re-used it for the new antenna. It looks store-bought, not a DIY.
 
Look something like this?? This is 7 degrees, I think I'll need about 15 degrees to level mine. I'll have to measure actual angle next time out.

upload_2021-1-20_16-55-25.png
 
The mount TNT @TNT8808 posted will fix the angle no problem.

But to be honest, that's a 72 channel GPS. Funny since there are less then half that amount of satellites orbiting now. But being at that angle is not going to effect the accuracy of a 72 channel GPS. There isn't going to be 72 satellites in view any time soon.

That said a big piece of hardware is just as ugly as the wrong mount. I would get a hole saw, some starboard and a good belt sander and make a nice plastic wedge. It's not off that much.

EDIT: opps posted at the same time. Nice find on the wedge.
 
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As I read up on this, the issue seams to be the tilt will cause "false horizons" ie satellites will fall below the sensors horizon, before they actually fall below the earth horizon. However, even under a metal roof and large boats on all sides, I was seeing 12+ satellites no problem.

Also considering this sensor looks for GPS and GLONASS, but will also support Beidou and Galileo at some point, I dont thing seeing satellites is going to be the issue.
 
dtfeld said:
As I read up on this, the issue seams to be the tilt will cause "false horizons" ie satellites will fall below the sensors horizon, before they actually fall below the earth horizon. However, even under a metal roof and large boats on all sides, I was seeing 12+ satellites no problem. ...
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Yep false horizons, but that scenario also happens with sat's on the fringe of working. In your reading you should have also read that there is a difference between viewable and usable sat locks and that there are really only ~4 real locks that provide usable data even though 6,8,12 are viewable and look to be in use. But as some of those 4-5 lose their useful signal some of the others become active. With 24 of 32 (varies sometimes all 32 are in use) satellites in constant use around the globe and at varying azimuths, I am not sure false horizons is anything to be concerned with. Especially with that particular antenna, real nice antenna and what it supports.
 
You rocket scientists out there are really starting me to question my intelligence...
 
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I agree with the above comments about it not really being all that important in real life.

Easy way to level it... use stainless washers as shims and then fill the gap with sealant. Smooth the sealant nicely and it will look very good... although from your position at the helm, even if you do a bad smoothing job, you'll never notice it ;)
 
I know it’s winter but, You guys may be overthinking this. Here’s where the installer put our new RS150:

4E240BEB-E4B5-49A9-97A0-CC1CA098FC52.jpeg


That’s inside the helm (its tilted up in the photo), inside under the fiberglass hardtop and glass windows. Works just fine.
 
Henry Boyd said:
... That’s inside the helm (its tilted up in the photo), inside under the fiberglass hardtop and glass windows. Works just fine.
Click to expand...

Awe com'on Herry, we need to have the arch look like a space ship. That is taking all of the fun out of it. :)
 
Henry Boyd said:
I know it’s winter but, You guys may be overthinking this. Here’s where the installer put our new RS150:

View attachment 98106

That’s inside the helm (its tilted up in the photo), inside under the fiberglass hardtop and glass windows. Works just fine.
Click to expand...

Holy Crap!! I guess I'll stop worrying now!!!
 
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