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GPS antenna mounting

Old 07-26-2013, 03:41 PM
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Default GPS antenna mounting

My boat has 2 gps antennas that are both mounted about 18" off the t-top. I would like to put them on fixed pedestal mounts that are just a few inches tall and avoid the up and down thing. Just a much neater install. Also need to re-route GPS and radar cables but wondering if I will have troubles with the radome if I drop the gps antennas down to a fixed mount. Have searched a number of threads and all I can seem to find is that it really doesn't matter where you mount the gps antennas. Any ideas? Thanks! FB
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Old 07-26-2013, 04:00 PM
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I would just take the extension tubes of and thread them right onto the current mounts. This way you avoid having to try and find a fixed mount with the same bolt pattern. Typically they are circular three bolt styles.
Old 07-26-2013, 06:44 PM
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My GPS antenna is mounted beside and about the same height as the radome. No problems. See picture.


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Old 07-27-2013, 09:31 AM
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I would not mount them inline with the radar beam. but that is up to you.

(the radar will be fine, the gps might end up dying)
Old 07-27-2013, 10:38 AM
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Originally Posted by smac999 View Post
I would not mount them inline with the radar beam. but that is up to you.

(the radar will be fine, the gps [antenna] might end up dying)
2nd that.
Old 07-27-2013, 11:51 AM
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Originally Posted by smac999 View Post
I would not mount them inline with the radar beam. but that is up to you.

(the radar will be fine, the gps might end up dying)
X3 for 2 reasons

The GPS receivers are very sensitive in order to pick up the satellite signals. They don't like the 4000 watts of energy that your radar is throwing at them.

GPS receivers need a clear 360 degree view of the sky from low on the horizon to almost straight up. It depends on where the satellites are in relation to your receiver. If the radar is blocking their view, it will degrade or completely obscure the signal.

Whoever installed those antennas did it properly. I wouldn't undo a correct installation.
Old 07-27-2013, 02:24 PM
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There are reports of damaged GPS antennas by Radar--keep it 15 degrees below or 15 degrees above the center of the Radar beam. They are OK as is.
Old 07-28-2013, 12:47 PM
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Just to be picky, these are GPS receivers, not GPS antennas. GPS antennas are strictly passive devices and few marine chartplotters (any?) even provide for an actual external antenna, just an external GPS receiver (which, of course, contains its own antenna)

I used semi-portable Garmin GPS devices (mostly on motorcycles) for years that had removable external antennas that could be remoted (with a coax cable), or replaced entirely with higher-performance units. They required no power, they were simply passive antennas and not receivers, and were dirt-cheap.

Sorry to be sounding like Ron Widman...

Most (all?) current chartplotters have imbeded antennas with no provision to add an actual external remote antenna....they want to sell you an entire GPS receiver/antenna unit if reception in your mounting location is less than satisfactory...at about 20x the price that a remote antenna would actually serve the same purpose.
Old 08-01-2013, 05:47 PM
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I lost the gps reading when I 1st installed my radom and gps puck level with each other. Fortunately it didn't fry the puck but I had a hell of a time locating 8 crab pots at the end of the day.

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