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Bruce in alaska Bruce in alaska is offline
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First recorded activity by BoatBanter: Dec 2007
Posts: 153
Default GPS antenna location

In article
,
Rob wrote:

I have been getting conflicting advice about relative position in
regard to my radar dome. Both will be mounted on my mast about 12 to
24 inches apart. I have a choice of having the GPS right below the
bottom of the dome or I could put an extension and have it extend a
few inches above the dome. Any advice?
Thanks
Bob


Well, since GPS and XBand Radar use different, and Widely separated,
frequencies, the only real, or apparent, problems should be the effect
of the RF Peak Pulse Output, of the Radar, mixing, or overloading in the
Frontend of the GPS's Antenna Mounted Preamp. This could be mitigated
by mounting the GPS Antenna Unit, outside the Radars, Vertical Antenna
Pattern, which is typically, Plus or Minus 12 degrees from the horizon.
Now, if you put the GPS Antenna, BELOW the Radar, the Radar itself will
block some reception from above, where is shades the GPS Antenna. If you
mount the GPS Antenna DIRECTLY above the Radar, No Problems. If you
mount it off to the side of the Radar, then you should position it, WELL
OUTSIDE the Radar Antennas Vertical Beamwidth, and more distance is
better, due to our old friend, Inverse Square Law.

--
Bruce in alaska
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