Gilsson External GPS Antenna
All GPS units will perform better with an external antenna. While riding under heavy tree cover, in deep narrow canyons, and on heavily overcast days, I was sometimes having difficulties with dropped satellite lock and resulting loss of navigation and big gaps in my recorded track log. I have also seen random "flyers" or rogue track points that zip 200 or 300 feet off the trail for no reason other than poor or reflected satellite signals. I was hoping that this fix would cure those problems, or at least reduce them to a minor level.
The antenna I selected is a Gilsson amplified antenna that has a street price of only US$20. It is rated at 28 db gain, meaning it will significantly amplify weak signals and allow your gps to "see" more satellites. One source: $19.95 Amplified GPS External Remote Antenna Aerial Garmin. I ordered the white antenna with a three foot cable and 90 degree connector.
The antenna comes with two small but strong magnets under the base - these can be removed easily. The antenna can be magnetically mounted on a steel surface, or it can be screwed in place with the included hardware. I have a second antenna that I use in my vehicles, so I chose to screw this one down, mainly so that it won't come adrift in a crash. Gilsson recommends that a metal plate at least 2x2 inches be installed below the antenna to maximize performance, but I have read that many riders get adequate performance simply by mounting directly to plastic. I chose to make a steel mount, using a scrap of thin stainless from my metal junk box.
My Quest sitting on my office table, with no external antenna. Note the poor
position accuracy.
My Quest with the external antenna plugged in - the accuracy error is half and
there are more satellites and higher signal strength (longer bars).
The fabricated bracket and the antenna ready to mount onto the fender brace.
The bracket is secured with 1/8 inch aluminum pop rivets with reinforcing
aluminum washers to prevent the tails from pulling through the soft plastic. The
two large holes allow me to attach the antenna mounting screws without having to
remove the bracket from the fender brace. At top and bottom, you can see the two
empty cavities where the magnets used to be - normally they would be covered by
tape.
I applied a thin layer of clear silicone sealer to the base and screwed the
antenna in place.
The cable runs up to the front of the speedo mount, where the excess is loosely
coiled and wire-tied, and then to the TouraTech mount. It is important with any
antenna coax to NOT tie it against itself in tight layers - keep the curves
gentle! I made sure that the cable would not bind or chafe when the fork moves.
The loose cable is secured to the fender brace through a small hole with a 1/8
inch nylon tie, hidden by the headlight mask.
Finished installation - I think it looks Geeky Cool! The light is not obscured
and the antenna is well protected from trail damage.
The upper cable end is tied to the locking TouraTech mount and plugs in neatly
under the Quest, and is protected by the rubber weather flap that normally seals
the hole. It's a little tricky getting the cable plugged in when mounting the
gps, but I expect that will ease with practice. I normally leave the gps locked
in place onto the mount all day, and only remove it when transporting or storing
the bike. BTW, the orange flag is there to remind me to clean the air filter....
I will post a Ride Report here after using the antenna a while....
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New Mar 07, 2008 |