GPS ANTENNA QUESTION

[iampapajack]

Hey guys I'm installing a new Lowrance 332C on my 21' NW JET that has the soft top. Instructions say antenna must have "unrestricted view of sky" I'd like to install the antenna on the dash inside the boat windshield....Any problems with this? it would make install easy to use existing holes allready cut...Thanks for any replies or suggestions...Jack

[Half fast Toyn]

My lawrance is installed inside in my Alumiweld and I have not had any issues with it. It aquires satalites just as fast as my hand held, which is how I determined it wasnt affected by being inside. http://www.ifish.net/gallery/data/500/medium/PICT0244.JPG

[StickFish]

Big question would be will the location have full view of the sky. If portions of the frame block its line of site to more than 45 degrees above the horizon I would consider a different location. Glass doesn't ususally cause a problem, but some auto glass has a lamenant that reflects radio waves and lots of other things.

[OTH]

If you mount it inside, just make sure you get it away from the GPS unit a little. If it is right next to it, your GPS will not aquire. Lowrance reccomends a minimum 3 foot separation between your antenna and your unit, but a little less than that will work fine.

My antenna is mounted on the driver side next to the window. It does not see the whole sky, and it works perfect.

[ICHTHYDEMON]

I think you'll be fine mounting it there. My Garmin has an internal antenna and it works fine mounted like you want to do.It works with the top up as well.

I keep my Seahawk in our garage. I can even get my Garmin to work inside the garage. The windshield is probably 10' from the door.

[iampapajack]

Thanks guys, now I feel better I'll try it inside..Jack

[corrirod]

You can try it first but we just mounted one inside, next to the unit, like you have displayed and it had all kinds of troubles aquiring and keeping the satellites. :shrug:

[timinthegorge]

:yeahthat:

Inside is iffy at best. It's more of a hassle, but the best spot is on the gunnel, as close to the stern as possible, to avoid the top from becoming interference.

And internal and external antenna's are completely different. Just my :twocents:

[tomictime]

Those w canvas/sunbrella tops will also find reduced signal if the top is wet as in heavy weather..JUST when you MAY need it most. Hose her down well and see what happens to signal w satts low on horizon in pitching boat

[Magnum]

I have my Garmin 192c GPS antenae mounted on a Ram mount with a lowrance/gps combo base plate. My gps antenae sits 3" directly behind my gps unit. I have never had a problem with a gps signal. Personally, I think it all has to do with the degree of angle of ones boat windshield. I have a NR seahawk and the angle of the window is quite steep so my gps antenae has a direct shot through the window. Other boats may have a direct shot through the top & window frame, therefore, limiting their effectiveness. :twocents:

I do though agree that the overall BEST location for an antennae would be on the outside of the cabin.

Side view of base/unit:
http://www.ifish.net/gallery/data/500/medium/061606_001a.jpg

View from top of window straight down to gps unit. Nothing blocking the gps antennae but window.
http://www.ifish.net/gallery/data/500/medium/061606_003a.jpg

[iampapajack]

You guys are great, you really know your stuff...thanks again...Jack

[BiteFactory]

You may want to take a look at your GPS fix accuracy if you mount antenna inside. You may still get a fix, but it could easily be less accurate. Losing the WAAS signal is pretty easy too. Also if you mount antenna inside you may have better reception in some headings than others at various times.

It may work just great, but know your accuracy so you don't trust that icon position too much in dark fog and narrow channel/river. Or even worse end up losing signal in lousy weather at the wrong time.

There should be a menu/setup page somewhere that shows satellite signal strength and fix accuracy.

[Magnum]

I have my antennae mounted inside the cabin. When I zoom in, the GPS fix accuracy increases to within 4 ft. As I zoom out it decreases to around 50ft. Depending on how accruate I want to be I just adjust my zoom level. As for the WAAS singal, I have never lost it yet, but there is always a first for everthing.....That is why I also carry a handheld backup GPS.

[StrikeFighter]

If you have a radar, do not mount in in line of sight with radar dome. It has to be above or below radar dome. If its in the line of sight with the dome and you turn on the radar on a bad foggy day, you will lose your GPS signal. When I bought my boat I had the the electronic installed by the boat dealer (big mistake) and it almost got me run over by a large ship near the Golden Gate bridge on a bad day. It took me a while to figure it out. The GPS loss it signal and the bridge was throwing back scatter on the radar so it was confusing. The radar saved me that day.

To get my GPS antenna above my dome I made a GPS tower out of 1 inch PVC pipe. as you can see in this picture below ( Picture taken at Lake Tahoe in California with my son Bill Jr at the helm)

http://www.sheltonproducts.com/Tahoe8.jpg

If for any reason you try working with bending PVC pipe in a 90 degree angles and such it done much easier if you have a very flexible spring (lose fit) inside the PVC pipe where you make the bend. (If you have a spring inside then you can heat the bend area evenly all the way around-have a string attached to the spring so you can pull it out after the bend is done and reuse) If you don't have a spring then remember this when it comes to bending plastic pipe you much watch where you place the heat with a heat gun as in reality you don't bend plastic pipe you stretch one side around to make the bend. The inside of the bend has to be cooler because you do not want that side of the pipe to collapse but hold rigid. It also has to have held by walls on each side to prevented it from flatting out. Make a jig out of wood the same width as the pipe to keep it from flatting. It does require some practice and understanding of the principle to make it look good. Try practicing this with a throw away piece.

It may be a little overkill, but after almost being run over by a huge ship, there is no such thing as overkill in making sure you never lose a signal at the most critical time of your journey.

[BiteFactory]

Hey Magnum,

I'm sure your setup works just fine. For a good while I used a built-in flip-up antenna inside with rare "lost signal" messages. I don't think the accuracy varies with the zoom scale though. To see your accuracy (or estimated position error EPE) go to your MENU pages and see the GPS tab. There you can see the sat signal strengths and the EPE. You can move your boat or antenna around and see this vary. You can also see how WAAS is doing on that page. Try blocking the antenna a little to see the accuracy change.

I haven't used the 182 so maybe I'm all wet. I frequently learn here!

John