GPS Antenna direction

[idonthaveaname]

Recently I picked up a used Garmin 498 GPS and it needed an external antenna. Not knowing if the unit worked perfectly I didn't want to spend a bunch of money on a new antenna so I bought a cheapy $7 one I found on the internet computer machine. It works it seems (at least it locates me). My question is: How should it mount? It's a magnetic base (useless on an aluminum T top) so I need to "fix" mount it. The picture is shown. Does it matter which way it points? NSEW? Has anyone used one of these?



I have seen the round Garmin and generic satellite antennas but if this one works why change it? Do the more expensive satellite antennas work better? Is there a difference in satellite antennas?

Thanks.

 

[dingbat]

Re: GPS Antenna direction

It doesn't matter directionally. I would question the long term serviceability of equipment if it was not designed with the marine environment in mind.

I'm guessing the "How to mount" is the $82.49 cent question....lol

 

[idonthaveaname]

Re: GPS Antenna direction

It doesn't matter directionally. I would question the long term serviceability of equipment if it was not designed with the marine environment in mind.

Good to know direction doesn't count ;-) As far as serviceability at $7 I am not too worried. :facepalm: Actually, after running through some research I have seen a trend toward these small antennas. Essentially they are not unlike the ones you see on car and if the unit is sealed what can deteriorate?

I figure I can strap the thing onto the top of the T top without much hassle or place a small steel plate for it to stick on.

 

[K-2]

Re: GPS Antenna direction

I know lots of guys using similar products with no problems. They are using Navtrek on a laptop computer and it is hard to find a
"marine" gps antenna that has a USB plug on the end, but ones like yours are easy to find with USB end.

 

[idonthaveaname]

Re: GPS Antenna direction

Mine is a coax connection and designed for my Garmin 498 however I also have a satellite antenna with a USB connector for my laptop. Both are easy (and cheap) finds on the internet computer machine.

 

[Outsider]

Re: GPS Antenna direction

Let us know how it does in the South Florida sun and salt air ...

 

[idonthaveaname]

Re: GPS Antenna direction

They both work and -- so far -- have lasted just fine.

 

[dingbat]

Re: GPS Antenna direction

Good to know direction doesn't count ;-) As far as serviceability at $7 I am not too worried. :facepalm: Actually, after running through some research I have seen a trend toward these small antennas. Essentially they are not unlike the ones you see on car and if the unit is sealed what can deteriorate?

I figure I can strap the thing onto the top of the T top without much hassle or place a small steel plate for it to stick on.

I hope you don't mind rust stains all over your hardtop from your steel plate.

The "marine" units and cables are white to help protect from UV exposure. It would be interesting to see how your unit holds up to the sun over time.

 

[Bondo]

Re: GPS Antenna direction

I hope you don't mind rust stains all over your hardtop from your steel plate.

The "marine" units and cables are white to help protect from UV exposure. It would be interesting to see how your unit holds up to the sun over time.

Ayuh,.... Wouldn't a coat of Paint fix that issue,..??

 

[idonthaveaname]

Re: GPS Antenna direction

Ayuh,.... Wouldn't a coat of Paint fix that issue,..??

Yup. Pretty much Bondo but I see dingbat's point. Any how I don't have a hardtop just a T Top with canvas covering or I would just glue the GPS to the hardtop.

Funny thing about all this marine stuff being white...white doesn't hold up any better than any other color down here-it all fades and falls apart. And the units (GPS) you see on cars? Black usually and before you mention cars are not boats...it's southern FLA and there is salt air everywhere. Fact is...there are a lot of boats painted many other colors other than white down here. That said, there are a few ways to fasten this little booger; epoxy, gorilla glue, etc. I could fashion a piece of aluminum (no rust) or a sheet of some fiberglass body part I have left over and dab some epoxy on it. Matter of fact...the fiberglass board isn't a bad idea and I happen to have a piece from a hole I made fer a hatch door. Thanks for all the tips.

 

[UncleWillie]

Re: GPS Antenna direction

Does it matter which way it points? NSEW? Has anyone used one of these?....

If you think about it, How could you even mount it pointing in any particular direction on a moving vehicle that can drive around in circles?

The important thing is to keep the flat side UP. Do not mount it on a wall.
Mounting it under a fiberglass deck will have little effect.

 

[bruceb58]

Re: GPS Antenna direction

I put one of those on a motorhome. I just used some 3m 4200 to hold it in place on the roof.

 

[idonthaveaname]

Re: GPS Antenna direction

If you think about it, How could you even mount it pointing in any particular direction on a moving vehicle that can drive around in circles?

The important thing is to keep the flat side UP. Do not mount it on a wall.
Mounting it under a fiberglass deck will have little effect.

Yeah..when you think about triangulation and how it works it makes more sense and it definitely does not work under cover...at least not this little thing. There are antennas you can mount below deck however.

 

[idonthaveaname]

Re: GPS Antenna direction

I put one of those on a motorhome. I just used some 3m 4200 to hold it in place on the roof.

I think 4200 would work perfectly.

 

[bruceb58]

Re: GPS Antenna direction

Yeah..when you think about triangulation and how it works it makes more sense and it definitely does not work under cover...at least not this little thing. There are antennas you can mount below deck however.

Try it below deck and above deck and compare the signal strengths. My bet is they are similar.

 

[idonthaveaname]

Re: GPS Antenna direction

Try it below deck and above deck and compare the signal strengths. My bet is they are similar.

Been there/done that. Under cover there is no signal. This unit needs a clear shot at the sky. One...that's a concern in that what happens on cloudy days? A storm? The last thing you need is an unreliable antenna. My plan at this point is to test it and see how it works under different conditions. I figured for $7 one can't expect too much.

 

[Thalasso]

Re: GPS Antenna direction

Take some Velcro and fix to the dash. It will work just fine. This way when it quits working (the antenna) it's a easy removal without ruining anything. The antenna works just as well thru glass as on the top.

 

[bruceb58]

Re: GPS Antenna direction

Been there/done that. Under cover there is no signal.

Must be a pretty crappy GPS or antenna then. All my GPS units work fine inside a house or building! The frequency used for GPS penetrates fine with fairly low attenuation through fiberglass.

 

[idonthaveaname]

Re: GPS Antenna direction

Gimme a break boys. It was $7.

 

[bruceb58]

Re: GPS Antenna direction

Gimme a break boys. It was $7.

You have tested this particular antenna under the deck? You give the GPS enough time to acquire?