Not getting lock?

**Misanthro** · 12-20-2003, 05:09 PM

I've got a Deluo serial GPS, and use MapPoint 2004 with AGPS. I'm having real problems with the GPS getting lock on sattelites. It's definatly disconnected far more than it's connected, and makes it very hard to depend on for getting anywhere. I have it mounted on the rear board under my rear window. It has a clear view of the sky, as the window it tilted in a hatchback style. I modded the power so that it run's off of the car's 12v via a 5v regulator (so that it is on even when the computer is not), but I don't see how that could be a problem. Any suggestions?

**Jackso** · 12-20-2003, 11:28 PM

If your rear window had the defogging grid, it may be stopping the signal similar to a Faraday Cage. I mounted my newly gotten device on the front dash where there is no grid on the window.

**deadweasel** · 12-21-2003, 01:32 AM

Welcome to the Club Jackso!

Faraday Cage huh? Sounds like you know a thing or two about electromagnetic theory, hmm? Glad to have yet another tech-level geek on board!

**hijinks21** · 12-21-2003, 08:13 AM

either that or he watched the screensavers last week

**tom2112** · 12-21-2003, 08:14 AM

Originally Posted by Jackso

If your rear window had the defogging grid, it may be stopping the signal similar to a Faraday Cage. I mounted my newly gotten device on the front dash where there is no grid on the window.

Also, depending on your car, the clear view of the sky may not be as good as intended. Along with the Faraday Cage problem, if your rear windshield is ultra-violet (UV) coated, then the GPS will have problems getting the signal.

I have the Deluo GPS unit also, and it has a magnet built into the bottom. Just for trouble-shooting sake, pop that bad boy on the roof of your car and drive around. It'll stay there nicely as long as you don't pull any Dukes of Hazard maneuvers. Trying it that way will tell you if it's your rear windshield or not.

Another thing that I noticed was that until I sat in my driveway for a couple minutes - sitting still so the GPS could sync up and do it's initial lock, the GPS wouldn't lock on very well. I guess it needs to do this once to find itself, then it's OK. It only takes a few minutes, so resist the urge to pop it in the car and immediately drive around town - like I did.

Then I read the directions, and figured out what my problem was. Now it works like a charm.

**DodgeCummins** · 12-21-2003, 08:27 AM

Or spend the money and get a high quality GPS receiver.

**Jackso** · 12-22-2003, 01:29 AM

Originally Posted by deadweasel

Welcome to the Club Jackso!

Faraday Cage huh? Sounds like you know a thing or two about electromagnetic theory, hmm? Glad to have yet another tech-level geek on board!

Well thank you for the welcome. I was feeling inspired the other night. I'm actually a Computer Engineering student, but I switched from Elecrical Engineering. I all but have an associates in Electronics (need to transfer back the core classes, already have all the tech credits) from the local community college from when I was in High School. I know a little about electromagnetic theories, Gauss Law all that jazz, but I actually failed my Fields class. Oh well, it was an elective anywho. But I am the engineer for 6 local radio stations, so I have LOTS of hands on experience with real fields, none of the theory crap for me.

**deadweasel** · 12-22-2003, 01:36 AM

Originally Posted by Jackso

Well thank you for the welcome...
...none of the theory crap for me.

Point taken! Nothing like experience to get knowledge hammered home! I have a couple of electronics classes from high school under my belt, but I don't remember half of what I learned actually working as an electrician about seven years ago!

**tom2112** · 12-22-2003, 07:27 AM

Originally Posted by DodgeCummins

Or spend the money and get a high quality GPS receiver.

What do you mean? The Deluo works well and is acurate.

**Misanthro** · 12-22-2003, 02:55 PM

Turns out it was definatly the defroster on the rear window that was messing it up. I put it up under the windsheild and it works perfect. Very acurate too, I can even notice it on the GPS display when I change lanes. Thanks for the help everyone.

BTW: Doesn't the Faraday Cage effect only work when the cage is grounded? I disconnected the wires to the defroster and it had no effect.