Does GPS reciever need grounding?

**PharmD Heel** · 08-30-2006, 02:21 PM

Just wondering, does a GPS reciever need to be grounded? I've got my reciever plugged into a 4-point USB hub which has a 10 ft extension cable connecting it to the computer. Now the GPS reciever gets no signal sitting on the dash of the car. But, if I put it 5 inches away on the outside of the car, it gets great signal, as long as the magnet on the bottom of the GPS reciever is on the metal body of the car. I thought the USB would ground itself, but perhaps the hub and/or extension cable is preventing this? I'm thinking of just placing the GPS reciever on a metal plate, attaching a wire to it, and grounding the other end to the chasis of the car in hopes of fixing this problem. Anythoughts?

**shiltz** · 08-30-2006, 02:55 PM

I doubt grounding is an issue, the bottom i'm assuming is plastic as that's what everyone i've seen is and the car is painted so it's not being grounded being outside on the body of the car, I know i've read that GPS won't work thru certain types of glass though (polarized?) which some cars have, that could posibly be the problem.

**PharmD Heel** · 08-30-2006, 03:07 PM

The bottom is actually a big magnet, which is what made me think perhaps this is a grounding thing. The other weird part is the GPS receiver worked fine when I tested it out about a month ago using my laptop. That time I had the reciever plugged into the extension cable (no hub) and had it sitting on my dash (just like this time). The windsheild hasn't changed since then so all I could figure was the hub is keeping it from properly grounding....not really sure though. I'm gonna try some trouble shooting tonight to figure it out. But in the mean time I figured I'd see if anybody had any other ideas. Thanks a lot!

**shiltz** · 08-31-2006, 08:22 AM

I just though of it, but you said you have it on a hub, is it a powered hub or just a passive hub that uses the USB bus for power? I know unpowered can cause problems with some USB devices, I have that problem with my MP3 player actualy, I have a passive hub and my MP3 won't work properly with it because the hub doesn't provide enough power.

**PharmD Heel** · 08-31-2006, 09:46 AM

Thanks for the heads up on that. The hub is a passive one that just uses the USB for power. I'll plug her into an extension cable connected directly to the computer, place the reciever on the dash and see what happens. Hopefully that'll fix the issue. I won't be able to do it till this weekend, but I'll let ya know how it turns out.