gps loosing signal at gas station

erricson_nguyen · 09-22-2007, 01:24 AM

every time i stop for gas my gps loosing signal i checked b4 stop 4 gas at least there were 7/10 sat, any 1 have similar problem please help this newbie how to fix it i use MS usb reciever i believe it's a Pharos gps 500 Sirf III iguidance 4.0 i place it on dashboard , to get signal back i have to restart pc exit iguidance relaunch won't help

thank in advance

Marassa · 09-22-2007, 01:40 AM

Are you sure the gas station does not have a metal roof?

erricson_nguyen · 09-22-2007, 01:58 AM

Quote: Originally Posted by Marassa

Are you sure the gas station does not have a metal roof?

i have no idea but i went 5 different station same thing happened

BiG K · 09-22-2007, 04:37 AM

Simple fix really.....don't go to a gas station :P

The gas station will have somesort of a roof, which will block the signal from getting through, you could hack the GPS and fit a stronger aerial onto it.

GPS works by time. All the sattelites have a precise time, which they broadcast. The GPS receiver than works out where the satelites are judging by the time. GPS microwave signals take time to reach the ground, I can't be bothered working out the exact time, but the further away a satelite is, the longer the signal takes to reach you.
For example, if you have four satelites, each one will give a slightly different time down to the nanosecond, whch the GPS receiver can then work out where you are! With a roof, those times can get a little skewed and you'll have "lost signal" while in all reality, you won't have lost the signal completely, the GPS receiver will get widely varied times, so the GPS receiver cannot pinpoint your location.
At any one time, there are always three or more GPS satelites above us ;-)

With the launch of the European GPS satelites, we will actually be able to accurately work out where we are....to a meter!! Currently, US GPS sattelites can work out only to 10 meter range.

Try to use a petrol pump near the edge of the forecourt, which should help you with your signals

Laidback · 09-23-2007, 03:25 AM

I think you're all missing the point! When he drives out of the gas station he should get the signal back in seconds, not have to restart the pc.

eliza721 · 09-24-2007, 03:31 AM

I think it's normal, sometimes it also happened to me

erricson_nguyen · 09-26-2007, 11:34 AM

i dont think metal roof is the only cause the signal lost, there maybe something els
while im listening an AM radio with clear n clean reception then there're a tromendous amount of interference when approaching any gas station, i think this might also effect
and cause the gps signal lost, just my though

jonessc · 10-08-2007, 01:18 PM

Quote: Originally Posted by Laidback

I think you're all missing the point! When he drives out of the gas station he should get the signal back in seconds, not have to restart the pc.

the gps reciever should reaquire satellites within a few seconds...?

Sonicxtacy02 · 10-08-2007, 03:40 PM

personal experience pharos gps = garbage. I had two.. neither lasted a year after purchase. Got a BU-353.. its on my roof and rock solid no matter where i am.

kbreeden · 10-08-2007, 03:59 PM

+1 on BU-353. My BU-353 is in my trunk, covered by a closed metal trunk lid, and it's still rock solid no matter where I am.

Marvin Hlavac · 10-08-2007, 08:07 PM

For the past couple of months I've been using the same Microsoft/Pharos GPS-500 receiver without any problem. Mine isn't even on the dashboard close to the window, yet still works just fine (even at gas stations

). I suspect something else is at play here - perhaps something in your car is causing the GPS unit to not perform as it should. A metallic tint in the car's windows could reduce signal strength and make it more difficult to reacquire satellite fix. Interference from computer, LCD monitor, or other electronic equipment could cause the same. Chances are good that if you place the GPS receiver outside your car (at least for testing purposes) it will work just fine.

KryptonianJorel · 10-08-2007, 09:35 PM

I don't have experience with your particular receiver, but I am a big hardware person, and this def sounds like a hardware problem. As said above, metals and even glass mess with the signal, kinda the same concept how wifi doesn't go thru cinderblocks. The metal tops of the Gas Stations probably cause the loss of signal, and your receiver cant reaccuire these signals easily.

I suggest: Check for a firmware update, try a different USB-to-Serial software driver, and lastly try a different receiver. I have a BU-353 crammed between 2 metal plates and it works great, so something must be up with your receiver.

The BU-353 is like $35 on ebay. I know you probably dont want to have to buy a new receiver, but its probably necessary

erricson_nguyen · 10-14-2007, 09:48 AM

thanks all for your replies, after severals days of testing at exact locations i found that the usb reciver fail but the bluetooth worked the problem is if i plug direct to usb port on mobo it work fine , but it failed if run through non powred hub so i replace with a powered hub now it work fine almost every where