I've seen antenna boosters for cell phones. They are paper thin flat devices that are placed under the cell phone battery. I really don't know if they actually work and I would think the radio signals are a different wave length than GPS so this may be a totally different ball game. There are some members of this forum that are very technically knowledgeable about GPS. Would any of you know if this is a feasible approach to boosting the N810 GPS performance?

I have not seem evidence that the cell phone boosters work. They would need to act as a ground plane to do so.

The Antenna on the N810 is part of the upper backplate. The section above the battery cover.

If you remove this it connects to bads on the circuit board.

Theoretically you could be able to make a cover that replaces the antenna with an N connector allowing you to attach a external antenna.

The main advantage of this would be that you can place the antenna outside the car.

While you could put a higher gain antenna in. This would not help much with GPS. Antenna gain is archived at the price of making it more directional.

As this antenna needs to pick up 12 satellites in different directions. You are limited in how much gain you can add. But a little is possible.
PS a GPS works on 1227.6 MHz and 1575.42 MHz Cell phones are at 850 / 900 / 1800 / 1900 MHz depending on where you are world wide.

Thanks. You answered my question very well. I hadn't considered the directional component. I wonder if there's much impact between vertical and horizontal polarization as there is with CB. Looks like my idea is probably not worth pursuing.

Ok, just a quick question. Why would you want to do this? For the added bulk and complexity, you could just get a small bluetooth GPS right? Or was this some sort of internal booster you were thinking about?

I was thinking internal. I find my setup with agps-ui workable enough. For me this is more about fully understanding than solving a problem I have. If the fix time becomes an issue for me I definitely buy a bluetooth GPS receiver.

Ok, now I want to see inside of my N810. I had completely opened my N800 in the past to see about overclocking it at the hardware level but it was easy to get into that unit.

Anyone know how to open the N810 without damage?

GPS uses circular polarization.

I once bought a GPS repeater. It consists of an antenna and a magnet to put on the roof of the car, a cable and a battery pack and a little transmitter and an internal antenna. The idea is to have the internal antenna re-radiate the signal in case you use a GPS receiver inside a car which has metal-shielded windows or for other reasons block the signal.

I've never found out how well it works, if at all, because even my old Sirf star II receiver worked well enough in my own car as well as the rental cars I've used it with. And my new MTK chipset GPS receiver seems to work anywhere anyway.

It didn't cost much though - a few dollars from Hong Kong.

I also have a GPS repeater - somewhere. It had a small antenna I could place on the roof or near the window and a stick for inside the car or at my desk.

That repeater worked well, but then I started switching to roof mount modules (Garmin GPS16/GPS18) or the newer BT models that work from deep within a car.

I would appreciate it if you could point me to the repeater since I've wanted to get another one.