So I took the upper back cover off my N810 to fix the intermittent on the left speaker (and did that with no trouble). While I had it off, I noticed a little tiny coax connector with no cable connected to it, and on examination, the center pole connects to the ground plane, so it's a reverse-polarity connector. These are commonly used on WiFi and such because FCC regulations prohibit use of industry standard connectors on devices certified only with their provided antenna, and reversing the polarity is enough to be nonstandard, but allows them to use standard parts. So I'm strongly suspicious that it's an external WiFi/BT antenna, and if not, it has to be GPS.

Anyone seen this connector before? Can anyone confirm what radio it's for, and/or identify the connector designation so I can order a connector or pigtail? It'd be really awesome to be able to add an external antenna jack to my N810, for either WiFi or GPS.

If nobody has input over the weekend, I'll be able to measure it at work Monday and look up what it is. But I'd rather have parts ordered by then...

I remember reading in one post that the GPS antenna was in the upper left corner (same corner as the LED light, but on the keyboard half). I've never opened up the tablet or have any knowledge of electronics, so don't go take my "rememberings" of previous posts.

I have seen similar connectors on cell phones, probably for factory test.

BTW Reverse Polarity RF connectors do no reverse the signal and ground connections (That would work like crap with coax cables). What they did is switch the male and female pins. For example a normal SMA female connector has the male shell with a female pin in the centre. The reverse polarity version has a male pin in the same shell. BTW They are standard parts. Check any electronics distributer - Eg. here is an RP-SMA that would connect to many access points.

They also carry many adapters, so if you figure out what type of connector you could buy an adapter to use a standard antenna. Maybe you can find it here.

If you do add an external antenna you may need to reduce the transmit power to stay legal (Check FCC Part 15 or your local equivalent for the rules).

There was a post in this forum sometimes last summer where there were links to repair manuals (including schematics) of N800 and N810. Those propably would be helpful.

For some reason I can no longer find that thread... Did some threads get deleted when forum reorg happened?

I remember that is was in someones personal web site/server that do post here frequently... Sorry, can not remember more details any more.

EDIT: Found it here! It was actually just before Christmas...

Ah, I see, thanks. I'll have to take a closer look at it, then -- maybe the line I saw wasn't ground. (And yeah, I kind of wondered how they wired coax to a center-ground connector without excessive loss...)

solwise.co.uk have some very useful pictures of RF connectors in their shop, which could make identification easy.

Benson: please post your findings, this sounds very interesting...

Someone ping Qwerty

Lol, I gave them to milhouse and he uploaded them to his site that has been mentioned in this thread

So, did you guys see two very interesting items from those documents?

Page 94 from 'N810_rx-44_sm_13_14.pdf'
Shows you what the actual antenna inside the N810 looks like. It's tiny and completely covered by the plastic housing.

Page 3 from 'N810_Schematics.pdf'
Shows you the schematic portion of what the page above is showing you. It has the references to L6200 (the antenna), the N6200 (the GPS5300 chip), the X6200 (the connector or 'GPS test connector'.

Page 98 from 'N810_rx-44_sm_13_14.pdf'
Shows you how someone could access the 'test pad' without completely taking the N810 apart.

I'm going to open mine up in a moment and try to augment the antenna. Maybe even connect it to the metal plate on the back on the N810 if it isn't already connected. But, boy, I would sure like a working GPS instead of the terrible connection that I currently get.


UPDATE:
I found that the antenna, shown on Page 3 of the schematics, is actually connected to the metal back plate. I tested it with an ohm meter and yup, it's connected. It's not a perfect connection as sometimes it breaks or makes contact depending on how much pressure you put on it. Oh wait, maybe it's because it's an inductor it will show as a short. I'm not 100% sure.