On USB 802.11B and earlier routers manufacturers used UF.L connectors.

Now the thing is MHF connectors. They are made by i-pexconnectors.com.

I contacted them but have not received anything back from their headquarters in Texas, yet. I'll check my email again and get back to the board.

[Remove the black plastic rectangular ventilated shell at this point]

If you have a v1 (blue antenna chip), it's very easy to add an external connector. Get the CONREVSMA003.031, or the .062. If you get the .031, you need to spread the ground pins apart a bit, the board is actually slightly thicker than .031. If you use the .062 you must use a spacer. There is a very good guide online on how to do the modification: http://ronobvious.livejournal.com/296.html

In short: Desolder the blue antenna chip. And connect the CONREVSMA003 over the existing traces. Takes about 5-10 minutes.

Another guide exists, using a different connector, but it is a hack-job using a different connector, and very complex requiring a lot of different tools. I don't recommend it.

If you -had- a v1, and it 'died', you need to bake it. Put it in aluminium foil (without the case), preheat your oven to 200▫C, and bake for 7 minutes.

If you have a v2, or you do not want to remove the internal antenna on a v1, then you need an MHF connector from i-pexconnectors.com. It would be best to get a commercially-made MHF pigtail which terminates in an RP-SMA. When I hear more about the it I'll post.