I have an inspiron 1520 with the 1390 internal wlan card and I see there is a place for an external antenna.  I can't find anything on the Dell site about this plugin.  I want to get an external antenna to help with the times I am in a fringe area for wifi access.  I checked on the web and there are lots of antennas available but I don't know what connector I need. (MC-CARD, MMCX, SMA, RP-SMA, RP-TNC???????)  Can anyone shed any light on this? If you can recommend a particular antenna I would welcome that information also.

Thanks.