Have you deleted the old named hubs? Best to tidy up that list.
Download inSSIDer 2.0 Totally brilliant.
If using another card on a computer, you may have to not only turn off the wireless connection that's not being used, but also disable the drivers in Device Manager. This should give inSSIDer free range to start.
It will tell you lots about local live stations, and also the 'privacy' method they are using.
Putting my radio enhanced aerial on the floor doesn't show much increase in the signal from my friend's router, but it does reduce to half, the other signals on my channel. Much more stable.