With no links or pictures and the fact that what you are describing seems to be "homemade", I'm not sure exactly what you have there. However, that is not important since I am sure that you can get something commercially produced that is far superior in operation.
I recommend getting a high power USB wireless adapter
along with a very high gain parabolic grid antenna
, which will offer up to several miles of range. CyberGuys has a package deal
that includes everything you need for an excellent price.
Note that because "n" devices require multiple antennas to achieve higher speeds and very few if any public hotspots use "n" access points, you are much better off sticking with a high powered "g" adapter instead. Let me know what you end up using, and how well it works out. Scott.