{http://www.wireless.org.au/~jhecker/helix/a2.jpg helical} Helical Antenna are directional, but not as much as ParabolicAntenna. They are almost always HomeBrew. * (http://www.wireless.org.au/~jhecker/helix/ Jason Hecker's design) is one that is also covered at (http://www.seattlewireless.net/index.cgi/BuildingHelicalAntennas seattlewireless.net) They are usually about 18dbi gain. When using a Helical antenna make sure that the other end of the link also uses one or you will lose 3dbi of gain. Also make sure it's wound in the same direction as yours, or you will lose '''all''' signal.