Yagi

A Yagi is a type of directional antenna (or beam) made of of two or more parallel elements (usually metal rods). Because it is directional, you can use it to find the direction of a transmitter (as in a Fox Hunt). It also helps to hear distant or weak stations by blocking out noise and interference coming from other directions. I can also allow you to transmit with more gain in a particular direction, if you know the direction of the station you're trying to reach.

You can easily make a homemade yagi antenna out of a tape measure, some PVC pipe, and some coax with simple tools and a soldering iron.