The above description is the basic idea of what is going on with the Yagi-Uda antenna. Yagi antenna design is done most often via measurements, and sometimes computer simulations. For instance, let's look at a two-element Yagi antenna (1 reflector, 1 feed element, 0 directors).
Though there are no detailed records of when the sport of track and field began, experts say that track and field history can be traced back to 776 B.C. Track and Field History Experts say that track and field history can be traced back to 776 B.C when a cook named Koroibos, from Elis, won a race that was run over 600 feet distance. It is believed that this was the only athletic event for the initial 13 Olympic Games.
In the mid 1800's, the Reuters News Agency operated a live telex service using Homing Pigeons. Homing Pigeons were introduced to the United States in the mid 1800's. In the 1880's, the first 500 mile race took place in this country.