Ham is the word used to describe an Amateur Radio Operator. And why are we called Ham's

  The word Ham was applied in 1908 and was the call letters of one of the first Amateur wireless
stations operated but some members of the Harvard Radio Club. They were Albert S. Hyman ,
Bob Almy , and Peggie Murray. At first they called their station Hyman-Almy-Murray.
Tapping out such a long name in Code soon called for a revision and they changed it to
HY-AL-MU, using the first two letters of each name.

  Early in 1909 , some confusion resulted between signals from Amateur wireless HYALMU
and a Mexican ship named HYALMO, so they decided to use only the first letter of each name and the call became HAM.

  In early pioneer unregulated days of radio, Amateur Radio Operators picked their own frequency
and call letters. Then, as now , some Amateur had better signals than some commercial stations. The resulting interference finally came to the attention of congressional committees in Washington D.C. and they gave much time to proposed legislation designed to critically limit Amateur activity.

  In 1911, Albert Hyman chose the controversial Wireless Regulation Bill as the topic for his thesis at Harvard. His instructor insisted that a copy be sent to Senator David I. Walsh,
a member of one of the committees hearing the bill. The Senator was so impressed, he sent for Hyman to appear before the committee. He was put on the stand and described how the little
Amateur station was built. He almost cried when he told the crowded committee room that the bill went through , they would have to close up the station because they would could not afford the licensee fees and all the other requirements that were setup in the bill.

  The debate started and the little station HAM became a symbol of all the little Amateur stations in the country crying out to be saved from menace and greed of the big commercial stations who did not want them around. Finally, the bill got to the floor of Congress and every speaker talked about  the poor little station "HAM"
  You can find the whole story in the Congressional Record . And that is how an Amateur Radio Operator got associated with the word "HAM" from now to end of radios