Haraden Pratt was a noted American electrical engineer and radio pioneer.
Pratt was born in San Francisco, California, where his parents were telegraph operators. He learned Morse code when young and worked briefly as a shipboard wireless operator before entering the University of California. After graduation he joined the American Marconi Company and helped to install and operate its 300-kilowatt trans-Pacific radio station at Bolinas, California and its companion receiver station in Marshall, California.
From 1915-1920 Pratt was a radio aide to the United States Navy, leading its radio laboratory and engineering at Mare Island Navy Yard, California. In this role he installed radio equipment on Navy ships and maintained West Coast shore stations until 1918, when he moved to Washington, DC, to take charge of the construction and maintenance of all high-power Navy radio stations.
From 1920-1926 Pratt worked for the Federal Telegraph Company in Palo Alto, California, where he designed a system for commercial radio telegraph service. When in 1926 the United States Congress passed the Air Commerce Act to fund radio aids to air navigation, J. Howard Dellinger of the National Bureau of Standards tapped Pratt and Harry Diamond to create a suitable radio beacon system in 1927-1928.