William B. Ogden's Radio School 

In 1895 Guglielmo Marconi and brother Alfonso transmitted radio signals across the hills behind their home in Bologna, Italy.   In 1904 Ambrose Fleming invented the vacuum diode tube followed by Lee DeForest in 1906 improving on the diode tube with a triode tube.  These developments are credited with paving the way for the launching of broadcasting as we know it.  
The first U.S. government regulation of radio matters came under the jurisdiction of the radio act of 1912 administered by the Secretary of  Commerce and Labor although its regulations did not mention broadcasting.   
Westinghouse Corporation built the first commercial broadcast station at their plant in Pittsburgh, PA  and on October 27th, 1920 they were granted the very first US broadcasting license to operate the station with the call sign KDKA.   
In 1927 the U.S. government created the Radio Act of 1927 and with it created the Federal Radio Commission (FRC)  administered by the U.S Department of Commerce .  The act was replaced in 1934 by the Federal Communications Commission  (FCC) which has been the regulatory agency ever since.
From those early years of broadcasting through approximately 1972 the FCC regulations required operators of broadcasting transmitters to hold a First Class Radio Telephony license in order to operate directional antenna arrays mostly used during nighttime hours.   Operators holding such a license were hard to find.  Further, radio stations did not want to hire one person with a first class license to operate the transmitter and another  person to be an announcer (DJ).   This created what was to be known at the “combo-man”, primarily an announcer/dj who also had a First Class Radiotelephony license. 
The FCC First Class Radio Telephony (First Phone)  examination was a very difficult test and required many hours of study to pass. The William B. Ogden Radio Operational School (ROES)  was established in 1946 in Burbank, CA. offering a standard course of study lasting over a period of several months. However, at the request of broadcasters,  and to meet the high demand for first class licensed operators, owner Bill Ogden  converted  his standard course  in 1949 to a  concentrated course  (cram course) of 6- 8 weeks,  12-16 hours a day, seven days a week.  Bill was the main instructor, his wife Tally and her sister Thora ran the office and Major (the collie) offered encouragement.