By day, WOI is powered at 5,000 watts using a single non-directional antenna. Due to its low transmitting frequency and Iowa's flat land (with near-perfect ground conductivity), its daytime footprint is equivalent to that of a full-power FM station, providing at least secondary coverage to almost all of Iowa-as far east as Cedar Rapids and as far west as Sioux City. Its secondary signal also covers portions of Minnesota, Nebraska, Missouri and South Dakota. Its daytime coverage area is similar to that of central Iowa's most powerful AM station, 50,000-watt WHO. But 640 AM is a clear channel frequency reserved for Class AKFI in Los Angeles. To avoid interference, WOI reduces power at night to 1,000 watts, with power fed to both towers in a directional pattern that pushes the signal to the east, concentrating it in the Des Moines and Ames areas.[2] Programming is also heard on 250-watt FM translatorK284CN at 104.7 MHz.[3]
Historically, WOI is one of the oldest radio stations in the United States, having begun experimental transmissions in 1911.
History
Historical broadcasts
The history of WOI can be traced back to 1911. "Dad" Hoffman, a physics professor at what was then Iowa State College, installed a transmission line between the Campus Water Tower and the Engineering Building and set up a wireless telegraph station. By 1913, this was known as experimental station 9YI and it was sending and receiving weather reports by Morse code on a regular basis.
The first sound broadcast was an hour of concert music on November 21, 1921. The Commerce Department issued a full radio license to WOI in April 1922. The first regular broadcast took place on April 28, 1922; 102 years ago (April 28, 1922). The original call sign 9YI is now W0YI and is retained by the ISU Campus Radio Club, with the amateur radio station in the Electrical Engineering building.
The first regular programming on WOI was farm market reports gathered by ticker tape and Morse code, broadcast throughout the state. Another early staple was sporting events by Iowa State's athletic teams. In 1925, "The Music Shop" aired for the first time. One of the longest-running programs in the history of radio, it moved to WOI-FM in the 1970s before going off the air in 2006. In 1927. another longtime favorite, "The Book Club" was added; it also aired until 2006.
On December 1, 1949, Iowa State launched an FM sister station to WOI 640, WOI-FM at 90.1 MHz. WOI-TV was subsequently launched in 1950 as the first television station in central Iowa. It was also the first commercial TV station owned by an educational institution. It was affiliated with all four networks at the time: CBS, NBC, ABC and the Dumont Network. It became solely an ABC affiliate in 1955. WOI-TV was sold by the Iowa Board of Regents on March 1, 1994; the station is now owned by Tegna.
Today WOI's programming consists of both NPR and locally produced talk shows along with local news reports and BBC news updates. The classical music of the early years migrated exclusively to 90.1 WOI-FM in the 1960s. When the radio services of Iowa's state universities were merged into Iowa Public Radio in 2004, WOI became the flagship of IPR's Operations and IT services.