KOAC (550 AM) is a radio station licensed to Corvallis, Oregon. The station is owned by Oregon Public Broadcasting, and airs OPB's news and talk programming, consisting of syndicated programming from NPR, American Public Media and Public Radio Exchange, as well as locally produced offerings.

Due to its transmitter power and location near the bottom of the AM dial, KOAC's covers most of Oregon's densely populated area during the day, providing at least secondary coverage from Portland to Roseburg. It is the only directional AM radio station in the United States which uses a shunt-fed antenna.^[3]

History

KOAC is one of the oldest radio stations of its kind. It was first licensed, with the sequentially assigned call letters KFDJ, to the Oregon Agricultural College (later known as Oregon State University) on December 7, 1922,^[4] and made its debut broadcast on January 23, 1923. It became KOAC in late 1925.^[5] The station was one of a number of AM stations signed on by universities in the early days of radio. Unlike most of its contemporaries, KOAC was eventually able to have a frequency to itself full-time.^[3]

In 1932, the station's management was transferred from Oregon State University to the Oregon State Board of Higher Education's General Extension Division. However, the state headquarters and network studios remained at the Corvallis campus.^[6][7][8] The first broadcasts by KOAC were made from the original campus studio in Kearny Hall in 1923. From 1928 to 2006, KOAC's studio was based on campus in Covell Hall, where OSU faculty and students broadcast educational programs and later live news programs across the state. Starting in the 1950s, the board signed on a number of satellite radio stations, as well as a sister network of television stations fronted by KOAC-TV (channel 7, which signed on in 1957). This group became known as Oregon Educational Broadcasting, which evolved into the Oregon Educational and Public Broadcasting Service in 1971. The state-wide radio and TV studios (KOAC-AM-TV) remained on the Corvallis campus as the network flagship until 1981. The network was then spun-off from the Board of Higher Education and became a separate state agency known as Oregon Public Broadcasting. At that time, its Portland-based satellites, KOAP-FM-TV (now KOPB-FM-TV) became the flagship.