KTRS (AM)

KTRS (550 kHz) is a commercial AM radio station in St. Louis, Missouri. The station airs a talk radio format with some sports. The station is owned by KTRS-AM License, L.L.C., a consortium of local investors which includes actor and St. Louis native John Goodman. KTRS's studios and offices are located in Westport Plaza in Maryland Heights.

KTRS broadcasts with 5,000 watts of power, day and night. It uses a directional antenna at night to avoid interfering with other stations on AM 550. The transmitter is located near Gateway Motorsports Park in Madison, Illinois. KTRS can also be heard in St. Louis and its adjacent suburbs on 250-watt FM translator K291CW at 106.1 MHz.

On weekdays, KTRS airs local shows during the day and evenings. Zack Beining has an agricultural show with "Farmer Dave" Schumacher, followed by McGraw Milhaven in morning drive time, Frank Cusumano and Jill Farmer in late mornings, John Carney and Julie Buck in early afternoons, Heidi Glaus with and Josh Gilbert and Bob Ramsey in afternoon drive time, The Big Sports Show with Brendan Weise in the early evening. Two syndicated shows are heard: America at Night with Rich Valdés overnight and America in the Morning airs before sunrise.

Weekend programming includes shows on money, health, the outdoors, technology, home improvement, movies and pets, with occasional sports events. Most hours begin with world and national news from ABC News Radio.

The station was originally owned by the St. Louis Post-Dispatch daily newspaper. It began experimental broadcasts in 1921 at a wavelength of 360 meters (833 kHz) with 27 watts of power. The official sign-on took place on June 26, 1922. The original call sign was KSD, standing for Saint Louis Post-Dispatch. Along with WEW and WIL, KSD was among the earliest stations in St. Louis. KMOX didn't come on the air until 1925.

KSD moved to 550 AM in 1923. Power was increased to 5,000 watts daytime and 1,000 watts nighttime in 1934. KSD put a new transmitter in place in November 1948. The station was able to increased its night output to match its daytime output, 5,000 watts. But the nighttime signal required a directional antenna to protect other stations from interference.

KSD was one of the first eight radio stations of the NBC Red Network in 1926. KSD carried NBC's schedule of dramas, comedies, news, sports, soap operas, game shows and big band broadcasts during the "Golden Age of Radio." The NBC network affiliation lasted until the early 1980s. The studios were on the corner of 12th and Olive Streets.

At the end of World War II, KSD put a television station on the air. KSD-TV (now KSDK) debuted on February 8, 1947. Because of KSD Radio's long affiliation with NBC, the TV station also began broadcasting NBC shows. In 1980, the owners of KSD acquired FM station 93.7 KCFM. The call sign was changed to KSD-FM, since those call letters were already well known in the St. Louis radio market. In 1983, the AM station gave up the heritage call sign; the call letters continue on KSD-FM, now owned by iHeartMedia, Inc.