KNOW FM: История радиостанции и её программного наполнения.

KNOW FM (91.1 FM) is the flagship radio station of Minnesota Public Radio's news and information network, primarily broadcasting a talk radio format to the Minneapolis St. Paul market. The frequency was the original home of KSJN, but the purchase of a commercial station at 99.5 MHz in 1991 allowed MPR to broadcast distinct talk radio and classical music services. KNOW FM's studios are located in the MPR Broadcast Center on Cedar Street in downtown St. Paul, while its transmitter is located on the Telefarm Towers in Shoreview.

The KNOW intellectual unit dates from 1980, when WLOL (1330 AM) was purchased by MPR in 1980 and changed its call letters to KSJN AM, a simulcast of its FM sister. MPR was already making plans to offer a two channel network when it acquired the frequencies to do so, and bought the AM frequency as a stopgap. In 1989, KSJN AM changed its call letters to KNOW and began airing an expanded lineup of NPR programming. Two years later, MPR bought 99.5 FM–the former WLOL FM. At that time, MPR moved the KNOW call letters and intellectual unit to 91.1, while the KSJN calls moved to 99.5 as a full time classical music station. The AM signal was later spun off into a for profit subsidiary to help fund the public broadcaster, and was eventually sold off. The station has since reverted to its original WLOL call sign. In the 1970s, KSJN 91.1 FM and WLOL (99.5 FM) cooperated in an experimental use of quadraphonic stereo, with each station carrying two channels of audio. However, this "quadcast" had some undesirable "ping pong" effects, much like early stereo broadcasts using the same method did. As KNOW now mainly broadcasts spoken word programming, the station broadcasts in analog in monaural audio in order to extend the station's coverage to its fullest extent possible.

KNOW FM features "Radio Heartland", a Web and HD Radio service, on its HD Radio subchannel. Its playlist consists primarily of acoustic, singer songwriter, folk and Americana music. The service launched in December 2008. Radio Heartland's schedule also includes the programs Live from Here and American Routes from American Public Media, and the shows The Thistle & Shamrock and Mountain Stage from NPR. These additional shows were added to Radio Heartland's schedule in November 2009.

The callsign KNOW was also used by a major AC radio station in Austin, Texas, located at 1490 kHz. The station signed off in 1989 after operating for 50 years. The Spanish station KLGO assumed the frequency in 1993.

The callsign KNOW was also used by an oldies station in Lufkin, Texas, located at 1420 kHz, until it suffered a fire and shut down in 1987. It was owned by Pine Air, Inc.