the university was authorized to establish a "War Department Training and Rehabilitation School" station, with the call sign WX2. This was followed in early 1920 by the issuing of an experimental radio license, with the call sign 9XI. These operations were under the oversight of electrical engineering professor C. M. Jansky Jr., the older brother of Karl Jansky. In 1920 a one-kilowatt spark transmitter was installed. In addition to communicating with amateur and other university stations, 9XI, in conjunction with the U.S. Department of Agriculture, transmitted market and weather reports by radiotelegraph. The development of vacuum tube transmitters, capable of audio transmissions, would lead to further advances, and over time 9XI began including broadcasts for general audiences. On February 2, 1921, the station inaugurated audio transmissions, as part of its nightly 8:30 p.m. broadcasts of market reports. In the fall of 1921, the station gave "a running account of a Minnesota football game through notes brought to the station's studios by a relay of students from the sidelines at the field." December saw the beginning of a daily noon broadcast of livestock prices. These transmissions initially originated from the electrical engineering building on the Minneapolis campus, where a transmitter was installed on the roof. Early years Initially there were no formal standards for radio stations making broadcasts intended for the general public. However, effective December 1, 1921, the United States Department of Commerce, which supervised radio at this time, issued a regulation requiring that stations making broadcasts intended for the general public now had to operate under a "Limited Commercial" license." On January 13, 1922 the university was issued its new license, which was given the randomly assigned call letters WLB, and authorized the use of both broadcasting wavelengths: 360 meters (833 kHz) for "entertainment", and 485 meters (619 kHz) for "market and weather reports". This was the first broadcasting station license issued in the state of Minnesota. WHA, operated by the University of Wisconsin–Madison, was issued its first license on the same day, making WLB and WHA the first two broadcasting licenses issued to educational institutions, and early examples of college radio stations. Other Midwestern universities also doing early telegraph and radio experiments include the University of Iowa's WSUI and Iowa State University's WOI, both started in 1911, and St. Louis University's WEW in 1912. WHA began its experiments in 1915. In February 1922, when a heavy snowstorm knocked