Robert K. Karlowa had an longtime interest in radiotelegraphy, starting in 1907, and by early 1913 was "the chief operator of the Tri-Cities Wireless club", which met on the sixth floor of the Best Building in Rock Island, Illinois. In mid-1915, he and Ray E. Hall, representing the Tri-City Radio Laboratory, were issued an Experimental license for station 9XR, which also operated from the Best Building. This station used a spark transmitter and could only transmit Morse code, so it was never used for entertainment broadcasts. Moreover, effective April 6, 1917, with the entrance of the United States into World War One, all civilian stations were ordered to shut down for the duration of the war, and 9XR permanently disappeared.