Early Television Stations
W9XAT/W9ICI - Minneapolis
W9XAT began broadcasting in 1933 in Minneapolis. Doctor George Young, founder of radio station WDGY received a license for a 500 watt station in what was considered at the time the "Ultra High" frequency ranges of 42 to 50 and 60 to 86 MHz. At first, he used the Sanabria 45 line/15 fps triple interlace standard, but later experimented with pictures having up to 125 lines. The station left the air in 1938.
W9XAT's chief engineer was Meyer Eisenberg, who is credited with building the camera and transmitting equipment.
More information on W9XAT can be found here. Here is an article from the October, 1933 issue of Modern Mechanic magazine. It refers to call sign W9ICI, which may have been George Young's amateur call sign.
Here is an excerpt from The History of Radio Station WDNY, a graduate thesis by Jeremy Verne Haines, submitted to the University of Minnesota in 1970.
Broadcasting, October 1, 1938