WBAC's listed transmitting wavelength of 360 meters corresponds to 833 kilohertz. Despite the extensive plans, there are no reports that the proposed radio transmissions actually ever took place.
Des Moines Capital, April 21, 1922, page 1:

Kendall  To  Talk  Into  Radio  At  Drake  Relays

    Burt German, president of the Kiwanis club, which will broadcast the events at the Drake relays next Friday and Saturday, has secured Governor Kendall to make a brief radio address to the world at large before the events begin.
    Likewise star athletes from various colleges will send radio words of greeting to fellow students all over the country who will be waiting for air messages as to how the meet is going.
    The Kiwanis broadcasting machine will be located near the press box at the stadium.
    Arrangements have been made to take moving pictures of the governor and some of the visiting stars talking into the broadcaster.
Chicago Tribune, April 23, 1922, Part 2, page 1:

    Des Moines, Ia. April, 22.--Permission of the United States government to allow the use of radio instruments with a wave length of 360 meters in broadcasting the results of the Drake relay race here April 28 and 29 has been secured.
    For the first time in the history of athletics results of the Drake games will be flashed through the air by wireless the minute each event is concluded. The Kiwanis club of this city, co÷perating with the Thomas Electric company, will broadcast the results.
    Colleges and universities in nearly twenty states have announced the receiving sets are being installed by them in order to receive the results of the meet.
    The 360 meter wave length will be permitted between the hours of 2 and 5 o'clock on the two days of the meet. The temporary call letters of the Des Moines station will be WBAC. Thousands of people in all parts of the United States who will be unable to attend the meet will be informed of the positions in which their teams finish in each event.
    Although the final tabulation of the entries has not been completed, the meet will far surpass any track event ever held in this section, K. L. "Tug" Wilson, Drake director, believes.