WJAZ was the call sign used from 1922 to 1931 by a series of four separate, but closely related, broadcasting stations located in Chicago, Illinois and operated by the Chicago Radio Laboratory/Zenith Radio Corporations.
Audiences at the Edgewater Beach Hotel could watch WJAZ studio performances through sound-proofed plate-glass windows (1923)
In 1924-1925 the WJAZ call letters were assigned to a "motor truck" mounted portable transmitter, used to evaluate potential permanent transmitter sites around Chicago.
February 1926 publicity photograph of the WJAZ engineering staff dressed as "wave pirates".
Portable broadcasting stations in the United States
Portable broadcasting stations in the United States was a category of AM band radio stations, which were not restricted to operation in a specific community, but instead were permitted to be transported for broadcasting from various locations. These authorizations began in the early 1920s during a period when radio regulation in the United States was the responsibility of the Department of Commerce. However, after the newly formed Federal Radio Commission (FRC) took over in early 1927, it was decided that allowing stations to make unrestricted relocations was impractical, and in 1928 the FRC announced that existing portables that had not settled into permanent locations would be deleted. Station owner C. L. Carrell attempted to overturn the new policy, but was unsuccessful.
1928 publicity photograph of KGGM, used each evening along the route of a coast-to-coast foot race.
A. H. Grebe Company's WGMU, installed on a Lincoln automobile body and based in New York City (1925)
A. H. Grebe Company's WRMU, installed on the MU-1 yacht based in Richmond Hill, New York City (1926)
In 1924-1925 the WJAZ call letters were assigned to a "motor truck" mounted portable transmitter, used to evaluate potential permanent transmitter sites around Chicago.
