https://historymatters.gmu.edu/d/6544/Was looking up information about the public airwaves/advertisement "balance", and happened upon a historic article:
"Source: Congress, Senate, Committee of the Judiciary, Juvenile Delinquency (Television Programs), 84th Congress, 1st Session, April 6 and 7, 1955 (Washington: Government Printing Office, 1955)."
excerpt:
"Air Waves “are in the Public Domain”: Public Television Advocacy in the 1950s
Although educational radio stations flourished in the early 1920s—more than 200 existed prior to the introduction of network radio in 1926—most faltered shortly thereafter. One reason was the alignment of the Federal Radio Commission (FRC), created by legislation declaring that the airwaves belonged to the public, with commercial interests. When the Federal Communications Commission (FCC) replaced the FRC in 1934, educational, religious, and labor groups promoted an amendment requiring the allocation of one-fourth of all broadcast licenses to nonprofit organizations. The amendment failed to pass, and by 1937, only 38 educational radio stations remained in operation."