The struggle for educational television in the US was a struggle over frequency, moderated by the FCC.
Gilbert Seldes devotes a chapter to this in The Public Arts (1956), noting that both KUHT in Houston and WQED in Pittsburgh were doing well on the commercial spectrum, in contrast to "the well-financed station in Los Angeles" which was unable to build an audience.
This question of viability exercised Seldes as the alternative was commercial sponsorship, an awkward presence in the context of educational programs.
"The atmosphere in which broadcasters and educators debate is charged with recriminations. ... The assumption has always been that the broadcasters ought to put on educational programs although it is abundantly clear that nine-tenths of the people engaged in the business cannot possibly create educational programs and should not be allowed to do so if they could. A sponsor has no right to use his time on the air to 'educate' anyone in anything except the qualities of his product; a local station living on its share of the proceeds of network programs cannot possible afford to produce educationals." (274)
"We already know that the oldest method of all--Mark Hopkins at one end of the TV system and a student at the other--will work if our Mark Hopkins is pleasant-spoken and unpedantic and is content with the first phase of teaching: to stir the imagination, to arouse curiosity. It is too early to be sure about the methods that will not serve, because the actual schoolroom scenes and the carefully planned seminar discussions that pretend to be spontaneous, dreary as they are, may yet turn into something better." (275)