''When you start thinking of broadcasting as a business and less as a charitable enterprise, then the result is that you get people thinking about it in new ways,'' said Dan Brenner, Mr. Fowler's longtime top assistant and now a professor at the UCLA School of Law.

One of the results of the buying and selling of television stations is that many broadcasters are now heavily burdened by debt. That, in turn, makes the profit imperative all the more powerful. Rise of 'Barter Syndication'

There is, for example, the advent of ''barter syndication.'' In this practice, a program distributor makes programs available to stations at reduced cost or no cost in exchange for advertising time, which the distributor then sells. Cash-needy broadcasters faced with having to repay heavy debt might make programming choices based on the deal, rather than the program.

The Fowler era of deregulation created what Mr. Brenner called ''an environment for dramatic activity,'' such as takeovers. But it was a time of less dramatic changes as well.

For example, the F.C.C. once had a vigorously-enforced rule against the airing of program-length commercials - shows that essentially sought to promote a commercial product. But the commission under Mr. Fowler has shown leniency toward such programs, leading to controversy in one of broadcasting's most sensitive areas: children's programming. In recent years there has been a boom in children's television shows based on toys - shows whose characters are drawn from the shelves of toy stores and which are produced, in many cases, by toy manufacturers.

For the toy makers, who get enhanced promotion for their products, and for broadcasters, who get barter deals on most of the shows, program-length commercials are good business. Critics, however, maintain that children, unable to recognize a sales pitch packaged as programming, are unfairly exploited. ''It's outrageous that the potential of children's television as an educational medium has been supplanted by purely commercial considerations,'' said Representative Timothy E. Wirth, Democrat of Colorado, last year when he introduced a bill that would require educational programming from broadcasters. The bill was not passed. Mr. Wirth was vigorously opposed by broadcasters in his run for the Senate last November, but was elected. A Fowler Hallmark: Leniency