I’m not completely sure how the Fairness Doctrine was actually implemented by the broadcasters on a day-to-day basis, but I believe that they weren’t required to seek out someone to express opposing viewpoints, and they certainly weren’t required to air entire programs that had views 180 degrees opposite of their chosen programming (e.g. a station that broadcasts Limbaugh being forced to also broadcast Air America programming).
I thought that the stations in question simply had to allow people with opposing viewpoints a limited amount of time to present an editorial–and only at the request of the listener who wanted to editorialize.
See, that was the great thing about the Fairness Doctrine. All those misguided Dittoheads out there who believe that NPR and PBS only present a liberal viewpoint would be allowed to present editorials on the air to give the right-wing rebuttal.
Of course, in this particular case it would be a laughable exercise in futility because there are all ready a number of right-wing commentators on NPR and PBS presenting the views of Conservatives far more coherently than any reactionary, knuckle-dragging, Dittohead ever could.