For me it was in the mid 70s when Peter Newman, brother to Jeff, was the late night announcer on 6WF (now called Local ABC Perth), and at around 11.30 pm on a Friday night played the Cheese Shop Sketch from Monty Python.
There is a beeped version of this for radio, and the normal version. As it was playing, I was saying to myself will they or won’t they play the unbeeped version.
No they won’t, yes they will, no they won’t, YES THEY DID.
That was the first time I heard the F word on radio. Now it is commonplace.