even though this is very late, cable was developed in late 40s/early 50s. Those stations did not come until the 80s. So 30 years qualifies very early on I guess, but sounds more revisionist time to me.
Maybe revisionist but what most people think of as "cable" was broadband cable (maybe DirecTV, launched 1994) with lots of commercial channels. They don't think of having a 12 foot antenna scouring the sky for signals.
There was certainly some earlier cable, e.g. HBO, if you could pickup broadcast, that predated channels like CNN.