I can recall on three separate occasions (early 70s, mid 70s and mid 80s) hearing L.A. radio insiders say that if KFI turned off the transmitter after Lohman and Barkley signed off in the morning that the ratings wouldn't be affected. An exaggeration, but indicative of just how much that monster signal struggled.
From what I've heard, KFI had the Dodgers around that time too, and I'm sure that helped.
What about WLW in Cincinnati? Weren't they trailing WKRC in the ratings before Randy Michaels came in and tossed the dreadful NBC TalkNet nighttime lineup, among other things?
KRLA was 50k, right? Seems like they got very good at shooting themselves in the foot.(Maybe someone in the southland can correct me.)
WIND was mentioned...From what I can tell, they were Group W's red-headed stepkid despite some A1 talent in the 70's (Robert W. Morgan, Stu Collins, The Polish Princess, etc.)