My apologies for being late to this movie, but my two cents regarding WABC....
In college during the late '60s it was a reliable late evening listen where I was in eastern Iowa. We had a few dozen students from the NYC area. So naturally, they were the most ardent listeners. Cousin Brucie and the first hour of Ron Lundy. Then at midnight (Central), just about everyone flipped over to XERF and Wolfman Jack.
Other popular nighttime signals in the area were WBZ (Bruce Bradley/Dick Summer), WLAC (John R.), KAAY (Doc Holliday), KOMA (Charlie Tuna, Larry Lujack), and of course, WLS (Art Roberts). The closest thing to a local was KIOA Des Moines, 125 miles away but with a very listenable 5kw nighttime signal. (Dic Youngs...a statewide "institution").