The “channel” thing sprung from Chuck Blore’s KFWB “Color Channel 98” innovative Top 40 format in then later 60’s in LA. Ma ny stations adopted it, one of the stations in the group I interned at in Mexico City in 1963 was “canal 79” so when I built my first station in ‘64 I used the same jingle package as Radio Musical Canal 57.I don't remember much about its 1960s days, though I do remember the slogan: "K-Q-E-O, Channel 92". Already the literalist even in elementary school, I found that objectionable. "Radio stations don't have channel numbers!" I only knew about TV channel numbers at the time.