Two factors for major market board-ops in the 70's. FCC regs at the time called for a licensed operator on duty at all times. By then, remote control was permissible, so having a board-op/engineer allowed the the hiring of non-licensed talent in big markets - AND - live copy woven into commercial beds and back-timed sing-outs was much more common during the day.
Also, remember the tranisition from 45's to carts. Our first song carted - 1976 Life in the Fast Lane / Eagles, that had to be cut down to remove "Goddamed". Good news about carts: no more "groove burn" caused by cuing records, a big problem with soft intros, and of course, jocks had 45's laying all over the place unprotected - it wasn't unusual to bail out of a skipping record. And no 33/45 rpm mis-starts (ALWAYS FUNNY). Bad news- stereo carts had bad phase problems leading to phase errors and tinnyness in mono. And if you punched a song cart early, the re-cue time, even with FF was torturous.
BTW, tape noise on carts was a good reason to pre-compress songs when mastering to cart, and made for a more consistent jock to music ratio... I've read that Jahni Kaye uses this practice at K-Earth, obviously for the latter reason since music is now a digital file.
Also, remember the tranisition from 45's to carts. Our first song carted - 1976 Life in the Fast Lane / Eagles, that had to be cut down to remove "Goddamed". Good news about carts: no more "groove burn" caused by cuing records, a big problem with soft intros, and of course, jocks had 45's laying all over the place unprotected - it wasn't unusual to bail out of a skipping record. And no 33/45 rpm mis-starts (ALWAYS FUNNY). Bad news- stereo carts had bad phase problems leading to phase errors and tinnyness in mono. And if you punched a song cart early, the re-cue time, even with FF was torturous.
BTW, tape noise on carts was a good reason to pre-compress songs when mastering to cart, and made for a more consistent jock to music ratio... I've read that Jahni Kaye uses this practice at K-Earth, obviously for the latter reason since music is now a digital file.