recto101 said:What were KNBC-AM 680 Ratings and KNBC-FM 99.7 ratings before they became KNBR? I figured the reason the KCBS call letters stayed in SFO instead of migrating to LA was because they had years of high ratings even before the all-news era.
KNBC-FM ratings would have been negligible in those days - not sure about 680 AM. I'm pretty sure the first high-rated station format on 99.7 was KYUU in the late 70s. 680 would have been KNBR by the early 60s, when the calls migrated to Channel 4 in LA. By the mid or late 60s, KNBR was a popular MOR station - probably not as high rated as KSFO, but no slough either. David Kaye could possibly answer that.
When CBS decided to change KNXT in LA to KCBS-TV and KNX-FM to KCBS-FM, it was different. The FCC no longer required station owners to keep call letters within the same market, as they did in the early 60s. So I don't know the answer, but since the ratings for both KCBS 740 in San Francisco and KNX 1070 in LA were high, CBS probably decided it was stupid to change things.