A print ad, which appeared in the November 13, 1962, edition of the Oakland Tribune, announcing the change of KNBC's call letters to KNBR. At the time, KNBR was the NBC Radio owned-and-operated station in San Francisco, broadcasting on 680 AM and 99.7 FM.
The reason for the November 1962 name change was to allow NBC to move the KNBC calls from their radio station in San Francisco to their television station in Los Angeles, which had been known as KRCA (Channel 4). NBC had requested a reinstatement of the radio station's original call letters, KPO, but were rejected by the FCC. As an alternative, they asked for and were granted the new KNBR callsign.
The station had switched from KPO to KNBC on November 23, 1947.
The body text of the ad reads:
Brand new "R"adio name for NBC San Francisco! ... Delivering the top listening pleasure as usual with Doug Pledger 6:00-10:00 AM ... John Bowles 10:05 AM-12:00 NOON ... Evangeline Baker 12:15-12:55 PM ... Joe Gillespie 1:05-3:00 PM ... Owen Spann 3:05-6:00 PM ... NBC News on the hour ... KNBR California News on the half hour ... NBC Monitor on the weekend.
Research by Len Shapiro for the Bay Area Radio Museum