KNBR is an AM radio station licensed to San Francisco, broadcasting on a clear channel at 680 kHz from transmitting facilities near Belmont, California. KNBR's non-directional 50,000-watt class-A signal can be heard throughout much of the western United States and as far west as the Hawaiian Islands at night. For several decades, KNBR enjoyed a long history as the flagship station of NBC's West Coast radio operations.