Thursday, February 7, 2013

San Francisco's KNBR-680

I was up in the San Francisco Bay area for a couple of days last week. Stayed overnight in Belmont, about 20 miles south of the city, down on the peninsula. While there, I suddenly realized that I was less than a mile from the KNBR-680 transmitter site, so jumped in the truck early one morning to check out the site. The site is at the edge of a residential area, in the boggy area next to San Francisco Bay, and just south of the San Mateo - Hayward bridge (CA 92). KNBR broadcasts with a power of 50KW.

The single broadcast tower is impressive, some 550 feet tall. It is sectionalized, an FCC type 3, and is also a nice example of top-loading. The lower section is 400 feet tall, and the upper section 150 feet. With the top hat, KNBR realizes an electrical equivalent of .520 wavelength. Just feet from San Francisco Bay, its radials literally dangle in the boggy water. It's no wonder they call KNBR "The Flamethrower".

On the air since 1922, (as KPO, originally transmitting from downtown San Francisco) KNBR has had a long history. It became an affiliate of the NBC network in 1927, and was later sold to NBC and became their flagship station on the west coast. The call sign changed from KPO to KNBC in 1946 and remained until 1962 when it was changed to KNBR after the local NBC television affiliate assumed the KNBC call.

In 1987, when NBC got out of the radio business, KNBR was sold to Susquehanna Corporation, a longtime radio station operator. Currently, KNBR broadcasts a full-time sports format, and has so since 1990. KNBR is the longtime radio home of baseball's San Francisco Giants and had been affiliated with ESPN, but on January 2, 2013 became a charter affiliate of CBS Sports Radio.

KNBR "The Sports Leader" is owned by Cumulus Media Partners, LLC, a private partnership of Cumulus Media, Bain Capital, The Blackstone Group, and Thomas H. Lee Partners. It was purchased from Susquehanna in 2005 along with other Susquehanna Radio Corporation stations.

The tower site is located at latitude 37.54722222 (N) and longitude -122.23333333 (W). If you are ever in the area, be sure to check out this impressive site.

Headed home to southwestern Arizona last Tuesday, KNBR was easily logged on the truck radio while motoring through Needles, CA and into Arizona at mid-day with good signal strength, at distances exceeding 480 miles.

Note: As of this date, the FCC database still erroneously lists KNBR as being owned by the Susquehanna Radio Corporation.

KNBR-680, San Francisco, CA

KNBR-680 upper section and top hat.


gkinsman said...


What is the shorter tower in the KNBR tower photo?



Hi Gary,

Nice to hear from you again.

Very good question. Found a video clip which talks about both towers, but the audio is masked quite a bit by the wind.

Possibly used to fine tune the pattern of the big tower? Maybe someone else has additional info on this.


Chris Webster said...

A friend told me about X102.3 a few days ago. Now it’s programmed as number 1 on my car stereo. The music keeps me jamming, especially during their morning show. It’s always a great way to start my day. Tune in, you may even win some tickets like I did.