Skip Navigation
Photography @fedia.io
Matt Blaze @federate.social

KNBR (AM 680) Antennas, Redwood City, CA, 2024

Photography @fedia.io
Matt Blaze @federate.social

KNBR (AM 680) Antennas, Redwood City, CA, 2024
Photography @fedia.io
Matt Blaze @federate.social

KNBR (AM 680) Antennas, Redwood City, CA, 2024.
Photography @fedia.io
Matt Blaze @federate.social

KNBR (AM 680) Antenna, Redwood City, CA, 2024
45 comments

  • @mattblaze@federate.social Interesting that the guyed tower narrows at the base. Does it effectively have a single contact point with the ground? (BTW the alt text seems to confuse left and right.)

  • Rodenstock 50mm/4.0 HR Digaron-W lens (@ f/6.3), Phase One IQ4-150 digital back, Cambo 1250 camera (vertically shifted -23mm).

    This simple photo pushed the 50mm lens to the limits of its image circle with the large shift required to keep the tall antenna mast fully in the frame while maintaining its geometry. Hard vignetting of the upper corners was visible in the full sensor image, but fortunately the composition benefited from a narrower aspect ratio that cropped out the dark corners.

    • KNBR is a 50KW "Class A" (formerly "clear channel") mediumwave (AM) rado station broadcasting on 680 KHz, serving the San Francisco Bay area (and, at night, most of the west coast of the US). Opened in 1922, It was originally known as KPO, (later KNBC, and still later KNBR), and soon became the flagship station for the National Broadcasting Company (NBC)'s new western radio network. It is currently owned by Cumulus Media and now broadcasts a sports format. It sits next to the former KGEI site.

      • Mediumwave (AM) broadcast radio uses lower frequencies than other modern broadcasting and so requires much larger antennas (generally getting larger and larger as the frequency gets lower on the dial). This often entails highly customized antenna designs engineered for the particular site and station frequencies. For most radio stations (FM, TV, etc), the towers are there simply to get the relatively small antennas up high, but for AM stations like KNBR, the towers generally ARE the antennas.

45 comments