It’s like the “tuning fork of the city”

To much of the world, the most iconic image of San Francisco is the Golden Gate Bridge or the Transamerica Pyramid, but to many city dwellers the Sutro Tower stands as the most familiar sight.

The tower reaches 977 feet high, on many days rising out of the fog and appearing as the “tuning fork of the city,” as San Francisco Chronicle columnist C.W. Nevius describes it.

It went online in 1973 in part to provide Bay Area television viewers with relief from the ghost images, snowy pictures and other artifacts of the hilly terrain that defines the region. Cable and satellite TV eliminated those problems, but even today more than a million viewers still get over-the-air TV signals from antennas on the tower.

The tower is used by 11 television stations, four FM radio stations, satellite and cable providers, and nearly two dozen public safety and commercial wireless communication services. Signals from each TV studios are delivered to the Sutro’s transmission building by microwave or fiber optic cable, amplified in their transmitter equipment and sent up the tower to the antennas, which beam the signals throughout the region.

Sutro Tower wasn’t always an endearing part of the landscape. At its outset, many thought it an eyesore, as this episode of the Exploratorium’s Science in the City series shows.