California Historical Landmarks in Santa Clara County
California Historical Landmark 836
Pioneer Electronics Research Laboratory
Channing Avenue and Emerson Street (In Sidewalk, Southeast Corner)
This is the original site of the laboratory and factory of Federal Telegraph Company, founded in 1909 by Cyril F. Elwell. Here, Dr. Lee de Forest, inventor of the three-element radio vacuum tube, devised the first vacuum tube amplifier and oscillator in 1911-13. Worldwide developments based on this research led to modern radio communication, television, and the electronics age.
Citation from California Office of Historic Preservation