After the development by Lee de Forest of the triode vacuum tube in 1906, it was realized that the upper frequency at which the device could be used was limited by the spacing between internal components.
A series of selected letters, placed on both sides of the photograph, witnesses the highest acknowledgements expressed to Tesla by the greatest scientists of his time: Albert Einstein, William Crookes, Lord Kelvin, Wilhelm Conrad Röntgen, Robert A. Millikan, Lee de Forest, Edwin H. Armstrong, Arthur H. Compton, Arthur E. Kennelly, Popov and Pupin.
Black Forest | Robert E. Lee | Spike Lee | Jerry Lee Lewis | Bruce Lee | Peggy Lee | Lee Konitz | John Lee Hooker | forest | New Forest | Christopher Lee | United States Forest Service | Lee | Stan Lee | Lee Kuan Yew | Jamie Lee Curtis | Ang Lee | Forest of Dean | Nottingham Forest F.C. | Washington and Lee University | Tim Berners-Lee | Lee Hsien Loong | Wake Forest University | Lee Strasberg | Stewart Lee | Rickie Lee Jones | Lee Marvin | Lee Greenwood | Gypsy Rose Lee | Fort Lee, New Jersey |
Lee De Forest made a short film Songs of Yesteryear (1922) of Mitchell singing, using his DeForest Phonofilm sound-on-film process.
On 15 April 1923, she appeared in a short film, "From Far Seville", made by Lee de Forest in his Phonofilm sound-on-film process, and shown at the Rivoli Theater in New York City.
Based on the West Coast, he was in direct competition with Lee de Forest, a leading manufacturer of triodes sold under the Audion brand.
The Curtiss JN-4, known as "Jenny," was made by Curtiss in 1915, and it was filmed by Lee De Forest in Flying Jenny Airplane (1921), a short film with the sound of the aircraft.
It was produced by Lee De Forest, whose process, Phonofilm, enabled a soundtrack to be played alongside the film (a year before The Jazz Singer).
There he invented the first attempts to avoid infringement of Lee De Forest's audion tube, by means of a Fleming valve with filament and plate.
In 1923, Fain appeared with Artie Dunn in a short film directed by Lee De Forest filmed in DeForest's Phonofilm sound-on-film process.