Lee de Forest: The Con Man Who Invented Radio

Lee de Forest routinely called himself the “Father of Radio” (it was even the title of his autobiography) and in a way he was right.  He invented the idea of wireless broadcasting, conducted many of the first entertainment radio broadcasts and even invented the most important device in radio, the vacuum triode or the vacuum tube!  

However, de Forest accomplished these things because he outright stole most of his devices and ideas.

Table of Contents

Lee de Forest

Fessenden sues Forest

Forest’s Rise and Fall


Lee de Forest

Lee de Forest grew up in Alabama to a stern preacher from the north.  He was a lonely child, small and homely, ignored and abused by his family and neighbors.  He was always tinkering and, when he was 13 thought that he had invented a “perpetual motion machine” and became convinced that he was a genius, an opinion that never faltered. 

For example, in College he wrote in his journal that, “I never doubt for a moment my genius, that faith which became a part of myself at 13 yrs. of age” and in his 70s tried to convince his forth wife to write a book called, “I married a genius”).In 1896, when de Forest was 23 years old, he read a book about the Tesla coil and became infatuated with electricity and wireless. 

In fact, he became the first person to get his Ph.D. in the study of radio waves!  After trying (and failing) to get a job with first Tesla and then Marconi, de Forrest started his own company, The American de Forrest Wireless Telegraph Company with a man named Abraham White. 

White thought it was the perfect vehicle to use de Forest’s enthusiasm to oversell stock and de Forest agreed, writing in his diary, “Soon, we believe, the suckers will begin to bite!” and bite they did, the company soon had over a million dollars!

The biggest adversary to de Forest and White’s company was Marconi’s wireless.  And Marconi’s biggest weakness was in how they received signals.  Marconi’s wireless system used a “coherer” that was slow and erratic. 

De Forest made a solution that he called the “goo anti-coherer” based on some German ideas, which worked about as well as it sounded (meaning not well at all).  Then, in 1903, de Forrest visited a man named Reginald Fessenden a “found” a better detector… in Fessenden’s laboratory. 

Fessenden sues Forest

Soon, with the help of a Fessenden employee that de Forest lured to his company, Lee de Forrest started selling a “spade detector” that was identical to Fessenden’s electrolytic detector in all but name and quality.  Not surprisingly, Fessenden sued.

While the lawsuit raged on, de Forest and White create went to St. Luis for a world fair and constructed a 30 ft tower to promote their business.  While in St. Luis de Forest heard a talk from a Danish man named Valdemar Poulsen about a new type of radio transmitter called an arc transmitter where you used an arc lamp to amplify the signal and create smooth radio waves. 

Poulsen suggested that his device would be useful for sending sound wirelessly, an idea that sounded very interesting to de Forest. 

Now using radio to transmit sound wirelessly wasn’t a new idea.  Reginald Fessenden (the guy suing de Forest for “borrowing” a detector) had transferred sound with radio waves way back in 1900, although the quality wasn’t very good.  By 1904 Fessenden was working on an alternator or a machine that spun electromagnets very fast to create smooth radio waves for this very purpose (he succeeded in 1906 with “perfect fidelity”).

However, Fessenden and Poulsen and almost everyone else thought of using radio waves to make a wireless telephone.  None of them had an image of broadcast radio.  De Forest, however, immediately saw the potential and predicted that, “some day the news and even advertising will be sent out all over wireless”

De Forest tried to get his business partner interested in sending sound wirelessly with the Poulsen arc transmitter [Fessenden’s alternator was way too difficult for him to copy (or “independently invent”) and besides, Fessenden would probably no longer let de Forest into his laboratory or near his employees!], but White was uninterested as wireless telegraphy was raking in the cash. 

However, two years later, in 1906, Fessenden won his patent suit.  De Forest ran to Canada so that White could creatively rearrange their finances – which he did by backstabbing de Forest (as well as Fessenden) and destroying de Forest’s company!

Forest’s Rise and Fall

De Forest was devastated at the end of his company, “This is the funeral of my first born child!, “ he cried, stolen by a “robber who has fattened off my brain.  But my work goes on, while I live.” 

Broke but determined, De Forest started anew on “his” idea of wireless transmission of sound.  He created a new company, the De Forest Radio Telephone Company, with a new president James Dunlop Smith, who used it to… you guessed it… oversell stock.

Lee de Forest then “invented” a “crude carbon-arc transmitter,[1]” which was a Poulsen generator with a microphone attached.  What this did was make variations in the height of the Radio wave generated that depended on the intensity of the sound.  In other words, the amplitude (height) was modulated (varied). 

Eventually, this was called AM radio.  Of course, he “never got around to purchasing the rights to use Poulsen’s patents,[2]” and went with some vague theory that his arc transmitter was significantly different than Poulsen’s (the major difference was that it wasn’t as good).  By January 7th, of 1907, de Forest managed to transmit speech wirelessly across his laboratory and from then on he pretended that he was the first person to do so![3]

By February, de Forest was broadcasting signals miles from his laboratory in New York.  An operator at the Brooklyn Naval Yard called him up and said, “Am I drunk or crazy, or are you sending out some talk and music over that wireless of yours?[4]” 

By 1908, de Forest married a female engineer named Nora Stanton Blatch and de Forest and his new bride used “their” wireless to transmit music from the top of the Eiffel Tower.  In the beginning of 1910, de Forest even created the first broadcast of an opera from the stage!

It seemed like de Forest would be at the forefront of the Radio broadcasting boom.  However, his early broadcasts sounded terrible, his marriage fell apart as he didn’t want his wife to work, and by 1912, his company was charged with fraud.  By January 1st, 1914, two members of de Forest’s company were charged with stealing over 1 million dollars and sent to jail.  When de Forest was acquitted on a technicality he collapsed into his lawyer’s arms. 

Although he, personally, didn’t lead the way into radio, surprisingly, one of his devices did.  See, back in 1906, when de Forest was losing his first company because of stealing Fessenden’s detector, de Forest also was interested in “borrowing” a different detector, that was based on a light bulb called a “Fleming valve”. 

After failing with a direct copy, he made a new version of the Fleming valve adding electrodes and stray metal all over the place to make it “his”.  In 1907, de Forest filed for a patent for something he called an “Audion” that was a Fleming valve plus a zigzag of wire.  That little wire ended up making all the difference, and the Audion, that was renamed the triode or vacuum tube was to be one of the most important technical devices of the 20th century. 

However, de Forest wasn’t the one to figure it out.  How a college student named Howard Armstrong transformed wireless with a vacuum tube is next time on the secret history of electricity.


[1]p 221 “Father of Radio: the autobiography of Lee de Forest” Lee De Forest

[2]section 9 United States Early Radio History, Thomas H White

[3]p 2325 Radio News June 1925

[4]p 2213 Radio News June 1925

Love Kathy Loves Physics? Share This To Your Friends:

Leave a Comment

Your email address will not be published. Required fields are marked *