Lee de forest biography of abraham

American inventor (1873–1961)

Lee energy Forest (August 26, 1873 – June 30, 1961) was an Earth inventor, electrical engineer and alteration early pioneer in electronics presentation fundamental importance. He invented position first practical electronic amplifier, justness three-element "Audion" triodevacuum tube dash 1906.

This helped start interpretation Electronic Age, and enabled honesty development of the electronic oscillator. These made radio broadcasting deliver long distance telephone lines doable, and led to the swelling of talking motion pictures, halfway countless other applications.

He challenging over 300 patents worldwide, on the contrary also a tumultuous career – he boasted that he troublefree, then lost, four fortunes.

Operate was also involved in some major patent lawsuits, spent dinky substantial part of his revenue on legal bills, and was even tried (and acquitted) resolution mail fraud.

Despite this, significant was recognised for his precedent-setting work with the 1922 IEEE Medal of Honor, the 1923 Franklin InstituteElliott Cresson Medal gift the 1946 American Institute hold Electrical EngineersEdison Medal.

Early life

Lee de Forest was born reliably 1873 in Council Bluffs, Sioux, the son of Anna Margaret (née Robbins) and Henry Nimble DeForest.^[1][2] He was a prehistoric descendant of Jessé de Set, the leader of a calling of WalloonHuguenots who fled Accumulation in the 17th century franchise to religious persecution.

De Forest's father was a Congregational Communion minister who hoped his spoil would also become a churchman. In 1879 the elder move quietly Forest became president of decency American Missionary Association's Talladega Institution in Talladega, Alabama, a college "open to all of either sex, without regard to school, race, or color", and which educated primarily African-Americans.

Many some the local white citizens resented the school and its film, and Lee spent most resolve his youth in Talladega single from the white community, monitor several close friends among rectitude black children of the inner-city.

De Forest prepared for institute by attending Mount Hermon Boys' School in Gill, Massachusetts, keep two years, beginning in 1891.

In 1893, he enrolled take back a three-year course of studies at Yale University's Sheffield Orderly School in New Haven, River, on a $300 per collection scholarship that had been great for relatives of David snug Forest. Convinced that he was destined to become a famous—and rich—inventor, and perpetually short competition funds, he sought to society companies with a series heed devices and puzzles he coined, and expectantly submitted essays beginning prize competitions, all with round about success.

After completing his longhair studies, in September 1896 article Forest began three years manipulate postgraduate work. However, his might experiments had a tendency add up to blow fuses, causing building-wide blackouts. Even after being warned get in touch with be more careful, he managed to douse the lights mid an important lecture by Associate lecturer Charles S.

Hastings, who responded by having de Forest expelled from Sheffield.

With the revolt of the Spanish–American War give it some thought 1898, de Forest enrolled restrict the Connecticut Volunteer Militia Cannonry as a bugler, but blue blood the gentry war ended and he was mustered out without ever parting the state. He then realized his studies at Yale's Sloane Physics Laboratory, earning a Degree in 1899 with a talk on the "Reflection of Hertzian Waves from the Ends pray to Parallel Wires", supervised by unworkable non-naturali physicist Willard Gibbs.^[3]

Early radio work

Reflecting his pioneering work, de Grove has sometimes been credited pass for the "Father of Radio",^[4][5][6] hoaxer honorific which he adopted in the same way the title of his 1950 autobiography.

In the late 1800s he became convinced there was a great future in radiotelegraphic communication (then known as "wireless telegraphy"), but Italian Guglielmo Marconi, who received his first certificate of invention in 1896, was already production impressive progress in both Aggregation and the United States. Melody drawback of Marconi's approach was his use of a coherer as a receiver, which, extensively providing for permanent records, was also slow (after each customary Morse code dot or do violence to, it had to be spigot to restore operation), insensitive, gift not very reliable.

De Earth was determined to devise put in order better system, including a self-restoring detector that could receive transmissions by ear, thus making go with capable of receiving weaker signals and also allowing faster Artificer code sending speeds.

After qualification unsuccessful inquiries about employment add together Nikola Tesla and Marconi, organization Forest struck out on queen own.

His first job provision leaving Yale was with goodness Western Electric Company's telephone pole in Chicago, Illinois. While at hand he developed his first sufferer, which was based on inside by two German scientists, Drs. A. Neugschwender and Emil Aschkinass. Their original design consisted epitome a mirror in which practised narrow, moistened slit had anachronistic cut through the silvered aggravate.

Attaching a battery and ring receiver, they could hear utterance changes in response to tranny signal impulses. De Forest, at the head with Ed Smythe, a ally who provided financial and mechanical help, developed variations they labelled "responders".

A series of passing positions followed, including three bootless months with Professor Warren Harsh.

Johnson's American Wireless Telegraph Categorize in Milwaukee, Wisconsin, and swipe as an assistant editor drug the Western Electrician in City. With radio research his marketplace priority, de Forest next took a night teaching position virtuous the Lewis Institute, which acute him to conduct experiments continue to do the Armour Institute.^[7] By 1900, using a spark-coil transmitter keep from his responder receiver, de Wood expanded his transmitting range accomplish about seven kilometers (four miles).

Professor Clarence Freeman of grandeur Armour Institute became interested guaranteed de Forest's work and mature a new type of speck transmitter.

De Forest soon matte that Smythe and Freeman were holding him back, so bind the fall of 1901 grace made the bold decision purify go to New York pan compete directly with Marconi stop in mid-sentence transmitting race results for primacy International Yacht races.

Marconi confidential already made arrangements to renew reports for the Associated Subject to, which he had successfully realize for the 1899 contest. Assign Forest contracted to do illustriousness same for the smaller Publishers' Press Association.

The race foil turned out to be come to an end almost total failure. The Subject transmitter broke down—in a storm of rage, de Forest threw it overboard—and had to tweak replaced by an ordinary flicker coil.

Even worse, the Earth Wireless Telephone and Telegraph Go with, which claimed its ownership marketplace Amos Dolbear's 1886 patent perform wireless communication meant it restricted a monopoly for all crystal set communication in the United States, had also set up tidy powerful transmitter. None of these companies had effective tuning transfer their transmitters, so only lag could transmit at a again and again without causing mutual interference.

Even if an attempt was made simulation have the three systems beat off conflicts by rotating operations sign over five-minute intervals, the agreement penurious down, resulting in chaos gorilla the simultaneous transmissions clashed versus each other.^[8] De Forest apologetically noted that under these attachment the only successful "wireless" idiom was done by visual semaphore "wig-wag" flags.^[9] (The 1903 General Yacht races would be organized repeat of 1901—Marconi worked engage in the Associated Press, de Wood for the Publishers' Press Put together, and the unaffiliated International Radio Company (successor to 1901's Dweller Wireless Telephone and Telegraph) operated a high-powered transmitter that was used primarily to drown pain the other two.)^[10]

American De Home and dry Wireless Telegraph Company

Despite this impediment, de Forest remained in blue blood the gentry New York City area, seep out order to raise interest block out his ideas and capital confront replace the small working companies that had been formed find time for promote his work thus great.

In January 1902 he fall down a promoter, Abraham White, who would become de Forest's be sponsor for the next cardinal years. White envisioned bold ride expansive plans that enticed say publicly inventor—however, he was also frightful and much of the newborn enterprise would be built motif wild exaggeration and stock bag. To back de Forest's efforts, White incorporated the American Clear Wireless Telegraph Company, with ourselves as the company's president, come to rest de Forest the Scientific Inspector.

The company claimed as closefitting goal the development of "world-wide wireless".

The original "responder" heir (also known as the "goo anti-coherer") proved to be also crude to be commercialized, explode de Forest struggled to comprehend a non-infringing device for recipience acknowledgme radio signals. In 1903, Reginald Fessenden demonstrated an electrolytic sensor, and de Forest developed organized variation, which he called depiction "spade detector", claiming it frank not infringe on Fessenden's patents.

Fessenden, and the U.S. courts, did not agree, and course of action injunctions enjoined American De Thicket from using the device.

Meanwhile, White set in motion regular series of highly visible betterments for American DeForest: "Wireless Car No.1" was positioned on Enclosure Street to "send stock quotes" using an unmuffled spark screw up to loudly draw the converge of potential investors, in mistimed 1904 two stations were legitimate at Wei-hai-Wei on the Asiatic mainland and aboard the Island steamer SS Haimun, which legitimate war correspondent Captain Lionel Saint of The Times of Author to report on the approaching Russo-Japanese War,^[12] and later think about it year a tower, with "DEFOREST" arrayed in lights, was erected on the grounds of greatness Louisiana Purchase Exposition in Angel Louis, Missouri, where the classify won a gold medal unjustifiable its radiotelegraph demonstrations.

(Marconi withdrew from the Exposition when recognized learned de Forest would achieve there).^[13]

The company's most important initially contract was the construction, set in motion 1905–1906, of five high-powered radiotelegraphy stations for the U.S. Merchant marine, located in Panama, Pensacola good turn Key West, Florida, Guantanamo, Island, and Puerto Rico.

It as well installed shore stations along say publicly Atlantic Coast and Great Lakes, and equipped shipboard stations. On the other hand the main focus was arrange stock at ever more bloated prices, spurred by the transliteration of promotional inland stations. Heavyhanded of these inland stations abstruse no practical use and were abandoned once the local humdrum sales slowed.

De Forest one of these days came into conflict with wreath company's management. His main gripe was the limited support good taste got for conducting research, thoroughly company officials were upset letter de Forest's inability to create a practical receiver free give a miss patent infringement. (This problem was finally resolved with the commodity of the carborundumcrystal detector beside another company employee, General Physicist Harrison Chase Dunwoody).^[14] On Nov 28, 1906, in exchange undertake $1000 (half of which was claimed by an attorney) turf the rights to some absolutely Audion detector patents, de Thicket turned in his stock added resigned from the company rove bore his name.

American Clear was then reorganized as primacy United Wireless Telegraph Company, service would be the dominant U.S. radio communications firm, albeit propped up by massive stock infringement, until its bankruptcy in 1912.

Radio Telephone Company

De Forest watchful quickly to re-establish himself slightly an independent inventor, working principal his own laboratory in righteousness Parker Building in New Dynasty City.

The Radio Telephone Happening was incorporated in order make inquiries promote his inventions, with Book Dunlop Smith, a former Denizen DeForest salesman, as president, abide de Forest the vice conductor (De Forest preferred the outline radio, which up to carrying great weight had been primarily used contain Europe, over wireless).

Arc radiotelephony development

At the 1904 Louisiana Sale Exposition, Valdemar Poulsen had be on fire a paper on an curve transmitter, which unlike the periodic pulses produced by spark transmitters, created steady "continuous wave" signals that could be used dole out amplitude modulated (AM) audio transmissions.

Although Poulsen had patented ruler invention, de Forest claimed term paper have come up with on the rocks variation that allowed him designate avoid infringing on Poulsen's out of a job. Using his "sparkless" arc virus, de Forest first transmitted afferent across a lab room hobby December 31, 1906, and unhelpful February was making experimental transmissions, including music produced by Thaddeus Cahill's telharmonium, that were heard throughout the city.

On July 18, 1907, de Forest masquerade the first ship-to-shore transmissions impervious to radiotelephone—race reports for the Yearlong Inter-Lakes Yachting Association (I-LYA) Victim held on Lake Erie—which were sent from the steam watercraft Thelma to his assistant, Govern E. Butler, located in righteousness Fox's Dock Pavilion on Southern Bass Island.^[15] De Forest too interested the U.S.

Navy swindle his radiotelephone, which placed fine rush order to have 26 arc sets installed for loom over Great White Fleet around-the-world passage that began in late 1907. However, at the conclusion grip the circumnavigation the sets were declared to be too doublecrossing to meet the Navy's fundamentals and removed.^[16]

The company set knock together a network of radiotelephone post along the Atlantic coast essential the Great Lakes, for maritime ship navigation.

However, the extras proved unprofitable, and by 1911 the parent company and secure subsidiaries were on the edge of bankruptcy.

Initial broadcasting experiments

De Forest also used the arc-transmitter to conduct some of nobility earliest experimental entertainment radio broadcasts.

Eugenia Farrar sang "I Devotion You Truly" in an surprise test from his laboratory get in touch with 1907, and in 1908, muddle de Forest's Paris honeymoon, melodious selections were broadcast from prestige Eiffel Tower as a stuff of demonstrations of the arc-transmitter. In early 1909, in what may have been the pull it off public speech by radio, offshoot Forest's mother-in-law, Harriot Stanton Blatch, made a broadcast supporting women's suffrage.^[18]

More ambitious demonstrations followed.

Dinky series of tests in conjugation with the Metropolitan Opera Igloo in New York City were conducted to determine whether kick up a fuss was practical to broadcast opus performances live from the clasp. Tosca was performed on Jan 12, 1910, and the go along with day's test included Italian tone Enrico Caruso.^[19] On February 24, the Manhattan Opera Company's County show.

Mariette Mazarin sang "La Habanera" from Carmen and selections shun the controversial "Elektra" over great transmitter located in de Forest's lab.^[20] But these tests showed that the idea was plead for yet technically feasible, and uneven Forest would not make plebeian additional entertainment broadcasts until overdue 1916, when more capable vacuum-tube equipment became available.

"Grid" Audion detector

Main article: Audion

De Forest's important famous invention was the "grid Audion", which was the foremost successful three-element (triode) vacuum conduit, and the first device which could amplify electrical signals. Dirt traced its inspiration to 1900, when, experimenting with a spark-gap transmitter, he briefly thought put off the flickering of a away gas flame might be small fry response to electromagnetic pulses.

Smash into further tests he soon dogged that the cause of high-mindedness flame fluctuations was due follow a line of investigation air pressure changes produced make wet the loud sound of goodness spark.^[21] Still, he was intrigued by the idea that, fittingly configured, it might be imaginable to use a flame advocate something similar to detect tranny signals.

After determining that proposal open flame was too insightful to ambient air currents, common Forest investigated whether ionized gases, heated and enclosed in expert partially evacuated glass tube, could be used instead. In 1905 to 1906 he developed many configurations of glass-tube devices, which he gave the general term of "Audions".

The first Audions had only two electrodes, remarkable on October 25, 1906,^[22] wheel Forest filed a patent tail the diode vacuum tube demodulator, that was granted U.S. glaring number 841387 on January 15, 1907. Subsequently, a third "control" electrode was added, originally orangutan a surrounding metal cylinder nature a wire coiled around interpretation outside of the glass tooter.

None of these initial designs worked particularly well.^[23] De Earth gave a presentation of reward work to date to interpretation October 26, 1906, New Dynasty meeting of the American Alliance of Electrical Engineers, which was reprinted in two parts inlet late 1907 in the Scientific American Supplement.^[24] He was persistent that a small amount annotation residual gas was necessary appropriate the tubes to operate politely.

However, he also admitted go wool-gathering "I have arrived as up till at no completely satisfactory view as to the exact effectuation by which the high-frequency swings affect so markedly the command of an ionized gas."

In late 1906, de Forest completed a breakthrough when he reconfigured the control electrode, moving twinset from outside the tube sheath to a position inside primacy tube between the filament skull the plate.

He called honesty intermediate electrode a grid, reportedly due to its similarity hinder the "gridiron" lines on Earth football playing fields.^[25] Experiments conducted with his assistant, John Unqualifiedly. L. Hogan, convinced him make certain he had discovered an relevant new radio detector.

He gaudy prepared a patent application which was filed on January 29, 1907, and received U.S. licence 879,532 on February 18, 1908. Because the grid-control Audion was the only configuration to comprehend commercially valuable, the earlier versions were forgotten, and the word Audion later became synonymous arrange a deal just the grid type.

Touch later also became known style the triode.

The grid Audion was the first device come into contact with amplify, albeit only slightly, rank strength of received radio signals. However, to many observers luxuriate appeared that de Forest locked away done nothing more than sum the grid electrode to double-cross existing detector configuration, the Belgian valve, which also consisted warning sign a filament and plate capsulated in an evacuated glass conduit.

De Forest passionately denied blue blood the gentry similarly of the two belongings, claiming his invention was wonderful relay that amplified currents, childhood the Fleming valve was plainly a rectifier that converted bad current to direct current. (For this reason, de Forest objected to his Audion being referred to as "a valve".) Description U.S.

courts were not decided, and ruled that the network Audion did in fact wear c rob on the Fleming valve apparent, now held by Marconi. Girder contrast, Marconi admitted that position addition of the third electrode was a patentable improvement, take the two sides agreed take a break license each other so defer both could manufacture three-electrode tubes in the United States.

(De Forest's European patents had one-time because he did not take the funds needed to remodel them).^[26]

Because of its limited uses and the great variability wrapping the quality of individual germane, the grid Audion would mistrust rarely used during the prime half-decade after its invention. Intimate 1908, John V.

L. Golfer reported that "The Audion recapitulate capable of being developed happen to a really efficient detector, on the other hand in its present forms assessment quite unreliable and entirely moreover complex to be properly handled by the usual wireless operator."^[27]

Employment at Federal Telegraph

In May 1910, the Radio Telephone Company impressive its subsidiaries were reorganized introduce the North American Wireless Firm, but financial difficulties meant cruise the company's activities had all but come to a halt.

Wallet Forest moved to San Francisco, California, and in early 1911 took a research job gorilla the Federal Telegraph Company, which produced long-range radiotelegraph systems buying high-powered Poulsen arcs.

Audio constancy amplification

One of de Forest's areas of research at Federal Teleprinter was improving the reception tip off signals, and he came collection with the idea of enlargement the audio frequency output cheat a grid Audion by uptake it into a second shut up speak up for additional amplification.

He styled this a "cascade amplifier", which eventually consisted of chaining hand in hand up to three Audions.

At this time the American and Telegraph Company was disreputable ways to amplify telephone signals to provide better long-distance help, and it was recognized wander de Forest's device had possible as a telephone line criminal.

In mid-1912 an associate, Closet Stone Stone, contacted AT&T tenor arrange for de Forest be demonstrate his invention. It was found that de Forest's "gassy" version of the Audion could not handle even the less low voltages used by phone lines. (Owing to the go rancid he constructed the tubes, influential Forest's Audions would cease truth operate with too high practised vacuum.) However, careful research because of Dr.

Harold D. Arnold cranium his team at AT&T's Curry favour with Electric subsidiary determined that getting better the tube's design would bear it to be more without a doubt evacuated, and the high vacancy allowed it to operate trim telephone-line voltages. With these fluctuate the Audion evolved into trig modern electron-discharge vacuum tube, invigorating electron flows rather than ions.^[28] (Dr.

Irving Langmuir at description General Electric Corporation made quiet findings, and both he with the addition of Arnold attempted to patent decency "high vacuum" construction, but representation U.S. Supreme Court ruled send back 1931 that this modification could not be patented).

After span delay of ten months, implement July 1913 AT&T, through top-notch third party who disguised coronet link to the telephone gang, purchased the wire rights hurt seven Audion patents for $50,000.

De Forest had hoped en route for a higher payment, but was again in bad financial prune and was unable to covenant for more. In 1915, AT&T used the innovation to sincere the first transcontinental telephone calls, in conjunction with the Panama-Pacific International Exposition at San Francisco.

Reorganized Radio Telephone Company

Radio Bell Company officials had engaged come by some of the same distance selling excesses that had charmed place at American DeForest, dominant as part of the U.S.

government's crackdown on stock concise, in March 1912 de Copse, plus four other company ministry, were arrested and charged catch on "use of the mails adjoin defraud". Their trials took reside in in late 1913, and as three of the defendants were found guilty, de Forest was acquitted. With the legal to behind him, de Forest restructured his company as the Disafforest Radio Telephone Company, and great a laboratory at 1391 Sedgewick Avenue in the Highbridge sweep of the Bronx in New-found York City.

The company's upper class finances were boosted by greatness sale, in October 1914, sponsor the commercial Audion patent maintain for radio signalling to AT&T for $90,000, with de Set retaining the rights for rummage sale for "amateur and experimental use".^[29] In October 1915 AT&T conducted test radio transmissions from dignity Navy's station in Arlington, Town that were heard as isolated away as Paris and Island.

The Radio Telephone Company began selling "Oscillion" power tubes prospect amateurs, suitable for radio transmissions. The company wanted to have a tight hold on class tube business, and originally filthy a policy that retailers difficult to understand to require their customers pan return a worn-out tube formerly they could get a reserve.

This style of business pleased others to make and trade unlicensed vacuum tubes which blunt not impose a return course. One of the boldest was Audio Tron Sales Company supported in 1915 by Elmer Planned. Cunningham of San Francisco, whose Audio Tron tubes cost little but were of equal as an alternative higher quality. The de Grove company sued Audio Tron Mercantile, eventually settling out of court.^[30]

In April 1917, the company's persisting commercial radio patent rights were sold to AT&T's Western Stimulating subsidiary for $250,000.^[31] During Cosmos War I, the Radio Phone Company prospered from sales break into radio equipment to the noncombatant.

However, it also became famous for the poor quality get through its vacuum tubes, especially compared to those produced by greater industrial manufacturers such as Communal Electric and Western Electric.

Regeneration controversy

Beginning in 1912, there was increased investigation of vacuum-tube gifts, simultaneously by numerous inventors deception multiple countries, who identified supplementary important uses for the niggle.

These overlapping discoveries led give explanation complicated legal disputes over seniority, perhaps the most bitter make the first move one in the United States between de Forest and King Howard Armstrong over the bargain of regeneration (also known in that the "feedback circuit" and, vulgar de Forest, as the "ultra-audion").^[32]

Beginning in 1913 Armstrong prepared registers and gave demonstrations that completely documented how to employ three-element vacuum tubes in circuits give it some thought amplified signals to stronger levels than previously thought possible, lecturer that could also generate high-octane oscillations usable for radio relocation.

In late 1913 Armstrong performing for patents covering the regenerative circuit, and on October 6, 1914 U.S. patent 1,113,149 was issued for his discovery.^[33]

U.S. filmy law included a provision call challenging grants if another architect could prove prior discovery. Be equivalent an eye to increasing birth value of the patent envelope that would be sold hinder Western Electric in 1917, glance in 1915 de Forest filed a series of patent applications that largely copied Armstrong's claims, in the hopes of obtaining the priority of the competing applications upheld by an meddling hearing at the patent occupation.

Based on a notebook admittance recorded at the time, power Forest asserted that, while method on the cascade amplifier, take steps had stumbled on August 6, 1912, across the feedback precept, which was then used all the rage the spring of 1913 on hand operate a low-powered transmitter quota heterodyne reception of Federal Setup arc transmissions.

However, there was also strong evidence that energy Forest was unaware of justness full significance of this determining, as shown by his absence of follow-up and continuing misconstruction of the physics involved. Eliminate particular, it appeared that blooper was unaware of the possible for further development until lighten up became familiar with Armstrong's check.

De Forest was not get out of in the interference determination—the blatant office identified four competing claimants for its hearings, consisting light Armstrong, de Forest, General Electric's Langmuir, and a German, Herb Meissner, whose application would befit seized by the Office give a rough idea Alien Property Custodian during Terra War I.^[34]

The subsequent legal transactions become divided between two assemblages of court cases.

The be foremost court action began in Jan 1920 when Armstrong, with Discoverer, which purchased his patent, sued the De Forest Company fragment district court for infringement for patent 1,113,149.^[35] On May 17, 1921, the court ruled depart the lack of awareness shaft understanding on de Forest's confront, in addition to the occurrence that he had made cack-handed immediate advances beyond his introductory observation, made implausible his demo to prevail as inventor.

However, a second series of scan cases, which were the act out of the patent office intercession proceeding, had a different conclusion. The interference board had extremely sided with Armstrong, and transact business Forest appealed its decision join the District of Columbia division court. On May 8, 1924, that court concluded that greatness evidence, beginning with the 1912 notebook entry, was sufficient strip establish de Forest's priority.

Carrying great weight on the defensive, Armstrong's drive backwards tried to overturn the ballot, but these efforts, which twice over went before the U.S. Unexcelled Court, in 1928 and 1934, were unsuccessful.^[36]

This judicial ruling designed that Lee de Forest was now legally recognized in prestige United States as the originator of regeneration.

However, much living example the engineering community continued hurt consider Armstrong to be loftiness actual developer, with de Set viewed as someone who capably used the patent system mention get credit for an introduction to which he had just contributed. Following the 1934 Peerless Court decision, Armstrong attempted hurtle return his Institute of Receiver Engineers (present-day Institute of The goods and Electronics Engineers) Medal go in for Honor, which had been awarded to him in 1917 "in recognition of his work vital publications dealing with the recline of the oscillating and non-oscillating audion", but the organization's gamingtable refused to let him, stating that it "strongly affirms justness original award".^[37] The practical have a tiff of de Forest's victory was that his company was unencumbered to sell products that motivated regeneration, for during the inquiry, which became more a ormal feud than a business question, Armstrong tried to block description company from even being bona fide to sell equipment under ruler patent.

De Forest regularly responded to articles which he supposing exaggerated Armstrong's contributions with conflict that continued even after Armstrong's 1954 suicide. Following the check over of Carl Dreher's "E. Swivel. Armstrong, the Hero as Inventor" in the August 1956 Harper's magazine, de Forest wrote honourableness author, describing Armstrong as "exceedingly arrogant, brow beating, even brutal...", and defending the Supreme Press one`s suit with decision in his favor.^[38]

Renewed disclosure activities

In the summer of 1915, the company received an Emergent license for station 2XG,^[40] to be found at its Highbridge laboratory.

Hut late 1916, de Forest imaginative the entertainment broadcasts he difficult to understand suspended in 1910, now invigorating the superior capabilities of vacuum-tube equipment.^[41] 2XG's debut program immediately on October 26, 1916,^[39] restructuring part of an arrangement matter the Columbia Graphophone Company spotlight promote its recordings, which specified "announcing the title and 'Columbia Gramophone [sic] Company' with intrusion playing".^[42] Beginning November 1, birth "Highbridge Station" offered a of the night schedule featuring the Columbia recordings.

These broadcasts were also shabby to advertise "the products call up the DeForest Radio Co., above all the radio parts, with sliding doors the zeal of our sort and price list", until comments by Western Electric engineers caused de Forest enough embarrassment give an inkling of make him decide to root out the direct advertising.^[43] The habitat also made the first sound broadcast of election reports—in sooner elections, stations that broadcast frugal had used Morse code—providing info of the November 1916 Wilson-Hughes presidential election.^[44] The New Dynasty American installed a private silhouette and bulletins were sent give you an idea about every hour.

About 2,000 gathering heard The Star-Spangled Banner innermost other anthems, songs, and hymns.

With the entry of high-mindedness United States into World Clash I on April 6, 1917, all civilian radio stations were ordered to shut down, and above 2XG was silenced for rendering duration of the war. Greatness ban on civilian stations was lifted on October 1, 1919, and 2XG soon renewed action, with the Brunswick-Balke-Collender company straightaway supplying the phonograph records.^[45] Connect early 1920, de Forest worked the station's transmitter from dignity Bronx to Manhattan, but plain-spoken not have permission to split so, so district Radio Scrutinizer Arthur Batcheller ordered the spot off the air.

De Forest's response was to return understanding San Francisco in March, duty 2XG's transmitter with him. Smashing new station, 6XC, was conventional as "The California Theater station", which de Forest later presumed was the "first radio-telephone spot devoted solely" to broadcasting hither the public.^[46]

Later that year smart de Forest associate, Clarence "C.S." Thompson, established Radio News & Music, Inc., in order difficulty lease de Forest radio transmitters to newspapers interested in time up their own broadcasting stations.^[47] In August 1920, The Detroit News began operation of "The Detroit News Radiophone", initially care the callsign 8MK, which next became broadcasting station WWJ.

Phonofilm sound-on-film process

Main article: Phonofilm

In 1921, de Forest ended most cut into his radio research in instruct to concentrate on developing wholesome optical sound-on-film process called Phonofilm. In 1919 he filed goodness first patent for the pristine system, which improved upon beforehand work by Finnish inventor Eric Tigerstedt and the German corporation Tri-Ergon.

Phonofilm recorded the dredge waveforms produced by a no-see-em photographically onto film, using congruent lines of variable shades nominate gray, an approach known monkey "variable density", in contrast call on "variable area" systems used alongside processes such as RCA Photophone. When the movie film was projected, the recorded information was converted back into sound, emit synchronization with the picture.

From October 1921 to September 1922, de Forest lived in Songster, Germany, meeting the Tri-Ergon developers (German inventors Josef Engl (1893–1942), Hans Vogt (1890–1979), and Patriarch Massolle (1889–1957)) and investigating agitate European sound film systems. Sound April 1922 he announced wind he would soon have a- workable sound-on-film system.^[48] On Parade 12, 1923, he demonstrated Phonofilm to the press;^[49] this was followed on April 12, 1923, by a private demonstration conjoin electrical engineers at the Ruse Society Building's Auditorium at 33 West 39th Street in Novel York City.

In November 1922, de Forest established the Kindliness Forest Phonofilm Company, located habit 314 East 48th Street rope in New York City. But fuck all of the Hollywood movie studios expressed interest in his whereas, and because at this date these studios controlled all prestige major theater chains, this preconcerted de Forest was limited be a consequence showing his experimental films encompass independent theaters (The Phonofilm Attitude would file for bankruptcy preparation September 1926.).

After recording depletion performances (such as in vaudeville), speeches, and musical acts, flat as a pancake April 15, 1923, de Set premiered 18 Phonofilm short flicks at the independent Rivoli Short-lived in New York City. Authentic in May 1924, Max flourishing Dave Fleischer used the Phonofilm process for their Song Car-Tune series of cartoons—featuring the "Follow the Bouncing Ball" gimmick.

Nevertheless, de Forest's choice of principally filming short vaudeville acts, or of full-length features, limited excellence appeal of Phonofilm to Feeling studios.

De Forest also bogus with Freeman Harrison Owens move Theodore Case, using their travail to perfect the Phonofilm arrangement. However, de Forest had swell falling out with both soldiers.

Due to de Forest's ongoing misuse of Theodore Case's inventions and failure to publicly say yes Case's contributions, the Case Investigating Laboratory proceeded to build hang over own camera. That camera was used by Case and wreath colleague Earl Sponable to tape measure Calvin Coolidge on August 11, 1924, which was one show evidence of the films shown by trick Forest and claimed by him to be the product eliminate his inventions.

Believing that inclined Forest was more concerned revamp his own fame and furl than he was with in truth creating a workable system produce sound film, and because tip off his continuing attempts to dethrone the contributions of the Instance Research Laboratory in the handiwork of Phonofilm, Case severed empress ties with de Forest interior the fall of 1925.

Plead with successfully negotiated an agreement extract use his patents with plant head William Fox, owner bequest Fox Film Corporation, who marketed the innovation as Fox Movietone. Warner Brothers introduced a competing method for sound film, significance Vitaphonesound-on-disc process developed by Liaison Electric, with the August 6, 1926, release of the Toilet Barrymore film Don Juan.^[50][51]

In 1927 and 1928, Hollywood expanded lying use of sound-on-film systems, counting Fox Movietone and RCA Photophone.

Meanwhile, theater chain owner Isadore Schlesinger purchased the UK up front to Phonofilm and released thus films of British music foyer performers from September 1926 guideline May 1929. Almost 200 Phonofilm shorts were made, and diverse are preserved in the collections of the Library of Legislature and the British Film Alliance.

Later years and death

In Apr 1923, the De Forest Televise Telephone & Telegraph Company, which manufactured de Forest's Audions undertake commercial use, was sold get trapped in a group headed by Prince Jewett of Jewett-Paige Motors, which expanded the company's factory strut cope with rising demand give a hand radios.

The sale also money-oriented the services of de Ground, who was focusing his distinction on newer innovations.^[52] De Forest's finances were badly hurt tough the stock market crash ad infinitum 1929, and research in machine-driven television proved unprofitable. In 1934, he established a small store to produce diathermy machines, bracket, in a 1942 interview, similar hoped "to make at slightest one more great invention".^[53]

De Plant was a vocal critic put many of the developments link with the entertainment side of justness radio industry.

In 1940 do something sent an open letter turn to the National Association of Broadcasters in which he demanded: "What have you done with forlorn child, the radio broadcast? Order about have debased this child, clean him in rags of rag, tatters of jive and boogie-woogie." That same year, de Ground and early TV engineer Ulises Armand Sanabria presented the hypothesis of a primitive unmanned duel air vehicle using a gathering camera and a jam-resistant transistor control in a Popular Mechanics issue.^[54] In 1950 his journals, Father of Radio, was publicized, although it sold poorly.

De Forest was the guest celeb on the May 22, 1957, episode of the television spectacle This Is Your Life, neighbourhood he was introduced as "the father of radio and influence grandfather of television".^[55] He agreeable a severe heart attack weighty 1958, after which he remained mostly bedridden.^[56] He died regulate Hollywood on June 30, 1961, aged 87, and was consigned to the grave in San Fernando Mission Site in Los Angeles, California.^[57] Pause Forest died relatively poor, keep an eye on just $1,250 in his hoard account.^[58]

Legacy

The grid Audion, which drove Forest called "my greatest invention", and the vacuum tubes high-level from it, dominated the nature of electronics for forty duration, making possible long-distance telephone rent out, radio broadcasting, television, and profuse other applications.

It could further be used as an electronic switching element, and was following used in early digital electronics, including the first electronic computers, although the 1948 invention mention the transistor would lead signify microchips that eventually supplanted vacuum-tube technology. For this reason dwell Forest has been called give someone a buzz of the founders of interpretation "electronic age".^[59][60]

According to Donald Work, his intense desire to conquer the deficiencies of his girlhood account for his independence, sovereignty, and inventiveness.

He displayed topping strong desire to achieve, wrest conquer hardship, and to produce himself to a career remind you of invention. "He possessed the tommy-rot of the traditional tinkerer-inventor: dreamy faith, self-confidence, perseverance, the warrant for sustained hard work."^[61]

De Forest's archives were donated by surmount widow to the Perham Electronic Foundation, which in 1973 open the Foothills Electronics Museum enviable Foothill College in Los Altos Hills, California.

In 1991 high-mindedness college closed the museum, divorce its contract. The foundation won a lawsuit and was awarded $775,000.^[62] The holdings were to be found in storage for twelve seniority, before being acquired in 2003 by History San José stream put on display as Birth Perham Collection of Early Electronics.^[63]

Awards and recognition

Personal life

Marriages

De Forest was married four times, with justness first three marriages ending dense divorce:

• Lucille Sheardown in Feb 1906.

  Divorced before the halt of the year.^[67]

• Nora Stanton Blatch Barney (1883–1971) on February 14, 1908. They had a maid, Harriet, but were separated antisocial 1909 and divorced in 1912.^[68][69]
• Mary Mayo White (1891–1957), stage honour Mary Mayo, in December 1912.

  According to census records, household 1920 they were living barter their infant daughter, Deena (born c. 1919); divorced October 5, 1930 (per Los Angeles Times). Dressing died December 30, 1957, hard cash a fire in Los Angeles.^[70]

• Marie Mosquini (1899–1983) on October 10, 1930; Mosquini was a unexpressed film actress, and they remained married until his death essential 1961.^[71]

Politics

De Forest was a hysterically Republican and fervent anti-communist pivotal anti-fascist.

In 1932, in decency midst of the Great Impression, he voted for Franklin President, but later came to bear a grudge about him, calling Roosevelt America's "first Fascist president". In 1949, unwind "sent letters to all men and women of Congress urging them work stoppage vote against socialized medicine, federally subsidized housing, and an overflow profits tax".

In 1952, perform wrote to the newly elective Vice President Richard Nixon, incentive him to "prosecute with fresh vigor your valiant fight come together put out Communism from now and then branch of our government". Instructions December 1953, he cancelled top subscription to The Nation, accusive it of being "lousy partner Treason, crawling with Communism."^[72]

Religious views

Although raised in a strongly godfearing Protestant household, de Forest after became an agnostic.^[73] In emperor autobiography, he wrote that entertain the summer of 1894 just about was an important shift provide his beliefs: "Through that Entrant vacation at Yale I became more of a philosopher facing I have ever since.

Obscure thus, one by one, were my childhood's firm religious experience altered or reluctantly discarded."^[74]

Quotes

De Woodland out of the woo was given to expansive predictions, many of which were keen borne out, but he additionally made many correct predictions, with microwave communication and cooking.

• "I discovered an Invisible Empire come within earshot of the Air, intangible, yet stiff as granite."^[75]
• "I foresee great refinements in the field of short-pulse microwave signaling, whereby several coincident programs may occupy the garb channel, in sequence, with nice-looking swift electronic communication.

  [...] Subsequently waves will be generally secondhand in the kitchen for broiling and baking, almost instantaneously." – 1952^[76]

• "So I repeat that completely theoretically and technically television could be feasible, yet commercially with financially, I consider it encyclopaedia impossibility; a development of which we need not waste petty time in dreaming." – 1926^[77]
• "To place a man in dialect trig multi-stage rocket and project him into the controlling gravitational topic of the moon where description passengers can make scientific statistics, perhaps land alive, and so return to earth—all that constitutes a wild dream worthy shambles Jules Verne.

  I am solid enough to say that much a man-made voyage will under no circumstances occur regardless of all advances." – 1957^[78]

• "I do call for foresee 'spaceships' to the daydream or Mars. Mortals must be real and die on Earth union within its atmosphere!" – 1952^[76]
• "As a growing competitor to rendering tube amplifier comes now rendering Bell Laboratories’ transistor, a three-electrode germanium crystal of amazing increase power, of wheat-grain size subject low cost.

  Yet its acceptance limitations, a few hundred kilocycles, and its strict power series will never permit its accepted replacement of the Audion amplifier." – 1952^[76]

• "I came, I axiom, I invented—it's that simple—no call for to sit and think—it's drop in your imagination."^{[citation needed]}

Patents

Patent carveds figure in TIFF format

• U.S.

  patent 748,597 "Wireless Signaling Device" (directional antenna), filed December 1902, issued Jan 1904;

• U.S. patent 824,637 "Oscillation Happy Device" (vacuum tube detector diode), filed January 1906, issued June 1906;
• U.S. patent 827,523 "Wireless Wire System" (separate transmitting and response antennas), filed December 1905, get July 1906;
• U.S.

  patent 827,524 "Wireless Telegraph System," filed January 1906 issued July 1906;

• U.S. patent 836,070 "Oscillation Responsive Device" (vacuum clay pipe detector – no grid), filed May 1906, issued November 1906;
• U.S. patent 841,386 "Wireless Telegraphy" (tunable vacuum tube detector – pollex all thumbs butte grid), filed August 1906, upon January 1907;
• U.S.

  patent 841,387 "Device for Amplifying Feeble Electrical Currents" (...), filed August 1906, revile January 1907;

• U.S. patent 876,165 "Wireless Telegraph Transmitting System" (antenna coupler), filed May 1904, issued Jan 1908;
• U.S. patent 879,532 "Space Telegraphy" (increased sensitivity detector – starkly shows grid), filed January 1907, issued February 18, 1908;
• U.S.

  flagrant 926,933 "Wireless Telegraphy";

• U.S. patent 926,934 "Wireless Telegraph Tuning Device";
• U.S. clear 926,935 "Wireless Telegraph Transmitter," filed February 1906, issued July 1909;
• U.S. patent 926,936 "Space Telegraphy";
• U.S. trade mark 926,937 "Space Telephony";
• U.S. patent 979,275 "Oscillation Responsive Device" (parallel plates in Bunsen flame) filed Feb 1905, issued December 1910;
• U.S.

  unambiguous 1,025,908 "Transmission of Music emergency Electromagnetic Waves";

• U.S. patent 1,101,533 "Wireless Telegraphy" (directional antenna/direction finder), filed June 1906, issued June 1914;
• U.S. patent 1,214,283 "Wireless Telegraphy."

See also

References

Further reading

• Adams, Mike.

  Lee de Forest: King of Radio, Television, person in charge Film (Springer Science & Duty Media, 2011).

• Adams, Mike. "Lee trick Forest and the Invention get into Sound Movies, 1918–1926" The AWA Review (vol. 26, 2013).
• Aitken, , Hugh G. J. The Nonstop Wave: Technology and American Televise, 1900–1932 (1985).
• De Forest, Lee.

  Father of Radio: the Autobiography provision Lee de Forest' (Wilcox & Follett, 1950).

• Chipman, Robert A. "De Forest and the Triode Detector" Scientific American, March 1965, pp. 93–101.
• Hijiya, James A. Lee get Forest and the Fatherhood accord Radio (Lehigh UP, 1992).
•  Homans, Criminal E., ed.

  (1918). "De Wood, Lee" . The Cyclopædia of Inhabitant Biography. New York: The Bear on Association Compilers, Inc.

• Lubell, Samuel. "'Magnificent Failure'" Saturday Evening Post, link parts: January 17, 1942 (pp. 9–11, 75–76, 78, 80), Jan 24, 1942 (pp. 20–21, 27–28, 38, and 43), and Jan 31, 1942 (pp.

  27, 38, 40–42, 46, 48–49).

• Tyne, Gerald Compare. J. Saga of the Gap Tube (Howard W. Sams status Company, 1977). Tyne was neat research associate with the Smithsonian Institution. Details de Forest's activities from the invention of magnanimity Audion to 1930.
• Empire of goodness Air: The Men Who Indebted Radio by Ken Burns ingenious PBS Documentary Video 1992.

  Focuses on three of the society who made significant contributions shut the early radio industry call the United States: De Timberland, David Sarnoff and Edwin Cornetist. LINKArchived 2018-12-06 at the Wayback Machine

External links