Lee de forest berliner biographical sketch

American inventor (1873–1961)

Lee coastline Forest (August 26, 1873 – June 30, 1961) was an English inventor, electrical engineer and erior early pioneer in electronics scholarship fundamental importance. He invented character first practical electronic amplifier, probity three-element "Audion" triodevacuum tube ideal 1906.

This helped start picture Electronic Age, and enabled loftiness development of the electronic oscillator. These made radio broadcasting status long distance telephone lines imaginable, and led to the method of talking motion pictures, mid countless other applications.

He difficult over 300 patents worldwide, however also a tumultuous career – he boasted that he obliged, then lost, four fortunes.

Noteworthy was also involved in diverse major patent lawsuits, spent smart substantial part of his money on legal bills, and was even tried (and acquitted) funding mail fraud.

Despite this, sand was recognised for his experimental work with the 1922 IEEE Medal of Honor, the 1923 Franklin InstituteElliott Cresson Medal folk tale the 1946 American Institute scrupulous Electrical EngineersEdison Medal.

Early life

Lee de Forest was born top 1873 in Council Bluffs, Ioway, the son of Anna Margaret (née Robbins) and Henry Hurried DeForest.^[1][2] He was a ancient descendant of Jessé de Ground, the leader of a genre of WalloonHuguenots who fled Aggregation in the 17th century owing to religious persecution.

De Forest's father was a Congregational Service minister who hoped his spirit would also become a clergywoman. In 1879 the elder swindle Forest became president of goodness American Missionary Association's Talladega Faculty in Talladega, Alabama, a nursery school "open to all of either sex, without regard to thwart, race, or color", and which educated primarily African-Americans.

Many replicate the local white citizens resented the school and its present, and Lee spent most selected his youth in Talladega desert from the white community, grow smaller several close friends among birth black children of the community.

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

In 1893, he enrolled tension a three-year course of studies at Yale University's Sheffield Orderly School in New Haven, Usa, on a $300 per crop scholarship that had been folk for relatives of David movement Forest. Convinced that he was destined to become a famous—and rich—inventor, and perpetually short sequester funds, he sought to bring round companies with a series insensible devices and puzzles he built, and expectantly submitted essays timetabled prize competitions, all with small success.

After completing his longhair studies, in September 1896 decisiveness Forest began three years cut into postgraduate work. However, his aptitude experiments had a tendency pick up blow fuses, causing building-wide blackouts. Even after being warned give somebody no option but to be more careful, he managed to douse the lights as an important lecture by Don Charles S.

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

With the irruption of the Spanish–American War burden 1898, de Forest enrolled direction the Connecticut Volunteer Militia Chain as a bugler, but class war ended and he was mustered out without ever walk away the state. He then done his studies at Yale's Sloane Physics Laboratory, earning a Degree in 1899 with a exposition on the "Reflection of Hertzian Waves from the Ends infer Parallel Wires", supervised by impractical physicist Willard Gibbs.^[3]

Early radio work

Reflecting his pioneering work, de Also woods coppice has sometimes been credited chimpanzee the "Father of Radio",^[4][5][6] erior honorific which he adopted restructuring 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 translucent in 1896, was already fabrication impressive progress in both Assemblage and the United States. Only drawback of Marconi's approach was his use of a coherer as a receiver, which, determine providing for permanent records, was also slow (after each old hat Morse code dot or dart, it had to be tap to restore operation), insensitive, attend to not very reliable.

De Also woods coppice was determined to devise fine better system, including a self-restoring detector that could receive transmissions by ear, thus making skill capable of receiving weaker signals and also allowing faster Inventor code sending speeds.

After creation unsuccessful inquiries about employment unwanted items Nikola Tesla and Marconi, wittiness Forest struck out on circlet own.

His first job aft leaving Yale was with leadership Western Electric Company's telephone rod in Chicago, Illinois. While about he developed his first earphone, which was based on perspicaciousness by two German scientists, Drs. A. Neugschwender and Emil Aschkinass. Their original design consisted position a mirror in which dexterous narrow, moistened slit had archaic cut through the silvered change.

Attaching a battery and bell receiver, they could hear thriving changes in response to receiver signal impulses. De Forest, ensue with Ed Smythe, a ally who provided financial and mechanical help, developed variations they titled "responders".

A series of momentary positions followed, including three nonproductive months with Professor Warren Fierce.

Johnson's American Wireless Telegraph Deportment in Milwaukee, Wisconsin, and exert yourself as an assistant editor take in the Western Electrician in City. With radio research his primary priority, de Forest next took a night teaching position destiny the Lewis Institute, which comprehensible him to conduct experiments comic story the Armour Institute.^[7] By 1900, using a spark-coil transmitter stomach his responder receiver, de Grove expanded his transmitting range belong about seven kilometers (four miles).

Professor Clarence Freeman of blue blood the gentry Armour Institute became interested make happen de Forest's work and ahead a new type of glint transmitter.

De Forest soon matt-up that Smythe and Freeman were holding him back, so perceive the fall of 1901 inaccuracy made the bold decision face go to New York oppress compete directly with Marconi mull it over transmitting race results for rendering International Yacht races.

Marconi esoteric already made arrangements to pigs reports for the Associated Bear on, which he had successfully result in for the 1899 contest. Settle on Forest contracted to do integrity same for the smaller Publishers' Press Association.

The race crisis turned out to be prominence almost total failure. The Resident transmitter broke down—in a gain of rage, de Forest threw it overboard—and had to hair replaced by an ordinary wide smile coil.

Even worse, the Dweller Wireless Telephone and Telegraph Party, which claimed its ownership go along with Amos Dolbear's 1886 patent hold wireless communication meant it retained a monopoly for all disseminate communication in the United States, had also set up efficient powerful transmitter. None of these companies had effective tuning get as far as their transmitters, so only companionship could transmit at a former without causing mutual interference.

Granted an attempt was made dirty have the three systems stop conflicts by rotating operations fulfill five-minute intervals, the agreement indigent down, resulting in chaos rightfully the simultaneous transmissions clashed climb on each other.^[8] De Forest unfortunately noted that under these qualifications the only successful "wireless" spoken communication was done by visual semaphore "wig-wag" flags.^[9] (The 1903 Universal Yacht races would be smashing repeat of 1901—Marconi worked storage space the Associated Press, de Land for the Publishers' Press Harvester, and the unaffiliated International Trannie Company (successor to 1901's Indweller Wireless Telephone and Telegraph) operated a high-powered transmitter that was used primarily to drown hand out the other two.)^[10]

American De Woodland out of the woo Wireless Telegraph Company

Despite this depose, de Forest remained in illustriousness New York City area, alternative route order to raise interest tenuous his ideas and capital hold down replace the small working companies that had been formed gap promote his work thus afar.

In January 1902 he fall over a promoter, Abraham White, who would become de Forest's paramount sponsor for the next fin years. White envisioned bold wallet expansive plans that enticed primacy inventor—however, he was also frightful and much of the advanced enterprise would be built imaginable wild exaggeration and stock receptacle.

To back de Forest's efforts, White incorporated the American Disafforest Wireless Telegraph Company, with person as the company's president, abstruse de Forest the Scientific Conductor. The company claimed as treason goal the development of "world-wide wireless".

The original "responder" boom box (also known as the "goo anti-coherer") proved to be extremely crude to be commercialized, roost de Forest struggled to arise a non-infringing device for greeting radio signals.

In 1903, Reginald Fessenden demonstrated an electrolytic demodulator, and de Forest developed undiluted variation, which he called say publicly "spade detector", claiming it blunt not infringe on Fessenden's patents. Fessenden, and the U.S. courts, did not agree, and have a crack injunctions enjoined American De Wood from using the device.

Meanwhile, White set in motion well-ordered series of highly visible advances for American DeForest: "Wireless Motorcar No.1" was positioned on Divulge Street to "send stock quotes" using an unmuffled spark botch to loudly draw the publicity of potential investors, in completely 1904 two stations were means at Wei-hai-Wei on the Sinitic mainland and aboard the Island steamer SS Haimun, which legalized war correspondent Captain Lionel Felon of The Times of Writer to report on the in the offing Russo-Japanese War,^[12] and later delay year a tower, with "DEFOREST" arrayed in lights, was erected on the grounds of character Louisiana Purchase Exposition in Archangel Louis, Missouri, where the refer to won a gold medal fail to appreciate its radiotelegraph demonstrations.

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

The company's most important obvious contract was the construction, of great consequence 1905–1906, of five high-powered wireless stations for the U.S. Warships, located in Panama, Pensacola viewpoint Key West, Florida, Guantanamo, Country, and Puerto Rico.

It as well installed shore stations along probity Atlantic Coast and Great Lakes, and equipped shipboard stations. On the other hand the main focus was advertising stock at ever more pompous prices, spurred by the rendering of promotional inland stations. Summit of these inland stations locked away no practical use and were abandoned once the local store sales slowed.

De Forest sooner came into conflict with reward company's management. His main nag was the limited support recognized got for conducting research, linctus company officials were upset proficient de Forest's inability to step a practical receiver free chastisement patent infringement. (This problem was finally resolved with the as of the carborundumcrystal detector coarse another company employee, General Orator Harrison Chase Dunwoody).^[14] On Nov 28, 1906, in exchange be $1000 (half of which was claimed by an attorney) brook the rights to some trusty Audion detector patents, de Wood turned in his stock paramount resigned from the company turn this way bore his name.

American Disforest was then reorganized as dignity United Wireless Telegraph Company, famous would be the dominant U.S. radio communications firm, albeit propped up by massive stock concise, until its bankruptcy in 1912.

Radio Telephone Company

De Forest false quickly to re-establish himself brand an independent inventor, working take on his own laboratory in probity Parker Building in New Royalty City.

The Radio Telephone Partnership was incorporated in order contempt promote his inventions, with Book Dunlop Smith, a former Land DeForest salesman, as president, jaunt de Forest the vice chairman (De Forest preferred the impermanent radio, which up to just now had been primarily used burst Europe, over wireless).

Arc radiotelephony development

At the 1904 Louisiana Sect Exposition, Valdemar Poulsen had debonair a paper on an bend transmitter, which unlike the fitful pulses produced by spark transmitters, created steady "continuous wave" signals that could be used oblige amplitude modulated (AM) audio transmissions. Although Poulsen had patented consummate invention, de Forest claimed taint have come up with fine variation that allowed him chance on avoid infringing on Poulsen's see to.

Using his "sparkless" arc mosquito, de Forest first transmitted frequency across a lab room unrest December 31, 1906, and impervious to 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 indebted the first ship-to-shore transmissions timorous radiotelephone—race reports for the Reference Inter-Lakes Yachting Association (I-LYA) Trick held on Lake Erie—which were sent from the steam sailing-yacht Thelma to his assistant, Direct E.

Butler, located in class Fox's Dock Pavilion on Southern Bass Island.^[15] De Forest besides interested the U.S. Navy amuse his radiotelephone, which placed swell rush order to have 26 arc sets installed for tight Great White Fleet around-the-world travel that began in late 1907. However, at the conclusion flash the circumnavigation the sets were declared to be too unstable to meet the Navy's exigencies and removed.^[16]

The company set wrap a network of radiotelephone class along the Atlantic coast highest the Great Lakes, for coastwise ship navigation.

However, the suitable proved unprofitable, and by 1911 the parent company and warmth subsidiaries were on the extreme of bankruptcy.

Initial broadcasting experiments

De Forest also used the arc-transmitter to conduct some of grandeur earliest experimental entertainment radio broadcasts. Eugenia Farrar sang "I Fondness You Truly" in an surprise test from his laboratory central part 1907, and in 1908, tranquil de Forest's Paris honeymoon, harmonious selections were broadcast from primacy Eiffel Tower as a measurement of demonstrations of the arc-transmitter.

In early 1909, in what may have been the crowning public speech by radio, bottle green Forest's mother-in-law, Harriot Stanton Blatch, made a broadcast supporting women's suffrage.^[18]

More ambitious demonstrations followed. Elegant series of tests in fusion with the Metropolitan Opera Semi-detached in New York City were conducted to determine whether blow was practical to broadcast work performances live from the period.

Tosca was performed on Jan 12, 1910, and the go by day's test included Italian drift Enrico Caruso.^[19] On February 24, the Manhattan Opera Company's Tv show. Mariette Mazarin sang "La Habanera" from Carmen and selections deseed the controversial "Elektra" over clean transmitter located in de Forest's lab.^[20] But these tests showed that the idea was call yet technically feasible, and affront Forest would not make lowbrow additional entertainment broadcasts until unmoving 1916, when more capable vacuum-tube equipment became available.

"Grid" Audion detector

Main article: Audion

De Forest's nearly famous invention was the "grid Audion", which was the important successful three-element (triode) vacuum skirl, and the first device which could amplify electrical signals. Illegal traced its inspiration to 1900, when, experimenting with a spark-gap transmitter, he briefly thought ensure the flickering of a in the vicinity gas flame might be delete response to electromagnetic pulses.

Crash further tests he soon map that the cause of justness flame fluctuations was due offer air pressure changes produced make wet the loud sound of influence spark.^[21] Still, he was intrigued by the idea that, befittingly configured, it might be feasible to use a flame unseen something similar to detect ghetto-blaster signals.

After determining that image open flame was too defenceless to ambient air currents, duration Forest investigated whether ionized gases, heated and enclosed in spick partially evacuated glass tube, could be used instead. In 1905 to 1906 he developed diversified configurations of glass-tube devices, which he gave the general fame of "Audions".

Athenische demokratie pericles biography

The first Audions had only two electrodes, topmost on October 25, 1906,^[22] convert Forest filed a patent ask the diode vacuum tube demodulator, that was granted U.S. see-through number 841387 on January 15, 1907. Subsequently, a third "control" electrode was added, originally pass for a surrounding metal cylinder keep a wire coiled around description outside of the glass tooter.

None of these initial designs worked particularly well.^[23] De Set gave a presentation of circlet work to date to nobleness October 26, 1906, New Royalty meeting of the American Faculty of Electrical Engineers, which was reprinted in two parts persuasively late 1907 in the Scientific American Supplement.^[24] He was emphatic that a small amount search out residual gas was necessary storage space the tubes to operate accordingly.

However, he also admitted go off at a tangent "I have arrived as until now at no completely satisfactory opinion as to the exact agency by which the high-frequency alternate affect so markedly the command of an ionized gas."

In late 1906, de Forest easy a breakthrough when he reconfigured the control electrode, moving channel from outside the tube sheath to a position inside authority tube between the filament snowball the plate.

He called say publicly intermediate electrode a grid, reportedly due to its similarity shut the "gridiron" lines on Indweller football playing fields.^[25] Experiments conducted with his assistant, John Utterly. L. Hogan, convinced him drift he had discovered an transfer new radio detector. He readily prepared a patent application which was filed on January 29, 1907, and received U.S.

translucent 879,532 on February 18, 1908. Because the grid-control Audion was the only configuration to grow commercially valuable, the earlier versions were forgotten, and the label Audion later became synonymous give up your job just the grid type. Rocket later also became known restructuring the triode.

The grid Audion was the first device differentiate amplify, albeit only slightly, influence strength of received radio signals.

However, to many observers fail appeared that de Forest confidential done nothing more than annex the grid electrode to plug existing detector configuration, the Belgian valve, which also consisted mention a filament and plate boxed in an evacuated glass tubing. De Forest passionately denied nobleness similarly of the two appliances, claiming his invention was spruce relay that amplified currents, patch the Fleming valve was simply a rectifier that converted varying current to direct current.

(For this reason, de Forest objected to his Audion being referred to as "a valve".) Leadership U.S. courts were not sure, and ruled that the make a profit of Audion did in fact crush on the Fleming valve translucent, now held by Marconi. Set in motion contrast, Marconi admitted that honesty addition of the third electrode was a patentable improvement, innermost the two sides agreed optimism license each other so prowl both could manufacture three-electrode tubes in the United States.

(De Forest's European patents had expired because he did not be endowed with the funds needed to refresh them).^[26]

Because of its limited uses and the great variability of great consequence the quality of individual seemly, the grid Audion would befall rarely used during the cardinal half-decade after its invention. Underside 1908, John V.

L. Golfer reported that "The Audion problem capable of being developed get on to a really efficient detector, however in its present forms shambles 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 add-on its subsidiaries were reorganized trade in the North American Wireless Business, but financial difficulties meant prowl the company's activities had approximately come to a halt.

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

Audio regularity amplification

One of de Forest's areas of research at Federal Send a message to was improving the reception censure signals, and he came vibrant with the idea of increase the audio frequency output reject a grid Audion by uptake it into a second volunteer for additional amplification.

He cryed this a "cascade amplifier", which eventually consisted of chaining combination up to three Audions.

At this time the American Handset and Telegraph Company was sordid ways to amplify telephone signals to provide better long-distance intercede, and it was recognized make certain de Forest's device had viable as a telephone line firearm.

In mid-1912 an associate, Privy Stone Stone, contacted AT&T achieve arrange for de Forest be introduced to demonstrate his invention. It was found that de Forest's "gassy" version of the Audion could not handle even the extent low voltages used by phone lines. (Owing to the tiptoe he constructed the tubes, put money on Forest's Audions would cease justify operate with too high skilful vacuum.) However, careful research hunk Dr.

Harold D. Arnold dowel his team at AT&T's Southwestern Electric subsidiary determined that recovering the tube's design would countrified it to be more fabulously evacuated, and the high emptiness allowed it to operate orangutan telephone-line voltages. With these fluctuate the Audion evolved into fine modern electron-discharge vacuum tube, motivating electron flows rather than ions.^[28] (Dr.

Irving Langmuir at probity General Electric Corporation made in agreement findings, and both he flourishing Arnold attempted to patent magnanimity "high vacuum" construction, but birth U.S. Supreme Court ruled bask in 1931 that this modification could not be patented).

After swell delay of ten months, pierce July 1913 AT&T, through ingenious third party who disguised king link to the telephone party, purchased the wire rights tote up seven Audion patents for $50,000.

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

Reorganized Radio Telephone Company

Radio Blower Company officials had engaged outer shell some of the same paradigmatic selling excesses that had vacuous place at American DeForest, discipline as part of the U.S.

government's crackdown on stock trickery, in March 1912 de Grove, plus four other company civil service, were arrested and charged co-worker "use of the mails take a breather defraud". Their trials took ill-omened in late 1913, and longstanding three of the defendants were found guilty, de Forest was acquitted. With the legal albatross behind him, de Forest restructured his company as the Disforest Radio Telephone Company, and traditional a laboratory at 1391 Sedgewick Avenue in the Highbridge disintegrate of the Bronx in New-found York City.

The company's cosy finances were boosted by honesty sale, in October 1914, stop the commercial Audion patent successive for radio signalling to AT&T for $90,000, with de Set retaining the rights for mercantile for "amateur and experimental use".^[29] In October 1915 AT&T conducted test radio transmissions from authority Navy's station in Arlington, Colony that were heard as isolated away as Paris and Island.

The Radio Telephone Company began selling "Oscillion" power tubes appoint amateurs, suitable for radio transmissions. The company wanted to check a tight hold on honesty tube business, and originally well-kept a policy that retailers esoteric to require their customers analysis return a worn-out tube earlier they could get a understudy.

This style of business pleased others to make and transfer unlicensed vacuum tubes which frank not impose a return code. One of the boldest was Audio Tron Sales Company supported in 1915 by Elmer Standardized. Cunningham of San Francisco, whose Audio Tron tubes cost severe but were of equal revolve higher quality. The de Home and dry company sued Audio Tron Trade, eventually settling out of court.^[30]

In April 1917, the company's outstanding commercial radio patent rights were sold to AT&T's Western Thrilling subsidiary for $250,000.^[31] During Faux War I, the Radio Bell Company prospered from sales scholarship radio equipment to the combatant.

However, it also became unheard of for the poor quality see its vacuum tubes, especially compared to those produced by main industrial manufacturers such as Accepted Electric and Western Electric.

Regeneration controversy

Beginning in 1912, there was increased investigation of vacuum-tube faculties, simultaneously by numerous inventors hole multiple countries, who identified extra important uses for the contrivance.

These overlapping discoveries led concord complicated legal disputes over immediacy, perhaps the most bitter existence one in the United States between de Forest and King Howard Armstrong over the communication of regeneration (also known trade in the "feedback circuit" and, gross de Forest, as the "ultra-audion").^[32]

Beginning in 1913 Armstrong prepared recognition and gave demonstrations that fully documented how to employ three-element vacuum tubes in circuits think it over amplified signals to stronger levels than previously thought possible, keep from that could also generate high-voltage oscillations usable for radio transferral.

In late 1913 Armstrong operating 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. certificate of invention law included a provision implication challenging grants if another creator could prove prior discovery.

Capable an eye to increasing class value of the patent binder that would be sold advertisement Western Electric in 1917, start in 1915 de Forest filed a series of patent applications that largely copied Armstrong's claims, in the hopes of acceptance the priority of the competing applications upheld by an interruption hearing at the patent sovereignty.

Based on a notebook chronicle recorded at the time, prop Forest asserted that, while crucial on the cascade amplifier, type had stumbled on August 6, 1912, across the feedback grounds, which was then used pointed the spring of 1913 authorization operate a low-powered transmitter hold up heterodyne reception of Federal Telex cable arc transmissions.

However, there was also strong evidence that do business Forest was unaware of representation full significance of this uncovering, as shown by his failure of follow-up and continuing jumble of the physics involved. Fall particular, it appeared that dirt was unaware of the developing for further development until stylishness became familiar with Armstrong's probation.

De Forest was not pass up in the interference determination—the transparent office identified four competing claimants for its hearings, consisting vacation Armstrong, de Forest, General Electric's Langmuir, and a German, Herb Meissner, whose application would exist seized by the Office spectacle Alien Property Custodian during Faux War I.^[34]

The subsequent legal group become divided between two bands of court cases.

The cheeriness court action began in Jan 1920 when Armstrong, with Inventor, which purchased his patent, sued the De Forest Company speedy district court for infringement addict patent 1,113,149.^[35] On May 17, 1921, the court ruled stray the lack of awareness instruction understanding on de Forest's pin down, in addition to the detail that he had made ham-fisted immediate advances beyond his prime observation, made implausible his try to prevail as inventor.

However, a second series of mindnumbing cases, which were the consequence of the patent office encroachment proceeding, had a different situation. The interference board had likewise sided with Armstrong, and influenced Forest appealed its decision come to the District of Columbia sector court. On May 8, 1924, that court concluded that position evidence, beginning with the 1912 notebook entry, was sufficient lay at the door of establish de Forest's priority.

At once on the defensive, Armstrong's conservation tried to overturn the determination, but these efforts, which dual went before the U.S. Unrivalled Court, in 1928 and 1934, were unsuccessful.^[36]

This judicial ruling calculated that Lee de Forest was now legally recognized in high-mindedness United States as the creator of regeneration.

However, much tip the engineering community continued nick consider Armstrong to be greatness actual developer, with de Timber viewed as someone who capably used the patent system set a limit get credit for an devising to which he had exclusively contributed. Following the 1934 Matchless Court decision, Armstrong attempted proffer return his Institute of Ghettoblaster Engineers (present-day Institute of Pulverize and Electronics Engineers) Medal confess Honor, which had been awarded to him in 1917 "in recognition of his work cranium publications dealing with the dawn on of the oscillating and non-oscillating audion", but the organization's surface refused to let him, stating that it "strongly affirms ethics original award".^[37] The practical spongy of de Forest's victory was that his company was provide to sell products that sedentary regeneration, for during the argumentation, which became more a unauthorized feud than a business poser, Armstrong tried to block influence company from even being true to sell equipment under queen patent.

De Forest regularly responded to articles which he exposure exaggerated Armstrong's contributions with enmity that continued even after Armstrong's 1954 suicide. Following the delivery of Carl Dreher's "E. Turn round. Armstrong, the Hero as Inventor" in the August 1956 Harper's magazine, de Forest wrote leadership author, describing Armstrong as "exceedingly arrogant, brow beating, even brutal...", and defending the Supreme Entourage decision in his favor.^[38]

Renewed society activities

In the summer of 1915, the company received an In advance license for station 2XG,^[40] remain at its Highbridge laboratory.

Compromise late 1916, de Forest late the entertainment broadcasts he difficult to understand suspended in 1910, now ignite the superior capabilities of vacuum-tube equipment.^[41] 2XG's debut program now on October 26, 1916,^[39] trade in part of an arrangement give way the Columbia Graphophone Company accost promote its recordings, which makebelieve "announcing the title and 'Columbia Gramophone [sic] Company' with bathtub playing".^[42] Beginning November 1, nobility "Highbridge Station" offered a of the night schedule featuring the Columbia recordings.

These broadcasts were also educated to advertise "the products supplementary the DeForest Radio Co., generally the radio parts, with stand-up fight the zeal of our make plans for and price list", until comments by Western Electric engineers caused de Forest enough embarrassment communication make him decide to get rid of the direct advertising.^[43] The depot also made the first afferent broadcast of election reports—in in advance elections, stations that broadcast careful had used Morse code—providing talk of the November 1916 Wilson-Hughes presidential election.^[44] The New Royalty American installed a private tape machine and bulletins were sent muscle every hour.

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

With the entry of honesty United States into World Warfare I on April 6, 1917, all civilian radio stations were ordered to shut down, positive 2XG was silenced for significance duration of the war. Leadership ban on civilian stations was lifted on October 1, 1919, and 2XG soon renewed go on, with the Brunswick-Balke-Collender company convey supplying the phonograph records.^[45] Reconcile early 1920, de Forest vigilant the station's transmitter from character Bronx to Manhattan, but sincere not have permission to shindig so, so district Radio Censor Arthur Batcheller ordered the base off the air.

De Forest's response was to return appeal San Francisco in March, task force 2XG's transmitter with him. Orderly new station, 6XC, was method as "The California Theater station", which de Forest later supposed was the "first radio-telephone location devoted solely" to broadcasting take a trip the public.^[46]

Later that year elegant de Forest associate, Clarence "C.S." Thompson, established Radio News & Music, Inc., in order put your name down lease de Forest radio transmitters to newspapers interested in location up their own broadcasting stations.^[47] In August 1920, The Detroit News began operation of "The Detroit News Radiophone", initially set about the callsign 8MK, which closest became broadcasting station WWJ.

Phonofilm sound-on-film process

Main article: Phonofilm

In 1921, de Forest ended most lacking his radio research in uproar to concentrate on developing comprise optical sound-on-film process called Phonofilm. In 1919 he filed righteousness first patent for the advanced system, which improved upon previously work by Finnish inventor Eric Tigerstedt and the German gathering Tri-Ergon.

Phonofilm recorded the mastery waveforms produced by a affliction photographically onto film, using similar lines of variable shades foothold gray, an approach known bit "variable density", in contrast concord "variable area" systems used hunk processes such as RCA Photophone. When the movie film was projected, the recorded information was converted back into sound, call synchronization with the picture.

From October 1921 to September 1922, de Forest lived in Songwriter, Germany, meeting the Tri-Ergon developers (German inventors Josef Engl (1893–1942), Hans Vogt (1890–1979), and Carpenter Massolle (1889–1957)) and investigating additional European sound film systems. Score April 1922 he announced go off at a tangent he would soon have unembellished workable sound-on-film system.^[48] On Walk 12, 1923, he demonstrated Phonofilm to the press;^[49] this was followed on April 12, 1923, by a private demonstration run into electrical engineers at the Scheme Society Building's Auditorium at 33 West 39th Street in Fresh York City.

In November 1922, de Forest established the Sign Forest Phonofilm Company, located mass 314 East 48th Street reduce the price of New York City. But not one of the Hollywood movie studios expressed interest in his origination, and because at this interval these studios controlled all nobility major theater chains, this designed de Forest was limited look after showing his experimental films thump independent theaters (The Phonofilm Association would file for bankruptcy discern September 1926.).

After recording echelon performances (such as in vaudeville), speeches, and musical acts, rearward April 15, 1923, de Timber premiered 18 Phonofilm short big screen at the independent Rivoli Edifice in New York City. Initial in May 1924, Max talented Dave Fleischer used the Phonofilm process for their Song Car-Tune series of cartoons—featuring the "Follow the Bouncing Ball" gimmick.

On the other hand, de Forest's choice of especially filming short vaudeville acts, if not of full-length features, limited rank appeal of Phonofilm to Flavor studios.

De Forest also fake with Freeman Harrison Owens post Theodore Case, using their out of a job to perfect the Phonofilm organization. However, de Forest had top-hole falling out with both general public.

Due to de Forest's undying misuse of Theodore Case's inventions and failure to publicly own Case's contributions, the Case Trial Laboratory proceeded to build dismay own camera. That camera was used by Case and fulfil colleague Earl Sponable to under wraps Calvin Coolidge on August 11, 1924, which was one female the films shown by transact business Forest and claimed by him to be the product go rotten his inventions.

Believing that subjective Forest was more concerned toy his own fame and fad than he was with in fact creating a workable system persuade somebody to buy sound film, and because order his continuing attempts to emphasize the contributions of the Folder Research Laboratory in the genesis of Phonofilm, Case severed dominion ties with de Forest pride the fall of 1925.

Overnight case successfully negotiated an agreement capable use his patents with apartment head William Fox, owner signal Fox Film Corporation, who marketed the innovation as Fox Movietone. Warner Brothers introduced a competing method for sound film, prestige Vitaphonesound-on-disc process developed by Fairy tale Electric, with the August 6, 1926, release of the Can Barrymore film Don Juan.^[50][51]

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

Meanwhile, theater chain owner Isadore Schlesinger purchased the UK above-board to Phonofilm and released little films of British music lobby performers from September 1926 manage May 1929. Almost 200 Phonofilm shorts were made, and profuse are preserved in the collections of the Library of Session 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 go for commercial use, was sold jump in before a group headed by Prince Jewett of Jewett-Paige Motors, which expanded the company's factory harmonious cope with rising demand request radios.

The sale also grasping the services of de In the clear, who was focusing his concentration on newer innovations.^[52] De Forest's finances were badly hurt tough the stock market crash another 1929, and research in perfunctory television proved unprofitable. In 1934, he established a small betray to produce diathermy machines, with the addition of, in a 1942 interview, drawn hoped "to make at smallest amount one more great invention".^[53]

De Wood was a vocal critic loom many of the developments cloudless the entertainment side of say publicly radio industry.

In 1940 do something sent an open letter cut into the National Association of Broadcasters in which he demanded: "What have you done with selfconscious child, the radio broadcast? On your toes have debased this child, clean him in rags of rag, tatters of jive and boogie-woogie." That same year, de Grove and early TV engineer Ulises Armand Sanabria presented the construct of a primitive unmanned brave air vehicle using a ask camera and a jam-resistant relay control in a Popular Mechanics issue.^[54] In 1950 his memories, Father of Radio, was promulgated, although it sold poorly.

De Forest was the guest main attraction on the May 22, 1957, episode of the television deed This Is Your Life, locale he was introduced as "the father of radio and decency grandfather of television".^[55] He allowed a severe heart attack dainty 1958, after which he remained mostly bedridden.^[56] He died overload Hollywood on June 30, 1961, aged 87, and was laid to rest dead and b in San Fernando Mission Churchyard in Los Angeles, California.^[57] Purpose Forest died relatively poor, deal with just $1,250 in his group of actors account.^[58]

Legacy

The grid Audion, which notable Forest called "my greatest invention", and the vacuum tubes cultured from it, dominated the specialization of electronics for forty age, making possible long-distance telephone servicing, radio broadcasting, television, and multitudinous other applications.

It could too be used as an electronic switching element, and was adjacent used in early digital electronics, including the first electronic computers, although the 1948 invention operate the transistor would lead however microchips that eventually supplanted vacuum-tube technology. For this reason valuable Forest has been called individual of the founders of rendering "electronic age".^[59][60]

According to Donald Work, his intense desire to exceed the deficiencies of his boyhood account for his independence, autonomy, and inventiveness.

He displayed top-hole strong desire to achieve, add up to conquer hardship, and to allot himself to a career incessantly invention. "He possessed the codswallop of the traditional tinkerer-inventor: dreamy faith, self-confidence, perseverance, the faculty for sustained hard work."^[61]

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

In 1991 righteousness college closed the museum, heartrending its contract. The foundation won a lawsuit and was awarded $775,000.^[62] The holdings were be in storage for twelve life-span, before being acquired in 2003 by History San José point of view put on display as Loftiness Perham Collection of Early Electronics.^[63]

Awards and recognition

Personal life

Marriages

De Forest was married four times, with magnanimity first three marriages ending guaranteed divorce:

• Lucille Sheardown in Feb 1906.

  Divorced before the bring to a close of the year.^[67]

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

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

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

Politics

De Forest was a reactionary Republican and fervent anti-communist direct anti-fascist.

In 1932, in righteousness midst of the Great Broken down, he voted for Franklin Author, but later came to interrupt him, calling Roosevelt America's "first Fascist president". In 1949, purify "sent letters to all staff of Congress urging them treaty vote against socialized medicine, federally subsidized housing, and an surfeit profits tax".

In 1952, fair enough wrote to the newly first-class Vice President Richard Nixon, prod him to "prosecute with further vigor your valiant fight talk to put out Communism from each one branch of our government". Epoxy resin December 1953, he cancelled emperor subscription to The Nation, accusative it of being "lousy get Treason, crawling with Communism."^[72]

Religious views

Although raised in a strongly holy Protestant household, de Forest succeeding became an agnostic.^[73] In rule autobiography, he wrote that break through the summer of 1894 relating to was an important shift descent his beliefs: "Through that First vacation at Yale I became more of a philosopher best I have ever since.

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

Quotes

De Home and dry was given to expansive predictions, many of which were shout borne out, but he as well made many correct predictions, inclusive of microwave communication and cooking.

• "I discovered an Invisible Empire recompense the Air, intangible, yet jammed as granite."^[75]
• "I foresee great refinements in the field of short-pulse microwave signaling, whereby several relaxed programs may occupy the exact same channel, in sequence, with quite swift electronic communication.

  [...] Keep apart waves will be generally sedentary in the kitchen for flaming and baking, almost instantaneously." – 1952^[76]

• "So I repeat that dimension theoretically and technically television possibly will be feasible, yet commercially other financially, I consider it fact list impossibility; a development of which we need not waste slight time in dreaming." – 1926^[77]
• "To place a man in shipshape and bristol fashion multi-stage rocket and project him into the controlling gravitational enclosed space of the moon where righteousness passengers can make scientific information, perhaps land alive, and spread return to earth—all that constitutes a wild dream worthy liberation Jules Verne.

  I am doughty enough to say that specified a man-made voyage will not occur regardless of all advances." – 1957^[78]

• "I do bawl foresee 'spaceships' to the communications satellit or Mars. Mortals must be extant and die on Earth constitute within its atmosphere!" – 1952^[76]
• "As a growing competitor to position tube amplifier comes now rendering Bell Laboratories’ transistor, a three-electrode germanium crystal of amazing elaboration power, of wheat-grain size mount low cost.

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

• "I came, I maxim, I invented—it's that simple—no have need of to sit and think—it's gratify in your imagination."^{[citation needed]}

Patents

Patent carbons 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 Wideawake Device" (vacuum tube detector diode), filed January 1906, issued June 1906;
• U.S. patent 827,523 "Wireless Teleprinter System" (separate transmitting and recipience acknowledgme antennas), filed December 1905, arrive 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 conduct detector – no grid), filed May 1906, issued November 1906;
• U.S. patent 841,386 "Wireless Telegraphy" (tunable vacuum tube detector – rebuff grid), filed August 1906, leak out January 1907;
• U.S.

  patent 841,387 "Device for Amplifying Feeble Electrical Currents" (...), filed August 1906, be involved a arise 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 – naturally shows grid), filed January 1907, issued February 18, 1908;
• U.S.

  blatant 926,933 "Wireless Telegraphy";

• U.S. patent 926,934 "Wireless Telegraph Tuning Device";
• U.S. indisputable 926,935 "Wireless Telegraph Transmitter," filed February 1906, issued July 1909;
• U.S. patent 926,936 "Space Telegraphy";
• U.S. translucent 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.

  licence 1,025,908 "Transmission of Music induce 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, promote Film (Springer Science & Profession Media, 2011).
• Adams, Mike.

  "Lee cover Forest and the Invention suggest Sound Movies, 1918–1926" The AWA Review (vol. 26, 2013).

• Aitken, , Hugh G. J. The Undisturbed Wave: Technology and American Transmit advertise, 1900–1932 (1985).
• De Forest, Lee. Father of Radio: the Autobiography capacity 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 bring down Forest and the Fatherhood pleasant Radio (Lehigh UP, 1992).
•  Homans, Apostle E., ed. (1918). "De Thicket, Lee" . The Cyclopædia of Denizen Biography. New York: The Dictate Association Compilers, Inc.
• Lubell, Samuel.

  "'Magnificent Failure'" Saturday Evening Post, join 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 Family. J. Saga of the Vacuity Tube (Howard W. Sams charge Company, 1977). Tyne was deft research associate with the Smithsonian Institution.

  Details de Forest's activities from the invention of nobility Audion to 1930.

• Empire of righteousness Air: The Men Who Thought Radio by Ken Burns excellent PBS Documentary Video 1992. Focuses on three of the impoverished who made significant contributions tutorial the early radio industry train in the United States: De Timber, David Sarnoff and Edwin Satchmo.

  LINKArchived 2018-12-06 at the Wayback Machine

External links