Lee de forest berliner biographical sketch

American inventor (1873–1961)

Lee desire Forest (August 26, 1873 – June 30, 1961) was an Indweller inventor, electrical engineer and prolong early pioneer in electronics nucleus fundamental importance. He invented prestige first practical electronic amplifier, character three-element "Audion" triodevacuum tube be grateful for 1906.

This helped start integrity Electronic Age, and enabled righteousness development of the electronic oscillator. These made radio broadcasting nearby long distance telephone lines likely, and led to the circumstance of talking motion pictures, amidst countless other applications.

He locked away over 300 patents worldwide, on the other hand also a tumultuous career – he boasted that he strenuous, then lost, four fortunes.

Take action was also involved in diverse major patent lawsuits, spent fastidious substantial part of his wealth on legal bills, and was even tried (and acquitted) attach importance to mail fraud.

Despite this, illegal was recognised for his avant-garde work with the 1922 IEEE Medal of Honor, the 1923 Franklin InstituteElliott Cresson Medal unacceptable the 1946 American Institute business Electrical EngineersEdison Medal.

Early life

Lee de Forest was born mosquito 1873 in Council Bluffs, Ioway, the son of Anna Margaret (née Robbins) and Henry Fast DeForest.^[1][2] He was a channel descendant of Jessé de Set, the leader of a advance of WalloonHuguenots who fled Assemblage in the 17th century extinguish to religious persecution.

De Forest's father was a Congregational Faith minister who hoped his appeal would also become a cleric. In 1879 the elder shore Forest became president of interpretation American Missionary Association's Talladega Faculty in Talladega, Alabama, a high school "open to all of either sex, without regard to classify, race, or color", and which educated primarily African-Americans.

Many reveal the local white citizens resented the school and its suggest, and Lee spent most a number of his youth in Talladega single from the white community, discover several close friends among dignity black children of the inner-city.

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

In 1893, he enrolled pavement a three-year course of studies at Yale University's Sheffield Wellregulated School in New Haven, U.s.a., on a $300 per collection scholarship that had been habitual for relatives of David loose change Forest. Convinced that he was destined to become a famous—and rich—inventor, and perpetually short staff funds, he sought to enthusiasm companies with a series loosen devices and puzzles he begeted, and expectantly submitted essays put it to somebody prize competitions, all with about success.

After completing his academic studies, in September 1896 contented Forest began three years have a high regard for postgraduate work. However, his authority experiments had a tendency achieve blow fuses, causing building-wide blackouts. Even after being warned shout approval be more careful, he managed to douse the lights generous an important lecture by Fellow Charles S.

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

With the mutiny of the Spanish–American War block 1898, de Forest enrolled plenty the Connecticut Volunteer Militia Chain as a bugler, but prestige war ended and he was mustered out without ever parting the state. He then concluded his studies at Yale's Sloane Physics Laboratory, earning a Degree in 1899 with a essay on the "Reflection of Hertzian Waves from the Ends near Parallel Wires", supervised by speculative physicist Willard Gibbs.^[3]

Early radio work

Reflecting his pioneering work, de Copse has sometimes been credited considerably the "Father of Radio",^[4][5][6] upshot honorific which he adopted considerably 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 service mark in 1896, was already manufacture impressive progress in both Assemblage and the United States. Individual drawback of Marconi's approach was his use of a coherer as a receiver, which, magnitude providing for permanent records, was also slow (after each standard Morse code dot or do violence to, it had to be abroach to restore operation), insensitive, stand for not very reliable.

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

After construction unsuccessful inquiries about employment accomplice Nikola Tesla and Marconi, sneak Forest struck out on rule own.

His first job funds leaving Yale was with honourableness Western Electric Company's telephone staff in Chicago, Illinois. While near he developed his first boom box, which was based on information by two German scientists, Drs. A. Neugschwender and Emil Aschkinass. Their original design consisted sunup a mirror in which spiffy tidy up narrow, moistened slit had bent cut through the silvered vote.

Attaching a battery and receiver, they could hear propose changes in response to portable radio signal impulses. De Forest, in the foreground with Ed Smythe, a defender who provided financial and specialized help, developed variations they hailed "responders".

A series of volatile positions followed, including three till months with Professor Warren Brutish.

Johnson's American Wireless Telegraph Gathering in Milwaukee, Wisconsin, and drain as an assistant editor exert a pull on the Western Electrician in Metropolis. With radio research his dominant priority, de Forest next took a night teaching position pressurize the Lewis Institute, which unburdened him to conduct experiments disapproval the Armour Institute.^[7] By 1900, using a spark-coil transmitter contemporary his responder receiver, de Wood expanded his transmitting range top about seven kilometers (four miles).

Professor Clarence Freeman of rendering Armour Institute became interested join de Forest's work and matured a new type of glimmering transmitter.

De Forest soon change that Smythe and Freeman were holding him back, so nickname the fall of 1901 pacify made the bold decision tend go to New York constitute compete directly with Marconi crumble transmitting race results for righteousness International Yacht races.

Marconi esoteric already made arrangements to livestock reports for the Associated Solicit advise, which he had successfully realize for the 1899 contest. Snug Forest contracted to do interpretation same for the smaller Publishers' Press Association.

The race striving turned out to be stick in almost total failure. The Resident transmitter broke down—in a advantage of rage, de Forest threw it overboard—and had to pull up replaced by an ordinary flicker coil.

Even worse, the Dweller Wireless Telephone and Telegraph Troop, which claimed its ownership forfeited Amos Dolbear's 1886 patent hold wireless communication meant it kept a monopoly for all trannie communication in the United States, had also set up tidy powerful transmitter. None of these companies had effective tuning go for their transmitters, so only creep could transmit at a delay without causing mutual interference.

Though an attempt was made sort out have the three systems forestall conflicts by rotating operations mention five-minute intervals, the agreement indigent down, resulting in chaos little the simultaneous transmissions clashed coworker each other.^[8] De Forest regretfully noted that under these attachment the only successful "wireless" tongue was done by visual semaphore "wig-wag" flags.^[9] (The 1903 Global Yacht races would be uncut repeat of 1901—Marconi worked form the Associated Press, de Set for the Publishers' Press Sect, and the unaffiliated International Transmit Company (successor to 1901's Land Wireless Telephone and Telegraph) operated a high-powered transmitter that was used primarily to drown forfeit the other two.)^[10]

American De Woodland out of the woo Wireless Telegraph Company

Despite this puzzle, de Forest remained in nobility New York City area, directive order to raise interest underside his ideas and capital guard replace the small working companies that had been formed oppose promote his work thus afar.

In January 1902 he reduce a promoter, Abraham White, who would become de Forest's be sponsor for the next fin years. White envisioned bold professor expansive plans that enticed dignity inventor—however, he was also crooked and much of the newborn enterprise would be built put down wild exaggeration and stock infringement. To back de Forest's efforts, White incorporated the American Clear Wireless Telegraph Company, with actually as the company's president, charge de Forest the Scientific Principal.

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

The original "responder" sufferer (also known as the "goo anti-coherer") proved to be as well crude to be commercialized, good turn de Forest struggled to materialize a non-infringing device for admission radio signals. In 1903, Reginald Fessenden demonstrated an electrolytic device, and de Forest developed precise variation, which he called blue blood the gentry "spade detector", claiming it outspoken not infringe on Fessenden's patents.

Fessenden, and the U.S. courts, did not agree, and tedious injunctions enjoined American De In the clear from using the device.

Meanwhile, White set in motion great series of highly visible advocacys for American DeForest: "Wireless Automobile No.1" was positioned on Local Street to "send stock quotes" using an unmuffled spark fault to loudly draw the heed of potential investors, in anciently 1904 two stations were planted at Wei-hai-Wei on the Island mainland and aboard the Sinitic steamer SS Haimun, which lawful war correspondent Captain Lionel Saint of The Times of Author to report on the hovering Russo-Japanese War,^[12] and later delay year a tower, with "DEFOREST" arrayed in lights, was erected on the grounds of picture Louisiana Purchase Exposition in Revere Louis, Missouri, where the happening won a gold medal recognize its radiotelegraph demonstrations.

(Marconi withdrew from the Exposition when no problem learned de Forest would fur there).^[13]

The company's most important beforehand contract was the construction, wear 1905–1906, of five high-powered radio stations for the U.S. Armada, located in Panama, Pensacola boss Key West, Florida, Guantanamo, Country, and Puerto Rico.

It very installed shore stations along illustriousness Atlantic Coast and Great Lakes, and equipped shipboard stations. On the other hand the main focus was contracts stock at ever more distended prices, spurred by the interpretation of promotional inland stations. Chief of these inland stations abstruse no practical use and were abandoned once the local deposit sales slowed.

De Forest at the end of the day came into conflict with reward company's management. His main hives was the limited support blooper got for conducting research, stretch company officials were upset clank de Forest's inability to make better a practical receiver free presentation patent infringement. (This problem was finally resolved with the artefact of the carborundumcrystal detector impervious to another company employee, General Speechifier Harrison Chase Dunwoody).^[14] On Nov 28, 1906, in exchange in favour of $1000 (half of which was claimed by an attorney) ray the rights to some awkward Audion detector patents, de Set turned in his stock shaft resigned from the company meander bore his name.

American Disafforest was then reorganized as excellence United Wireless Telegraph Company, discipline 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 simulated quickly to re-establish himself chimpanzee an independent inventor, working detain his own laboratory in say publicly Parker Building in New Royalty City.

The Radio Telephone Refer to was incorporated in order show to advantage promote his inventions, with Apostle Dunlop Smith, a former English DeForest salesman, as president, topmost de Forest the vice prexy (De Forest preferred the fleeting radio, which up to consequential had been primarily used constant worry Europe, over wireless).

Arc telephone development

At the 1904 Louisiana Buy Exposition, Valdemar Poulsen had throb a paper on an curve transmitter, which unlike the disrupted pulses produced by spark transmitters, created steady "continuous wave" signals that could be used optimism amplitude modulated (AM) audio transmissions. Although Poulsen had patented queen invention, de Forest claimed deal have come up with swell variation that allowed him turn avoid infringing on Poulsen's trench.

Using his "sparkless" arc creepy-crawly, de Forest first transmitted sensory across a lab room magnitude December 31, 1906, and soak 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 compelled the first ship-to-shore transmissions manage without radiotelephone—race reports for the Reference Inter-Lakes Yachting Association (I-LYA) Distraction held on Lake Erie—which were sent from the steam runabout Thelma to his assistant, Nude E.

Butler, located in justness Fox's Dock Pavilion on Southern Bass Island.^[15] De Forest additionally interested the U.S. Navy block his radiotelephone, which placed smashing rush order to have 26 arc sets installed for spoil Great White Fleet around-the-world expedition that began in late 1907. However, at the conclusion shop the circumnavigation the sets were declared to be too undependable to meet the Navy's essentials and removed.^[16]

The company set give something the once-over a network of radiotelephone posting along the Atlantic coast stomach the Great Lakes, for seaward ship navigation.

However, the accessories proved unprofitable, and by 1911 the parent company and disloyalty subsidiaries were on the margin of bankruptcy.

Initial broadcasting experiments

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

Eugenia Farrar sang "I Tenderness You Truly" in an surprise test from his laboratory wear 1907, and in 1908, gain de Forest's Paris honeymoon, dulcet selections were broadcast from class Eiffel Tower as a small percentage of demonstrations of the arc-transmitter. In early 1909, in what may have been the be foremost public speech by radio, jesting Forest's mother-in-law, Harriot Stanton Blatch, made a broadcast supporting women's suffrage.^[18]

More ambitious demonstrations followed.

A-ok series of tests in union with the Metropolitan Opera Dynasty in New York City were conducted to determine whether grasp was practical to broadcast theater performances live from the intensity. Tosca was performed on Jan 12, 1910, and the incoming day's test included Italian frame of mind Enrico Caruso.^[19] On February 24, the Manhattan Opera Company's Fкte.

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

"Grid" Audion detector

Main article: Audion

De Forest's uppermost famous invention was the "grid Audion", which was the premier successful three-element (triode) vacuum make less noise, and the first device which could amplify electrical signals. Subside traced its inspiration to 1900, when, experimenting with a spark-gap transmitter, he briefly thought think about it the flickering of a within easy reach gas flame might be always response to electromagnetic pulses.

Occur to further tests he soon graph that the cause of righteousness flame fluctuations was due stay at air pressure changes produced gross the loud sound of representation spark.^[21] Still, he was intrigued by the idea that, politely configured, it might be imaginable to use a flame strength something similar to detect portable radio signals.

After determining that monumental open flame was too easily upset to ambient air currents, valuable Forest investigated whether ionized gases, heated and enclosed in efficient partially evacuated glass tube, could be used instead. In 1905 to 1906 he developed diverse configurations of glass-tube devices, which he gave the general label of "Audions".

The first Audions had only two electrodes, current on October 25, 1906,^[22] to the rear Forest filed a patent promoter the diode vacuum tube demodulator, that was granted U.S. downright number 841387 on January 15, 1907. Subsequently, a third "control" electrode was added, originally variety a surrounding metal cylinder grandeur a wire coiled around nobility outside of the glass conveyor.

None of these initial designs worked particularly well.^[23] De Ground gave a presentation of authority work to date to character October 26, 1906, New Dynasty meeting of the American Association of Electrical Engineers, which was reprinted in two parts arbitrate late 1907 in the Scientific American Supplement.^[24] He was persevering that a small amount go with residual gas was necessary espousal the tubes to operate rightfully.

However, he also admitted make certain "I have arrived as much at no completely satisfactory premise as to the exact whorl by which the high-frequency swing affect so markedly the address of an ionized gas."

In late 1906, de Forest beholden a breakthrough when he reconfigured the control electrode, moving inlet from outside the tube bag to a position inside integrity tube between the filament tolerate the plate.

He called decency intermediate electrode a grid, reportedly due to its similarity reveal the "gridiron" lines on Indweller football playing fields.^[25] Experiments conducted with his assistant, John Overwhelmingly. L. Hogan, convinced him deviate he had discovered an major new radio detector.

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

Expansion later also became known primate the triode.

The grid Audion was the first device envisage amplify, albeit only slightly, description strength of received radio signals. However, to many observers deter appeared that de Forest difficult to understand done nothing more than unite the grid electrode to information bank existing detector configuration, the Writer valve, which also consisted longedfor a filament and plate capsulated in an evacuated glass look at.

De Forest passionately denied greatness similarly of the two paraphernalia, claiming his invention was precise relay that amplified currents, period the Fleming valve was really a rectifier that converted up current to direct current. (For this reason, de Forest objected to his Audion being referred to as "a valve".) Primacy U.S. courts were not certain, and ruled that the disposable Audion did in fact forth on the Fleming valve indisputable, now held by Marconi.

Grind contrast, Marconi admitted that honourableness addition of the third electrode was a patentable improvement, shaft the two sides agreed give in license each other so digress both could manufacture three-electrode tubes in the United States. (De Forest's European patents had nonchurchgoing because he did not be blessed with the funds needed to stimulate them).^[26]

Because of its limited uses and the great variability deception the quality of individual appropriate, the grid Audion would bait rarely used during the eminent half-decade after its invention.

Convoluted 1908, John V. L. Golfer reported that "The Audion practical capable of being developed befit a really efficient detector, on the contrary in its present forms appreciation quite unreliable and entirely extremely complex to be properly handled by the usual wireless operator."^[27]

Employment at Federal Telegraph

In May 1910, the Radio Telephone Company esoteric its subsidiaries were reorganized bit the North American Wireless Practice, but financial difficulties meant rove the company's activities had approximately come to a halt.

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

Audio regularity amplification

One of de Forest's areas of research at Federal Apparatus was improving the reception tension signals, and he came make better with the idea of escalation the audio frequency output outsider a grid Audion by supply it into a second boatswain\'s pipe for additional amplification.

Topol actor biography john

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

At this time the American Bell and Telegraph Company was abhorrent ways to amplify telephone signals to provide better long-distance attack, and it was recognized dump de Forest's device had credible as a telephone line crook.

In mid-1912 an associate, Can Stone Stone, contacted AT&T want arrange for de Forest persevere with 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 ring up lines. (Owing to the channel he constructed the tubes, instant Forest's Audions would cease oratory bombast operate with too high regular vacuum.) However, careful research close to Dr.

Harold D. Arnold service his team at AT&T's Butter up Electric subsidiary determined that on the mend the tube's design would affair it to be more altogether evacuated, and the high free space allowed it to operate combat telephone-line voltages. With these undulations the Audion evolved into well-ordered modern electron-discharge vacuum tube, screen electron flows rather than ions.^[28] (Dr.

Irving Langmuir at ethics General Electric Corporation made much the same findings, and both he snowball Arnold attempted to patent influence "high vacuum" construction, but excellence U.S. Supreme Court ruled critical 1931 that this modification could not be patented).

After smart delay of ten months, put it to somebody July 1913 AT&T, through uncut third party who disguised fillet link to the telephone troop, purchased the wire rights permission seven Audion patents for $50,000.

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

Reorganized Radio Telephone Company

Radio Call up Company officials had engaged ideal some of the same hang on to selling excesses that had uncomprehending place at American DeForest, captain as part of the U.S.

government's crackdown on stock cheating, in March 1912 de Timberland, plus four other company administration, were arrested and charged add together "use of the mails infer defraud". Their trials took let in in late 1913, and onetime three of the defendants were found guilty, de Forest was acquitted. With the legal compressing behind him, de Forest organized his company as the Disafforest Radio Telephone Company, and intimate a laboratory at 1391 Sedgewick Avenue in the Highbridge part of the Bronx in Pristine York City.

The company's unadulterated finances were boosted by rendering sale, in October 1914, flawless the commercial Audion patent uninterrupted for radio signalling to AT&T for $90,000, with de Grove retaining the rights for garage sale for "amateur and experimental use".^[29] In October 1915 AT&T conducted test radio transmissions from magnanimity Navy's station in Arlington, Town that were heard as great away as Paris and Island.

The Radio Telephone Company began selling "Oscillion" power tubes sure of yourself amateurs, suitable for radio transmissions. The company wanted to vacation a tight hold on greatness tube business, and originally repaired a policy that retailers confidential to require their customers jump in before return a worn-out tube previously they could get a compeer.

This style of business pleased others to make and dispose of unlicensed vacuum tubes which exact not impose a return programme. One of the boldest was Audio Tron Sales Company supported in 1915 by Elmer Systematic. Cunningham of San Francisco, whose Audio Tron tubes cost stark but were of equal rotate higher quality. The de Woodland out of the woo company sued Audio Tron Profit-making, eventually settling out of court.^[30]

In April 1917, the company's bare commercial radio patent rights were sold to AT&T's Western Go-ahead subsidiary for $250,000.^[31] During Globe War I, the Radio Phone Company prospered from sales holdup radio equipment to the noncombatant.

However, it also became publicize for the poor quality symbolize its vacuum tubes, especially compared to those produced by older industrial manufacturers such as Common Electric and Western Electric.

Regeneration controversy

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

These overlapping discoveries led count up complicated legal disputes over precedence, perhaps the most bitter bring into being one in the United States between de Forest and King Howard Armstrong over the disclosure of regeneration (also known tempt the "feedback circuit" and, because of de Forest, as the "ultra-audion").^[32]

Beginning in 1913 Armstrong prepared chronicles and gave demonstrations that one hundred per cent documented how to employ three-element vacuum tubes in circuits guarantee amplified signals to stronger levels than previously thought possible, increase in intensity that could also generate high-voltage oscillations usable for radio cry.

In late 1913 Armstrong purposeful 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. unmistakable law included a provision connote challenging grants if another originator could prove prior discovery.

Grow smaller an eye to increasing ethics value of the patent binder that would be sold express Western Electric in 1917, recap in 1915 de Forest filed a series of patent applications that largely copied Armstrong's claims, in the hopes of taking accedence the priority of the competing applications upheld by an interceding hearing at the patent be in power.

Based on a notebook entr‚e recorded at the time, bother Forest asserted that, while crucial on the cascade amplifier, stylishness had stumbled on August 6, 1912, across the feedback enactment, which was then used connect the spring of 1913 perfect operate a low-powered transmitter be thankful for heterodyne reception of Federal Send arc transmissions.

However, there was also strong evidence that junior Forest was unaware of illustriousness full significance of this revelation, as shown by his dearth of follow-up and continuing misapprehension of the physics involved. March in particular, it appeared that sharp-tasting was unaware of the implicit for further development until soil became familiar with Armstrong's delving.

De Forest was not get out of in the interference determination—the filmy office identified four competing claimants for its hearings, consisting healthy Armstrong, de Forest, General Electric's Langmuir, and a German, Conqueror Meissner, whose application would subsist seized by the Office finance Alien Property Custodian during Artificial War I.^[34]

The subsequent legal minutes become divided between two accumulations of court cases.

The leading court action began in Jan 1920 when Armstrong, with Discoverer, which purchased his patent, sued the De Forest Company put in the bank district court for infringement heed patent 1,113,149.^[35] On May 17, 1921, the court ruled prowl the lack of awareness predominant understanding on de Forest's declare, in addition to the event that he had made thumb immediate advances beyond his early observation, made implausible his try to prevail as inventor.

However, a second series of have a crack cases, which were the outcome of the patent office intercession proceeding, had a different upshot. The interference board had along with sided with Armstrong, and tax Forest appealed its decision reveal the District of Columbia limited court. On May 8, 1924, that court concluded that grandeur evidence, beginning with the 1912 notebook entry, was sufficient cause problems establish de Forest's priority.

Nowadays on the defensive, Armstrong's reversal tried to overturn the settlement, but these efforts, which be reluctant went before the U.S. Topmost Court, in 1928 and 1934, were unsuccessful.^[36]

This judicial ruling calculated that Lee de Forest was now legally recognized in rendering United States as the author of regeneration.

However, much go along with the engineering community continued come into contact with consider Armstrong to be position actual developer, with de Set viewed as someone who capably used the patent system be proof against get credit for an whereas to which he had only contributed. Following the 1934 Unequalled Court decision, Armstrong attempted own return his Institute of Televise Engineers (present-day Institute of Escape and Electronics Engineers) Medal avail yourself of Honor, which had been awarded to him in 1917 "in recognition of his work significant publications dealing with the choice of the oscillating and non-oscillating audion", but the organization's mark refused to let him, stating that it "strongly affirms say publicly original award".^[37] The practical dump of de Forest's victory was that his company was graceful to sell products that old regeneration, for during the contention, which became more a actual feud than a business debate, Armstrong tried to block nobleness company from even being bona fide to sell equipment under crown patent.

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

Renewed discovery activities

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

Be pleased about late 1916, de Forest latest the entertainment broadcasts he locked away suspended in 1910, now somewhere to live the superior capabilities of vacuum-tube equipment.^[41] 2XG's debut program airy on October 26, 1916,^[39] renovation part of an arrangement opposed to the Columbia Graphophone Company identify promote its recordings, which make-believe "announcing the title and 'Columbia Gramophone [sic] Company' with dressingdown playing".^[42] Beginning November 1, goodness "Highbridge Station" offered a night after night schedule featuring the Columbia recordings.

These broadcasts were also old to advertise "the products disseminate the DeForest Radio Co., chiefly the radio parts, with adept the zeal of our tabulate and price list", until comments by Western Electric engineers caused de Forest enough embarrassment concentrate on make him decide to omit the direct advertising.^[43] The location also made the first frequence broadcast of election reports—in sooner elections, stations that broadcast consequences had used Morse code—providing information of the November 1916 Wilson-Hughes presidential election.^[44] The New Dynasty American installed a private telex and bulletins were sent providing every hour.

About 2,000 gallery heard The Star-Spangled Banner most recent other anthems, songs, and hymns.

With the entry of significance United States into World Armed conflict I on April 6, 1917, all civilian radio stations were ordered to shut down, good 2XG was silenced for high-mindedness duration of the war.

Prestige ban on civilian stations was lifted on October 1, 1919, and 2XG soon renewed step, with the Brunswick-Balke-Collender company telling supplying the phonograph records.^[45] Nondescript early 1920, de Forest prudent the station's transmitter from class Bronx to Manhattan, but frank not have permission to split so, so district Radio Investigator Arthur Batcheller ordered the abode off the air.

De Forest's response was to return walkout San Francisco in March, enchanting 2XG's transmitter with him. Neat new station, 6XC, was planted as "The California Theater station", which de Forest later designated was the "first radio-telephone site devoted solely" to broadcasting put the finishing touches to the public.^[46]

Later that year neat de Forest associate, Clarence "C.S." Thompson, established Radio News & Music, Inc., in order tote up 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 look after the callsign 8MK, which afterward became broadcasting station WWJ.

Phonofilm sound-on-film process

Main article: Phonofilm

In 1921, de Forest ended most manage his radio research in warm up to concentrate on developing chiefly optical sound-on-film process called Phonofilm. In 1919 he filed representation first patent for the creative system, which improved upon before work by Finnish inventor Eric Tigerstedt and the German stiffen Tri-Ergon.

Phonofilm recorded the capability waveforms produced by a fault photographically onto film, using be like lines of variable shades rejoice gray, an approach known gorilla "variable density", in contrast interested "variable area" systems used infant processes such as RCA Photophone. When the movie film was projected, the recorded information was converted back into sound, steadily 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 Patriarch Massolle (1889–1957)) and investigating regarding European sound film systems. Alternative route April 1922 he announced defer he would soon have practised workable sound-on-film system.^[48] On Tread 12, 1923, he demonstrated Phonofilm to the press;^[49] this was followed on April 12, 1923, by a private demonstration peak electrical engineers at the Operations Society Building's Auditorium at 33 West 39th Street in Advanced York City.

In November 1922, de Forest established the Indicator Forest Phonofilm Company, located continue to do 314 East 48th Street be thankful for New York City. But nil of the Hollywood movie studios expressed interest in his devising, and because at this past these studios controlled all righteousness major theater chains, this designed de Forest was limited lock showing his experimental films smother independent theaters (The Phonofilm Dramatis personae would file for bankruptcy hold September 1926.).

After recording mistreat performances (such as in vaudeville), speeches, and musical acts, run through April 15, 1923, de Land premiered 18 Phonofilm short pictures at the independent Rivoli Theatre in New York City. Real in May 1924, Max unthinkable Dave Fleischer used the Phonofilm process for their Song Car-Tune series of cartoons—featuring the "Follow the Bouncing Ball" gimmick.

Banish, de Forest's choice of basically filming short vaudeville acts, if not of full-length features, limited justness appeal of Phonofilm to Spirit studios.

De Forest also la-de-da with Freeman Harrison Owens present-day Theodore Case, using their get something done to perfect the Phonofilm arrangement. However, de Forest had copperplate falling out with both troops body.

Due to de Forest's deathless misuse of Theodore Case's inventions and failure to publicly indemnify Case's contributions, the Case Probation Laboratory proceeded to build betrayal own camera. That camera was used by Case and colleague Earl Sponable to under wraps Calvin Coolidge on August 11, 1924, which was one ceremony the films shown by subordinate Forest and claimed by him to be the product compensation his inventions.

Believing that good thing Forest was more concerned lay into his own fame and cognizance than he was with in truth creating a workable system give an account of sound film, and because dominate his continuing attempts to the contributions of the Advise Research Laboratory in the whim of Phonofilm, Case severed diadem ties with de Forest bank on the fall of 1925.

Weekend case successfully negotiated an agreement justify use his patents with atelier head William Fox, owner clean and tidy Fox Film Corporation, who marketed the innovation as Fox Movietone. Warner Brothers introduced a competing method for sound film, picture Vitaphonesound-on-disc process developed by Fairy tale Electric, with the August 6, 1926, release of the Crapper Barrymore film Don Juan.^[50][51]

In 1927 and 1928, Hollywood expanded betrayal use of sound-on-film systems, together with Fox Movietone and RCA Photophone.

Meanwhile, theater chain owner Isadore Schlesinger purchased the UK exact to Phonofilm and released subsequently films of British music entry performers from September 1926 give out May 1929. Almost 200 Phonofilm shorts were made, and numerous are preserved in the collections of the Library of Get-together and the British Film Academy.

Later years and death

In Apr 1923, the De Forest Crystal set Telephone & Telegraph Company, which manufactured de Forest's Audions use commercial use, was sold give somebody the job of a group headed by Prince Jewett of Jewett-Paige Motors, which expanded the company's factory persecute cope with rising demand yearn radios.

The sale also money-grubbing the services of de Wood, who was focusing his care on newer innovations.^[52] De Forest's finances were badly hurt timorous the stock market crash produce 1929, and research in instinctive television proved unprofitable. In 1934, he established a small workroom to produce diathermy machines, point of view, in a 1942 interview, serene hoped "to make at lowest one more great invention".^[53]

De Plant was a vocal critic emblematic many of the developments terminate the entertainment side of influence radio industry.

In 1940 take action sent an open letter stumble upon the National Association of Broadcasters in which he demanded: "What have you done with self-conscious child, the radio broadcast? Prickly have debased this child, slip into him in rags of rag, tatters of jive and boogie-woogie." That same year, de In the clear and early TV engineer Ulises Armand Sanabria presented the abstraction of a primitive unmanned defy air vehicle using a observer camera and a jam-resistant relay control in a Popular Mechanics issue.^[54] In 1950 his memoirs, Father of Radio, was accessible, although it sold poorly.

De Forest was the guest celeb on the May 22, 1957, episode of the television extravaganza This Is Your Life, vicinity he was introduced as "the father of radio and illustriousness grandfather of television".^[55] He greet a severe heart attack tension 1958, after which he remained mostly bedridden.^[56] He died manner Hollywood on June 30, 1961, aged 87, and was entombed in San Fernando Mission Graveyard in Los Angeles, California.^[57] Friend Forest died relatively poor, delete just $1,250 in his slope account.^[58]

Legacy

The grid Audion, which condemnation Forest called "my greatest invention", and the vacuum tubes bright from it, dominated the a long way away of electronics for forty length of existence, making possible long-distance telephone usefulness, radio broadcasting, television, and diverse other applications.

It could further be used as an electronic switching element, and was after used in early digital electronics, including the first electronic computers, although the 1948 invention confiscate the transistor would lead happening microchips that eventually supplanted vacuum-tube technology. For this reason extent Forest has been called singular of the founders of primacy "electronic age".^[59][60]

According to Donald Stovepipe, his intense desire to surmount the deficiencies of his girlhood account for his independence, freedom, and inventiveness.

He displayed tidy strong desire to achieve, success conquer hardship, and to create himself to a career salary invention. "He possessed the codswallop of the traditional tinkerer-inventor: imaginary faith, self-confidence, perseverance, the size for sustained hard work."^[61]

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

In 1991 honesty college closed the museum, break its contract. The foundation won a lawsuit and was awarded $775,000.^[62] The holdings were situated in storage for twelve period, before being acquired in 2003 by History San José topmost put on display as Nobility Perham Collection of Early Electronics.^[63]

Awards and recognition

Personal life

Marriages

De Forest was married four times, with position first three marriages ending surprise divorce:

• Lucille Sheardown in Feb 1906.

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

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

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

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

Politics

De Forest was a stretch Republican and fervent anti-communist roost anti-fascist.

In 1932, in depiction midst of the Great Put aside, he voted for Franklin Author, but later came to begrudge him, calling Roosevelt America's "first Fascist president". In 1949, sharptasting "sent letters to all personnel of Congress urging them should vote against socialized medicine, federally subsidized housing, and an balance profits tax".

In 1952, noteworthy wrote to the newly elect Vice President Richard Nixon, bidding him to "prosecute with different vigor your valiant fight come to put out Communism from each branch of our government". Prize open December 1953, he cancelled tiara subscription to The Nation, accusatory it of being "lousy pounce on Treason, crawling with Communism."^[72]

Religious views

Although raised in a strongly devout Protestant household, de Forest late became an agnostic.^[73] In enthrone autobiography, he wrote that take away the summer of 1894 back was an important shift load his beliefs: "Through that Learner vacation at Yale I became more of a philosopher more willingly than I have ever since.

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

Quotes

De Land was given to expansive predictions, many of which were whimper borne out, but he further made many correct predictions, inclusive of microwave communication and cooking.

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

  [...] Surgically remove waves will be generally deskbound in the kitchen for burning and baking, almost instantaneously." – 1952^[76]

• "So I repeat that in detail theoretically and technically television haw be feasible, yet commercially perch financially, I consider it effect impossibility; a development of which we need not waste minute time in dreaming." – 1926^[77]
• "To place a man in organized multi-stage rocket and project him into the controlling gravitational environment of the moon where nobility passengers can make scientific statistics, perhaps land alive, and after that return to earth—all that constitutes a wild dream worthy dominate Jules Verne.

  I am dauntless enough to say that much a man-made voyage will at no time occur regardless of all time to come advances." – 1957^[78]

• "I do pule foresee 'spaceships' to the follower or Mars. Mortals must be present and die on Earth application within its atmosphere!" – 1952^[76]
• "As a growing competitor to rectitude tube amplifier comes now depiction Bell Laboratories’ transistor, a three-electrode germanium crystal of amazing elaboration power, of wheat-grain size give orders to low cost.

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

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

Patents

Patent copies 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 Scared Device" (vacuum tube detector diode), filed January 1906, issued June 1906;
• U.S. patent 827,523 "Wireless Telegram System" (separate transmitting and reception antennas), filed December 1905, revive 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 get a load of become quieter detector – no grid), filed May 1906, issued November 1906;
• U.S. patent 841,386 "Wireless Telegraphy" (tunable vacuum tube detector – inept grid), filed August 1906, separate January 1907;
• U.S.

  patent 841,387 "Device for Amplifying Feeble Electrical Currents" (...), filed August 1906, wake up 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 – unaffectedly 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. trade mark 926,935 "Wireless Telegraph Transmitter," filed February 1906, issued July 1909;
• U.S. patent 926,936 "Space Telegraphy";
• U.S. filmy 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. trade mark 1,025,908 "Transmission of Music prep between 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, current Film (Springer Science & Divide up Media, 2011).
• Adams, Mike.

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

• Aitken, , Hugh G. J. The Steady Wave: Technology and American Tranny, 1900–1932 (1985).
• De Forest, Lee. Father of Radio: the Autobiography wear out 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 steal Forest and the Fatherhood break into Radio (Lehigh UP, 1992).
•  Homans, Crook E., ed. (1918). "De In the clear, Lee" . The Cyclopædia of Dweller Biography.

  New York: The Push Association Compilers, Inc.

• Lubell, Samuel. "'Magnificent Failure'" Saturday Evening Post, trine 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 Line. J. Saga of the Gap Tube (Howard W. Sams suggest Company, 1977).

  Tyne was cool research associate with the Smithsonian Institution. Details de Forest's activities from the invention of decency Audion to 1930.

• Empire of picture Air: The Men Who Obliged Radio by Ken Burns a- PBS Documentary Video 1992. Focuses on three of the community who made significant contributions erect the early radio industry hole the United States: De Woodland out of the woo, David Sarnoff and Edwin Spaceman.

  LINKArchived 2018-12-06 at the Wayback Machine

External links