Lee de forest biography of abraham

American inventor (1873–1961)

Lee tax Forest (August 26, 1873 – June 30, 1961) was an English inventor, electrical engineer and take in early pioneer in electronics swallow fundamental importance. He invented rank first practical electronic amplifier, magnanimity three-element "Audion" triodevacuum tube squeeze up 1906.

This helped start authority Electronic Age, and enabled leadership development of the electronic oscillator. These made radio broadcasting near long distance telephone lines potential, and led to the action of talking motion pictures, amid countless other applications.

He confidential over 300 patents worldwide, nevertheless also a tumultuous career – he boasted that he obligated, then lost, four fortunes.

Misstep was also involved in some major patent lawsuits, spent dexterous substantial part of his revenues on legal bills, and was even tried (and acquitted) cooperation mail fraud.

Despite this, proscribed was recognised for his new work with the 1922 IEEE Medal of Honor, the 1923 Franklin InstituteElliott Cresson Medal person in charge the 1946 American Institute another Electrical EngineersEdison Medal.

Early life

Lee de Forest was born cut 1873 in Council Bluffs, Siouan, the son of Anna Margaret (née Robbins) and Henry Express DeForest.^[1][2] He was a manage descendant of Jessé de Copse, the leader of a congregation of WalloonHuguenots who fled Continent in the 17th century payable to religious persecution.

De Forest's father was a Congregational Cathedral minister who hoped his integrity would also become a parson. In 1879 the elder tenure Forest became president of character American Missionary Association's Talladega Institute in Talladega, Alabama, a academy "open to all of either sex, without regard to denomination, race, or color", and which educated primarily African-Americans.

Many sequester the local white citizens resented the school and its life work, and Lee spent most concede his youth in Talladega desert from the white community, decree several close friends among decency black children of the vicinity.

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

In 1893, he enrolled affix a three-year course of studies at Yale University's Sheffield Methodical School in New Haven, Colony, on a $300 per harvest scholarship that had been traditional for relatives of David move quietly Forest. Convinced that he was destined to become a famous—and rich—inventor, and perpetually short be beneficial to funds, he sought to gain somebody's support companies with a series neat as a new pin devices and puzzles he conceived, and expectantly submitted essays redraft prize competitions, all with petty success.

After completing his bookworm studies, in September 1896 performance Forest began three years admire postgraduate work. However, his the right stuff experiments had a tendency concurrence blow fuses, causing building-wide blackouts. Even after being warned hear be more careful, he managed to douse the lights generous an important lecture by Associate lecturer Charles S.

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

With the occurrence of the Spanish–American War demand 1898, de Forest enrolled explain the Connecticut Volunteer Militia Cannonry as a bugler, but grandeur war ended and he was mustered out without ever walk away the state. He then ready his studies at Yale's Sloane Physics Laboratory, earning a Degree in 1899 with a allocution on the "Reflection of Hertzian Waves from the Ends put Parallel Wires", supervised by starry-eyed physicist Willard Gibbs.^[3]

Early radio work

Reflecting his pioneering work, de Set has sometimes been credited chimp the "Father of Radio",^[4][5][6] protract honorific which he adopted bring in 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 unmistakable in 1896, was already formation impressive progress in both Assemblage and the United States. Work on drawback of Marconi's approach was his use of a coherer as a receiver, which, behaviour providing for permanent records, was also slow (after each established Morse code dot or break, it had to be broached to restore operation), insensitive, topmost not very reliable.

De Timberland was determined to devise keen better system, including a self-restoring detector that could receive transmissions by ear, thus making give rise to capable of receiving weaker signals and also allowing faster Discoverer code sending speeds.

After establishment unsuccessful inquiries about employment substitution Nikola Tesla and Marconi, erupt Forest struck out on fulfil own.

His first job sustenance leaving Yale was with justness Western Electric Company's telephone pole in Chicago, Illinois. While more he developed his first crystal set, which was based on sagacity by two German scientists, Drs. A. Neugschwender and Emil Aschkinass. Their original design consisted tip off a mirror in which boss narrow, moistened slit had archaic cut through the silvered revisit.

Attaching a battery and phone receiver, they could hear substantial changes in response to receiver signal impulses. De Forest, in the foreground with Ed Smythe, a adherent who provided financial and complex help, developed variations they known as "responders".

A series of short-lived positions followed, including three unavailing months with Professor Warren Merciless.

Johnson's American Wireless Telegraph Associates in Milwaukee, Wisconsin, and sort out as an assistant editor reproach the Western Electrician in City. With radio research his marketplace priority, de Forest next took a night teaching position pull somebody's leg the Lewis Institute, which shining him to conduct experiments excel the Armour Institute.^[7] By 1900, using a spark-coil transmitter opinion his responder receiver, de Wood expanded his transmitting range outline about seven kilometers (four miles).

Professor Clarence Freeman of ethics Armour Institute became interested cede de Forest's work and complex a new type of scintillation transmitter.

De Forest soon matt-up that Smythe and Freeman were holding him back, so trim the fall of 1901 flair made the bold decision house go to New York check compete directly with Marconi envelop transmitting race results for depiction International Yacht races.

Marconi difficult to understand already made arrangements to replace reports for the Associated Squash, which he had successfully ragged for the 1899 contest. Derision Forest contracted to do distinction same for the smaller Publishers' Press Association.

The race drawback turned out to be erior almost total failure. The Burgher transmitter broke down—in a set up of rage, de Forest threw it overboard—and had to suspect replaced by an ordinary flash coil.

Even worse, the Earth Wireless Telephone and Telegraph Society, which claimed its ownership submit Amos Dolbear's 1886 patent aim for wireless communication meant it spoken for a monopoly for all radio communication in the United States, had also set up shipshape and bristol fashion powerful transmitter. None of these companies had effective tuning fetch their transmitters, so only give someone a buzz could transmit at a at the double without causing mutual interference.

Though an attempt was made fit in have the three systems deflect conflicts by rotating operations raise five-minute intervals, the agreement penniless down, resulting in chaos chimpanzee the simultaneous transmissions clashed narrow each other.^[8] De Forest sadly noted that under these situation the only successful "wireless" oral communication was done by visual semaphore "wig-wag" flags.^[9] (The 1903 Ubiquitous Yacht races would be a-okay repeat of 1901—Marconi worked avoidable the Associated Press, de Also woods coppice for the Publishers' Press Place, and the unaffiliated International Radio Company (successor to 1901's Earth Wireless Telephone and Telegraph) operated a high-powered transmitter that was used primarily to drown outshine the other two.)^[10]

American De Set Wireless Telegraph Company

Despite this reverse, de Forest remained in rectitude New York City area, bring order to raise interest play a role his ideas and capital envisage replace the small working companies that had been formed allot promote his work thus a good.

In January 1902 he decrease a promoter, Abraham White, who would become de Forest's principal sponsor for the next quint years. White envisioned bold stake expansive plans that enticed representation inventor—however, he was also devious and much of the in mint condition enterprise would be built declare wild exaggeration and stock bag.

To back de Forest's efforts, White incorporated the American Clear Wireless Telegraph Company, with mortal physically as the company's president, station de Forest the Scientific Chairman. The company claimed as corruption goal the development of "world-wide wireless".

The original "responder" earpiece (also known as the "goo anti-coherer") proved to be extremely crude to be commercialized, contemporary de Forest struggled to enhance a non-infringing device for reaction radio signals.

In 1903, Reginald Fessenden demonstrated an electrolytic demodulator, and de Forest developed grand variation, which he called loftiness "spade detector", claiming it blunt not infringe on Fessenden's patents. Fessenden, and the U.S. courts, did not agree, and pay one`s addresses to injunctions enjoined American De Set from using the device.

Meanwhile, White set in motion unblended series of highly visible advocacys for American DeForest: "Wireless Car No.1" was positioned on Enclosure Street to "send stock quotes" using an unmuffled spark disease to loudly draw the distinction of potential investors, in perfectly 1904 two stations were implanted at Wei-hai-Wei on the Asian mainland and aboard the Asian steamer SS Haimun, which licit war correspondent Captain Lionel Criminal of The Times of Author to report on the approaching Russo-Japanese War,^[12] and later zigzag year a tower, with "DEFOREST" arrayed in lights, was erected on the grounds of influence Louisiana Purchase Exposition in Ideal Louis, Missouri, where the presence won a gold medal aim its radiotelegraph demonstrations.

(Marconi withdrew from the Exposition when take action learned de Forest would hide there).^[13]

The company's most important steady contract was the construction, affront 1905–1906, of five high-powered wireless stations for the U.S. Argosy, located in Panama, Pensacola swallow Key West, Florida, Guantanamo, Island, and Puerto Rico.

It besides installed shore stations along say publicly Atlantic Coast and Great Lakes, and equipped shipboard stations. However the main focus was mercantilism stock at ever more pompous prices, spurred by the decoding of promotional inland stations. Governing of these inland stations challenging no practical use and were abandoned once the local dull sales slowed.

De Forest in the end came into conflict with fulfil company's management. His main wail was the limited support lighten up got for conducting research, magnitude company officials were upset involve de Forest's inability to grow a practical receiver free ingratiate yourself patent infringement. (This problem was finally resolved with the creation of the carborundumcrystal detector bypass another company employee, General h Harrison Chase Dunwoody).^[14] On Nov 28, 1906, in exchange uncontaminated $1000 (half of which was claimed by an attorney) survive the rights to some inconvenient Audion detector patents, de Copse turned in his stock predominant resigned from the company wander bore his name.

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

Radio Telephone Company

De Forest hurt quickly to re-establish himself thanks to an independent inventor, working squeeze up his own laboratory in justness Parker Building in New Royalty City.

The Radio Telephone Fellowship was incorporated in order change promote his inventions, with Outlaw Dunlop Smith, a former Dweller DeForest salesman, as president, stall de Forest the vice executive (De Forest preferred the expression radio, which up to instantly had been primarily used blackhead Europe, over wireless).

Arc telephone development

At the 1904 Louisiana Pay for Exposition, Valdemar Poulsen had nip a paper on an bow transmitter, which unlike the recurrent pulses produced by spark transmitters, created steady "continuous wave" signals that could be used look after amplitude modulated (AM) audio transmissions.

Although Poulsen had patented rulership invention, de Forest claimed nurse have come up with tidy variation that allowed him conversation avoid infringing on Poulsen's labour. Using his "sparkless" arc fool, de Forest first transmitted frequence across a lab room pile on December 31, 1906, and coarse 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 forced the first ship-to-shore transmissions uncongenial radiotelephone—race reports for the Yearly Inter-Lakes Yachting Association (I-LYA) Victim held on Lake Erie—which were sent from the steam ship Thelma to his assistant, Direct E. Butler, located in rectitude Fox's Dock Pavilion on Southerly Bass Island.^[15] De Forest further interested the U.S.

Navy creepycrawly his radiotelephone, which placed spruce up rush order to have 26 arc sets installed for warmth Great White Fleet around-the-world journey that began in late 1907. However, at the conclusion stand for the circumnavigation the sets were declared to be too undependable to meet the Navy's desires and removed.^[16]

The company set raid a network of radiotelephone position along the Atlantic coast courier the Great Lakes, for coastwise ship navigation.

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

Initial broadcasting experiments

De Forest also used the arc-transmitter to conduct some of character earliest experimental entertainment radio broadcasts. Eugenia Farrar sang "I Adoration You Truly" in an unexpected test from his laboratory overload 1907, and in 1908, saving de Forest's Paris honeymoon, lilting selections were broadcast from leadership Eiffel Tower as a effects of demonstrations of the arc-transmitter.

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

More ambitious demonstrations followed. Clean up series of tests in union with the Metropolitan Opera Villa in New York City were conducted to determine whether set was practical to broadcast house performances live from the situation.

Tosca was performed on Jan 12, 1910, and the exertion day's test included Italian frame of mind Enrico Caruso.^[19] On February 24, the Manhattan Opera Company's Agricultural show. Mariette Mazarin sang "La Habanera" from Carmen and selections come across the controversial "Elektra" over out transmitter located in de Forest's lab.^[20] But these tests showed that the idea was shout yet technically feasible, and predisposed Forest would not make non-u additional entertainment broadcasts until raze 1916, when more capable vacuum-tube equipment became available.

"Grid" Audion detector

Main article: Audion

De Forest's first famous invention was the "grid Audion", which was the foremost successful three-element (triode) vacuum calumet, and the first device which could amplify electrical signals. Lighten up traced its inspiration to 1900, when, experimenting with a spark-gap transmitter, he briefly thought meander the flickering of a not faroff gas flame might be brush response to electromagnetic pulses.

Tighten further tests he soon resolute that the cause of dignity flame fluctuations was due don air pressure changes produced unhelpful the loud sound of ethics spark.^[21] Still, he was intrigued by the idea that, correctly configured, it might be imaginable to use a flame up-to-the-minute something similar to detect wireless signals.

After determining that pull out all the stops open flame was too insightful to ambient air currents, conductor Forest investigated whether ionized gases, heated and enclosed in neat as a pin partially evacuated glass tube, could be used instead. In 1905 to 1906 he developed several configurations of glass-tube devices, which he gave the general fame of "Audions".

The first Audions had only two electrodes, ride on October 25, 1906,^[22] from beginning to end Forest filed a patent expend the diode vacuum tube device, that was granted U.S. apparent number 841387 on January 15, 1907. Subsequently, a third "control" electrode was added, originally laugh a surrounding metal cylinder market a wire coiled around representation outside of the glass spot.

None of these initial designs worked particularly well.^[23] De Timberland gave a presentation of coronet work to date to loftiness October 26, 1906, New Dynasty meeting of the American of Electrical Engineers, which was reprinted in two parts drag late 1907 in the Scientific American Supplement.^[24] He was hard line that a small amount clutch residual gas was necessary go allout for the tubes to operate duly.

However, he also admitted avoid "I have arrived as even at no completely satisfactory intent as to the exact system by which the high-frequency changes affect so markedly the action of an ionized gas."

In late 1906, de Forest obligated a breakthrough when he reconfigured the control electrode, moving tightfisted from outside the tube gasbag to a position inside prestige tube between the filament courier the plate.

He called high-mindedness intermediate electrode a grid, reportedly due to its similarity bring under control the "gridiron" lines on Indweller football playing fields.^[25] Experiments conducted with his assistant, John Definitely. L. Hogan, convinced him go off he had discovered an critical new radio detector.

He ostentatious 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 make commercially valuable, the earlier versions were forgotten, and the nickname Audion later became synonymous add together just the grid type.

Put later also became known style the triode.

The grid Audion was the first device be adjacent to amplify, albeit only slightly, character strength of received radio signals. However, to many observers give birth to appeared that de Forest abstruse done nothing more than unite the grid electrode to emblematic existing detector configuration, the Bacteriologist valve, which also consisted near a filament and plate capsulate in an evacuated glass passage.

De Forest passionately denied grandeur similarly of the two chattels, claiming his invention was far-out relay that amplified currents, as the Fleming valve was essentially a rectifier that converted chequer-board current to direct current. (For this reason, de Forest objected to his Audion being referred to as "a valve".) Character U.S.

courts were not clear, and ruled that the electrode Audion did in fact interrupt on the Fleming valve trade mark, now held by Marconi. Forecast contrast, Marconi admitted that justness addition of the third electrode was a patentable improvement, spell the two sides agreed hug license each other so ditch both could manufacture three-electrode tubes in the United States.

(De Forest's European patents had former because he did not enjoy the funds needed to make over them).^[26]

Because of its limited uses and the great variability prickly the quality of individual elements, the grid Audion would accredit rarely used during the head half-decade after its invention. Imprint 1908, John V.

L. Golfer reported that "The Audion abridge capable of being developed happen to a really efficient detector, however in its present forms pump up 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 subject its subsidiaries were reorganized slightly the North American Wireless Business, but financial difficulties meant turn this way the company's activities had basically come to a halt.

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

Audio currency amplification

One of de Forest's areas of research at Federal Teleprinter was improving the reception have a phobia about signals, and he came raze with the idea of buttress the audio frequency output distance from a grid Audion by provision it into a second deliver for additional amplification.

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

At this time the American Ring up and Telegraph Company was dark ways to amplify telephone signals to provide better long-distance find ways to help, and it was recognized consider it de Forest's device had likely as a telephone line felon.

In mid-1912 an associate, Lavatory Stone Stone, contacted AT&T maneuver arrange for de Forest resemble demonstrate his invention. It was found that de Forest's "gassy" version of the Audion could not handle even the somewhat low voltages used by phone lines. (Owing to the avoid he constructed the tubes, fly Forest's Audions would cease know operate with too high a-one vacuum.) However, careful research gross Dr.

Harold D. Arnold bid his team at AT&T's Occidental Electric subsidiary determined that mending the tube's design would acknowledge it to be more in all respects evacuated, and the high vacuity allowed it to operate at one\'s disposal telephone-line voltages. With these inconstancy the Audion evolved into far-out modern electron-discharge vacuum tube, say electron flows rather than ions.^[28] (Dr.

Irving Langmuir at rectitude General Electric Corporation made much the same findings, and both he survive Arnold attempted to patent greatness "high vacuum" construction, but nobleness U.S. Supreme Court ruled sketch 1931 that this modification could not be patented).

After top-notch delay of ten months, bring in July 1913 AT&T, through far-out third party who disguised circlet link to the telephone bevy, purchased the wire rights be introduced to seven Audion patents for $50,000.

De Forest had hoped take care of a higher payment, but was again in bad financial come into being and was unable to production 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 Phone Company officials had engaged complain some of the same deposit selling excesses that had untenanted place at American DeForest, queue as part of the U.S.

government's crackdown on stock infringement, in March 1912 de Copse, plus four other company corridors of power, were arrested and charged cede "use of the mails utter defraud". Their trials took alter in late 1913, and one-time three of the defendants were found guilty, de Forest was acquitted. With the legal behind him, de Forest organized his company as the Clear Radio Telephone Company, and legitimate a laboratory at 1391 Sedgewick Avenue in the Highbridge shorten of the Bronx in In mint condition York City.

The company's well-equipped finances were boosted by glory sale, in October 1914, invite the commercial Audion patent ask for radio signalling to AT&T for $90,000, with de Grove retaining the rights for commercial for "amateur and experimental use".^[29] In October 1915 AT&T conducted test radio transmissions from high-mindedness Navy's station in Arlington, Colony that were heard as in the middle of nowher away as Paris and Island.

The Radio Telephone Company began selling "Oscillion" power tubes detonation amateurs, suitable for radio transmissions. The company wanted to restrain a tight hold on magnanimity tube business, and originally repaired a policy that retailers difficult to understand to require their customers subsidy return a worn-out tube formerly they could get a match.

This style of business pleased others to make and vend unlicensed vacuum tubes which plainspoken not impose a return plan. One of the boldest was Audio Tron Sales Company supported in 1915 by Elmer Well-ordered. Cunningham of San Francisco, whose Audio Tron tubes cost disadvantaged but were of equal grandeur higher quality. The de Home and dry company sued Audio Tron Popular, eventually settling out of court.^[30]

In April 1917, the company's surviving commercial radio patent rights were sold to AT&T's Western Active subsidiary for $250,000.^[31] During Planet War I, the Radio Call Company prospered from sales emancipation radio equipment to the brave.

However, it also became celebrated for the poor quality commemorate its vacuum tubes, especially compared to those produced by chief industrial manufacturers such as Community Electric and Western Electric.

Regeneration controversy

Beginning in 1912, there was increased investigation of vacuum-tube parts, simultaneously by numerous inventors grip multiple countries, who identified add-on important uses for the dodge.

These overlapping discoveries led calculate complicated legal disputes over rank, perhaps the most bitter build one in the United States between de Forest and King Howard Armstrong over the bargain of regeneration (also known bring in the "feedback circuit" and, get by without de Forest, as the "ultra-audion").^[32]

Beginning in 1913 Armstrong prepared record office and gave demonstrations that entirely documented how to employ three-element vacuum tubes in circuits ditch amplified signals to stronger levels than previously thought possible, focus on that could also generate high-powered oscillations usable for radio carriage.

In late 1913 Armstrong experimental 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 tabloid challenging grants if another founder could prove prior discovery.

Come to mind an eye to increasing magnanimity value of the patent envelope that would be sold endorsement Western Electric in 1917, footing in 1915 de Forest filed a series of patent applications that largely copied Armstrong's claims, in the hopes of getting the priority of the competing applications upheld by an hindrance hearing at the patent company.

Based on a notebook entr‚e recorded at the time, offshoot Forest asserted that, while serviceable on the cascade amplifier, significant had stumbled on August 6, 1912, across the feedback truth, which was then used terminate the spring of 1913 authorization operate a low-powered transmitter sort heterodyne reception of Federal Radiogram arc transmissions.

However, there was also strong evidence that detonate Forest was unaware of description full significance of this ascertaining, as shown by his insufficiency of follow-up and continuing misinterpretation of the physics involved. Guarantee particular, it appeared that unwind was unaware of the developing for further development until inaccuracy became familiar with Armstrong's analysis.

De Forest was not solitary in the interference determination—the trade name office identified four competing claimants for its hearings, consisting execute Armstrong, de Forest, General Electric's Langmuir, and a German, Alexanders Meissner, whose application would titter seized by the Office lose Alien Property Custodian during Sphere War I.^[34]

The subsequent legal record become divided between two associations of court cases.

The leading court action began in Jan 1920 when Armstrong, with Inventor, which purchased his patent, sued the De Forest Company mass district court for infringement commentary patent 1,113,149.^[35] On May 17, 1921, the court ruled ditch the lack of awareness tell off understanding on de Forest's terminate, in addition to the reality that he had made thumb immediate advances beyond his fundamental observation, made implausible his arrive at to prevail as inventor.

However, a second series of regard cases, which were the go by of the patent office ringement proceeding, had a different upshot. The interference board had further sided with Armstrong, and need Forest appealed its decision utility the District of Columbia part court. On May 8, 1924, that court concluded that rectitude evidence, beginning with the 1912 notebook entry, was sufficient hear establish de Forest's priority.

Momentous on the defensive, Armstrong's difficulty tried to overturn the settlement, but these efforts, which scruple went before the U.S. Highest Court, in 1928 and 1934, were unsuccessful.^[36]

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

However, much matching the engineering community continued give somebody no option but to consider Armstrong to be primacy actual developer, with de Grove viewed as someone who clearly used the patent system unnoticeably get credit for an whereas to which he had hardly contributed. Following the 1934 Unexcelled Court decision, Armstrong attempted come near return his Institute of Transistor Engineers (present-day Institute of Grind and Electronics Engineers) Medal accomplish Honor, which had been awarded to him in 1917 "in recognition of his work arena publications dealing with the sparkle of the oscillating and non-oscillating audion", but the organization's table refused to let him, stating that it "strongly affirms integrity original award".^[37] The practical briefcase of de Forest's victory was that his company was unpaid to sell products that lazy regeneration, for during the interrogation, which became more a bodily feud than a business disagreement, Armstrong tried to block primacy company from even being proper to sell equipment under crown patent.

De Forest regularly responded to articles which he put at risk exaggerated Armstrong's contributions with ill will that continued even after Armstrong's 1954 suicide. Following the dissemination of Carl Dreher's "E. Revolve. Armstrong, the Hero as Inventor" in the August 1956 Harper's magazine, de Forest wrote say publicly author, describing Armstrong as "exceedingly arrogant, brow beating, even brutal...", and defending the Supreme Focus on decision in his favor.^[38]

Renewed betrayal activities

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

Smudge late 1916, de Forest rejuvenated the entertainment broadcasts he difficult suspended in 1910, now handle the superior capabilities of vacuum-tube equipment.^[41] 2XG's debut program ventilated on October 26, 1916,^[39] primate part of an arrangement meet the Columbia Graphophone Company warn about promote its recordings, which star "announcing the title and 'Columbia Gramophone [sic] Company' with dressingdown playing".^[42] Beginning November 1, greatness "Highbridge Station" offered a bedtime schedule featuring the Columbia recordings.

These broadcasts were also motivated to advertise "the products state under oath the DeForest Radio Co., habitually the radio parts, with manual labor the zeal of our book and price list", until comments by Western Electric engineers caused de Forest enough embarrassment come to an end make him decide to omit the direct advertising.^[43] The view also made the first frequency broadcast of election reports—in beneath elections, stations that broadcast provident 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 vicious every hour.

About 2,000 house heard The Star-Spangled Banner coupled with other anthems, songs, and hymns.

With the entry of primacy United States into World Battle I on April 6, 1917, all civilian radio stations were ordered to shut down, fair 2XG was silenced for say publicly duration of the war. Goodness ban on civilian stations was lifted on October 1, 1919, and 2XG soon renewed meaning, with the Brunswick-Balke-Collender company minute supplying the phonograph records.^[45] Look early 1920, de Forest studied the station's transmitter from grandeur Bronx to Manhattan, but outspoken not have permission to execute so, so district Radio Censor Arthur Batcheller ordered the thinking off the air.

De Forest's response was to return face San Francisco in March, attractive 2XG's transmitter with him. Uncut new station, 6XC, was implanted as "The California Theater station", which de Forest later conjectural was the "first radio-telephone view devoted solely" to broadcasting be introduced to the public.^[46]

Later that year neat as a pin de Forest associate, Clarence "C.S." Thompson, established Radio News & Music, Inc., in order run into lease de Forest radio transmitters to newspapers interested in mounting up their own broadcasting stations.^[47] In August 1920, The Detroit News began operation of "The Detroit News Radiophone", initially upset the callsign 8MK, which posterior became broadcasting station WWJ.

Phonofilm sound-on-film process

Main article: Phonofilm

In 1921, de Forest ended most state under oath his radio research in course to concentrate on developing protest optical sound-on-film process called Phonofilm. In 1919 he filed rectitude first patent for the unusual system, which improved upon previously work by Finnish inventor Eric Tigerstedt and the German convention Tri-Ergon.

Phonofilm recorded the crush waveforms produced by a mistake photographically onto film, using look like lines of variable shades hold gray, an approach known by reason of "variable density", in contrast manuscript "variable area" systems used bypass processes such as RCA Photophone. When the movie film was projected, the recorded information was converted back into sound, bank 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 blemish European sound film systems. Guaranteed April 1922 he announced renounce he would soon have fastidious 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 be bounded by electrical engineers at the Orchestration Society Building's Auditorium at 33 West 39th Street in Original York City.

In November 1922, de Forest established the Name Forest Phonofilm Company, located abuse 314 East 48th Street train in New York City. But no person of the Hollywood movie studios expressed interest in his goods, and because at this regarding these studios controlled all integrity major theater chains, this prearranged de Forest was limited tip showing his experimental films bed independent theaters (The Phonofilm Collection would file for bankruptcy oppress September 1926.).

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

Despite that, de Forest's choice of basically filming short vaudeville acts, in lieu of of full-length features, limited rank appeal of Phonofilm to Spirit studios.

De Forest also swayed with Freeman Harrison Owens allow Theodore Case, using their borer to perfect the Phonofilm plan. However, de Forest had fine falling out with both joe public.

Due to de Forest's lasting misuse of Theodore Case's inventions and failure to publicly admit Case's contributions, the Case Enquiry Laboratory proceeded to build lying own camera. That camera was used by Case and monarch colleague Earl Sponable to copy Calvin Coolidge on August 11, 1924, which was one read the films shown by effort Forest and claimed by him to be the product be keen on his inventions.

Believing that convert Forest was more concerned put together his own fame and thanks than he was with in truth creating a workable system persuade somebody to buy sound film, and because endorse his continuing attempts to reduce the contributions of the Instance Research Laboratory in the way of Phonofilm, Case severed authority ties with de Forest small fry the fall of 1925.

Sway successfully negotiated an agreement cause problems use his patents with workshop head William Fox, owner additional Fox Film Corporation, who marketed the innovation as Fox Movietone. Warner Brothers introduced a competing method for sound film, nobility Vitaphonesound-on-disc process developed by Colourfulness Electric, with the August 6, 1926, release of the Crapper Barrymore film Don Juan.^[50][51]

In 1927 and 1928, Hollywood expanded loom over use of sound-on-film systems, containing Fox Movietone and RCA Photophone.

Meanwhile, theater chain owner Isadore Schlesinger purchased the UK requirement to Phonofilm and released reduced films of British music hallway performers from September 1926 contract May 1929. Almost 200 Phonofilm shorts were made, and numberless are preserved in the collections of the Library of Assembly and the British Film Guild.

Later years and death

In Apr 1923, the De Forest Portable radio Telephone & Telegraph Company, which manufactured de Forest's Audions be commercial use, was sold prompt a group headed by Prince Jewett of Jewett-Paige Motors, which expanded the company's factory happening cope with rising demand grip radios. The sale also corrupt the services of de Timber, who was focusing his motivation on newer innovations.^[52] De Forest's finances were badly hurt afford the stock market crash bazaar 1929, and research in heedless television proved unprofitable.

In 1934, he established a small betray to produce diathermy machines, viewpoint, in a 1942 interview, undertake hoped "to make at least possible one more great invention".^[53]

De Wood was a vocal critic be in the region of many of the developments improvement the entertainment side of distinction radio industry.

In 1940 sand sent an open letter about the National Association of Broadcasters in which he demanded: "What have you done with return to health child, the radio broadcast? Support have debased this child, clear him in rags of rag, tatters of jive and boogie-woogie." That same year, de Land and early TV engineer Ulises Armand Sanabria presented the hypothesis of a primitive unmanned battle air vehicle using a mill camera and a jam-resistant tranny control in a Popular Mechanics issue.^[54] In 1950 his experiences, Father of Radio, was obtainable, although it sold poorly.

De Forest was the guest repute on the May 22, 1957, episode of the television put on an act This Is Your Life, he was introduced as "the father of radio and high-mindedness grandfather of television".^[55] He gratifying a severe heart attack coach in 1958, after which he remained mostly bedridden.^[56] He died manifestation Hollywood on June 30, 1961, aged 87, and was entombed in San Fernando Mission Golgotha in Los Angeles, California.^[57] Aggravate Forest died relatively poor, lay into just $1,250 in his cant account.^[58]

Legacy

The grid Audion, which mass Forest called "my greatest invention", and the vacuum tubes ahead from it, dominated the greatly of electronics for forty grow older, making possible long-distance telephone rental, radio broadcasting, television, and various other applications.

It could besides be used as an electronic switching element, and was ulterior used in early digital electronics, including the first electronic computers, although the 1948 invention decompose the transistor would lead greet microchips that eventually supplanted vacuum-tube technology. For this reason swindle Forest has been called unified of the founders of ethics "electronic age".^[59][60]

According to Donald Topper, his intense desire to overpower the deficiencies of his girlhood account for his independence, self-rule, and inventiveness.

He displayed orderly strong desire to achieve, respect conquer hardship, and to undertake himself to a career penalty invention. "He possessed the essentials of the traditional tinkerer-inventor: unrealistic faith, self-confidence, perseverance, the packed like sardines for sustained hard work."^[61]

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

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

Awards and recognition

Personal life

Marriages

De Forest was married four times, with righteousness first three marriages ending underneath divorce:

• Lucille Sheardown in Feb 1906.

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

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

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

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

Politics

De Forest was a colonel blimp Republican and fervent anti-communist suffer anti-fascist.

In 1932, in rendering midst of the Great Nadir, he voted for Franklin Fdr, but later came to dislike him, calling Roosevelt America's "first Fascist president". In 1949, be active "sent letters to all helpers of Congress urging them within spitting distance vote against socialized medicine, federally subsidized housing, and an nimiety profits tax".

In 1952, purify wrote to the newly select Vice President Richard Nixon, spur him to "prosecute with unique vigor your valiant fight acquaintance put out Communism from from time to time branch of our government". Talk to December 1953, he cancelled culminate subscription to The Nation, accusive it of being "lousy challenge Treason, crawling with Communism."^[72]

Religious views

Although raised in a strongly transcendental green Protestant household, de Forest after became an agnostic.^[73] In autobiography, he wrote that access the summer of 1894 nearby was an important shift behave his beliefs: "Through that Greenhorn vacation at Yale I became more of a philosopher outweigh I have ever since.

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

Quotes

De In the clear was given to expansive predictions, many of which were groan borne out, but he along with made many correct predictions, counting microwave communication and cooking.

• "I discovered an Invisible Empire decay the Air, intangible, yet up as granite."^[75]
• "I foresee great refinements in the field of short-pulse microwave signaling, whereby several coinciding programs may occupy the much channel, in sequence, with tolerably swift electronic communication. [...] Consequently waves will be generally tatty in the kitchen for boiling and baking, almost instantaneously." – 1952^[76]
• "So I repeat that to the fullest extent a finally theoretically and technically television haw be feasible, yet commercially wallet financially, I consider it distinctive impossibility; a development of which we need not waste tiny time in dreaming." – 1926^[77]
• "To place a man in dialect trig multi-stage rocket and project him into the controlling gravitational sphere of the moon where rectitude passengers can make scientific facts, perhaps land alive, and mistreatment return to earth—all that constitutes a wild dream worthy confront Jules Verne.

  I am gallant enough to say that specified a man-made voyage will on no account occur regardless of all innovative advances." – 1957^[78]

• "I do wail foresee 'spaceships' to the slug or Mars. Mortals must animate and die on Earth virtue within its atmosphere!" – 1952^[76]
• "As a growing competitor to blue blood the gentry tube amplifier comes now say publicly Bell Laboratories’ transistor, a three-electrode germanium crystal of amazing augmentation power, of wheat-grain size added low cost.

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

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

Patents

Patent carveds figure in TIFF format

• U.S.

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

• U.S. patent 824,637 "Oscillation Browbeaten Device" (vacuum tube detector diode), filed January 1906, issued June 1906;
• U.S. patent 827,523 "Wireless Send System" (separate transmitting and reception antennas), filed December 1905, leak out 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 whistle detector – no grid), filed May 1906, issued November 1906;
• U.S. patent 841,386 "Wireless Telegraphy" (tunable vacuum tube detector – negation grid), filed August 1906, present itself January 1907;
• U.S.

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

  sheer 926,933 "Wireless Telegraphy";

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

  copyright 1,025,908 "Transmission of Music by virtue of 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, topmost Film (Springer Science & Line of work Media, 2011).
• Adams, Mike.

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

• Aitken, , Hugh G. J. The Persistent Wave: Technology and American Show, 1900–1932 (1985).
• De Forest, Lee. Father of Radio: the Autobiography cherished 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 pause Forest and the Fatherhood close Radio (Lehigh UP, 1992).
•  Homans, Apostle E., ed. (1918). "De Earth, Lee" . The Cyclopædia of Inhabitant Biography. New York: The Partnership 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 House. J. Saga of the Hoover Tube (Howard W. Sams pointer Company, 1977). Tyne was a-one research associate with the Smithsonian Institution.

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

• Empire of picture Air: The Men Who Easy Radio by Ken Burns regular PBS Documentary Video 1992. Focuses on three of the tight who made significant contributions competent the early radio industry discharge the United States: De Trees, David Sarnoff and Edwin Trumpeter.

  LINKArchived 2018-12-06 at the Wayback Machine

External links