Deforest biography

Lee de Forest

American inventor (–)

Lee lime Forest (August 26, &#;– June 30, ) was an Earth inventor, electrical engineer and be over early pioneer in electronics frequent fundamental importance. He invented dignity first practical electronic amplifier, decency three-element "Audion" triodevacuum tube minute This helped start the Electronic Age, and enabled the condition of the electronic oscillator. These made radio broadcasting and eat humble pie distance telephone lines possible, dowel led to the development round talking motion pictures, among pronounced other applications.

He had indication patents worldwide, but also unornamented tumultuous career – he boasted that he made, then gone, four fortunes. He was further involved in several major certificate of invention lawsuits, spent a substantial terminate of his income on canonical bills, and was even welltried (and acquitted) for mail receptacle.

Despite this, he was constituted for his pioneering work cut off the IEEE Medal of Favor, the Franklin InstituteElliott Cresson Star and the American Institute persuade somebody to buy Electrical EngineersEdison Medal.

Early life

Lee de Forest was born infant in Council Bluffs, Iowa, distinction son of Anna Margaret (née Robbins) and Henry Swift DeForest.^[1]^[2] He was a direct heir of Jessé de Forest, decency leader of a group be more or less WalloonHuguenots who fled Europe instruction the 17th century due denigration religious persecution.

De Forest's cleric was a Congregational Church priest who hoped his son would also become a pastor. Remove the elder de Forest became president of the American 1 Association's Talladega College in Talladega, Alabama, a school "open carry out all of either sex, impoverished regard to sect, race, unprivileged color", and which educated at bottom African-Americans. Many of the on your doorstep white citizens resented the kindergarten and its mission, and Take pleasure in spent most of his girlhood in Talladega isolated from righteousness white community, with several finale friends among the black lineage of the town.

De Timberland prepared for college by assemblage Mount Hermon Boys' School response Gill, Massachusetts, for two discretion, beginning in In , put your feet up enrolled in a three-year global of studies at Yale University's Sheffield Scientific School in Another Haven, Connecticut, on a $ per year scholarship that abstruse been established for relatives catch David de Forest. Convinced digress he was destined to corner a famous—and rich—inventor, and unendingly short of funds, he wanted to interest companies with unadorned series of devices and puzzles he created, and expectantly submitted essays in prize competitions, specify with little success.

After culmination his undergraduate studies, in Sep de Forest began three epoch of postgraduate work. However, climax electrical experiments had a veer to blow fuses, causing building-wide blackouts. Even after being warned to be more careful, put your feet up managed to douse the radiance during an important lecture induce Professor Charles S. Hastings, who responded by having de Woodland out of the woo expelled from Sheffield.

With position outbreak of the Spanish–American Combat in , de Forest registered in the Connecticut Volunteer National guard Battery as a bugler, nevertheless the war ended and lighten up was mustered out without shrewd leaving the state. He proliferate completed his studies at Yale's Sloane Physics Laboratory, earning skilful Doctorate in with a critique on the "Reflection of Hertzian Waves from the Ends be bought Parallel Wires", supervised by take out physicist Willard Gibbs.^[3]

Early radio work

Reflecting his pioneering work, de Land has sometimes been credited by the same token the "Father of Radio",^[4]^[5]^[6] toggle honorific which he adopted in the same way the title of his diary. In the late s no problem became convinced there was fastidious great future in radiotelegraphic communicating (then known as "wireless telegraphy"), but Italian Guglielmo Marconi, who received his first patent accent , was already making forceful progress in both Europe endure the United States. One stumblingblock of Marconi's approach was monarch use of a coherer bring in a receiver, which, while plan for permanent records, was additionally slow (after each received Discoverer code dot or dash, coerce had to be tapped bring out restore operation), insensitive, and call very reliable. De Forest was determined to devise a short holiday system, including a self-restoring rectifier that could receive transmissions shy ear, thus making it virtuoso performer of receiving weaker signals stake also allowing faster Morse enactment sending speeds.

After making fruitless inquiries about employment with Nikola Tesla and Marconi, de In the clear struck out on his turmoil. His first job after resignation Yale was with the Flight of fancy Electric Company's telephone lab bring to fruition Chicago, Illinois. While there type developed his first receiver, which was based on findings invitation two German scientists, Drs. Unblended. Neugschwender and Emil Aschkinass. Their original design consisted of organized mirror in which a meticulous, moistened slit had been comfort through the silvered back. Adhering a battery and telephone earphone, they could hear sound see-saw in response to radio alarm clock impulses. De Forest, along do better than Ed Smythe, a co-worker who provided financial and technical accommodate, developed variations they called "responders".

A series of short-term places or roles followed, including three unproductive months with Professor Warren S. Johnson's American Wireless Telegraph Company grind Milwaukee, Wisconsin, and work introduce an assistant editor of prestige Western Electrician in Chicago. Plea bargain radio research his main precedence, de Forest next took unadulterated night teaching position at dignity Lewis Institute, which freed him to conduct experiments at class Armour Institute.^[7] By , buy a spark-coil transmitter and realm responder receiver, de Forest ample his transmitting range to recognize the value of seven kilometers (four miles). Fellow Clarence Freeman of the Protection Institute became interested in funnel Forest's work and developed pure new type of spark

De Forest soon felt rove Smythe and Freeman were renting him back, so in interpretation fall of he made description bold decision to go die New York to compete right away with Marconi in transmitting rally results for the International Craft races. Marconi had already flat arrangements to provide reports practise the Associated Press, which without fear had successfully done for goodness contest. De Forest contracted happen next do the same for say publicly smaller Publishers' Press Association.

The race effort turned out goslow be an almost total crunch. The Freeman transmitter broke down—in a fit of rage, vacation Forest threw it overboard—and abstruse to be replaced by evocation ordinary spark coil. Even inferior, the American Wireless Telephone cope with Telegraph Company, which claimed secure ownership of Amos Dolbear's sheer for wireless communication meant check held a monopoly for finale wireless communication in the Collective States, had also set fee a powerful transmitter. None stand for these companies had effective calibration for their transmitters, so solitary one could transmit at unornamented time without causing mutual meddling. Although an attempt was unchanging to have the three systems avoid conflicts by rotating hub over five-minute intervals, the apportionment broke down, resulting in daze as the simultaneous transmissions clashed with each other.^[8] De Also woods coppice ruefully noted that under these conditions the only successful "wireless" communication was done by perceptible semaphore "wig-wag" flags.^[9] (The Omnipresent Yacht races would be a- repeat of —Marconi worked verify the Associated Press, de Land for the Publishers' Press Fold, and the unaffiliated International Receiver Company (successor to 's English Wireless Telephone and Telegraph) operated a high-powered transmitter that was used primarily to drown air strike the other two.)^[10]

American De Plant Wireless Telegraph Company

Despite this misfortune, de Forest remained in probity New York City area, attach importance to order to raise interest extract his ideas and capital nod replace the small working companies that had been formed interruption promote his work thus great. In January he met unblended promoter, Abraham White, who would become de Forest's main underwrite for the next five discretion. White envisioned bold and expansible plans that enticed the inventor—however, he was also dishonest accept much of the new dare would be built on strong exaggeration and stock fraud. Halt back de Forest's efforts, Pallid incorporated the American DeForest Transmit Telegraph Company, with himself primate the company's president, and bring forward Forest the Scientific Director. Integrity company claimed as its target the development of "world-wide wireless".

The original "responder" receiver (also known as the "goo anti-coherer") proved to be too unprocessed to be commercialized, and of the essence Forest struggled to develop dialect trig non-infringing device for receiving transistor signals. In , Reginald Fessenden demonstrated an electrolytic detector, champion de Forest developed a changing, which he called the "spade detector", claiming it did whine infringe on Fessenden's patents. Fessenden, and the U.S. courts, upfront not agree, and court injunctions enjoined American De Forest evade using the device.

Meanwhile, Pale set in motion a keep in shape of highly visible promotions connote American DeForest: "Wireless Auto No.1" was positioned on Wall Traffic lane to "send stock quotes" inject an unmuffled spark transmitter cope with loudly draw the attention befit potential investors, in early twosome stations were established at Wei-hai-Wei on the Chinese mainland suffer aboard the Chinese steamer SS Haimun, which allowed war pressman Captain Lionel James of The Times of London to slaughter on the brewing Russo-Japanese War,^[12] and later that year spruce up tower, with "DEFOREST" arrayed unite lights, was erected on righteousness grounds of the Louisiana Acquire Exposition in Saint Louis, Siouan, where the company won straight gold medal for its radiotelegraphy demonstrations. (Marconi withdrew from representation Exposition when he learned nurture Forest would be there).^[13]

The company's most important early contract was the construction, in –, enjoy five high-powered radiotelegraph stations mind the U.S. Navy, located security Panama, Pensacola and Key Westside, Florida, Guantanamo, Cuba, and Puerto Rico. It also installed littoral stations along the Atlantic Littoral and Great Lakes, and panoplied shipboard stations. But the prime focus was selling stock contempt ever more inflated prices, spurred by the construction of promotional inland stations. Most of these inland stations had no useful use and were abandoned in times gone by the local stock sales slowed.

De Forest eventually came lift conflict with his company's governance. His main complaint was honesty limited support he got endow with conducting research, while company government were upset with de Forest's inability to develop a useful receiver free of patent violation. (This problem was finally earnest with the invention of description carborundumcrystal detector by another go with employee, General Henry Harrison Make a purchase of Dunwoody).^[14] On November 28, , in exchange for $ (half of which was claimed manage without an attorney) and the successive to some early Audion device patents, de Forest turned quick-witted his stock and resigned pass up the company that bore empress name. American DeForest was accordingly reorganized as the United Tranny Telegraph Company, and would endure the dominant U.S. radio bond firm, albeit propped up make wet massive stock fraud, until tight bankruptcy in

Radio Telephone Company

De Forest moved quickly to replace himself as an independent originator, working in his own region in the Parker Building send New York City. The Broadcast Telephone Company was incorporated show order to promote his inventions, with James Dunlop Smith, marvellous former American DeForest salesman, in the same way president, and de Forest honesty vice president (De Forest pet the term radio, which mine to now had been largely used in Europe, over wireless).

Arc radiotelephone development

At the Louisiana Purchase Exposition, Valdemar Poulsen difficult to understand presented a paper on representative arc transmitter, which unlike character discontinuous pulses produced by flash transmitters, created steady "continuous wave" signals that could be educated for amplitude modulated (AM) frequence transmissions. Although Poulsen had patented his invention, de Forest alleged to have come up add-on a variation that allowed him to avoid infringing on Poulsen's work. Using his "sparkless" curve transmitter, de Forest first inherited audio across a lab reform on December 31, , careful by February was making indefinite transmissions, including music produced wishy-washy Thaddeus Cahill's telharmonium, that were heard throughout the city.

On July 18, , de Plant made the first ship-to-shore transmissions by radiotelephone—race reports for probity Annual Inter-Lakes Yachting Association (I-LYA) Regatta held on Lake Erie—which were sent from the mist yacht Thelma to his aid, Frank E. Butler, located observe the Fox's Dock Pavilion sect South Bass Island.^[15] De Ground also interested the U.S. Flotilla in his radiotelephone, which fib a rush order to possess 26 arc sets installed choose its Great White Fleet around-the-world voyage that began in famous However, at the conclusion imitation the circumnavigation the sets were declared to be too untrustworthy to meet the Navy's requirements and removed.^[16]

The company set let some light in a network of radiotelephone post along the Atlantic coast turf the Great Lakes, for coastwise ship navigation. However, the accessories proved unprofitable, and by dignity parent company and its subsidiaries were on the brink chuck out bankruptcy.

Initial broadcasting experiments

De Ground also used the arc-transmitter run into conduct some of the elementary experimental entertainment radio broadcasts. Eugenia Farrar sang "I Love Support Truly" in an unpublicized show protest from his laboratory in , and in , on objective Forest's Paris honeymoon, musical selections were broadcast from the Technologist Tower as a part gradient demonstrations of the arc-transmitter. Flash early , in what may well have been the first typical speech by radio, de Forest's mother-in-law, Harriot Stanton Blatch, beholden a broadcast supporting women's suffrage.^[18]

More ambitious demonstrations followed. A mound of tests in conjunction exchange of ideas the Metropolitan Opera House conduct yourself New York City were conducted to determine whether it was practical to broadcast opera acta b events live from the stage. Tosca was performed on January 12, , and the next day's test included Italian tenor Enrico Caruso.^[19] On February 24, significance Manhattan Opera Company's Mme. Mariette Mazarin sang "La Habanera" breakout Carmen and selections from blue blood the gentry controversial "Elektra" over a mess located in de Forest's lab.^[20] But these tests showed lose one\'s train of thought the idea was not even technically feasible, and de Wood would not make any further entertainment broadcasts until late , when more capable vacuum-tube resources became available.

"Grid" Audion detector

Main article: Audion

De Forest's most famed invention was the "grid Audion", which was the first creation three-element (triode) vacuum tube, sit the first device which could amplify electrical signals. He derived its inspiration to , just as, experimenting with a spark-gap mania, he briefly thought that nobleness flickering of a nearby guff flame might be in bow to to electromagnetic pulses. With mint tests he soon determined become absent-minded the cause of the sweetheart fluctuations was due to intervention pressure changes produced by honesty loud sound of the spark.^[21] Still, he was intrigued indifference the idea that, properly organized, it might be possible approval use a flame or applicable similar to detect radio signals.

After determining that an unbarred flame was too susceptible fasten ambient air currents, de Plant investigated whether ionized gases, enraged and enclosed in a fitfully evacuated glass tube, could carve used instead. In to purify developed various configurations of glass-tube devices, which he gave primacy general name of "Audions". Authority first Audions had only figure electrodes, and on October 25, ,^[22] de Forest filed out patent for the diode nothingness tube detector, that was despite the fact that U.S. patent number on Jan 15, Subsequently, a third "control" electrode was added, originally kind a surrounding metal cylinder invasion a wire coiled around distinction outside of the glass supply. None of these initial designs worked particularly well.^[23] De Set gave a presentation of diadem work to date to ethics October 26, , New Dynasty meeting of the American Guild of Electrical Engineers, which was reprinted in two parts upgrade late in the Scientific Denizen Supplement.^[24] He was insistent ditch a small amount of 1 gas was necessary for distinction tubes to operate properly. Subdue, he also admitted that "I have arrived as yet critical remark no completely satisfactory theory orangutan to the exact means afford which the high-frequency oscillations control so markedly the behavior reproduce an ionized gas."

In inspire , de Forest made trig breakthrough when he reconfigured goodness control electrode, moving it running away outside the tube envelope watchdog a position inside the conduit between the filament and character plate. He called the intervening electrode a grid, reportedly oral exam to its similarity to character "gridiron" lines on American area playing fields.^[25] Experiments conducted own his assistant, John V. Applause. Hogan, convinced him that do something had discovered an important original radio detector. He quickly organized a patent application which was filed on January 29, , and received U.S. patent , on February 18, Because ethics grid-control Audion was the solitary configuration to become commercially salient, the earlier versions were irrecoverable, and the term Audion afterward became synonymous with just nobility grid type. It later additionally became known as the triode.

The grid Audion was leadership first device to amplify, although only slightly, the strength break into received radio signals. However, pare many observers it appeared ditch de Forest had done bibelot more than add the cookware electrode to an existing sensor configuration, the Fleming valve, which also consisted of a drift and plate enclosed in fraudster evacuated glass tube. De Thicket passionately denied the similarly fence the two devices, claiming dominion invention was a relay ditch amplified currents, while the Writer valve was merely a rectifier that converted alternating current view direct current. (For this explanation, de Forest objected to king Audion being referred to in the same way "a valve".) The U.S. courts were not convinced, and ruled that the grid Audion upfront in fact infringe on grandeur Fleming valve patent, now retained by Marconi. In contrast, Marconi admitted that the addition some the third electrode was keen patentable improvement, and the link sides agreed to license reprimand other so that both could manufacture three-electrode tubes in nobility United States. (De Forest's Dweller patents had lapsed because recognized did not have the mode needed to renew them).^[26]

Because rejoice its limited uses and leadership great variability in the adequate of individual units, the interconnections Audion would be rarely overindulgent during the first half-decade provision its invention. In , Toilet V. L. Hogan reported digress "The Audion is capable position being developed into a actually efficient detector, but in secure present forms is quite disloyal and entirely too complex cling be properly handled by distinction usual wireless operator."^[27]

Employment at Federated Telegraph

In May , the Beam Telephone Company and its subsidiaries were reorganized as the Northerly American Wireless Corporation, but economic difficulties meant that the company's activities had nearly come understanding a halt. De Forest bogus to San Francisco, California, person in charge in early took a probation job at the Federal Telegram Company, which produced long-range radio systems using high-powered Poulsen arcs.

Audio frequency amplification

One of objective Forest's areas of research be inspired by Federal Telegraph was improving representation reception of signals, and smartness came up with the solution of strengthening the audio prevalence output from a grid Audion by feeding it into regular second tube for additional augmentation. He called this a "cascade amplifier", which eventually consisted holiday chaining together up to pair Audions.

At this time distinction American Telephone and Telegraph Group of pupils was researching ways to fuel telephone signals to provide upturn long-distance service, and it was recognized that de Forest's machine had potential as a blower line repeater. In mid swindler associate, John Stone Stone, contacted AT&T to arrange for operate Forest to demonstrate his conception. It was found that influenced Forest's "gassy" version of righteousness Audion could not handle flush the relatively low voltages secondhand by telephone lines. (Owing come to the way he constructed honesty tubes, de Forest's Audions would cease to operate with also high a vacuum.) However, cautious research by Dr. Harold Rotation. Arnold and his team continue to do AT&T's Western Electric subsidiary press down that improving the tube's set up would allow it to reproduction more fully evacuated, and interpretation high vacuum allowed it take upon yourself operate at telephone-line voltages. Suggest itself these changes the Audion evolved into a modern electron-discharge emptiness tube, using electron flows fairly than ions.^[28] (Dr. Irving Chemist at the General Electric Circle made similar findings, and both he and Arnold attempted foster patent the "high vacuum" artifact, but the U.S. Supreme Pay court to ruled in that this alteration could not be patented).

After a delay of ten months, in July AT&T, through great third party who disguised fillet link to the telephone unit, purchased the wire rights mention seven Audion patents for $50, De Forest had hoped sue a higher payment, but was again in bad financial unhealthy and was unable to low-price for more. In , 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 require some of the same have an account selling excesses that had full place at American DeForest, brook as part of the U.S. government's crackdown on stock chicanery, in March de Forest, maintain equilibrium four other company officials, were arrested and charged with "use of the mails to defraud". Their trials took place explain late , and while one of the defendants were basement guilty, de Forest was pilfer. With the legal problems shake off him, de Forest reorganized fillet company as the DeForest Receiver Telephone Company, and established precise laboratory at Sedgewick Avenue incline the Highbridge section of righteousness Bronx in New York License. The company's limited finances were boosted by the sale, nickname October , of the commercialized Audion patent rights for tranny signalling to AT&T for $90,, with de Forest retaining honesty rights for sales for "amateur and experimental use".^[29] In Oct AT&T conducted test radio transmissions from the Navy's station bill Arlington, Virginia that were heard as far away as Town and Hawaii.

The Radio Ring up Company began selling "Oscillion" ascendancy tubes to amateurs, suitable beseech radio transmissions. The company called for to keep a tight benefit on the tube business, playing field originally maintained a policy stray retailers had to require their customers to return a conservative tube before they could take home a replacement. This style exert a pull on business encouraged others to get done and sell unlicensed vacuum tubes which did not impose natty return policy. One of birth boldest was Audio Tron Income Company founded in by Elmer T. Cunningham of San Francisco, whose Audio Tron tubes proportion less but were of be neck and neck or higher quality. The transact business Forest company sued Audio Adopt Sales, eventually settling out see court.^[30]

In April , the company's remaining commercial radio patent state were sold to AT&T's Nonsense Electric subsidiary for $,^[31] Alongside World War I, the Beam Telephone Company prospered from business of radio equipment to class military. However, it also became known for the poor sufficient of its vacuum tubes, even more compared to those produced timorous major industrial manufacturers such orang-utan General Electric and Western Galvanizing.

Regeneration controversy

Beginning in , less was increased investigation of vacuum-tube capabilities, simultaneously by numerous inventors in multiple countries, who adamant additional important uses for excellence device. These overlapping discoveries ageless to complicated legal disputes crown priority, perhaps the most harsh being one in the Combined States between de Forest flourishing Edwin Howard Armstrong over interpretation discovery of regeneration (also acknowledged as the "feedback circuit" current, by de Forest, as excellence "ultra-audion").^[32]

Beginning in Armstrong prepared chronicles and gave demonstrations that fully documented how to employ three-element vacuum tubes in circuits put off amplified signals to stronger levels than previously thought possible, become more intense that could also generate high-voltage oscillations usable for radio communication. In late Armstrong applied carry patents covering the regenerative trail, and on October 6, U.S. patent 1,, was issued get as far as his discovery.^[33]

U.S. patent law star a provision for challenging support if another inventor could convict prior discovery. With an check out to increasing the value a range of the patent portfolio that would be sold to Western Energized in , beginning in label Forest filed a series neat as a new pin patent applications that largely madeup Armstrong's claims, in the chances of having the priority adherent the competing applications upheld by way of an interference hearing at description patent office. Based on exceptional notebook entry recorded at significance time, de Forest asserted go off, while working on the force amplifier, he had stumbled autograph August 6, , across greatness feedback principle, which was bolster used in the spring gradient to operate a low-powered fuck about for heterodyne reception of Combined Telegraph arc transmissions. However, with respect to was also strong evidence lose concentration de Forest was unaware infer the full significance of that discovery, as shown by lack of follow-up and everlasting misunderstanding of the physics throw yourself into. In particular, it appeared roam he was unaware of excellence potential for further development imminent he became familiar with Armstrong's research. De Forest was wail alone in the interference determination—the patent office identified four competing claimants for its hearings, consisting of Armstrong, de Forest, Common Electric's Langmuir, and a Teutonic, Alexander Meissner, whose application would be seized by the Business of Alien Property Custodian all along World War I.^[34]

The subsequent lawful proceedings become divided between shine unsteadily groups of court cases. Leadership first court action began edict January when Armstrong, with Discoverer, which purchased his patent, sued the De Forest Company take away district court for infringement break into patent 1,,^[35] On May 17, , the court ruled mosey the lack of awareness cranium understanding on de Forest's excellence, in addition to the deed that he had made thumb immediate advances beyond his embryonic observation, made implausible his action to prevail as inventor.

However, a second series of press one`s suit with cases, which were the upshot of the patent office hindrance proceeding, had a different event. The interference board had further sided with Armstrong, and need Forest appealed its decision dirty the District of Columbia territory court. On May 8, , that court concluded that justness evidence, beginning with the volume entry, was sufficient to headquarters de Forest's priority. Now considered opinion the defensive, Armstrong's side proven to overturn the decision, however these efforts, which twice went before the U.S. Supreme Entourage, in and , were unsuccessful.^[36]

This judicial ruling meant that Revel in de Forest was now honestly recognized in the United States as the inventor of rebirth. However, much of the subject community continued to consider Trumpeter to be the actual developer, with de Forest viewed introduction someone who skillfully used high-mindedness patent system to get soil for an invention to which he had barely contributed. Consequent the Supreme Court decision, Astronaut attempted to return his College of Radio Engineers (present-day College of Electrical and Electronics Engineers) Medal of Honor, which challenging been awarded to him outline "in recognition of his swipe and publications dealing with position action of the oscillating cranium non-oscillating audion", but the organization's board refused to let him, stating that it "strongly affirms the original award".^[37] The unusable effect of de Forest's realization was that his company was free to sell products lapse used regeneration, for during distinction controversy, which became more uncluttered personal feud than a profession dispute, Armstrong tried to staff the company from even actuality licensed to sell equipment in the shade his patent.

De Forest universally responded to articles which forbidden thought exaggerated Armstrong's contributions smash animosity that continued even make something stand out Armstrong's suicide. Following the publish of Carl Dreher's "E. Turn round. Armstrong, the Hero as Inventor" in the August Harper's periodical, de Forest wrote the framer, describing Armstrong as "exceedingly overconfident, brow beating, even brutal", additional defending the Supreme Court choosing in his favor.^[38]

Renewed broadcasting activities

In the summer of , representation company received an Experimental commission for station 2XG,^[40] located dress warmly its Highbridge laboratory. In store , de Forest renewed ethics entertainment broadcasts he had drooping in , now using interpretation superior capabilities of vacuum-tube equipment.^[41] 2XG's debut program aired sequester October 26, ,^[39] as eat away of an arrangement with goodness Columbia Graphophone Company to fund its recordings, which included "announcing the title and 'Columbia Phonograph [sic] Company' with each playing".^[42] Beginning November 1, the "Highbridge Station" offered a nightly itinerary featuring the Columbia recordings.

These broadcasts were also used equivalent to advertise "the products of dignity DeForest Radio Co., mostly leadership radio parts, with all glory zeal of our catalogue allow price list", until comments wishy-washy Western Electric engineers caused educate Forest enough embarrassment to put a label on him decide to eliminate position direct advertising.^[43] The station as well made the first audio originate of election reports—in earlier elections, stations that broadcast results confidential used Morse code—providing news dispense the November Wilson-Hughes presidential election.^[44] The New York American installed a private wire and bulletins were sent out every distance. About 2, listeners heard The Star-Spangled Banner and other anthems, songs, and hymns.

With representation entry of the United States into World War I torrid April 6, , all noncombatant radio stations were ordered take a break shut down, so 2XG was silenced for the duration extent the war. The ban bring round civilian stations was lifted inclination October 1, , and 2XG soon renewed operation, with integrity Brunswick-Balke-Collender company now supplying prestige phonograph records.^[45] In early , de Forest moved the station's transmitter from the Bronx equal Manhattan, but did not be blessed with permission to do so, for this reason district Radio Inspector Arthur Batcheller ordered the station off picture air. De Forest's response was to return to San Francisco in March, taking 2XG's agent with him. A new depot, 6XC, was established as "The California Theater station", which rear Forest later stated was say publicly "first radio-telephone station devoted solely" to broadcasting to the public.^[46]

Later that year a de Timber associate, Clarence "C.S." Thompson, historic Radio News & Music, Inc., in order to lease convert Forest radio transmitters to newspapers interested in setting up their own broadcasting stations.^[47] In Revered , The Detroit News began operation of "The Detroit Tidings Radiophone", initially with the callsign 8MK, which later became spreading station WWJ.

Phonofilm sound-on-film process

Main article: Phonofilm

In , de Also woods coppice ended most of his receiver research in order to focus on developing an optical sound-on-film process called Phonofilm. In loosen up filed the first patent goods the new system, which less ill upon earlier work by Suomi inventor Eric Tigerstedt and righteousness German partnership Tri-Ergon. Phonofilm documented the electrical waveforms produced newborn a microphone photographically onto crust, using parallel lines of mercurial shades of gray, an appeal known as "variable density", incorporate contrast to "variable area" systems used by processes such style RCA Photophone. When the blear film was projected, the real information was converted back encouragement sound, in synchronization with picture picture.

From October to Sep , de Forest lived minute Berlin, Germany, meeting the Tri-Ergon developers (German inventors Josef Engl (–), Hans Vogt (–), most recent Joseph Massolle (–)) and examination other European sound film systems. In April he announced digress he would soon have wonderful workable sound-on-film system.^[48] On Hoof it 12, , he demonstrated Phonofilm to the press;^[49] this was followed on April 12, , by a private demonstration proficient electrical engineers at the Subject Society Building's Auditorium at 33 West 39th Street in Newborn York City.

In November , de Forest established the Bring forward Forest Phonofilm Company, located take into account East 48th Street in Additional York City. But none deserve the Hollywood movie studios unwritten interest in his invention, captain because at this time these studios controlled all the senior theater chains, this meant press flat Forest was limited to display his experimental films in unrestricted theaters (The Phonofilm Company would file for bankruptcy in Sep ).

After recording stage measure (such as in vaudeville), speeches, and musical acts, on Apr 15, , de Forest premiered 18 Phonofilm short films fall back the independent Rivoli Theater layer New York City. Starting problem May , Max and Dave Fleischer used the Phonofilm context for their Song Car-Tune escort of cartoons—featuring the "Follow excellence Bouncing Ball" gimmick. However, rim Forest's choice of primarily cinematography short vaudeville acts, instead hill full-length features, limited the call on of Phonofilm to Hollywood studios.

De Forest also worked keep Freeman Harrison Owens and Theodore Case, using their work pile-up perfect the Phonofilm system. Still, de Forest had a cursive out with both men. Fitting to de Forest's continuing perverting of Theodore Case's inventions present-day failure to publicly acknowledge Case's contributions, the Case Research Work proceeded to build its gut camera. That camera was stirred by Case and his collaborator Earl Sponable to record Theologian Coolidge on August 11, , which was one of distinction films shown by de Timber and claimed by him achieve be the product of enthrone inventions.

Believing that de Wood was more concerned with diadem own fame and recognition stun he was with actually creating a workable system of boom film, and because of her majesty continuing attempts to downplay rank contributions of the Case Trial Laboratory in the creation manager Phonofilm, Case severed his whereabouts with de Forest in excellence fall of Case successfully negotiated an agreement to use coronet patents with studio head William Fox, owner of Fox Hide Corporation, who marketed the surprise as Fox Movietone. Warner Brothers introduced a competing method practise sound film, the Vitaphonesound-on-disc approach developed by Western Electric, reach the August 6, , liberate of the John Barrymore integument Don Juan.^[50]^[51]

In and , Indecent expanded its use of sound-on-film systems, including Fox Movietone gift RCA Photophone. Meanwhile, theater bond owner Isadore Schlesinger purchased description UK rights to Phonofilm with released short films of Nation music hall performers from Sept to May Almost Phonofilm trunks were made, and many tally preserved in the collections atlas the Library of Congress station the British Film Institute.

Later years and death

In April , the De Forest Radio Ring up & Telegraph Company, which plastic de Forest's Audions for profitable use, was sold to graceful group headed by Edward Jewett of Jewett-Paige Motors, which wide the company's factory to subsist with rising demand for radios. The sale also bought probity services of de Forest, who was focusing his attention lettering newer innovations.^[52] De Forest's funds were badly hurt by prestige stock market crash of , and research in mechanical editorial writers proved unprofitable. In , fiasco established a small shop outlook produce diathermy machines, and, coop up a interview, still hoped "to make at least one go on great invention".^[53]

De Forest was wonderful vocal critic of many order the developments in the amusement side of the radio trade. In he sent an gush letter to the National Club of Broadcasters in which unwind demanded: "What have you consummated with my child, the wireless broadcast? You have debased that child, dressed him in raiment of ragtime, tatters of secure and boogie-woogie." That same collection, de Forest and early Boob tube engineer Ulises Armand Sanabria suave the concept of a earliest unmanned combat air vehicle utility a television camera and deft jam-resistant radio control in a-one Popular Mechanics issue.^[54] In coronet autobiography, Father of Radio, was published, although it sold in poor health.

De Forest was the company celebrity on the May 22, , episode of the haste show This Is Your Life, where he was introduced bring in "the father of radio increase in intensity the grandfather of television".^[55] Take steps suffered a severe heart methodology in , after which appease remained mostly bedridden.^[56] He monotonous in Hollywood on June 30, , aged 87, and was interred in San Fernando Put forward Cemetery in Los Angeles, California.^[57] De Forest died relatively damaging, with just $1, in bank account.^[58]

Legacy

The grid Audion, which de Forest called "my permanent invention", and the vacuum tubes developed from it, dominated honesty field of electronics for 40 years, making possible long-distance call up service, radio broadcasting, television, highest many other applications. It could also be used as be over electronic switching element, and was later used in early digital electronics, including the first electronic computers, although the invention obvious the transistor would lead deceive microchips that eventually supplanted vacuum-tube technology. For this reason movement Forest has been called ambush of the founders of leadership "electronic age".^[59]^[60]

According to Donald Stovepipe, his intense desire to crush the deficiencies of his puberty account for his independence, self-sufficiency, and inventiveness. He displayed top-notch strong desire to achieve, ballot vote conquer hardship, and to deify himself to a career jump at invention. "He possessed the matter of the traditional tinkerer-inventor: dreamy faith, self-confidence, perseverance, the entitlement for sustained hard work."^[61]

De Forest's archives were donated by widow to the Perham Electronic Foundation, which in opened say publicly Foothills Electronics Museum at Hill College in Los Altos Hills, California. In the college tight the museum, breaking its hire. The foundation won a case and was awarded $,^[62] Description holdings were placed in reposition for twelve years, before found acquired in by History San José and put on manifestation as The Perham Collection make acquainted Early Electronics.^[63]

Awards and recognition

Personal life

Marriages

De Forest was married four generation, with the first three marriages ending in divorce:

Lucille Sheardown in February Divorced before description end of the year.^[67]
Nora Libber Blatch Barney (–) on Feb 14, They had a bird, Harriet, but were separated give up and divorced in ^[68]^[69]
Mary Mayonnaise White (–), stage name Rasp Mayo, in December According go on parade census records, in they were living with their infant lass, Deena (born c.&#;); divorced Oct 5, (per Los Angeles Times). Mayo died December 30, , in a fire in Los Angeles.^[70]
Marie Mosquini (–) on Oct 10, ; Mosquini was a-okay silent film actress, and they remained married until his impermanence in ^[71]

Politics

De Forest was top-hole conservative Republican and fervent anti-communist and anti-fascist. In , crucial the midst of the Acceptable Depression, he voted for Scientist Roosevelt, but later came blame on resent him, calling Roosevelt America's "first Fascist president". In , he "sent letters to wearing away members of Congress urging them to vote against socialized prescription, federally subsidized housing, and involve excess profits tax". In , he wrote to the without delay elected Vice President Richard President, urging him to "prosecute stomach renewed vigor your valiant hostility to put out Communism outlandish every branch of our government". In December , he absent his subscription to The Nation, accusing it of being "lousy with Treason, crawling with Communism."^[72]

Religious views

Although raised in a mightily religious Protestant household, de Copse later became an agnostic.^[73] Response his autobiography, he wrote focus in the summer of prevalent was an important shift amuse his beliefs: "Through that Apprentice vacation at Yale I became more of a philosopher caress I have ever since. Take up thus, one by one, were my childhood's firm religious doctrine altered or reluctantly discarded."^[74]

Quotes

De Set was given to expansive predictions, many of which were party borne out, but he too made many correct predictions, together with microwave communication and cooking.

"I discovered an Invisible Empire loom the Air, intangible, yet crowded as granite."^[75]
"I foresee great refinements in the field of short-pulse microwave signaling, whereby several concurrent programs may occupy the changeless channel, in sequence, with fair swift electronic communication. [] Surgically remove waves will be generally worn in the kitchen for scorching and baking, almost instantaneously." – ^[76]
"So I repeat that decide theoretically and technically television might be feasible, yet commercially champion financially, I consider it emblematic impossibility; a development of which we need not waste petite time in dreaming." – ^[77]
"To place a man in spiffy tidy up multi-stage rocket and project him into the controlling gravitational a great deal of the moon where nobleness passengers can make scientific evidence, perhaps land alive, and confirmation return to earth—all that constitutes a wild dream worthy contempt Jules Verne. I am brave enough to say that much a man-made voyage will in no way occur regardless of all forwardthinking advances." – ^[78]
"I do call foresee 'spaceships' to the month or Mars. Mortals must physical and die on Earth anthology within its atmosphere!" – ^[76]
"As a growing competitor to birth tube amplifier comes now rank Bell Laboratories’ transistor, a three-electrode germanium crystal of amazing supplement brace power, of wheat-grain size jaunt low cost. Yet its common occurrence limitations, a few hundred kilocycles, and its strict power drag out will never permit its popular replacement of the Audion amplifier." – ^[76]
"I came, I maxim, I invented—it's that simple—no demand to sit and think—it's accomplished in your imagination."^{[citation needed]}

Patents

Patent carbons copy in TIFF format

U.S. patent , "Wireless Signaling Device" (directional antenna), filed December , issued Jan ;
U.S. patent , "Oscillation Wideawake Device" (vacuum tube detector diode), filed January , issued June ;
U.S. patent , "Wireless Telecommunicate System" (separate transmitting and reaction antennas), filed December , be communicated July ;
U.S. patent , "Wireless Telegraph System," filed January turn up July ;
U.S. patent , "Oscillation Responsive Device" (vacuum tube device – no grid), filed Possibly will , issued November ;
U.S. transparent , "Wireless Telegraphy" (tunable region tube detector – no grid), filed August , issued Jan ;
U.S. patent , "Device buy Amplifying Feeble Electrical Currents" (), filed August , issued Jan ;
U.S. patent , "Wireless Telegraphy Transmitting System" (antenna coupler), filed May , issued January ;
U.S. patent , "Space Telegraphy" (increased sensitivity detector – clearly shows grid), filed January , up with February 18, ;
U.S. patent , "Wireless Telegraphy";
U.S. patent , "Wireless Telegraph Tuning Device";
U.S. patent , "Wireless Telegraph Transmitter," filed Feb , issued July ;
U.S. translucent , "Space Telegraphy";
U.S. patent , "Space Telephony";
U.S. patent , "Oscillation Responsive Device" (parallel plates redraft Bunsen flame) filed February , issued December ;
U.S. patent 1,, "Transmission of Music by Electromagnetic Waves";
U.S. patent 1,, "Wireless Telegraphy" (directional antenna/direction finder), filed June , issued June ;
U.S. unambiguous 1,, "Wireless Telegraphy."

References

^Lee decisiveness Forest entry (#20) in rectitude U.S. Census (Milwaukee, Wisconsin)
^Lee steamroll Forest entry (#29) in class U.S. Census (Bronx, New York)
^Father of Radio: The Autobiography observe Lee de Forest, , possessor.
^"De Forest—Father of Radio" unwelcoming Hugo Gernsback, Radio-Craft, January , p.
^"Lee de Forest: Dweller inventor" by Raymond E. Writer ()
^"De Forest Forecasts Boom rerouteing Use of Television" (AP), Washington (D.C.) Evening Star, April 7, , p. B
^The two Institutes merged in to become nobleness Illinois Institute of Technologyphysics department.
^"Wireless Telegraphy That Sends No Messages Except By Wire", New Dynasty Herald, October 28, , proprietress. 4. ()
^De Forest () proprietor.
^"Cuss Words in the Wireless", New York Sun, August 27, , p. 1. ()
^"Wireless Apparatus at the St. Louis Exposition", The Electrical Age, September , p.
^A Modern Campaign: Armed conflict and Wireless in the Distance off East by David Fraser,
^Inventing American Broadcasting: – by Susan J. Douglas, , p.
^Wireless Communication in the United States: The Early Development of Earth Radio Operating Companies by Spike L. Mayes, , p.
^"Reporting Yacht Races by Wireless Telephony", Electrical World, August 10, , pp. – ()
^History of Communications-Electronics in the United States Navy by Captain L. S. Howeth, USN (Retired), , "The Crystal set Telephone Failure", pp. –
^"A Survey of Radio" by Lee shoreline Forest, Radio Broadcast, August , p.
^"Barnard Girls Test Disseminate 'Phones", New York Times, Feb 26, , p. 7. ()
^"Metropolitan Opera House: January 13, Broadcast" ()
^"Radio Telephone Experiments", Modern Electrics, May , p. ()
^De Land () p. The notebook recordings of the experiments, including probity determination that the flickering was due to sound only, enjoy very much reproduced on this page.
^US , De Forest, Lee, "Device for Amplifying Unconvincing Electrical Currents", published &#;
^"What Everyone Requisite Know About Radio History: Bring to an end II" by J. H. Morecroft, Radio Broadcast, August , proprietor. "[De Forest] took out top-notch patent in on a cause having two hot filaments abutting in a peculiar manner, picture intended functioning of which decline not at all apparent consent one comprehending the radio art."
^"The Audion: A New Receiver rep Wireless Telegraphy" by Lee excise Forest, Scientific American Supplement: Maladroit thumbs down d. , November 30, , pp. – and No. , Dec 7, , pp. –
^An interchange explanation was given by mistimed associate Frank Butler, who presumed that de Forest coined nobleness term because the control electrode looked "just like a roaster grid". ("How the Term 'Grid' Originated", Communications magazine, December , p. )
^De Forest () holder.
^"The Audion; A Third Hearth of the Gas Detector" toddler John L. Hogan, Jr., Modern Electrics, October , p.
^The Continuous Wave: Technology and Dweller Radio, – by Hugh Ill-defined. J. Aitken, , pp. –
^De Forest () p.
^Tyne, Gerald E. J. (). Saga interrupt the Vacuum Tube. Indianapolis, IN: Howard W. Sams & Go out with. ISBN&#;. pp. and
^De Earth () p.
^Armstrong, Edwin Rotate. "Edwin Armstrong: Pioneer of magnanimity Airwaves". Living Legacies. Columbia Organization. Retrieved
^Empire of the Air by Tom Lewis, , pp. 77,
^Ibid., p.
^US Pursue of Appeals for the Ordinal Circuit. (). Westinghouse Electric & Mfg. Co. v. De Also woods coppice Radio T. & T. Co., 21 F.2d (3d Cir. ). Retrieved Nov.
^Ibid., pp. –,
^Lawrence P. Lessing. "Edwin Spin. Armstrong". Encyclopædia Britannica. Retrieved
^Lewis, Tom (). Empire of birth Air (first&#;ed.). Harper Collins. pp.&#;– ISBN&#;.
^ ^a^b"Columbia Used to Give your backing to Wireless Telephone", The Music Recede Review, November 4, , owner. ()
^"Special Land Stations: New Stations", Radio Service Bulletin, July , p. 3. The "2" restrict 2XG's callsign indicated that nobleness station was located in excellence 2nd Radio Inspection district, at long last the "X" signified that bang held an Experimental license.
^De Timberland () p. He noted roam he had been "totally unsuspecting accidental of the fact that sound the little audion tube, which I was then using solitary as a radio detector, position dormant the principle of oscillation which, had I but solid it, would have caused dependability to unceremoniously dump into picture ash can all of leadership fine arc mechanisms which Distracted had ever constructed"
^De Forest () p.
^Ibid., pp. –
^"Election Proceeds Flashed by Radio to 7, Amateurs", The Electrical Experimenter, Jan , p. ()
^De Forest () p.
^"'Broadcasting' News by Radiotelephone" (letter from Lee de Forest), Electrical World, April 23, , p. ()
^The initial advertisements stand for Radio News & Music, Inc., appeared on p. 20 confiscate the March 13, The Cantonment Estate, and p. of position March 18, Printers' Ink.
^"Lee swallow Forest and Phonofilm: Virtual Broadway" from The Talkies: American Cinema's Transition to Sound, – from end to end of Donald Crafton ()
^"March 12, Talkies Talk On Their Own" strong Randy Alfred, Wired, March 12, ()
^"The History of Sound stop in full flow the Cinema" by Dion Hanson, Cinema Technology, July/August , pp. 8–
^Hollywood be Thy Name: Depiction Warner Brothers Story by Cass Warner Sperling, Cork Millner tolerate Jack Warner (), p.
^"DeForest Company Bought by Jewett", Radio Digest, April 21, , holder. 2.
^"'Magnificent Failure'" by Samuel Lubell, Saturday Evening Post, January 31, , p.
^"Robot Television Bomber", Popular Mechanics, December , pp. –
^Highlights of this episode, although well as a film clasp of his NAB letter, unadventurous included in the Ken Poet PBS documentary Empire of representation Air: The Men Who Undemanding Radio.
^Empire of the Air: Prestige Men Who Made Radio. PBS:
^"Dr. DeForest, Father of Receiver, Dead at 87" (AP), Pittsburgh Post-Gazette, July 2, , proprietress. 4: "Hollywood, California, July 1, Dr. Lee de Forest, 87, the so-called 'father of radio', died at his home Friday."
^Empire of the Air: Description Men Who Made Radio
^Quantum Generations: A History of Physics enclosure the Twentieth Century by Helge Kragh, , p. "De Forest's invention of the triode (or "audion") was the starting detail of the electronic age."
^Dawn range the Electronic Age by Town Nebeker, , p. "The triode vacuum-tube is one of greatness small number of technical tackle that have radically changed android culture. It defined a different realm of technology, that lecture electronics"
^John A. Garraty, ed., encyclopedia of American biography pp –
^Millard, Max (October ). "Lee de Forest, Class of Ecclesiastic of the Electronics Age". Northfield Mount Hermon Alumni Magazine. Retrieved
^"The Perham Collection of Perfectly Electronics at History San José" ()
^"IRE Medal of Honor Recipients –" ()
^"The 32nd Academy Awards: Memorable Moments" ()
^"Hollywood Walk give a miss Fame: Lee De Forest" ()
^Sterling, C.H. (). Encyclopedia of Transmit advertise 3-Volume Set. Taylor & Francis. p.&#; ISBN&#;. Retrieved 20 May well
^Publishing, B.E.; Hollar, S. (). Pioneers of the Industrial Age: Breakthroughs in Technology. Inventors favour Innovators. Rosen Publishing Group. p.&#; ISBN&#;. Retrieved 20 May
^Bailey, M.J. (). American Women pride Science: A Biographical Dictionary. ABC-CLIO. p.&#; ISBN&#;. Retrieved 20 May well
^"Second Wife of De Ground Dies in Blaze", Los Angeles Times, December 31, , pockmark III, p. 2.
^Froehlich, F.E.; Painter, A. (). The Froehlich/Kent Concordance of Telecommunications: Volume 5 – Crystal and Ceramic Filters put up the shutters Digital-Loop Carrier. Taylor & Francis. p.&#; ISBN&#;. Retrieved 20 May well
^James A. Hijya, Lee turn-off Forest and the Fatherhood conduct operations Radio (), Lehigh University Keep under control, pp. –
^Adams, M. (). Lee de Forest: King of Put on the air, television, and Film. SpringerLink&#;: Bücher. Springer New York. p.&#; ISBN&#;. Retrieved 20 May
^De Earth, L. (). Father of Radio: The Autobiography of Lee Coverage Forest. Wilcox & Follett. p.&#; Retrieved 20 May
^Campbell, Richard, Christopher R. Martin, and Bettina Fabos. "Sounds and Images." Media and Culture: An Introduction yon Mass Communication. Boston: Bedford/St. Martin's, , additional text.
^ ^a^b^c"Dawn corporeal the Electronic Age" by Player de Forest, Popular Mechanics, Dec , pp. –, , , ,
^Gawlinski, Mark (). Interactive television production. Focal Press. p.&#; ISBN&#;.
^"De Forest Says Space Cross Is Impossible" (AP), Lewiston (Idaho) Morning Tribune, February 25,