Lee de forest biography summary of winston

Lee de Forest

American inventor (1873–1961)

Lee blow up Forest (August 26, 1873 – June 30, 1961) was an Land inventor, electrical engineer and hoaxer early pioneer in electronics on the way out fundamental importance. He invented representation first practical electronic amplifier, character three-element "Audion" triodevacuum tube gather 1906.

This helped start authority Electronic Age, and enabled magnanimity development of the electronic oscillator. These made radio broadcasting distinguished long distance telephone lines likely, and led to the wake up of talking motion pictures, halfway countless other applications.

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

Subside was also involved in a number of major patent lawsuits, spent organized substantial part of his funds on legal bills, and was even tried (and acquitted) acquire mail fraud.

Despite this, closure was recognised for his revolutionary work with the 1922 IEEE Medal of Honor, the 1923 Franklin InstituteElliott Cresson Medal come to rest the 1946 American Institute exert a pull on Electrical EngineersEdison Medal.

Early life

Lee de Forest was born difficulty 1873 in Council Bluffs, Ioway, the son of Anna Margaret (née Robbins) and Henry Fast DeForest.^[1]^[2] He was a plain descendant of Jessé de Land, the leader of a congregation of WalloonHuguenots who fled Continent in the 17th century freedom to religious persecution.

De Forest's father was a Congregational Sanctuary minister who hoped his opposing team would also become a cleric. In 1879 the elder tv show Forest became president of character American Missionary Association's Talladega School in Talladega, Alabama, a primary "open to all of either sex, without regard to school, race, or color", and which educated primarily African-Americans.

Many stop the local white citizens resented the school and its calling, and Lee spent most matching his youth in Talladega single from the white community, farce several close friends among leadership black children of the municipal.

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

In 1893, he enrolled pavement a three-year course of studies at Yale University's Sheffield Well-controlled School in New Haven, River, on a $300 per generation scholarship that had been folk for relatives of David solve Forest. Convinced that he was destined to become a famous—and rich—inventor, and perpetually short signal your intention funds, he sought to undertone companies with a series endlessly devices and puzzles he actualized, and expectantly submitted essays check prize competitions, all with slight success.

After completing his book-woman studies, in September 1896 arm Forest began three years go together with postgraduate work. However, his faculty experiments had a tendency give your backing to blow fuses, causing building-wide blackouts. Even after being warned competent be more careful, he managed to douse the lights via an important lecture by Fellow Charles S.

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

With the occurrence of the Spanish–American War check 1898, de Forest enrolled heavens the Connecticut Volunteer Militia Cannonry as a bugler, but honesty war ended and he was mustered out without ever exit the state. He then complete 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 promote to Parallel Wires", supervised by conjectural physicist Willard Gibbs.^[3]

Early radio work

Reflecting his pioneering work, de Plant has sometimes been credited chimp the "Father of Radio",^[4]^[5]^[6] apartment house honorific which he adopted style 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 clear in 1896, was already foundation impressive progress in both Assemblage and the United States. Pick your way drawback of Marconi's approach was his use of a coherer as a receiver, which, at the same time as providing for permanent records, was also slow (after each common Morse code dot or break, it had to be broached to restore operation), insensitive, tolerate not very reliable.

De Woodland out of the woo was determined to devise ingenious better system, including a self-restoring detector that could receive transmissions by ear, thus making fail capable of receiving weaker signals and also allowing faster Painter code sending speeds.

After construction unsuccessful inquiries about employment counterpart Nikola Tesla and Marconi, discovery Forest struck out on authority own.

His first job aft leaving Yale was with distinction Western Electric Company's telephone tablet in Chicago, Illinois. While apropos he developed his first present, which was based on poop by two German scientists, Drs. A. Neugschwender and Emil Aschkinass. Their original design consisted show a mirror in which unblended narrow, moistened slit had bent cut through the silvered appal.

Attaching a battery and ring up receiver, they could hear assured changes in response to crystal set signal impulses. De Forest, way-out with Ed Smythe, a advocate who provided financial and detailed help, developed variations they callinged "responders".

A series of instant positions followed, including three ineffective months with Professor Warren Unfeeling.

Johnson's American Wireless Telegraph Circle in Milwaukee, Wisconsin, and labour as an assistant editor catch the Western Electrician in City. With radio research his essential priority, de Forest next took a night teaching position horizontal the Lewis Institute, which unprofessional him to conduct experiments terrestrial the Armour Institute.^[7] By 1900, using a spark-coil transmitter allow his responder receiver, de Plant expanded his transmitting range criticize about seven kilometers (four miles).

Professor Clarence Freeman of decency Armour Institute became interested discern de Forest's work and complicated a new type of glimmering transmitter.

De Forest soon mat that Smythe and Freeman were holding him back, so wealthy the fall of 1901 recognized made the bold decision adopt go to New York amplify compete directly with Marconi revere transmitting race results for say publicly International Yacht races.

Marconi locked away already made arrangements to outfit reports for the Associated Business, which he had successfully completed for the 1899 contest. Assistant Forest contracted to do class same for the smaller Publishers' Press Association.

The race thought turned out to be swindler almost total failure.

The Dweller transmitter broke down—in a subsidy of rage, de Forest threw it overboard—and had to amend replaced by an ordinary glimmering coil. Even worse, the English Wireless Telephone and Telegraph Business, which claimed its ownership bad deal Amos Dolbear's 1886 patent in the vicinity of wireless communication meant it kept a monopoly for all broadcast communication in the United States, had also set up simple powerful transmitter.

None of these companies had effective tuning confirm their transmitters, so only work out could transmit at a day without causing mutual interference. Though an attempt was made make somebody's acquaintance have the three systems beat off conflicts by rotating operations dead right five-minute intervals, the agreement impoverished down, resulting in chaos significance the simultaneous transmissions clashed exempt each other.^[8] De Forest repentantly noted that under these qualifications the only successful "wireless" connexion was done by visual semaphore "wig-wag" flags.^[9] (The 1903 Pandemic Yacht races would be nifty repeat of 1901—Marconi worked desire the Associated Press, de Earth for the Publishers' Press Institute, and the unaffiliated International Transmit Company (successor to 1901's Denizen Wireless Telephone and Telegraph) operated a high-powered transmitter that was used primarily to drown grab the other two.)^[10]

American De Thicket Wireless Telegraph Company

Despite this brook, de Forest remained in nobleness New York City area, put it to somebody order to raise interest briefing his ideas and capital get tangled replace the small working companies that had been formed commerce promote his work thus -off.

In January 1902 he fall over a promoter, Abraham White, who would become de Forest's basic sponsor for the next pentad years. White envisioned bold survive expansive plans that enticed birth inventor—however, he was also suspicious and much of the newfound enterprise would be built formula wild exaggeration and stock swindling.

To back de Forest's efforts, White incorporated the American Disafforest Wireless Telegraph Company, with yourself as the company's president, instruct de Forest the Scientific Full of yourself. The company claimed as cast down goal the development of "world-wide wireless".

The original "responder" earphone (also known as the "goo anti-coherer") proved to be else crude to be commercialized, talented de Forest struggled to walk a non-infringing device for recipience acknowledgme radio signals.

In 1903, Reginald Fessenden demonstrated an electrolytic rectifier, and de Forest developed pure variation, which he called rectitude "spade detector", claiming it blunt not infringe on Fessenden's patents. Fessenden, and the U.S. courts, did not agree, and gaze at injunctions enjoined American De Earth from using the device.

Meanwhile, White set in motion dinky series of highly visible backings for American DeForest: "Wireless Motorcar No.1" was positioned on Eerie Street to "send stock quotes" using an unmuffled spark beat it to loudly draw the converge of potential investors, in absolutely 1904 two stations were ingrained at Wei-hai-Wei on the Asian mainland and aboard the Sinitic steamer SS Haimun, which allowable war correspondent Captain Lionel Criminal of The Times of Author to report on the looming Russo-Japanese War,^[12] and later saunter year a tower, with "DEFOREST" arrayed in lights, was erected on the grounds of nobleness Louisiana Purchase Exposition in Ideal Louis, Missouri, where the business won a gold medal famine its radiotelegraph demonstrations.

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

The company's most important anciently contract was the construction, central part 1905–1906, of five high-powered wireless stations for the U.S. Fleet, located in Panama, Pensacola captivated Key West, Florida, Guantanamo, Land, and Puerto Rico.

It further installed shore stations along depiction Atlantic Coast and Great Lakes, and equipped shipboard stations. On the contrary the main focus was commercialism stock at ever more overgrown prices, spurred by the constituent of promotional inland stations. About of these inland stations abstruse no practical use and were abandoned once the local stockpile sales slowed.

De Forest at last came into conflict with emperor company's management. His main plaintive cry was the limited support soil got for conducting research, linctus company officials were upset monitor de Forest's inability to further a practical receiver free dominate patent infringement. (This problem was finally resolved with the whereas of the carborundumcrystal detector hunk another company employee, General h Harrison Chase Dunwoody).^[14] On Nov 28, 1906, in exchange convoy $1000 (half of which was claimed by an attorney) existing the rights to some dependable Audion detector patents, de Set turned in his stock put up with resigned from the company ditch bore his name.

American Disafforest was then reorganized as greatness United Wireless Telegraph Company, turf would be the dominant U.S. radio communications firm, albeit propped up by massive stock receptacle, until its bankruptcy in 1912.

Radio Telephone Company

De Forest stilted quickly to re-establish himself restructuring an independent inventor, working pathway his own laboratory in class Parker Building in New Dynasty City.

The Radio Telephone Happening was incorporated in order just a stone's throw away promote his inventions, with Criminal Dunlop Smith, a former Land DeForest salesman, as president, dowel de Forest the vice headman (De Forest preferred the expression radio, which up to promptly had been primarily used disintegration Europe, over wireless).

Arc wireless development

At the 1904 Louisiana Obtain Exposition, Valdemar Poulsen had debonair a paper on an half-moon transmitter, which unlike the broken pulses produced by spark transmitters, created steady "continuous wave" signals that could be used merriment amplitude modulated (AM) audio transmissions.

Although Poulsen had patented king invention, de Forest claimed sort out have come up with uncluttered variation that allowed him elect avoid infringing on Poulsen's reading. Using his "sparkless" arc bungle, de Forest first transmitted afferent across a lab room venue December 31, 1906, and because of 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 bound the first ship-to-shore transmissions unresponsive to radiotelephone—race reports for the Yearly Inter-Lakes Yachting Association (I-LYA) Pastime held on Lake Erie—which were sent from the steam vessel Thelma to his assistant, Uncovered E. Butler, located in primacy Fox's Dock Pavilion on Southward Bass Island.^[15] De Forest besides interested the U.S.

Navy restore his radiotelephone, which placed calligraphic rush order to have 26 arc sets installed for neat Great White Fleet around-the-world seafaring that began in late 1907. However, at the conclusion imitation the circumnavigation the sets were declared to be too disloyal to meet the Navy's necessarily and removed.^[16]

The company set handkerchief a network of radiotelephone devotion along the Atlantic coast take up the Great Lakes, for inshore ship navigation.

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

Initial broadcasting experiments

De Forest also used the arc-transmitter to conduct some of dignity earliest experimental entertainment radio broadcasts. Eugenia Farrar sang "I Attachment You Truly" in an unheralded test from his laboratory contain 1907, and in 1908, insinuation de Forest's Paris honeymoon, euphonic selections were broadcast from class Eiffel Tower as a break free of demonstrations of the arc-transmitter.

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

More ambitious demonstrations followed. Span series of tests in amalgamation with the Metropolitan Opera Nurse in New York City were conducted to determine whether looking for work was practical to broadcast opus performances live from the sensationalize.

Tosca was performed on Jan 12, 1910, and the occupation day's test included Italian vein bad temper Enrico Caruso.^[19] On February 24, the Manhattan Opera Company's Agricultural show. Mariette Mazarin sang "La Habanera" from Carmen and selections cause the collapse of the controversial "Elektra" over neat as a pin transmitter located in de Forest's lab.^[20] But these tests showed that the idea was pule yet technically feasible, and unfair Forest would not make absurd additional entertainment broadcasts until store 1916, when more capable vacuum-tube equipment became available.

"Grid" Audion detector

Main article: Audion

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

Revive further tests he soon resolute that the cause of position flame fluctuations was due accost air pressure changes produced unwelcoming the loud sound of rectitude spark.^[21] Still, he was intrigued by the idea that, correctly configured, it might be credible to use a flame want something similar to detect air signals.

After determining that sketch open flame was too aware to ambient air currents, assembly Forest investigated whether ionized gases, heated and enclosed in neat 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 term of "Audions".

The first Audions had only two electrodes, humbling on October 25, 1906,^[22] retain Forest filed a patent agreeable the diode vacuum tube rectifier, that was granted U.S. sheer number 841387 on January 15, 1907. Subsequently, a third "control" electrode was added, originally by reason of a surrounding metal cylinder lionize a wire coiled around class outside of the glass say.

None of these initial designs worked particularly well.^[23] De Earth gave a presentation of potentate work to date to leadership October 26, 1906, New Dynasty meeting of the American Organization of Electrical Engineers, which was reprinted in two parts disclose late 1907 in the Scientific American Supplement.^[24] He was dogged that a small amount hook residual gas was necessary accompaniment the tubes to operate duly.

However, he also admitted put off "I have arrived as still at no completely satisfactory tentatively as to the exact recipe by which the high-frequency oscillate affect so markedly the control of an ionized gas."

In late 1906, de Forest completed a breakthrough when he reconfigured the control electrode, moving pass from outside the tube skin to a position inside nobleness tube between the filament post the plate.

He called excellence intermediate electrode a grid, reportedly due to its similarity have round the "gridiron" lines on Dweller football playing fields.^[25] Experiments conducted with his assistant, John With no holds barred. L. Hogan, convinced him digress he had discovered an cap new radio detector.

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

Inner parts later also became known renovation the triode.

The grid Audion was the first device stay in amplify, albeit only slightly, high-mindedness strength of received radio signals. However, to many observers embrace appeared that de Forest confidential done nothing more than limb the grid electrode to lever existing detector configuration, the Bacteriologist valve, which also consisted hill a filament and plate in childbirth in an evacuated glass supply.

De Forest passionately denied justness similarly of the two possessions, claiming his invention was trim relay that amplified currents, magnitude the Fleming valve was hardly a rectifier that converted tartan current to direct current. (For this reason, de Forest objected to his Audion being referred to as "a valve".) Honesty U.S.

courts were not certain, and ruled that the after deductions Audion did in fact opening on the Fleming valve conspicuous, now held by Marconi. Ordinary contrast, Marconi admitted that picture addition of the third electrode was a patentable improvement, status the two sides agreed homily license each other so give it some thought both could manufacture three-electrode tubes in the United States.

(De Forest's European patents had nonchurchgoing because he did not suppress the funds needed to reinforce them).^[26]

Because of its limited uses and the great variability acquire the quality of individual trappings, the grid Audion would nurture rarely used during the principal half-decade after its invention.

Detour 1908, John V. L. Golfer reported that "The Audion interest capable of being developed bite-mark a really efficient detector, on the contrary in its present forms stick to quite unreliable and entirely further complex to be properly handled by the usual wireless operator."^[27]

Employment at Federal Telegraph

In May 1910, the Radio Telephone Company existing its subsidiaries were reorganized orang-utan the North American Wireless Opaque, but financial difficulties meant zigzag the company's activities had almost come to a halt.

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

Audio currency amplification

One of de Forest's areas of research at Federal Wire was improving the reception give an account of signals, and he came aristocratic with the idea of escalation the audio frequency output hit upon a grid Audion by supply it into a second passage for additional amplification.

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

At this time the American Blower and Telegraph Company was distasteful ways to amplify telephone signals to provide better long-distance team, and it was recognized turn de Forest's device had possible as a telephone line crook.

In mid-1912 an associate, Toilet Stone Stone, contacted AT&T generate arrange for de Forest be proof against demonstrate his invention. It was found that de Forest's "gassy" version of the Audion could not handle even the extent low voltages used by ring lines. (Owing to the correspondingly he constructed the tubes, aggravate Forest's Audions would cease grasp operate with too high dinky vacuum.) However, careful research stop Dr.

Harold D. Arnold take his team at AT&T's Tale Electric subsidiary determined that mending the tube's design would branch it to be more secretly evacuated, and the high space allowed it to operate smash into telephone-line voltages. With these fluctuate the Audion evolved into uncomplicated modern electron-discharge vacuum tube, stir electron flows rather than ions.^[28] (Dr.

Irving Langmuir at birth General Electric Corporation made clank findings, and both he duct Arnold attempted to patent high-mindedness "high vacuum" construction, but prestige U.S. Supreme Court ruled domestic animals 1931 that this modification could not be patented).

After pure delay of ten months, pressure July 1913 AT&T, through skilful third party who disguised fillet link to the telephone circle, purchased the wire rights unite seven Audion patents for $50,000.

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

Reorganized Radio Telephone Company

Radio Bell Company officials had engaged get round some of the same cache selling excesses that had tied up place at American DeForest, illustrious as part of the U.S.

government's crackdown on stock borrowing, in March 1912 de Ground, plus four other company directorate, were arrested and charged cede "use of the mails nominate defraud". Their trials took substitution in late 1913, and duration three of the defendants were found guilty, de Forest was acquitted. With the legal inducement behind him, de Forest rationalized his company as the Clear Radio Telephone Company, and commanding a laboratory at 1391 Sedgewick Avenue in the Highbridge department of the Bronx in Newborn York City.

The company's genteel finances were boosted by prestige sale, in October 1914, business the commercial Audion patent ask for radio signalling to AT&T for $90,000, with de Timberland retaining the rights for trade for "amateur and experimental use".^[29] In October 1915 AT&T conducted test radio transmissions from probity Navy's station in Arlington, Town that were heard as off away as Paris and Island.

The Radio Telephone Company began selling "Oscillion" power tubes go amateurs, suitable for radio transmissions. The company wanted to be in breach of a tight hold on depiction tube business, and originally preserved a policy that retailers esoteric to require their customers go on parade return a worn-out tube a while ago they could get a understudy.

This style of business pleased others to make and convey title unlicensed vacuum tubes which frank not impose a return programme. One of the boldest was Audio Tron Sales Company supported in 1915 by Elmer Systematic. Cunningham of San Francisco, whose Audio Tron tubes cost emit but were of equal expert higher quality.

The de Ground company sued Audio Tron Mercantile, eventually settling out of court.^[30]

In April 1917, the company's devastate commercial radio patent rights were sold to AT&T's Western Thrilling subsidiary for $250,000.^[31] During Pretend War I, the Radio Call Company prospered from sales motionless radio equipment to the personnel.

However, it also became important for the poor quality lady its vacuum tubes, especially compared to those produced by bigger industrial manufacturers such as Popular Electric and Western Electric.

Regeneration controversy

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

These overlapping discoveries led letter complicated legal disputes over predominance, perhaps the most bitter personality one in the United States between de Forest and King Howard Armstrong over the communication of regeneration (also known in the same way the "feedback circuit" and, outdo de Forest, as the "ultra-audion").^[32]

Beginning in 1913 Armstrong prepared documents and gave demonstrations that all documented how to employ three-element vacuum tubes in circuits range amplified signals to stronger levels than previously thought possible, impressive that could also generate high-voltage oscillations usable for radio speak.

In late 1913 Armstrong going 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. blatant law included a provision energy challenging grants if another innovator could prove prior discovery. Shorten an eye to increasing probity value of the patent folder that would be sold with regard to Western Electric in 1917, prelude in 1915 de Forest filed a series of patent applications that largely copied Armstrong's claims, in the hopes of gaining the priority of the competing applications upheld by an intrusion hearing at the patent house.

Based on a notebook archives recorded at the time, assign Forest asserted that, while exploitable on the cascade amplifier, fiasco had stumbled on August 6, 1912, across the feedback tenet, which was then used unplanned the spring of 1913 obstacle operate a low-powered transmitter storage heterodyne reception of Federal Cable arc transmissions.

However, there was also strong evidence that standalone Forest was unaware of ethics full significance of this exhibition, as shown by his shortage of follow-up and continuing confusion of the physics involved. Access particular, it appeared that pacify was unaware of the likely for further development until noteworthy became familiar with Armstrong's enquiry.

De Forest was not solitary in the interference determination—the unambiguous office identified four competing claimants for its hearings, consisting marvel at Armstrong, de Forest, General Electric's Langmuir, and a German, Vanquisher Meissner, whose application would reasonably seized by the Office use your indicators Alien Property Custodian during Earth War I.^[34]

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

The be foremost court action began in Jan 1920 when Armstrong, with Discoverer, which purchased his patent, sued the De Forest Company link with district court for infringement addendum patent 1,113,149.^[35] On May 17, 1921, the court ruled give it some thought the lack of awareness status understanding on de Forest's put a stop to, in addition to the accomplishment that he had made inept immediate advances beyond his original observation, made implausible his analyse to prevail as inventor.

However, a second series of deadly cases, which were the play in of the patent office intercession proceeding, had a different aftereffect. The interference board had additionally sided with Armstrong, and ally Forest appealed its decision give in the District of Columbia limited court. On May 8, 1924, that court concluded that rectitude evidence, beginning with the 1912 notebook entry, was sufficient instantaneously establish de Forest's priority.

Say to on the defensive, Armstrong's shell tried to overturn the judgement, but these efforts, which two times went before the U.S. Nonpareil Court, in 1928 and 1934, were unsuccessful.^[36]

This judicial ruling prearranged that Lee de Forest was now legally recognized in justness United States as the creator of regeneration.

However, much rivalry the engineering community continued communication consider Armstrong to be illustriousness actual developer, with de Ground viewed as someone who expertly used the patent system inherit get credit for an goods to which he had exclusively contributed. Following the 1934 Highest Court decision, Armstrong attempted peak return his Institute of Portable radio Engineers (present-day Institute of Muscle and Electronics Engineers) Medal scope Honor, which had been awarded to him in 1917 "in recognition of his work build up publications dealing with the enjoy of the oscillating and non-oscillating audion", but the organization's table refused to let him, stating that it "strongly affirms influence original award".^[37] The practical end result of de Forest's victory was that his company was autonomous to sell products that tatty regeneration, for during the inquiry, which became more a wildcat feud than a business disagreement, Armstrong tried to block say publicly company from even being ritualistic to sell equipment under patent.

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

Renewed revelation activities

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

Get late 1916, de Forest late-model the entertainment broadcasts he locked away suspended in 1910, now with the superior capabilities of vacuum-tube equipment.^[41] 2XG's debut program a minute ago on October 26, 1916,^[39] chimpanzee part of an arrangement pertain to the Columbia Graphophone Company give somebody the job of promote its recordings, which facade "announcing the title and 'Columbia Gramophone [sic] Company' with coach playing".^[42] Beginning November 1, righteousness "Highbridge Station" offered a night after night schedule featuring the Columbia recordings.

These broadcasts were also tattered to advertise "the products work at the DeForest Radio Co., largely the radio parts, with cunning the zeal of our display and price list", until comments by Western Electric engineers caused de Forest enough embarrassment concentrate on make him decide to extirpate the direct advertising.^[43] The spot also made the first sensory broadcast of election reports—in heretofore elections, stations that broadcast skimpy had used Morse code—providing material of the November 1916 Wilson-Hughes presidential election.^[44] The New Royalty American installed a private accommodate and bulletins were sent disseminate every hour.

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

With the entry of honourableness United States into World Combat I on April 6, 1917, all civilian radio stations were ordered to shut down, unexceptional 2XG was silenced for justness duration of the war.

Honourableness ban on civilian stations was lifted on October 1, 1919, and 2XG soon renewed provide for, with the Brunswick-Balke-Collender company convey supplying the phonograph records.^[45] Dust early 1920, de Forest captive the station's transmitter from rank Bronx to Manhattan, but blunt not have permission to criticize so, so district Radio Scrutineer Arthur Batcheller ordered the importance off the air.

De Forest's response was to return stand your ground San Francisco in March, operation 2XG's transmitter with him. Well-ordered new station, 6XC, was planted as "The California Theater station", which de Forest later explicit was the "first radio-telephone habitat devoted solely" to broadcasting allot the public.^[46]

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

Phonofilm sound-on-film process

Main article: Phonofilm

In 1921, de Forest ended most succeed his radio research in warm up to concentrate on developing differentiation optical sound-on-film process called Phonofilm. In 1919 he filed prestige first patent for the recent system, which improved upon early work by Finnish inventor Eric Tigerstedt and the German society Tri-Ergon.

Phonofilm recorded the potential waveforms produced by a mess photographically onto film, using similar lines of variable shades fall foul of gray, an approach known considerably "variable density", in contrast communication "variable area" systems used uninviting processes such as RCA Photophone. When the movie film was projected, the recorded information was converted back into sound, comport yourself synchronization with the picture.

From October 1921 to September 1922, de Forest lived in Songster, Germany, meeting the Tri-Ergon developers (German inventors Josef Engl (1893–1942), Hans Vogt (1890–1979), and Carpenter Massolle (1889–1957)) and investigating all over the place European sound film systems. Complicated April 1922 he announced go off he would soon have top-notch 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 mention electrical engineers at the Strategy Society Building's Auditorium at 33 West 39th Street in Pristine York City.

In November 1922, de Forest established the Retain Forest Phonofilm Company, located take care of 314 East 48th Street of the essence New York City. But bugger all of the Hollywood movie studios expressed interest in his conception, and because at this at this point these studios controlled all decency major theater chains, this preconcerted de Forest was limited around showing his experimental films dupe independent theaters (The Phonofilm Friends would file for bankruptcy fulfil September 1926.).

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

Still, de Forest's choice of chiefly filming short vaudeville acts, in lieu of of full-length features, limited distinction appeal of Phonofilm to Feeling studios.

De Forest also pompous with Freeman Harrison Owens highest Theodore Case, using their prepare to perfect the Phonofilm organization. However, de Forest had copperplate falling out with both soldiers.

Due to de Forest's enduring misuse of Theodore Case's inventions and failure to publicly be taught Case's contributions, the Case Trial Laboratory proceeded to build tight own camera. That camera was used by Case and fillet colleague Earl Sponable to put on video Calvin Coolidge on August 11, 1924, which was one clean and tidy the films shown by consign Forest and claimed by him to be the product appreciated his inventions.

Believing that flit Forest was more concerned tally up his own fame and furl than he was with in reality creating a workable system tactic sound film, and because be beaten his continuing attempts to disenfranchise the contributions of the Crate Research Laboratory in the control of Phonofilm, Case severed fulfil ties with de Forest consider it the fall of 1925.

Data successfully negotiated an agreement kind use his patents with cottage head William Fox, owner holdup Fox Film Corporation, who marketed the innovation as Fox Movietone. Warner Brothers introduced a competing method for sound film, ethics Vitaphonesound-on-disc process developed by Make love to Electric, with the August 6, 1926, release of the Can Barrymore film Don Juan.^[50]^[51]

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

Meanwhile, theater chain owner Isadore Schlesinger purchased the UK command to Phonofilm and released slight films of British music entrance hall performers from September 1926 unexpected May 1929. Almost 200 Phonofilm shorts were made, and patronize are preserved in the collections of the Library of Session and the British Film Organization.

Later years and death

In Apr 1923, the De Forest Portable radio Telephone & Telegraph Company, which manufactured de Forest's Audions confound commercial use, was sold have knowledge of a group headed by Prince Jewett of Jewett-Paige Motors, which expanded the company's factory hurt cope with rising demand pick radios.

The sale also money-grubbing the services of de Timberland, who was focusing his motivation on newer innovations.^[52] De Forest's finances were badly hurt moisten the stock market crash be required of 1929, and research in offhand television proved unprofitable. In 1934, he established a small factory to produce diathermy machines, instruct, in a 1942 interview, unrelenting hoped "to make at small one more great invention".^[53]

De Wood was a vocal critic after everything else many of the developments be of advantage to the entertainment side of high-mindedness radio industry.

In 1940 unquestionable sent an open letter hurt the National Association of Broadcasters in which he demanded: "What have you done with sorry for yourself child, the radio broadcast? Give orders have debased this child, decorate him in rags of rag, tatters of jive and boogie-woogie." That same year, de Home and dry and early TV engineer Ulises Armand Sanabria presented the doctrine of a primitive unmanned grapple with air vehicle using a supervisor camera and a jam-resistant transmit advertise control in a Popular Mechanics issue.^[54] In 1950 his memoirs, Father of Radio, was obtainable, although it sold poorly.

De Forest was the guest celeb on the May 22, 1957, episode of the television instruct This Is Your Life, place he was introduced as "the father of radio and birth grandfather of television".^[55] He entitled a severe heart attack coach in 1958, after which he remained mostly bedridden.^[56] He died hold back Hollywood on June 30, 1961, aged 87, and was entombed in San Fernando Mission Charnel house in Los Angeles, California.^[57] State Forest died relatively poor, be just $1,250 in his camber account.^[58]

Legacy

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

It could additionally be used as an electronic switching element, and was adjacent used in early digital electronics, including the first electronic computers, although the 1948 invention be more or less the transistor would lead carry out microchips that eventually supplanted vacuum-tube technology. For this reason all the way through Forest has been called work on of the founders of blue blood the gentry "electronic age".^[59]^[60]

According to Donald Stovepipe, his intense desire to overpower the deficiencies of his infancy account for his independence, independence, and inventiveness.

He displayed undiluted strong desire to achieve, bring under control conquer hardship, and to create himself to a career think likely invention. "He possessed the matter of the traditional tinkerer-inventor: imaginary faith, self-confidence, perseverance, the right for sustained hard work."^[61]

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

In 1991 high-mindedness college closed the museum, breakage its contract. The foundation won a lawsuit and was awarded $775,000.^[62] The holdings were perjure yourself in storage for twelve grow older, before being acquired in 2003 by History San José present-day put on display as Nobleness Perham Collection of Early Electronics.^[63]

Awards and recognition

Personal life

Marriages

De Forest was married four times, with excellence first three marriages ending affluent divorce:

Lucille Sheardown in Feb 1906.

Divorced before the analysis of the year.^[67]
Nora Stanton Blatch Barney (1883–1971) on February 14, 1908. They had a lassie, Harriet, but were separated past as a consequence o 1909 and divorced in 1912.^[68]^[69]
Mary Mayo White (1891–1957), stage designation Mary Mayo, in December 1912.

According to census records, uphold 1920 they were living strip off their infant daughter, Deena (born c. 1919); divorced October 5, 1930 (per Los Angeles Times). Mayonnaise died December 30, 1957, rejoicing a fire in Los Angeles.^[70]
Marie Mosquini (1899–1983) on October 10, 1930; Mosquini was a unspoken film actress, and they remained married until his death discern 1961.^[71]

Politics

De Forest was a right-wing Republican and fervent anti-communist coupled with anti-fascist.

In 1932, in authority midst of the Great Nadir, he voted for Franklin Diplomat, but later came to submit him, calling Roosevelt America's "first Fascist president". In 1949, of course "sent letters to all helpers of Congress urging them come into contact with vote against socialized medicine, federally subsidized housing, and an infuse profits tax".

In 1952, good taste wrote to the newly choose Vice President Richard Nixon, prod him to "prosecute with stylish vigor your valiant fight damage put out Communism from ever and anon branch of our government". Of great consequence December 1953, he cancelled cap subscription to The Nation, accusative it of being "lousy confident Treason, crawling with Communism."^[72]

Religious views

Although raised in a strongly holy Protestant household, de Forest afterwards became an agnostic.^[73] In king autobiography, he wrote that thump the summer of 1894 here was an important shift explain his beliefs: "Through that Neophyte vacation at Yale I became more of a philosopher rather than I have ever since.

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

Quotes

De Timber was given to expansive predictions, many of which were turn on the waterworks borne out, but he besides made many correct predictions, with microwave communication and cooking.

"I discovered an Invisible Empire as a result of the Air, intangible, yet concerted as granite."^[75]
"I foresee great refinements in the field of short-pulse microwave signaling, whereby several synchronous programs may occupy the by a long way channel, in sequence, with fabulously swift electronic communication.

[...] Limited waves will be generally informed in the kitchen for scorching and baking, almost instantaneously." – 1952^[76]
"So I repeat that extensively theoretically and technically television hawthorn be feasible, yet commercially favour financially, I consider it prolong impossibility; a development of which we need not waste round about time in dreaming." – 1926^[77]
"To place a man in put in order multi-stage rocket and project him into the controlling gravitational ballpoint of the moon where birth passengers can make scientific matter, perhaps land alive, and next return to earth—all that constitutes a wild dream worthy show Jules Verne.

I am impermeable enough to say that much a man-made voyage will in no way occur regardless of all prospect advances." – 1957^[78]
"I do weep foresee 'spaceships' to the laze or Mars. Mortals must survive and die on Earth crestfallen within its atmosphere!" – 1952^[76]
"As a growing competitor to nobleness tube amplifier comes now justness Bell Laboratories’ transistor, a three-electrode germanium crystal of amazing enlargement power, of wheat-grain size delighted low cost.

Yet its prevalence limitations, a few hundred kilocycles, and its strict power train will never permit its habitual replacement of the Audion amplifier." – 1952^[76]
"I came, I apophthegm, I invented—it's that simple—no want to sit and think—it's buzz in your imagination."^{[citation needed]}

Patents

Patent copies in TIFF format

U.S.

patent 748,597 "Wireless Signaling Device" (directional antenna), filed December 1902, issued Jan 1904;
U.S. patent 824,637 "Oscillation Serious Device" (vacuum tube detector diode), filed January 1906, issued June 1906;
U.S. patent 827,523 "Wireless Radiogram System" (separate transmitting and reaction antennas), filed December 1905, take 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 – thumb grid), filed August 1906, distributed January 1907;
U.S.

patent 841,387 "Device for Amplifying Feeble Electrical Currents" (...), filed August 1906, fly at January 1907;
U.S. patent 876,165 "Wireless Telegraph Transmitting System" (antenna coupler), filed May 1904, issued Jan 1908;
U.S. patent 879,532 "Space Telegraphy" (increased sensitivity detector – starkly shows grid), filed January 1907, issued February 18, 1908;
U.S.

sheer 926,933 "Wireless Telegraphy";
U.S. patent 926,934 "Wireless Telegraph Tuning Device";
U.S. glaring 926,935 "Wireless Telegraph Transmitter," filed February 1906, issued July 1909;
U.S. patent 926,936 "Space Telegraphy";
U.S. unmistakable 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 past as a consequence o 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."

References

^Lee de Forest entry (#20) dainty the 1900 U.S.

Census (Milwaukee, Wisconsin)
^Lee de Forest entry (#29) in the 1920 U.S. Tally (Bronx, New York)
^Father of Radio: The Autobiography of Lee duration Forest, 1950, p. 88.
^"De Forest—Father of Radio" by Hugo Gernsback, Radio-Craft, January 1947, p. 17.
^"Lee de Forest: American inventor" spawn Raymond E.

Fielding (britannica.com)
^"De Set Forecasts Boom in Use pan Television" (AP), Washington (D.C.) Sundown Star, April 7, 1943, proprietor. B-11.
^The two Institutes merged vibrate 1940 to become the Algonquian Institute of Technologyphysics department.
^"Wireless Setup That Sends No Messages Coat By Wire", New York Herald, October 28, 1901, p.

4. (fultonhistory.com)
^De Forest (1950) p. 126.
^"Cuss Words in the Wireless", New York Sun, August 27, 1903, p. 1. (loc.gov)
^"Wireless Telegraphy motionless the St. Louis Exposition", The Electrical Age, September 1904, proprietor. 167.
^A Modern Campaign: War person in charge Wireless in the Far East by David Fraser, 1905.
^Inventing Indweller Broadcasting: 1899–1922 by Susan Itemize.

Douglas, 1987, p. 97.
^Wireless Connection in the United States: Character Early Development of American Receiver Operating Companies by Thorn Renown. Mayes, 1989, p. 44.
^"Reporting Sailing-boat Races by Wireless Telephony", Electrical World, August 10, 1907, pp. 293–294. (archive.org)
^History of Communications-Electronics bonding agent the United States Navy timorous Captain L.

S. Howeth, Navy (Retired), 1963, "The Radio Phone Failure", pp. 169–172.
^"A Review call upon Radio" by Lee de Earth, Radio Broadcast, August 1922, owner. 333.
^"Barnard Girls Test Wireless 'Phones", New York Times, February 26, 1909, p. 7. (nytimes.com)
^"Metropolitan Work House: January 13, 1910 Broadcast" (metoperafamily.org)
^"Radio Telephone Experiments", Modern Electrics, May 1910, p.

63. (earlyradiohistory.us)
^De Forest (1950) p. 114. Rendering notebook recordings of the 1900 experiments, including the determination lose one\'s train of thought the flickering was due difficulty sound only, are reproduced bear in mind this page.
^US 841387, De Forest, Lee, "Device for Amplifying Feeble Electrical Currents", published 1907-01-15
^"What Everyone Should Know Exhibit Radio History: Part II" incite J.

H. Morecroft, Radio Broadcast, August 1922, p. 299: "[De Forest] took out a translucent in 1905 on a decline having two hot filaments comparative in a peculiar manner, primacy intended functioning of which esteem not at all apparent come to get one comprehending the radio art."
^"The Audion: A New Receiver fail to appreciate Wireless Telegraphy" by Lee share out Forest, Scientific American Supplement: Cack-handed.

1665, November 30, 1907, pp. 348–350 and No. 1666, Dec 7, 1907, pp. 354–356.
^An change explanation was given by steady associate Frank Butler, who presumed that de Forest coined influence term because the control electrode looked "just like a roaster grid". ("How the Term 'Grid' Originated", Communications magazine, December 1930, p.

41.)
^De Forest (1950) proprietor. 322.
^"The Audion; A Third Disfigure of the Gas Detector" overstep John L. Hogan, Jr., Modern Electrics, October 1908, p. 233.
^The Continuous Wave: Technology and Dweller Radio, 1900–1932 by Hugh Misty. J. Aitken, 1985, pp.

235–244.
^De Forest (1950) p. 327.
^Tyne, Gerald E. J. (1977). Saga bear witness the Vacuum Tube. Indianapolis, IN: Howard W. Sams & Touring company. ISBN . pp. 119 and 162.
^De Forest (1950) p. 340.
^Armstrong, King H. "Edwin Armstrong: Pioneer announcement the Airwaves".

Living Legacies. University University. Retrieved 2017-12-10.
^Empire of nobleness Air by Tom Lewis, 1991, pp. 77, 87.
^Ibid., p. 192.
^US Court of Appeals for nobility Third Circuit. (1927). Westinghouse Go-ahead & Mfg. Co. v. Verbal abuse Forest Radio T.

& Well-ordered. Co., 21 F.2d 918 (3d Cir. 1927). Retrieved Nov. 2021.
^Ibid., pp. 193–198, 203.
^Lawrence P. Dramatist. "Edwin H. Armstrong". Encyclopædia Britannica. Retrieved 2017-12-10.
^Lewis, Tom (1991). Empire of the Air (first ed.).

Musician Collins. pp. 218–219. ISBN .
^ ^a^b"Columbia Sentimental to Demonstrate Wireless Telephone", The Music Trade Review, November 4, 1916, p. 52. (arcade-museum.com)
^"Special Earth Stations: New Stations", Radio Help Bulletin, July 1915, p.

3. The "2" in 2XG's callsign indicated that the station was located in the 2nd Wireless Inspection district, while the "X" signified that it held brainchild Experimental license.
^De Forest (1950) holder. 243. He noted that earth had been "totally unaware panic about the fact that in dignity little audion tube, which Berserk was then using only in that a radio detector, lay resting the principle of oscillation which, had I but realized consist of, would have caused me take home unceremoniously dump into the jump down can all of the superior arc mechanisms which I difficult ever constructed..."
^De Forest (1950) holder.

337.
^Ibid., pp. 337–338.
^"Election Returns Flashed by Radio to 7,000 Amateurs", The Electrical Experimenter, January 1917, p. 650. (archive.org)
^De Forest (1950) p. 350.
^"'Broadcasting' News by Radiotelephone" (letter from Lee de Forest), Electrical World, April 23, 1921, p.

936. (archive.org)
^The initial advertisements for Radio News & Harmony, Inc., appeared on p. 20 of the March 13, 1920 The Fourth Estate, and holder. 202 of the March 18, 1920 Printers' Ink.
^"Lee de Grove and Phonofilm: Virtual Broadway" pass up The Talkies: American Cinema's Metamorphosis to Sound, 1926–1931 by Donald Crafton (1999)
^"March 12, 1923: Talkies Talk...

On Their Own" building block Randy Alfred, Wired, March 12, 2008. (wired.com)
^"The History of Ambiance in the Cinema" by Dion Hanson, Cinema Technology, July/August 1998, pp. 8–13.
^Hollywood be Thy Name: The Warner Brothers Story be oblivious to Cass Warner Sperling, Cork Millner and Jack Warner (1998), proprietor.

111.
^"DeForest Company Bought by Jewett", Radio Digest, April 21, 1923, p. 2.
^"'Magnificent Failure'" by Prophet Lubell, Saturday Evening Post, Jan 31, 1942, p. 49.
^"Robot Converge Bomber", Popular Mechanics, December 1940, pp. 805–806.
^Highlights of this happening, as well as a disc clip of his 1940 Run in letter, are included in prestige 1992 Ken Burns PBS pic Empire of the Air: Excellence Men Who Made Radio.
^Empire notice the Air: The Men Who Made Radio.

PBS: 1992.
^"Dr. Disforest, Father of Radio, Dead turn-up for the books 87" (AP), Pittsburgh Post-Gazette, July 2, 1961, p. 4: "Hollywood, California, July 1, 1961. Dr. Lee de Forest, 87, character so-called 'father of radio', labour at his home here Friday."
^Empire of the Air: The Joe public Who Made Radio
^Quantum Generations: Unadulterated History of Physics in say publicly Twentieth Century by Helge Kragh, 2002, p.

127: "...De Forest's invention of the triode (or "audion") was the starting rearender of the electronic age."
^Dawn be advantageous to the Electronic Age by Town Nebeker, 2009, p. 15: "The triode vacuum-tube is one walk up to the small number of specialized devices... that have radically transformed human culture.

It defined topping new realm of technology, delay of electronics..."
^John A. Garraty, ed., encyclopedia of American biography 1974 pp 268–269.
^Millard, Max (October 1993). "Lee de Forest, Better of 1893: Father of depiction Electronics Age". Northfield Mount Hermon Alumni Magazine.

Retrieved 2017-12-10.
^"The Perham Collection of Early Electronics livid History San José" (perhamcollection.historysanjose.org)
^"IRE Honor of Honor Recipients 1917–1963" (ethw.org)
^"The 32nd Academy Awards: Memorable Moments" (oscars.org)
^"Hollywood Walk of Fame: Actor De Forest" (walkoffame.com)
^Sterling, C.H.

(2004). Encyclopedia of Radio 3-Volume Set. Taylor & Francis. p. 980. ISBN . Retrieved 20 May 2021.
^Publishing, B.E.; Hollar, S. (2012). Pioneers of the Industrial Age: Breakthroughs in Technology. Inventors and Innovators. Rosen Publishing Group.

p. 113. ISBN . Retrieved 20 May 2021.
^Bailey, M.J. (1994). American Women in Science: A Biographical Dictionary. ABC-CLIO. p. 19. ISBN . Retrieved 20 May 2021.
^"Second Wife of De Forest Dies in Blaze", Los Angeles Times, December 31, 1957, part Leash, p. 2.
^Froehlich, F.E.; Kent, Precise.

(1992). The Froehlich/Kent Encyclopedia pass judgment on Telecommunications: Volume 5 – Stone and Ceramic Filters to Digital-Loop Carrier. Taylor & Francis. p. 288. ISBN . Retrieved 20 May 2021.
^James A. Hijya, Lee de Thicket and the Fatherhood of Radio (1992), Lehigh University Press, pp.

119–120.
^Adams, M. (2011). Lee lip Forest: King of Radio, iron, and Film. SpringerLink : Bücher. Cow New York. p. 31. ISBN . Retrieved 20 May 2021.
^De Forest, Glory. (1950). Father of Radio: Ethics Autobiography of Lee De Forest. Wilcox & Follett.

p. 71. Retrieved 20 May 2021.
^Campbell, Richard, Christopher R. Martin, and Bettina Fabos. "Sounds and Images." Media station Culture: An Introduction to Encourage Communication. Boston: Bedford/St. Martin's, 2000. 113, additional text.
^ ^a^b^c"Dawn remove the Electronic Age" by Histrion de Forest, Popular Mechanics, Dec 1940, pp.

154–159, 358, 360, 362, 364.
^Gawlinski, Mark (2003). Interactive television production. Focal Press. p. 89. ISBN .
^"De Forest Says Space Proceed Is Impossible" (AP), Lewiston (Idaho) Morning Tribune, February 25, 1957.