View source for Wave Transmitter

{{Infobox product
| title            = Wave Transmitter
| logo             = 
| logo_caption     = 
| logo_alt         = 
| image            = Esq_eletr_transm_ondas_color.jpg
| image_size       = 
| alt              = 
| caption          = Schematics of the Wave Transmitter, 1904
| type             = [[Radio transmitter]]/[[Radio receiver|receiver]]
| inventor         = [[Roberto Landell de Moura]]
| inception        = {{start date|1904}}
| manufacturer     = 
| available        = 
| current supplier = 
| last production  = 
| models           = 
| slogan           = 
| website          = 
| notes            = <ref>Patent {{patent|US|771917A}}</ref>
}}
The '''Wave Transmitter''' was a [[radio]] transmitter/receiver, described in a patent by [[Roberto Landell de Moura]] in 1904, capable of transmitting audio via radio waves as well as light (similar to a [[photophone]]). It was developed after many years of  Landell de Moura experimenting with multi-function devices that were combinations of [[megaphone]]s, photophones, and [[radio telegraph]]s.

== History ==

=== Background ===

{{Wikisource|pt:Jornal do Commercio/1899/O Teleforo|O Teleforo (Portuguese Wikisource)}}
Landell de Moura began experiments in wireless communication in the mid 1890s.<ref name="to-day">[https://babel.hathitrust.org/cgi/pt?id=uc1.b3850105&view=1up&seq=46 "Landell de Moura"] by Arthur Dias, ''The Brazil of To-day'', 1907, pages 38-39.</ref> He worked with electrically powered [[megaphone]]s, [[photophone]]s, and when radio technology came along, incorporated  [[radio telegraph]]y. By 1900 Landell de Moura was giving public demonstration of a device that seemed to use light (a photophone), a device he received a Brazilian patent for  in 1901.{{sfn|Rybak|2002|p=[https://archive.org/details/otbfebruary200200unse/page/67/mode/1up 67]}}{{sfnm|1a1=Almeida|1y=2023|1p=128|2a1=Almeida|2y=2012|2p=22}}{{Sfn|''Jornal do Commercio'', 14 de junho de|1899|p=[[:s:pt:Jornal do Commercio/1899/O Teleforo|1]]}}

On 14 June 1901, he boarded the steamship ''Piemonte'' for Europe, from where he then went to the United States, where he sought to patent his inventions,{{Sfn|''A Verdade'', 8 de fevereiro de|1903|p=4}}{{Sfn|Almeida|2006|p=73}} and set up a workshop in New York. During his stay in the U.S., he received patents for a Photophone with radio wave bell or buzzer to alert the user at the other end and a stand-alone wireless telegraph using light or radio waves.{{sfn|Rybak|2002|p=[https://archive.org/details/otbfebruary200200unse/page/67/mode/1up 67]}} He had to change his patent descriptions several times due to the requirements of the Patent Office.{{Sfn|Almeida|2006|pp=73-74}}

{{Wikisource|en:United States patent 771917|United States patent 771917}}

In 1904, he received a patent for his wave transmitter, patent no. 771917.{{Sfn|Almeida, ''s.d''|p=9}}{{Sfn|Moura|1904}} According to the American technicians who analyzed his research during the patent issuance process, his wireless transmission system was superior to what had already been developed, and regarding radiotelephony itself, he was "the discoverer and creator of the principles on which it is based."{{Sfn|''Pacotilha'', 28 de junho de|1904|p=1}}{{Sfn|Almeida|2006|p=80}} With the public announcement about his patents, several entrepreneurs offered to buy the rights, but Landell de Moura refused them, declaring: "'''The inventions no longer belong to me. By the grace of God, I am merely their custodian. I will take them to my homeland, Brazil, which will be responsible for delivering them to humanity''.'"{{Sfn|Santos|2003|p=6}}

[[File:Patente_transmissor_de_ondas.jpg|left|thumb|231x231px|U.S. patent certificate]]

At the end of 1904, he had to return to Brazil with a debt of US$4,000 {{USDCY|4000|1904}}, hoping to return to New York in a short time, and, according to Ernani Fornari, patent other six inventions, but he had to abandon his plans.{{Sfnm|1a1=Almeida, ''s.d''|1pp=9-10|2a1=Ferreira|2y=2022|2loc=Aventura em São Paulo|3a1=Almeida|3y=2006|3p=120}} He sought to gain support from the Brazilian government to demonstrate his equipment offshore. However, when meeting with a government representative, he stated that the ships could be at any distance from each other, even suggesting the possibility of interplanetary communication, which was not well received by the government official. He also sought support from the [[Legislative Assembly of São Paulo]] to finance the commercialization of his invention, without success.{{Sfn|Almeida, ''s.d''|p=10}}{{Sfn|Santos|2003|p=6}} According to Alencar, after the Brazilian government's refusal, Landell de Moura would have destroyed his experiments and given up scientific research.{{Sfn|Alencar|2012|pp=72-73}} After these events, the federal government began to invest in radio telegraphy for the Armed Forces.{{Sfn|Almeida|2006|p=117}}

=== Operation ===

The Wave Transmitter, originally called the ''Gouradphone'',{{Sfn|Almeida|2006|p=75}}{{Efn|J. Rodrigo Botet indicates that the device was also called ''Telephono''.{{sfn|Almeida|2006|p=66}}}} built in an artisanal way,{{Sfn|Almeida|2006|p=67}} used an electromechanical microphone, invented by Landell, capable of collecting, according to Claudia Zaltrão, "sound waves through a resonance chamber," whose metallic diaphragm "opened and closed the primary of a [[Ruhmkorff coil]], and induced a high voltage in the secondary of that coil which was radiated either through an antenna or two sparking spheres."{{Sfn|Zimmer|2020|p=[https://www.google.com.br/books/edition/A_filosofia_do_fracasso/TNIPEAAAQBAJ?hl=pt-BR&gbpv=1&dq=Landell%20transmissor%20de%20ondas&pg=PT87&printsec=frontcover 87]}} The two spheres are called "phonetic interrupter," which, when exposed to the vibrations of the human voice or other sounds, create a series of electric sparks or flashes of light that, when they reach the receiver, are made understandable through a telephone, a lamp, or a Morse code device.{{Sfn|''Western Electrician'', 29 October|1904|p=348}} However, the radiated voice did not contain the characteristics of the speaker's timbre, requiring training to understand the content of the messages. However, the signal contained many harmonics, allowing it to be detected over a wide range of frequencies.{{Sfn|Almeida|2006|p=93}}

According to the ''Cientec'' team, who replicated the invention, the "phonetic interrupter" was Landell's true innovation, as the other parts of the equipment were already known.{{Sfn|Almeida|2012|p=27}} According to a report from ''A Federação'', 1905, the transmission of light waves would reach 30 to 50 kilometers and would not have climatic interference, as the beam of light would be modified both by mechanical vibration and by the electrical vibrations produced by the voice.{{Sfn|''A Federação'', 27 de março de|1905|p=1}}

The device also used both radio waves and light beams, in addition to using continuous waves, with Landell advocating the use of short waves for long-distance communication,{{Sfn|Almeida, ''s.d''|p=9}} something that Marconi only recognized as useful in 1916.{{Sfn|Almeida|2006|p=90}} D'Arisbo notes that the device for transmitting light waves would be different from that for transmitting electromagnetic waves,{{Sfn|D'Arisbo|2012|p=78}} while the patent issued in the US explains that the vibrations of the phonetic interrupter are transformed into both electrical and light waves,{{Sfn|Moura|1904|p=[[:s:en:Page:United States patent 771917.pdf/3|1]]|loc=45}}{{Efn|James P. Rybak explains that the focus of this invention, although it also considers light transmission, would be the transmission of radio waves, which, in the researcher's view, would be superior. {{sfn|Rybak|2002|p=[https://archive.org/details/otbfebruary200200unse/page/67/mode/1up 67]}}}} with Bruscato explaining that the "telephone" and the "wireless telegraph" are those that used light beams.{{Sfn|Bruscato|2012|p=123}} The biographer Hamilton Almeida reports that Landell took more than 10 years to develop his equipment, having started to develop his ideas around 1886, after returning from his studies in Rome.{{Sfn|Ferreira|2022|loc=Empreendedor}} Essentially, Landell sought to establish a point-to-point connection with electromagnetic waves,{{Sfn|Ferraretto|2012|p=51}} with the Wave Transmitter radiating information in all directions.{{Sfn|Almeida|2006|p=92}} Drawing a comparison between the experiments of Landell and Marconi, researchers César Augusto dos Santos and Otto Albuquerque explain as follows:{{Sfn|Fapesp|2006|loc=Sem apoio}}

Landell's patent, in 1901, according to Albuquerque, had priority of speech transmission in a photonic-electronic system, while Marconi's patent focused only on the transmission of signals in Morse code. Both researchers agree that Marconi and Landell conducted similar experiments, but with different aims, with Santos explaining that "the priest-scientist was the first radio amateur in voice telegraphy and the first broadcaster with continued contacts in the country and abroad."{{Sfn|Fapesp|2006|loc=Sem apoio}}

==== Legacy ====
In the 1980s, a working group from [[Telebrás]], when analyzing the patents issued by the United States, considered that Landell was the first to carry out continuous wave transmissions, using a valve equivalent to the [[Triode|three-electrode valve]] patented by [[Lee De Forest]] in 1907.{{Sfn|Almeida|2012|p=20}} At the same time, Edson Benedicto Ramos Féris, then an engineer at the Telebrás Research and Development Center and a professor at USP, explained, after analyzing the patents, that the luminous system used by Landell was a predecessor of [[fiber optic]]s, as, despite the differences, they are based on the same principle.{{Sfn|Almeida|2006|p=87}} When discussing the importance of these patents, Hamilton Almeida, in a 1983 book, states that "''the wave transmitter patented by Father Landell in the United States is the precursor of the radio''."{{Sfn|Zaltrão|2006|p=15}}

Regarding Landell's experiments, in 1993, the Italian work "''Tu piccola scatola... La radio: fatti, cose, persone''," by Laura De Luca and Walter Lobina, states that he conducted the "''first radio transmission of which there is any record. The municipality of São Paulo witnessed the emission and reception of electromagnetic and luminous waves. Radio was born, but no one noticed.''".{{Sfn|Almeida, ''s.d''|p=12}} In the authors' view, the radio did not find an environment in the country where it could develop.{{Sfn|Almeida|2012|p=34}} According to Professor Luiz Artur Ferraretto from [[UFRGS]], with the experiences of 1899 and 1900, "''Father Landell came close to what, more than a decade later, was named broadcasting''."{{Sfn|Almeida|2023|p=124}} Meanwhile, as Claudia Zaltrão acknowledges, Landell's name and his work remain forgotten in his own country and abroad,{{Sfn|Zaltrão|2006|pp=26-27}} while Almeida notes that in life, Landell's invention received recognition from inventors in the USA.{{Sfn|Ferreira|2022|loc=Aventura em São Paulo}}

=== Replics ===
In 1984, the ''Fundação de Ciência e Tecnologia'' (Cientec), from [[Rio Grande do Sul]], after three months of work by engineer Antonio Carlos Solano and technicians José Clóvis Totel and Antônio Felipe Pepe, presented a functional replica of the Wave Transmitter. One of the many difficulties they faced was understanding the scale of the device and what materials to use in its construction. On 7 September of that year, at the closing of the ''Semana da Pátria'' (Week of the Motherland), the replica was presented to the public at an event where Governor Jair Soares conveyed the words "Porto Alegre." In 2004, another functional replica was made by Marco Aurélio Cardoso Moura, after two years of work.{{sfnm|1a1=Almeida|1y=2012|1pp=26-27|2a1=Almeida|2y=2006|2pp=100, 102}}

The 1984 replica had a range of up to 50 meters over a wide frequency band, including FM, with Ferraretto noting that at Landell's time the result would have been better due to the absence of external interference. However, it had difficulty reproducing the intonation of the human voice, a problem that led Landell to suggest a code of words for better communication. The 2004 replica had better reception with medium waves, around 540 kHz, in addition to recognizing FM - otherwise, the performance was similar to the 1984 replica.{{sfnm|1a1=Ferraretto|1y=2012|1pp=46-47|2a1=Moura|2y=1904|2p=[[:s:en:Page:United States patent 771917.pdf/4|2]]|2loc=3|3a1=Almeida|3y=2006|3p=101}}

== References ==
{{Reflist}}

== Notes ==
<references group="lower-alpha" />

== Bibliography ==
{{Refbegin|30em}}
;Primary source
*{{Cite patent|inventor=Roberto Landell de Moura|inventorlink=Roberto Landell de Moura|title=Wave-transmitter.|country-code=US|country=United States|patent-number=771917A|status=| pubdate	=1904-10-11|gdate=1904-10-11|URL=https://patents.google.com/patent/US771917A/en|ref={{harvid|Moura|1904}}}}
;Articles
*{{Cite journal|url=https://www.aminharadio.com/radio/files/GT%20historia%20da%20midia%20sonora_Hamilton_Almeida_%20ALCAR%202021.pdf|title=A primeira transmissão de voz por ondas de rádio da história: a façanha de Roberto Landell de Moura, padre-cientista brasileiro|first=Hamilton|last=Almeida|pages=15|journal=XIII Encontro Nacional de História da Mídia|issn=2175-6945|ref={{harvid|Almeida, ''s.d''}}|language=pt-br}}
* {{Cite book|url=https://editora.pucrs.br/edipucrs/acessolivre/Ebooks/Web/978-85-397-0226-8/pages/v2.pdf|title=Por que o Padre Roberto Landell de Moura foi inovador? |editor-first=Luciano|editor-last=Klöckner|editor-first2=Manolo Silveiro|editor-last2=Cachafeiro|year=2012|place=Porto Alegre|publisher=EdiPUCRS|edition=1|isbn=978-85-397-0226-8|chapter=A Longa (e Interminável) construção da biografia do Padre Landell|pages=17–37|first=Hamilton|last=Almeida|lang=pt-br}}
*{{Cite journal |url=https://www.revistas.usp.br/khronos/article/view/206421 |title=Padre Landell: o autor das primeiras transmissões de voz e música por ondas de rádio do mundo |date=2023-02-13 |journal=Khronos |issue=14 |last=Almeida |first=Hamilton |pages=120–143 |doi=10.11606/issn.2447-2158.i14p120-143 |issn=2447-2158|lang=pt-br|doi-access=free }}
*{{Cite web|last=Almeida|first=Hamilton|url=https://amanha.com.br/categoria/memoria/os-125-anos-da-primeira-transmissao-de-radio-do-mundo|title=Os 125 anos da primeira transmissão de rádio do mundo|date=2024-07-17|ref={{harvid|Almeida|2024a}}|website=Grupo Amanhã|lang=pt-br}}
*{{Cite web|last=Almeida|first=Hamilton|url=https://www.diariozonanorte.com.br/padre-roberto-landell-de-moura-os-120-anos-da-patente-do-transmissor-de-ondas/|title=Padre Roberto Landell de Moura: os 120 anos da patente do Transmissor de Ondas|date=2024-10-14|ref={{harvid|Almeida|2024b}}|website=DiárioZonaNorte|lang=pt-BR}}
* {{Cite book|url=https://editora.pucrs.br/edipucrs/acessolivre/Ebooks/Web/978-85-397-0226-8/pages/v2.pdf|title=Por que o Padre Roberto Landell de Moura foi inovador? |editor-first=Luciano|editor-last=Klöckner|editor-first2=Manolo Silveiro|editor-last2=Cachafeiro|year=2012|place=Porto Alegre|publisher=EdiPUCRS|edition=1|isbn=978-85-397-0226-8|chapter=O Padre Landell de Moura e a invenção da comunicação sem fio|last=Alencar|first=Marcelo Sampaio de|lang=pt-br|pages=67–74}}
* {{Cite book|url=https://editora.pucrs.br/edipucrs/acessolivre/Ebooks/Web/978-85-397-0226-8/pages/v2.pdf|title=Por que o Padre Roberto Landell de Moura foi inovador? |editor-first=Luciano|editor-last=Klöckner|editor-first2=Manolo Silveiro|editor-last2=Cachafeiro|year=2012|place=Porto Alegre|publisher=EdiPUCRS|edition=1|isbn=978-85-397-0226-8|chapter=Conceitos da Física nos Inventos do Padre Roberto Landell de Moura|last=Bruscato|first=Gentil César|pages=131}}
*{{Cite book|url=https://editora.pucrs.br/edipucrs/acessolivre/Ebooks/Web/978-85-397-0226-8/pages/v2.pdf|title=Por que o Padre Roberto Landell de Moura foi inovador? |editor-first=Luciano|editor-last=Klöckner|editor-first2=Manolo Silveiro|editor-last2=Cachafeiro|year=2012|place=Porto Alegre|publisher=EdiPUCRS|edition=1|isbn=978-85-397-0226-8|chapter=Landell de Moura: Ondas de Rádio nas Transformações no Final do Século XIX|last=D'Arisbo|first=Daltro|pages=75–79}}
*{{Cite web|last=Fapesp|first=Agência|url=https://www.observatoriodaimprensa.com.br/interesse-publico/quem-inventou-o-radio/|title=Quem inventou o rádio?|date=2006-06-20|website=Observatório da Imprensa|language=pt-br}}
* {{Cite book|url=https://editora.pucrs.br/edipucrs/acessolivre/Ebooks/Web/978-85-397-0226-8/pages/v2.pdf|title=Por que o Padre Roberto Landell de Moura foi inovador? |editor-first=Luciano|editor-last=Klöckner|editor-first2=Manolo Silveiro|editor-last2=Cachafeiro|year=2012|place=Porto Alegre|publisher=EdiPUCRS|edition=1|isbn=978-85-397-0226-8|chapter=Roberto Landell de Moura: O Pioneiro Brasileiro das Comunicações|pages=38–52|first=Luiz Artur|last=Ferraretto}}
*{{Cite web|last=Ferreira|first=Luiz Claudio|url=https://agenciabrasil.ebc.com.br/geral/noticia/2022-05/cem-anos-do-r%C3%A1dio-no-brasil-o-padre-brasileiro-que-inventou-o-radio|title=Cem anos do rádio no Brasil: o padre brasileiro que inventou o rádio|date=2022-05-31|website=Agência Brasil|language=pt-br}}
*{{Cite web|last=Rocha|first=Lucas|url=https://www.cnnbrasil.com.br/nacional/landell-de-moura-conheca-o-padre-brasileiro-que-inventou-o-radio/|title=Landell de Moura: conheça o padre brasileiro que inventou o rádio|date=2022-09-07|website=CNN Brasil|language=pt-BR}}
*{{Cite magazine|url=https://archive.org/details/otbfebruary200200unse|title=Father Landell de Moura: Brazil's Wireless Telephony Pioneer|pages=66–67,69|magazine=The OTB|date=February 2002|volume=43|issue=1|first=James P.|last=Rybak}}
*{{cite journal|date=2003 |first=César Augusto Azevedo dos |journal=XXVI Congresso Brasileiro de Ciências da Comunicação |last=Santos |pages=15163 |publisher=Universidade do Passo Fundo |title=Landell de Moura ou Marconi, quem é o pioneiro? |url=http://www.intercom.org.br/papers/nacionais/2003/www/pdf/2003_NP06_santos.pdf}}<!-- auto-translated from Portuguese by Module:CS1 translator -->
* {{Cite book|url=https://editora.pucrs.br/edipucrs/acessolivre/Ebooks/Web/978-85-397-0226-8/pages/v2.pdf|title=Por que o Padre Roberto Landell de Moura foi inovador? |editor-first=Luciano|editor-last=Klöckner|editor-first2=Manolo Silveiro|editor-last2=Cachafeiro|year=2012|place=Porto Alegre|publisher=EdiPUCRS|edition=1|isbn=978-85-397-0226-8|chapter=Landell de Moura - O Padre-Inventor|first1=Ana Celina F. da|last1=Silva|first2=Cidara |last2=Loguércio|first3=David K.|last3=Minuzzo|first4=Eliane|last4=Muratore|first5=Jeanice T.|last5=Ramos|first6=Letíssia|last6=Crestani|first7=Luciana|last7=Brito|first8=Manolo Silveiro|last8=Cachafeiro|first9=Michele P.|last9=Souza|first10=Marlise|last10=Giovana|ref={{harvid|Silva|Loguércio|Minuzzo|2012}}|pages=88–100}}
;Newspapers and magazines from the time period
*{{Cite news|url=https://memoria.bn.gov.br/DocReader/DocReader.aspx?bib=364568_08&pesq=%22O%20TELEFORO%22&hf=memoria.bn.gov.br&pagfis=32445|title=O Teleforo|newspaper=Jornal do Commercio|volume=79|issue=164|date=1899-06-14|page=1|ref={{harvid|''Jornal do Commercio'', 14 de junho de|1899}}|lang=pt}}
*{{Cite magazine|url=http://memoria.bn.gov.br/DocReader/829447/4516|title=Março|page=32|magazine=Almanak Litterario e Estatistico do Rio Grande do Sul|volume=15|year=1903|ref={{harvid|''Almanak Litterario e Estatistico do Rio Grande do Sul''|1903}}|lang=pt}}
*{{Cite news|url=http://memoria.bn.gov.br/DocReader/884391/40|title=O Rev. Padre Landell de Moura|date=1903-02-08|newspaper=A Verdade|page=4|volume=1|issue=10|ref={{harvid|''A Verdade'', 8 de fevereiro de|1903}}|lang=pt}}
*{{Cite news|url=http://memoria.bn.gov.br/DocReader/168319_01/27840|title=Telephonia sem fios|newspaper=Pacotilha|page=1|volume=XXIV|date=1904-06-28|issue=152|place=Maranhão|ref={{harvid|''Pacotilha'', 28 de junho de|1904}}|lang=pt}}
*{{Cite magazine|url=https://books.google.com/books?id=4ngxAQAAMAAJ&dq=Roberto%20Landell%20de%20Moura&pg=RA1-PA348|title=Phonetic Interrupter for Space Telegraphy|date=1904-10-29|page=348|magazine=Western Electrician|place=Chicago|volume=XXXV|issue=18|ref={{harvid|''Western Electrician'', 29 October|1904}}}}
*{{cite news|date=1905-03-27 |journal=A Federação |number=73 |page=1 |ref={{harvid|''A Federação'', 27 de março de|1905|p=1}} |title=Novos inventos |url=http://memoria.bn.gov.br/DocReader/388653/16390 |volume=XXII}}<!-- auto-translated from Portuguese by Module:CS1 translator -->
;Monography
*{{Cite thesis |last=Zaltrão |first=Claudia Josiani dos Santos |date=2006 |title=Resgate da Memória Científica Nacional: a Obra do Padre Roberto Landell de Moura |type=monography |place=Curitiba|url=https://acervodigital.ufpr.br/xmlui/bitstream/handle/1884/48295/CLAUDIA-JOSIANI-DOS-SANTOS-ZALTRAO.pdf?sequence=1&isAllowed=y |institution=[[Universidade Federal do Paraná|UFP]]|lang=pt-br}}
*{{Cite thesis|last=Alencar|first=Marcelo S.|date=2003|title=Historical Evolution of Telecomunications in Brazil|institution=[[Universidade Federal de Campina Grande]]|language=en|pages=63–71|chapter=The Repercussion of Father Landell de Moura's Inventions|url=https://www.researchgate.net/publication/220016491}}
;Books
* {{Cite book|title=Padre Landell de Moura: Um Herói sem Glória|date=2006|publisher=Editora Record|language=pt-BR|first=Hamilton|last=Almeida|pages=319|isbn=85-01-07260-5|edition=1|place=Rio de Janeiro|ol=31764290M|oclc=124027826|lccn=2007315336}}
*{{Cite book|url=https://catalog.hathitrust.org/Record/006734071|title=The Brazil of To-day|pages=628|first=Artur|last=Dias|year=1917|publisher=Nivelles, Lanneau & Despret.|edition=1}}
*{{Cite book|url=https://books.google.com/books?id=TNIPEAAAQBAJ|title=A filosofia do fracasso|last=Zimmer|first=Ianker|date=2020-12-17|publisher=Viseu|isbn=9786556744766}}

;Additional reading
*{{Cite web|url=http://rlandell.tripod.com/engpatbraland.html|title=Patent n. 3279, of March 9, 1901|translator=Arsenio Fornaro|language=en|archiveurl=https://web.archive.org/web/20160305133947/http://rlandell.tripod.com/engpatbraland.html|archivedate=2016-03-05|url-status=dead}}
*{{cite journal|date=2024-04-27 |doi=10.53660/CLM-3284-24H08 |first1=Ricardo Luiz Perez |first2=Ricardo |issn=0010-5236 |language=pt-br |last1=Teixeira |last2=Shitsuka |number=7 |pages=492–506 |periodical=Concilium |title=Father Roberto Landell de Moura and his contribution in the history of science and mobile communications |volume=24 |trans-title=Padre Roberto Landell de Moura e a sua contribuição na história da ciência e das comunicações móveis |url=https://www.researchgate.net/publication/380151842}}<!-- auto-translated from Portuguese by Module:CS1 translator -->
* {{Cite book|url=https://editora.pucrs.br/edipucrs/acessolivre/Ebooks/Web/978-85-397-0226-8/pages/v2.pdf|title=Por que o Padre Roberto Landell de Moura foi inovador? |editor-first=Luciano|editor-last=Klöckner|editor-first2=Manolo Silveiro|editor-last2=Cachafeiro|year=2012|place=Porto Alegre|publisher=EdiPUCRS|edition=1|isbn=978-85-397-0226-8|chapter=Padre Landell de Moura e o Primeiro Transmissor-Receptor de Voz sem Fio|first=Carlos Guerra|last=Lima|pages=109–122}}
{{Refend}}

[[Category:Radio in Brazil]]
[[Category:Radio technology]]
[[Category:History of radio]]
[[Category:Brazilian inventions]]
[[Category:1899 in Brazil]]
[[Category:19th-century inventions]]
[[Category:Discovery and invention controversies]]