Alexander Popov – a Great Contributor to the Development of Wireless Communication

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Alexander Popov – a Great Contributor to the 

Development of Wireless Communication 

 

Anna P. Konstantinova 

Student of the 

St Petersburg State Electrotechnical University “LETI”  

IEEE Student Member  

Co-author: Dr. Larisa I. Zolotinkina 

Memorial Museum of A. Popov in St Petersburg State Electrotechnical University Director  

 

Abstract “This paper is devoted to the life 

and scientific activities of Alexander 

Popov who is regarded in Russia as the 

inventor of radio communication. It 

touches upon the most important 

contributions made by Popov to the 

development of electrical and radio 

engineering.  In addition, it presents a 

brief review of the collection of the 

Memorial Museum of A.Popov in LETI 

(The St Petersburg State Electrotechnical 

University).” 

 

I. Introduction 

 

Looking back at the most amazing 

discoveries and inventions of the 20th 

century we, the people of the 21st century, 

can’t help feeling admiration of those of 

them, which had profound influence on the 

further development of mankind. 

One of the most significant achievements 

of the very end of the 19th century and the 

beginning of the 20th century was the birth 

of wireless communication. 

 

This important event is surely a 

milestone in the formation of the new 

information environment and consequently 

in the formation of modern lifestyles. 

Nowadays it is impossible to imagine any 

successful cooperation, cultural or human 

contacts without such a considerable 

technological breakthrough as the 

transmission of electromagnetic signals, that 

is “inventing” wireless.  

It is absolutely obvious that our ability to 

communicate with each other easily has 

made our life more enjoyable and has 

allowed us to exchange information 

including information on science and 

technology. 

We have got this wonderful opportunity 

due to joint efforts of many prominent 

scientists. Among the great pioneers of 

wireless are such outstanding scientists as 

Mickle Faradey,  James Maxwell, Henri 

Hertz, Edouard Branly, Nickolas Tesla, 

Oliver Lodge etc.  

It is broadly agreed that the works of 

Mickle Faraday, Maxwell, Henry Hertz 

were vital in laying the foundation for 

practical application of electromagnetic 

waves. 

Oliver Lodge provided independently a 

number of the essential elements that 

enabled to develop a system of wireless 

communication. 

In most European countries Guglielmo 

Marconi is generally recognized as the first 

to exploit the practical application of 

electromagnetic waves. While in Russia 

Alexander Popov is regarded as the inventor 

of radio communication. 

 

 

1

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II.  Popov’s biography and scientific 

activities 

 

Alexander S. Popov was born on the 16th 

of March in 1859 in Tourinskii Mining 

Village in the Urals where his father was a 

priest. He received a free seminary 

education to encourage him to follow his 

father’s profession.  

After graduating from the seminary in 

Perm he didn’t continue his clerical 

education for he had become interested 

instead in physics, mathematics and 

engineering. He was admitted to the Faculty 

of Physics and Mathematics of St Petersburg 

University in 1877. While still a student 

Alexander Popov worked as a guide at the 

first Electrical Engineering exhibition in 

1880 and an assistant to a professor of 

physics. In 1881 he began to work at the 

Electrotechnik workshop which ran the first 

electric power stations in Russia and the first 

electric lighting installations using arc 

lamps. 

Thus Alexander Popov graduated from 

the University being not only an educated 

physicist, but also an experienced electrical 

engineer. 

After graduating the St Petersburg 

University where he was awarded a higher 

degree upon completion of his dissertation, 

Alexander Popov was recommended by the 

Scientific Counsel to remain at the 

University in order to prepare for an 

academic career. However in summer of 

1883 Popov was offered the post of a 

lecturer and the head of the physical 

laboratory in Kronstadt where he could do 

experimental research in electrical 

engineering.  

In 1883 he started to teach at the 

Kronstadt Torpedo School, one of the most 

prestigious Higher Naval Engineering 

Schools in Russia at that time which trained 

naval specialists in all branches of electrical 

engineering. 

In 1890 Alexander Popov began teaching 

in the Marine Engineering School which 

belonged to Naval Department. He was 

obliged to make a signed statement on non-

divulgence of military secrets which later 

prevented him from getting a patent for his 

invention. He taught electrical engineering, 

mathematics and physics. Popov also 

conducted laboratory sessions in electricity 

and magnetism as well as on electrical 

machines and motors. It was in Kronstadt 

that he realized quite well the Russian 

navy’s acute need for wireless 

communication. 

 The excellent equipment of the physics 

laboratory enabled Alexander Popov to run 

many physical experiments. He stayed at 

Kronstadt until 1901. 

At the beginning of 1895, Popov re-ran 

the experiments of Henry Hertz and Oliver 

Lodge and refined the Branly-Lodge 

coherer. He ensured automatic sensitivity 

restoration of a coherer after receiving a 

signal by its shaking with a bell clapper. 

Besides, Popov added a receiving antenna 

and a relay to his scheme. As a result Popov 

designed the wireless telegraphy working 

receiver which was both reliable and stable. 

Using this apparatus A. Popov demonstrated 

that it was possible to transmit short, 

continuous signals (applying an improved 

Hertz oscillator as the transmitter) over a 

distance up to 64 meters.  

In a public lecture “On the Relation of 

Metallic Powders to Electrical Oscillations” 

presented on the 7

th

 of May 1895 to the 

Physical Section of the Russian Physical and 

Chemical Society in St Petersburg, 

Alexander Popov demonstrated the 

reception of electromagnetic signals for the 

first time. An account of this meeting was 

subsequently published in the August 1895 

issue of the Russian Physical Chemical 

Society Journal which was widely known in 

the international scientific community. 

The newspaper “Kronstadtskiy vestnik” 

 

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reported:  

“Honorable Prof Popov… combined a 

special portable device responding to 

electric oscillation by a ringing bell, the 

device being sensitive to the Herz waves at a 

distance of up to 30 sazhens. 

Last Tuesday Prof. Popov reported on his 

experiments to the Physical Department of 

the Russian Physical and Chemical Society 

and his report was met with a great interest 

and enthusiasm. These experiments were 

induced by a theoretical possibility of 

wireless signaling, like it is with optical 

telegraph but using the electric beams.” 

In January 1896 the same journal carried 

an article by A.Popov together with a 

detailed circuit diagram of the wireless 

apparatus which was called “an Apparatus 

for Detecting and Recording Electrical 

Oscillations”. (See Popov’s apparatus 

scheme in the reference №1 in the 

Appendix)  

The article concluded with the following 

words: “… I hope that my apparatus, when 

perfected, may be used for the transmission 

of signals over a distance with the help of 

rapid electrical oscillations as soon as a 

source of such vibrations with sufficient 

energy is discovered”. 

In the summer of 1895 A. Popov had 

adapted his instrument for the automatic 

registration of atmospheric oscillatory 

discharges; it was later called a lightning 

recorder. Experiments with it led A. Popov 

to study the possible influence of 

atmospheric disturbances on the 

transmission of signals. Popov’s lightning 

recorder was in wide use all over the world. 

A. Popov went on to perfect his device 

for wireless communication enhancing the 

sensitivity of the apparatus and increasing 

the distance over which the signals could be 

carried. By the beginning of 1896 A. Popov 

had substantially improved his receiver and 

had obtained important results in 

transmitting and receiving signals.  He 

demonstrated his apparatus at the meeting of 

the scientific society in March 1896. The 

distance between the transmitter and the 

receiver was 250 meters. Apparently A. 

Popov had signaled “Heinrich Hertz” in 

Morse using the telegraphy apparatus and 

the words had been written down on a 

blackboard by professor Petruchevsky – the 

president of the Russian Physical and 

Chemical Society. Before the summer of 

1896 the improved apparatus was described 

in a total of 11 publications which made this 

invention accessible for a practical use. 

In May 1897 the signaling system using 

electromagnetic waves was well tested at 

Navy in the Gulf of Finland at the distance 

over 600 meters. 

 

III.

 

Practical Application of Popov’s 

Experimental Results 

 

A. Popov took an active part in bringing 

wireless telegraphy apparatus into practical 

application. The first of them were 

manufactured according to his instructions 

by E. Diucretet, a French engineer and 

businessman in 1899 in France. Both 

Russian and French Navy were equipped 

with the wireless telegraphy apparatus. Its 

production in France started under the name 

Popov-Diucretet. 

In 1899 A. Popov developed a wireless 

receiver based on the detector effect 

discovered by his assistants P. Ribkin and D. 

Troytskiy. This receiver was later patented 

in Russia, England and France.  

On January 22, 1900 - this receiver was 

patented in France (№296354), on April 7, 

1900 – it was patented in England (№2797), 

on November 30, 1901 - patented in Russia 

(№ 6066). 

There exists the document which describes 

the A. Popov invention of the first practical 

semiconductor crystal diode. The copy of 

the patent which A. Popov accepted in 

 

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England on the 7

th

 of April 1900 is enclosed. 

(See reference №2 in the Appendix) 

In 1900 The Diucretet Firm in France started 

the industrial production of such diodes and 

A. Popov’s detection radio receivers. 

In 1875 Braun worked on the subject of 

semiconductors but his works were only 

theoretical. They showed one way 

conductivity of contacts between different 

objects (crystal and amorphous). 

After the A. Popov’s patents Braun has 

returned to the matter in question. The 

Germans refused a patent to Popov as Braun 

has already made a research on this subject 

but there was no practical application of his 

works. 

As a result the German firm Siemens and 

Halske/Telefunken has signed a 3 sided 

agreement on the application of A. Popov’s 

invention for the radio apparatus production. 

In 1900 Popov’s device was used when a 

47 km kilometer long radio line, linking the 

island Kutsalo (town Kotka - Finland) and 

the island Gogland in the Finnish gulf was 

installed. The radio line was constructed to 

help a battleship “The General – Admiral 

Apraksin” which ran aground because of a 

navigation error. The first wireless message 

received by the radio line allowed saving the 

lives of 27 fishermen who had been carried 

away on a block of ice in the sea-way. That 

successful operation of the radio line 

resulted in taking a decision to use the radio 

at ships of the Russian Navy. This line was 

the first to use radio communication and it 

worked more than 3 months. 

Continuously improving his 

radiotelegraph Popov succeeded in 

implementing radio communication in the 

army, navy and newly born aviation as well 

as civil branches. But the development of 

radio in the tsarist armed forces proceeded 

very slowly, compared with those of other 

European countries. 

Popov was personally involved in 

launching the production of  Popov system 

equipment not only  at the E. Diucretet 

factory in Paris (1898), but also at the radio 

workshop in Kronstadt founded on his 

initiative in 1900 and at the Siemens and 

Halske factory in St Petersburg (1904).  

In 1901 A. Popov was appointed 

Professor of Physics at the St Petersburg 

Electrotechnical Institute where he set up a 

wireless telegraphy research laboratory and 

gave a course on the subject. 

Electrotechnical Institute founded in 

1886 became the first to specialize in 

electrical communications. Together with 

his post-graduate assistant S. Y. Lifchits in 

1904 A. Popov conducted experiments in 

transmitting the human voice via radio. 

In 1905 he became the first elected 

director of this institute. 

In December 1905 A. Popov was ordered 

by the Governor of St Petersburg to take 

repressive measures against student political 

disturbances (it was the time of the first 

Russian Revolution which was supported by 

many progressively – minded people 

including students and lectures). A. Popov 

refused to do it. He took these events too 

close to his heart which badly affected his 

health.  

He died on the 13

th

 of January 1906 at the 

relatively young age of 46. 

 

IV. A. Popov’s Heritage in St Petersburg 

 

Historians of science in many countries 

of the world including Russia do full justice 

to numerous experiments and investigations 

sifting out from them those facts and 

interpretations that remain meaningful 

today. It should be mentioned that the most 

valuable arguments for the history of science 

are supposed to be those facts which are 

confirmed by archives documents. 

There are 3 museums in St Petersburg 

that commemorate the prominent Russian 

scholar in the field of physics, electrical and 

radio engineering. 

 

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The first exposition of Popov’s 

experimental devices was opened in 

Kronstadt in 1906. 

The biggest collection is in The Central 

museum of communication named after A. 

S. Popov which keeps original devices 

designed by A. Popov himself such as his 

radio receiver, a lightning recorder, Hertz’s 

vibrator (oscillator) used by A. Popov as a 

transmitting device in his radio signaling 

system. 

The memorial museum of A. S. Popov in 

“LETI” (The St Petersburg State 

Electrotechnical University) is a scientific 

research and a scientific educational branch 

of St Petersburg State Electrotechical 

University which collects, keeps and studies 

apparatus, different publications, findings, 

historical facts, concerned with the life and 

activities of A. Popov – the inventor of radio 

and the founder of teaching programmes on 

wireless telegraphy for military and civil 

higher schools. 

The Museum also takes great interest in 

the documentary material on the origin and 

development of electrical engineering and 

its main directions, the foundation of which 

was laid by A. Popov, his co-workers and 

followers. In collaboration with the 

Electrotechnical University the museum 

carries out scientific research on the history 

of the development of electrical engineering, 

radio engineering, electronics and 

communication. 

On the basis of its scientific 

investigations the museum organizes 

different stationary and temporary 

exhibitions devoted to the history of science 

and engineering and to famous scientists and 

inventors. 

The memorial museum of professor 

Popov was opened on the 25th of June in 

1948 in his former laboratory in ETI where 

the scientist worked during the last period of 

his life from 1903 till 1906. A. Popov 

performed 42 laboratory experiments using 

his devices for the 1st and 2nd year students. 

A. Popov was an extremely gifted and 

many-sided scientist who carried on his own 

investigations in the field of electrical 

engineering, optics, radioactivity, wireless 

telegraphy. Physical devices and apparatus 

kept in the collection of the museum show 

Popov’s professional activities and scientific 

interests. Numerous museum stands 

demonstrate the main periods of the 

scientist’s life, his scientific and social 

activities. The museum collection started 

with over 80 devices which belonged to A. 

Popov and professors O. Hvolson and V. 

Skobeltzyn. The museum got these devices 

from the chair of physics of the 

Electrotechnical Institute.  

Of special value in the museum 

collection is Popov’s apparatus for 

transmitting and receiving signals made in 

1896. A. Popov demonstrated this apparatus 

– the receiver and the vibrator with 

parabolic reflector at the section of the 

Russian Physical and Chemical Society at 

the St Petersburg University on the 24th of 

March in 1896. The apparatus transmitted 

and received signals at the distance of 250 

meters between the buildings of St 

Petersburg University. At present the 

devices in the exposition of the museum – 

laboratory are arranged in such a way that it 

is possible to demonstrate the main 

phenomena of the electrical engineering just  

in the course of the excursion using the 

devices on display. 

For example, electromagnetic induction 

phenomenon can be shown by the 

experiment performed with the help of M. 

Faraday’s scheme. Riss’s spirals made as far 

back as 1900 can also operate quite well 

even now enabling to reproduce some 

experiments on fundamental physical 

phenomena.  

The museum collection consists of 

devices, instruments as well as scientific 

papers, letters and journals which are of 

 

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special interest to foreign scientists and 

historians in the field of science and 

engineering. 

The museum keeps Popov’s archives 

including the papers describing his first 

experiments in the field of wireless 

signalization as well as his own library and 

his correspondence with colleagues both in 

Russia and abroad. 

The museum collection exceeds 15 000 

items. Of special value are Popov’s personal 

archives containing over 1000 papers, his 

own instruments and devices designed in the 

period from 1889 to 1906 and a wireless 

telegraphing system of commercial 

production. 

As a matter of fact Popov’s memorial 

museum is a unique scientific technical 

museum with wonderful opportunities for 

young specialists who take interest in the 

origin and history of electrical and radio 

engineering. 

Speaking about the memorial museum 

one can’t help mentioning Popov’s younger 

daughter E.A. Popova-Kjandskaya (1899-

1976) who was the first director and founder 

of the museum. She was an honorable 

person of the Russian Federation involved in 

the arts and an honorable member of the 

scientific and technical society NTORES 

named after A. Popov. For many years the 

museum was supervised by her daughter 

E.G. Kjandskaya (1934-1994) who 

contributed to the foundation and 

development of the museum. A. Popov’s 

daughter published over 40 papers and 

presented about 50 reports. She took part in 

the work at 30 films devoted to Russian 

scientists and participated in the preparation 

of 46 museum expositions in Russia and 

abroad. 

Due to their efforts the museum was 

included in the catalogues of the museum of 

the world. It is popular with tourists of St 

Petersburg. It is visited by tourists and 

delegations from USA, Germany, Great 

Britain, France, Poland, China and other 

countries. 

In September 2003, the IEEE Russia 

North-West Section received High ranking 

Officers: IEEE President 2003 Michael 

Adler, his wife Virginia and 2001 IEEE 

President Joel Snyder in St. Petersburg. 

They visited the Alexander S. Popov 

museum. 

 

V.  Conclusion 

 

Every country is proud of its great 

people: writers, poets, actors, composers, 

painters, scientists and inventors. Russia is 

not an exception. It is proud of prominent 

scientists and inventors who made great 

contribution to the development of different 

scientific fields and more rapid progress in 

science and engineering. One of such 

scientists and inventors was A. Popov. 

To summarize Popov’s achievements it is 

to be noted that A. Popov’s scientific work 

can be treated as a balance between 

theoretical assumption and practical 

application of the latest findings. He 

succeeded in putting his own and other 

scholar’s concepts into practice. 

A. Popov often went abroad, he visited 

many European cities: Paris, Berlin, 

London, Zurich, made a trip to USA where 

he visited New York and Chicago.  He met 

foreign scientists, exchanged scientific 

information and kept up working contacts 

with them. They discussed many scientific 

problems of common interest which turned 

out to be fruitful and efficient for scientific 

and engineering progress. 

A. Popov wrote a letter to the editor of 

the Journal “The Electrician” on 26 

November 1897 concerning the problem in 

question: “I constructed an apparatus 

very useful for the demonstration of the 

properties of the Hertzian 

electromagnetic waves and rays in a 

large lecture-room, also fit for registering 

 

6

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atmospheric electric disturbances... On 

using a  sensitive relay in the circuit 

with the coherer tube, and an ordinary 

electric bell in a collateral line for sound 

signal and as an automatic tapper for the 

coherer, I received an apparatus which 

exactly answers every electric wave by a 

short ring and by rhythmical strokes, if 

electric vibrations be excited 

continuously...” 

Opening the International Conference on 

wireless telegraphy in Berlin in 1903 the 

Minister of Posts and Telegraphy of 

Germany Kretke said: “… in 1895 A. Popov 

invented reception of telegraph signals by 

means of the Hertz waves. It is him that we 

should thank for the first radiographic set.” 

At the end of the 19

th

 and at the 

beginning of the 20

th

 century Popov had 

close contacts with prominent scholars of 

Russia – D. Mendeleev, S. Makarov, A. 

Krylov, A. Lodygin and others. 

 All these allied to his foresight and wide 

knowledge enabled him to get recognition in 

scientific community. A. Popov’s 

contemporaries highly appreciated his 

achievements. 

One should make reference to O. Lodge’s 

letter dated September 1, 1908 “…I have 

always thought highly of Professor Popoffs 

work in connection with wireless telegraphy. 

It is true that I used an automatic hammer, or 

other vibrator driven by clockwork or other 

mechanism, to restore the coherer to 

sensitiveness; but Popoff was the first to 

make the signal itself actuate the tapper-

back; and that I think is the novelty we owe 

to Popoff…” 

“I conjecture that Popoff may have been 

one of the pioneers who applied the method 

to ship signaling of some rough kind at an 

early date.” 

“I shall be happy to answer any other 

questions, and am glad that professor Popoff 

should have his work recognized in his own 

country.” 

A. Popov was in the best and truest 

senses of the word both a remarkable 

personality and a genuine scientist: 

kindness, courtesy and consideration were 

part of his nature. These features of 

character enabled him to guide, assist and 

counsel on scientific, organizational and 

personal problems with a skill and tact 

which were highly effective. 

A. Popov paid great attention to all new 

investigations not only in the field of 

physics, radio-activity and electrical 

engineering, but in making electrical 

machines and designing roentgen devices. 

He designed and continually refined the 

apparatus used for radio communication, he 

organized the training of experts in this field 

and initiated the setting up of the first 

wireless telegraphy transmitters in Russia.  

During his lifetime A. Popov was being 

held in high esteem in Russia and abroad. 

He was given many honorary titles and 

awards as a great inventor. A. Popov had an 

honorary title of an electrical engineer. A. 

Popov was awarded a gold medal and 

diploma at the World Exhibition in Paris in 

1900 for developing wireless apparatus and 

a lightning recorder.  

Monuments have been erected to him in 

several Russian towns. A gold medal and 

prize have been instituted in his honor and 

awarded by the Russian Academy of 

Science to Russians and foreigners for their 

outstanding work in the field of radio 

engineering. 20 Russian scientists were 

awarded this medal. One of them is J. 

Alferov, Nobel Prize Winner in the field of 

physics, a graduate of the Electrotechnical 

Institute who was awarded the gold medal 

named after A. Popov in 2000. 

In 1945 on the 7

th

 of May a state holiday, 

the Day of Radio was established. Every 

year on the 7

th

 of May a tribute is paid to our 

great compatriot A. Popov – a great scientist 

and inventor. 

 

7

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VI.  Reference List 

 

1.

 

Berg A.I. Radio Invention by A. Popov. –  Moscow, 1966 

2.

 

Berg A.I. Radovsky M.I. Radio Invention by A. Popov.- Moscow, 1949 

3.

 

Brenev I.V. Radio Invention by A. Popov. -Moscow, 1965 

4.

 

Rybak D., Kryijanovski L. G. Marconi and the development of radio communication// 

Radio, - 1995. - №1 – p.15-17 

5.

 

Zolotinkina L.I. Radio Bibliography. – St Petersburg, 2002 

6.

 

Dictionary of Scientific Biography Vol.11 New York, 1975 

7.

 

EBU Technical Review.- Spring 1995.- №263 

8.

 

The Electrician.- 1925.- №4 

9.

 

Urvalov V.A. G. Marconi/Electrical Communication, - 1995. - №2 – p.37-40 

10.

 

The St Petersburg Electronics Journal. – 2002.  

 

VII.  Original Publications on A. Popov Invention 

 

1.

 

Kronstadtskiy Vestnik, 1895, 30 April (12 of May), №51, p.1 

2.

 

Protocol  № 151 (201) of the Physical Section of the Russian Physical and Chemical 

Society in St Petersburg on 25 of April 1895//Russian Physical Chemical Society Journal, 

1895, Vol. 27, p.259 

3.

 

Lachinov D.A. The Fundamentals of Meteorology and Climatology.- St Petersburg,1895, 

July 

4.

 

Popov A.S. The Apparatus for Detecting and Recording Electrical Oscillations.// Russian 

Physical Chemical Society, 1896, Vol. 28, №1, p.1-14 

5.

 

Popov A.S. The Apparatus for Detecting and Recording Electrical Oscillations. A 

reprint// Russian Physical Chemical Society Journal, 1896, St Petersburg, 14 p., 

6.

 

Popov A.S. The Apparatus for Detecting and Recording Electrical Oscillations.// The 

Electrician, 1896, № 13/14, p.177-189 

7.

 

Popov A.S. The Apparatus for Detecting and Recording Electrical Oscillations. A 

reprint// Metereologicheskiy Vestnik, St Petersburg, 1896, 7 p. 

8.

 

An Apparatus for Detecting and Recording Electrical Oscillations in the Atmosphere. 

//Metereologicheskiy Vestnik, 1896. №3 

9.

 

Protocol  № 158 of the Section of the Physical Section of the Russian Physical and 

Chemical Society on 12 of March 1896, Vol. 28, p.124 

10.

 

Scobelzin V.V. A.Popov’s apparatus for Detecting and Recording Electrical 

Oscillations.// Post – Telegraph Journal, 1896, April, Vol 46, p.546 

11.

 

Wireless Telegraphy. (A letter to the Editorial Office). //Kotlin, 1897, 8 January, № 5, p.2 

 

8

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Appendix 

Reference №1 

 

 

 

 

Reference №2 

A.D.1900 Feb 12 №2797 

Popov’s Complete Specification 

 

9

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10

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Date of Application, 12th Feb., 1900-Accepted, 7th Apr., 1900 

COMPLETE SPECIFICATION 

Improvements in Coherers for Telephonic and Telegraphic Signalling. 

I, 

ALEXANDER  STEPHANOVICH  POPOV

,

 

of Cronstadt, Russia, Professor, do hereby 

declare the nature of this invention and in what manner the same is to be 

performed, to be particularly described and ascertained in and by the following  

statement  

5 The improved receiver of messages sent into space by means of electromagnetic 

oscillations, is based upon Branly's discovery of the tubes filled with filings, known 

as coherers or radioconductors and presenting a great resistance to the passage of 

electric currents and adapted to become suddenly conductors when influenced by 

electric oscillations, even when these oscillations have but 

10 little strength, which reach said tubes either directly or through conductors secured to the 

tubes, said conductors serving to collect the electric waves. 

The change of resistance is ordinarily accomplished instantaneously and continued 

after the passage of the electric oscillation: in order to stop the conductibility of the 

metal filings, as quickly as is possible, the tube is ordinarily 

15 shaken or jogged, and to this end automatic devices have been invented. 

My improved receiver comprises the omission of this means for restoring' the 

resistance of the filings, and it will be sufficient to compose my tube with the 

result to be obtained in view. The result has a real importance and is attained by 

composing the tube of a conducting chain formed of carbon and 

20 metal portions placed alternately and having what is known as "free micro-phonic 

contacts." Thus the changes or variations of the resistance are less considerable, 

and of shorter duration and constancy. At the first influence, the resistance of 

such radioconductors decreasing, it maintains still a certain value, and during all 

the time of the influence of electric oscillation, said 

25 resistance will be varying without it being- necessary to shake or jog the tube. These 

variations of the resistance are easily perceived in the telephone. 

Under these conditions, the arrangement of the improved receiver, according to 

the accompanying drawings illustrating the invention by way of example, 

embodies in its main portion:—a circuit composing the tube filled 

30 with filings, one or more elements of a buttery, one or more telephonic 

apparatus in which the operator hears special sounds, which are dry, short or long 

and correspond to each discharge at the transmitting station; thus at the receiving 

station, I obtain a good reception of the signs of the Morse code. The character of the 

action of the switch for the induction coil is not at all affected 

35 and it is thus possible to distinguish from each other, cablegrams transmitted bv 

different stations and received at different moments. 

The employment of the telephone in connection with Hertz's sounding board at 

micrometric intervals has been realized by Mr. Turpin, but this arrangement is 

convenient only for classic experiments at short distances, and cannot be 

40 combined with my system of tube (special radioconductor) filled with steel grains, 

having free contacts, and producing the shortest distances between them which 

cannot be obtained by any Hertzian sending board. My improved device enables me to 

transmit messages without conducting-wires to very great distances. 

 

11

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№ 2797,—A.D. 1900. 

Popov's Improvements in Coherers for Telephonic and Telegraphic Signalling. 

      The radioconductors heretofore employed do not attain this result unless they 

are arranged as above indicated. To this end, the most convenient metal is merchant steel in the form 

of polished pearls, which when crushed, produce grains, by means of which I obtain radioconductors 

of steady and perfect sensitiveness. 

5 

The support of such radioconductors must protect the latter from too sudden jerks during the 

reception of a message, which result in easily obtained by securing the support by means of soft 

india rubber or in any other suitable way. 

The sound in the telephonic apparatus may be perceived at a certain distance from the ear. The 

employment оf two telephonic apparatus enables the  

10 operator to be insulated from the exterior sounds.    The addition of a telephonic apparatus 

arranged in microtelephonic relays for the alarm and for recording messages, is well known. 

The radioconductor (or coherer) I preferably employ, is arranged as follows: — 

(see Fig. 1 of the drawings):—within a small tube of glues or other insulating 15 material arc secured two 

small blades of platina arranged in proximity to each other; said blades are secured to the mountings or 

pieces, and two outer conductors  terminate  these  electrodes. The interior of the tube, receives 

hard steal grains produced by means of crushed pearls as already stated. However metals or hard carbon 

may be employed for the same purpose. 

        2 0  

The size of the grains depends on the distance between the inner blades.  

The groins produced by means of hard steel pearls have on their polished portions a thin layer of oxide, 

whilst the inner portions of the pearl have a thicker layer of oxide. Furthermore the parts which are 

broken away, present points or projections on which no oxide is formed. This variation of the state of 

oxidation on the surface of the metal grains, together-with the similarity of their form, ensures a 

perfect sensitiveness and steadiness, and the improved radioconductor is thus convenient for the telephonic 

reception of electromagnetic waves, produced at large distances. 

In order to facilitate the uniform distribution of the grains, the tube may   30 be divided by 

means of partitions made of non-conducting material, into several sections or chambers. 

Fig. 2 illustrates the most simple form of the device at the receiving station, but is possible to 

combine other devices intended to guard against the effect of  atmospheric  electricity and  telluric  

currents; said devices are applied  to 35 the wire or collector C о and to the ground wire and their 

circuits. 

Fig. 3 shows a device having: a converter Т r (I I' are the primary and secondary windings) as 

employed at microtelephonic stations; said device i n creases the intensity of telephonic sounds, but 

muy be omitted. 

Having now  particularly  described  and  ascertained the  nature of  my said   40 invention, and in 

what manner the same in to be performed, I declare that what I claim is: — 

1.—The combination of radioconductors with one or more telephonic appara- 

tuses, for  the   purpose   of   dispensing  with   the   usual means  for   shaking   or jogging the  radioconductor 

(or  coherer),  and   with   the relay  usually  inserted      45 into .the circuit of the radioconductor. 

2.—The application of steel pearls crushed to grains of suitable size substantially as and for the 

purpose set forth. 

Dated tins 12th day of February 1900. 

ROBERT E. PHILLIPS, Assoc. M.Inst.C.E,,M.I. Mech. F..       50 

Chartered Patent  Agent, 70, Chaneery Lane, London, W.C., Associate Agent. 

Printed for Her Majesty's Stationery Office, by Malconisou & Co., Ltd.—1900. 

 

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Document Outline

• The radioconductors heretofore employed do not attain this r