Lev Theremin's skill at invention was not lost on the Soviet machine. Not long after his musical instrument was patented, the radio watchman security device it was based on started being employed to guard the treasures of gold and silver Lenin had plundered from church and clergy. The watchman was also being used to protect the state bank. Setting up and installing these early electronic traps took him away from his primary interest in scientific research. Just as he was approaching the limits of his frustration his mentor at the Institute gave him a new problem to solve, that of "distance vision" or the transmission and reception of moving images over the airwaves. The embryonic idea for television was in the air at the time but no one had figured out how to make it a reality. The race was on and the Soviets wanted to be first to crack the puzzle.
Having researched the issue extensively in the published literature, Lev was ready to apply the powers of his mind towards a solution. In the Soviet Union parts weren't always readily available. Some were smuggled in, and others had to be scavenged from flea markets -the latter a process very familiar to radio junkies. By 1925 he had created a prototype from his junk box using a rotating disk with mirrors that directed light onto a photo cell. The received image had a resolution of sixteen lines, and it was possible to make out the shape of an object or person but not the identifiable details. Other inventors in Russia and abroad were also tackling the issue. Fine tuning the instrument over the next year he doubled the resolution to 32 lines and then, using interlaced scanning, to 64. Having created a rudimentary "Mechanism of Electric Distance Vision" he demonstrated the device and defended his thesis before students and faculty from the physics department at the Polytechnic Institute. Theremin had built the first functional television in Russia.
After this period Lev embarked to Europe and then America where he lived for just over a decade engaging the public, generating interest in his musical instrument, and doing work with RCA. As Hitler gathered power he was anxious about the encroaching war and returned home to the Soviet Union in 1938. He barely had time to settle back in when he was sent to the Kolmya gold mines for enforced labor for the better part of a year. This was done as a way of breaking him, a fear tactic that could be held over his head if he didn't cooperate: do what we say or go back to the mines. The state had better uses for him. He was picked up by the police overlord Lavrenti Beria who sent him to work in a secret laboratory that was part of the Gulag camp system. One of his first jobs was to build a radio beacon whose signals would help track down missing submarines, aircraft and smuggled cargo.
With WWII winding to a close the Cold War was dawning and Russia was on the offensive, trying to extend its reach and gather intelligence on such lighthearted subjects as the building of atomic bombs. In their efforts at organized espionage the Soviets sifted for all the data they could get from foreign consulates. Having succeeded with his beacon Lev was given another assignment. This time the goal wasn't to track down cargo or vehicles but to intercept U.S. secrets from inside Spaso House, the residence of the U.S. Ambassador. Failure to do the bidding of his boss would mean a return to the mines. His boss had high demands for the specifications of the bug Lev was to plant. The proposed system could have no microphones and no wires and was to be encased in something that didn't draw attention to itself.
The bug ended up being put inside a wooden carving of the Great Seal of the United States and was delivered by a delegation of Soviet Pioneers (their version of Boy Scouts) on July 4, 1945. Deep inside this "gesture of friendship" was a miniature metal cylinder with a nine inch antenna tail. The device was passive and was not detected by the X-Rays used at Spaso house in their routine scans. It only activated when a microwave beam of 330 Mhz was directed at the seal from a nearby building. There was a metal plate inside the cylinder that when hit with the beam resonated as a tuned circuit. Below the beak of the eagle the wood was thin enough to act as a diaphragm and the vibrations from it caused fluctuations in the capacitance between the plate and the diaphragm creating a microphone. The modulations this produced were picked up by the antenna and then transmitted out to the receiver at a Soviet listening post. Using this judiciously the Soviets were able to gain intelligence to aid them in a number of strategic decisions. The Great Seal bug is considered to be a grandfather to RFID technology.
This wasn't the last time Lev was asked to develop wireless eavesdropping technology. For the next job his overseers upped the ante on him. No device could be planted in the site targeted for surveillance. The operation was code named Snowstorm. Lev used his interest in optics to figure out a method. Knowing that window panes in a room vibrate slightly when people talked he needed a method to detect and read the vibrations from a distance. Resonating glass contains many simultaneous harmonics and it would be a difficult to find the place of least distortion to get a voice signal from. Then there was the obstacle of reinterpreting the signal back into a speech pattern. Using an infrared beam focused on the optimum spot and catching its reflection back in an interferometer with a photo element he was able to pick up communications. Back at his monitoring post he used his equipment and skills to reduce the large amounts of noise from the signal.
A few years later Lev was released from his duties at the lab, but was kept on a tight leash and not allowed to leave Moscow.
HOW TO BUILD A THEREMIN FROM THREE AM RADIOS
For those amateurs wishing to build and play a theremin there are many commercial kits available on the market. However a simple theremin can be built using just three AM radios. If you don't already have these laying around the house they can easily be obtained from your local thrift store.
One of the radios will be a fixed transmitter, another a variable transmitter and the third would be the receiver. The volume knobs on the fixed and variable transmitters can be turned all the way down, as they are just used to produce the intermediate frequency oscillations that will be picked up by the receiver. The receiver radio should be set on an unused frequency in the upper range of the AM band such as 1500 Khz. If it is in use tune to a nearby space where only static is heard. The fixed and variable transmitters should then be tuned 455 Khz below where your receiver is set, in this example 1045 Khz. 455 Khz is a common difference in the local oscillator frequency, although there can be variations. As these frequencies are set the receiver should start to make a whistling type sound, the production of a beat frequency.
The next step is to open up the variable radio and look for the variable capacitor, often housed in white plastic with four screws. Find the terminal that takes the station out of tune and use an aligator clip attached to the antenna, or solder a wire from the antenna to the oscillator terminal. Now the controls will have to be adjusted slightly again. Tune the fixed transmitter until the receiver starts whistling and have fun playing with the sounds it creates.
Theremin: Ether Music and Espionage by Albert Glinsky, University of Illinois Press, 2000
How to Make a Basic Theremin by eltunene: https://app.box.com/s/kgdstzwaoc/1/17284427/181802859/1
The sound of the theremin has become synonymous with the spectral and spooky sci-fi horror flicks of the 1940's and '50's. It's trilling oscillations conjure up images of flying saucers made from hub caps and fishing line. When most folks hear and see the theremin they tend to think of it as little more than a novelty or scientific amusement. While it may have fallen out favor in horror movie soundtracks it has remained a mainstay within the field of electronic music. It is distinguished among all musical instruments by being the only one that is played without touching the instrument itself. To the radio and electronics buff the theremin is worth exploring as a way of learning about electromagnetic fields and the creative use of the heterodyning effect for artistic purposes. Whether or not the quivering sounds the instrument pulls out of the ether are appealing to a listener is a matter of individual preference.
The inventor of the theremin, or etherphone as it was first dubbed, was Lev Teremen. He was born in Russia in 1896 a few years before Marconi achieved wireless telegraphy. As a young boy he spent his time reading the family encyclopedia and was fascinated by physics and electricity. At five he had started playing piano, and by nine had taken up the cello, an instrument that has an important influence on the way theremins are played. After showing promise in class he was asked to do independent research with electricity at the school physics lab. There he began an earnest study of high-frequency currents and magnetic fields, alongside optics and astronomy. It was around this time Lev met Abram Ioffe, a rising physicist whom he would work under in a variety of capacities. Yet his studies in atomic theory and music were overshadowed by the outbreak of WWI. In 1916 he was summoned by the draft and moved to Petrograd where his electrical experience saved him from the front lines. He was placed in a military engineering school where he landed in the Radio Technical Department to do work on transmitters and oversee the construction of a powerful and strategic radio station. In the course of the war the station had to be disassembled and Lev oversaw the blowing up of a 120 meter antenna mast. Another war time duty was as a teacher instructing other students to become radio specialists.
As Lev's reputation grew among engineers and academic scientists he was eventually asked to go and work with Ioffe Abram at the Physico-Technical Institute where he became the supervisor of a high-frequency oscillations laboratory. Lev's first assignment was to study the crystal structure of various objects using X-Rays. At this time he was also experimenting with hypnosis and Ioffe suggested he take his findings on trance-induced subjects to psychologist Ivan Pavlov. Though Lev resented radio work in preference for his love of exploration of atomic structures, Ioffe pushed him to work more systematically with radio technology. Now in the early 1920's Lev busied himself thinking of novel uses for the audion tube.
His first project involved the exploration of the human body's natural electrical capacitance to set up a simple burglar alarm circuit that he called the "radio watchman". The device was made by using an audion as a transmitter at a specific high frequency directed to an antenna. This antenna only radiated a small field of about sixteen feet. The circuits were calibrated so that when a person walked into the radiation pattern it would change the capacitance, cause a contact switch to close, and set off an audible signal. He was next asked to create a tool for measuring the dielectric constant of gases in a variety of conditions. For this he made a circuit and placed a gas between two plates of a capacitor. Changes in temperature were measured by a needle on a meter. This device was so sensitive it could be set off by the slightest movement of the hand. This device was refined by adding an audion oscillator and tuned circuit. The harmonics generated by the oscillator were filtered out to leave a single frequency that could be listened to on headphones.
As Lev played with this tool he noticed again how the presence of his movements near the circuitry were registered as variations in the density of the gas, and now measured by a change in the pitch. Closer to the capacitor the pitch became higher, while further away it became lower. Shaking his hand created vibrato. His musical self, long dormant under the influence of communism, came alive and he started to use this instrument to tease out the fragments he loved from his classical repertoire. Word quickly traveled around the institute that Theremin was playing music on a voltmeter. Ioffe encouraged Lev to refine what he had discovered -the capacitance of the body interacting with a circuit to change its frequency- into an instrument. To increase the range and have greater control of the pitch he employed the heterodyning principle. He used two high-frequency oscillators to generate the same note in the range of 300 khz :-beyond human hearing. One frequency was fixed, the other variable and could move out of sync with the first. He attached the variable circuit to a vertical antenna on the right hand side of the instrument. This served as one plate of the capacitor while the human hand formed another. The capacitance rose or fell depending on where the hand was in relation to the antenna. The two frequencies were then mixed into a beat frequency within audible range. To play a song the hand is moved at various distances from the antenna creating a series beat frequency notes.
To refine his etherphone further he designed a horizontal loop antenna that came out of the box at a right angle. Connected to carefully adjusted amplifier tubes and circuits this antenna was used by the other hand to control volume. The new born instrument had a range of four octaves and was played in a similar manner to the cello, as far as the motions of the two hands were concerned. After playing the instrument for his mentor, he performed a concert in November of 1920 to an audience of spellbound physics students. In 1921 he filed for a Russian patent on the device.
Theremin: Ether Music and Espionage by Albert Glinsky, 2000, University of Illinois
No man works in a vacuum. Before the industry of radio got off the ground it had been customary for researchers to use each-others discoveries with complete abandon. As technical progress in the field of wireless communication moved from the domain of scientific exploration to commercial development financial assets came to be at stake and rival inventors soon got involved in one of the great American pastimes: lawsuits. The self-styled "Father of Radio" Lee De Forest was involved in a number of infringement controversies. The most famous of these involved his invention of the audion (from audio and ionize) an electronic amplifying vacuum tube.
It was Edison who first produced the ancestor of what became the audion. While working on the electric light bulb he noticed that one side of the carbon filament behaved in a way that caused the blackening of the glass. Working on this problem he inserted a small electrode and was able to demonstrate that it would only operate when connected to the positive side of a battery. Edison had formed a one way valve. This electrical phenomenon made quite the impression on another experimenter, Dr. J. Ambrose Fleming, who brought the device back to life twenty years later when he realized it could be used as a radio wave detector.
At the time Fleming was working for Marconi as one of his advisers. It occurred to him that "if the plate of the Edison effect bulb were connected with the antenna, and the filament to the ground, and a telephone placed in the circuit, the frequencies would be so reduced that the receiver might register audibly the effect of the waves." Fleming made these adjustments. He also substituted a metal cylinder for Edison's flat plate. The sensitivity of the device was improved by increasing electronic emissions. This great idea in wireless communication was called the Fleming valve.
Fleming had patented this two-electrode tube in England in 1904 before giving the rights to the Marconi Company who took out American patents in 1905. Meanwhile Lee De Forest had read a report from a meeting of the Royal Society where Fleming had lectured on the operation of his detector. De Forest immediately began experimentation with the apparatus on his own and found himself dissatisfied. Between the cathode and anode he added a third element made up of a platinum grid that received current coming in from the antenna. This addition proved to transform the field of radio, setting powerful forces of electricity, as well as litigation, into motion.
The audion increased amplification on the receiving side but radio enthusiasts were doubtful about the ability of the triode tube to be used with success as a transmitter. De Forest had been set upon by financial troubles involving various scandals in the wireless world and was persuaded to sell his audion patent in 1913.
Edwin Howard Armstrong had been fascinated by radio since his boyhood and was an amateur by age fifteen when he began his career. Some of his experimentation was with the early audions that were not perfect vacuums (De Forest had mistakenly thought a little bit of gas left inside was beneficial to receiving). Armstrong took a close interest in how the audion worked and developed a keen scientific understanding of its principles and operation. By the time he was a young man at Columbia University in 1914, working alongside Professor Morecroft he used an oscillograph to make comprehensive studies based on his fresh and original ideas. In doing so he discovered the regenerative feedback principle that was yet another revolution for the wireless industry. Armstrong revealed that when feedback was increased beyond a certain point a vacuum tube would go into oscillation and could be used as a continuous-wave transmitter. Armstrong received a patent for the regenerative circuit.
De Forest in turn claimed he had already come up with the regenerative principle in his own lab, and so the lawsuits began, and continued for twenty years with victories that alternated as fast as electric current. Finally in 1934 the Supreme Court decided De Forest had the right in the matter. Armstrong however would achieve lasting fame for his superheterodyne receiver invented in 1918.
Around 1915 De Forest used heterodyning to create an instrument out of his triode valve, the Audion Piano. This was to be the first musical instrument created with vacuum tubes. Nearly all electronic instruments after if it were based on its general schematic up until the invention of the transistor.
The instrument consisted of a single keyboard manual and used one triode valve per octave. The set of keys allowed one monophonic note to be played per octave. Out of this limited palette it created variety by processing the audio signal through a series of resistors and capacitors to vary the timbre. The Audion Piano is also notable for its spatial effects, prefiguring the role electronics would play in the spatial movement of sound. The output could be sent to a number of speakers placed around the room to create an enveloping ambiance. De Forest later planned to build an improved version with separate tubes for each key giving it full polyphony, but it is not known if it was ever created.
In his grandiose autobiography De Forest described his instrument as making "sounds resembling a violin, cello, woodwind, muted brass and other sounds resembling nothing ever heard from an orchestra or by the human ear up to that time – of the sort now often heard in nerve racking maniacal cacophonies of a lunatic swing band. Such tones led me to dub my new instrument the ‘Squawk-a-phone’….The Pitch of the notes is very easily regulated by changing the capacity or the inductance in the circuits, which can be easily effected by a sliding contact or simply by turning the knob of a condenser. In fact, the pitch of the notes can be changed by merely putting the finger on certain parts of the circuit. In this way very weird and beautiful effects can easily be obtained.”
In 1915 an Audion Piano concert was held for the National Electric Light Association. A reporter wrote the following: “Not only does De Forest detect with the Audion musical sounds silently sent by wireless from great distances, but he creates the music of a flute, a violin or the singing of a bird by pressing a button. The tone quality and the intensity are regulated by the resistors and by induction coils…You have doubtless heard the peculiar, plaintive notes of the Hawaiian ukulele, produced by the players sliding their fingers along the strings after they have been put in vibration. Now, this same effect, which can be weirdly pleasing when skilfully made, can he obtained with the musical Audion.”
Fast forward to 1960. The Russian immigrant and composer Vladimir Ussachevsky is doing deep work in the trenches of the cutting edge facilities at the Columbia-Princeton Electronic Music Center, one of the first electronic music studios anywhere. Its flagship piece of equipment was the RCA Mark II Sound Synthesizer, banks of reel-to-reels and customized equipment. Ussachevsky received a commission from a group of amateur radio enthusiasts, the De Forest Pioneers, to create a piece in tribute to their namesake. In the studio Vladimir composed something evocative of the early days of radio and titled it "Wireless Fantasy". He recorded morse code signals tapped out by early radio guru Ed G. Raser on an old spark generator in the W2ZL Historical Wireless Museum in Trenton, New Jersey. Among the signals used were: QST; DF the station ID of Manhattan Beach Radio, a well known early broadcaster with a range from Nova Scotia to the Caribbean; WA NY for the Waldorf-Astoria station that started transmitting in 1910; and DOC DF, De Forests own code nickname. The piece ends suitably with AR, for end of message, and GN for good night. Woven into the various wireless sounds used in this piece are strains of Wagner's Parsifal, treated with the studio equipment to sound as if it were a short wave transmission. Lee De Forest had played a recording of Parsifal, then heard for the first time outside of Germany, in his first musical broadcast.
It is also available on the CD: Vladimir Ussachevsky, Electronic and Acoustic Works 1957-1972 New World Records
History of Radio to 1926 by Gleason L. Archer, The American Historical Society, 1938
The Father of Radio by Lee De Forest
Antennas and monochords have a lot in common. A monochord is an ancient musical and scientific lab instrument made of one long string, similar in that respect to a long single wire antenna, only the string is stretched over a sounding box of equal length. One or more movable bridges are then moved up and down the string to demonstrate the mathematical relationships among the frequencies produced and for measuring musical intervals. Though it was first mentioned in Sumerian clay tablets, many attribute it's invention to Pythagoras around 6 BCE. These ancients saw within the monochord a mystic holism in which notes, numbers, ratios and intervals combined with the sense of hearing and mathematical reason. Monochords are related to other instruments such as the Japanese koto, the hurdy-gurdy, and the Scandinavian psalmodikon this last used as an accompaniment to voice in sacred music. In medicine the sonometer, a variation of the monochord, continues to be used to diagnose hearing loss and bone density for those who may be at risk for osteoporosis.
The discovery of the precise relationship between the pitch of a musical note and the length of the string that produces it is also attributed to Pythagoras. If he had been able to put electricity into wire strings it might have been Pythagoras who discovered the principle of resonance that makes an antenna match a frequency. What Pythagoras did propose was the idea of the Music of the Spheres, a philosophical concept that conjectures that the movement of celestial bodies creates a form of heavenly music. This theory has continued to haunt the imagination of the West since it was first proposed. Later Plato described astronomy and music as "twinned" studies of sense recognition that both required knowledge of numerical proportions. Astronomy was for the eyes and music was for the ears. Now millenia later astronomy can be studied with the ears of a radio receiver and number crunching supercomputers.
In 1618 the physician, scientist and mystic Robert Fludd conceived a divine or celestial monochord linking the Ptolemaic conception of the universe to musical intervals, suggesting that the instrument could also be used to demonstrate the harmony of the spheres. In Fludd's picture a divine hand reaches down from out of a cloud to tune the monochord to the celestial frequencies of the planets and the stars. Around two and a half centuries later scientists unknowingly started tuning into the terrestrial frequencies that were unknowingly being picked up by telegraph and telephone lines.
In his masterful book Earth Sound Earth Signal Douglas Kahn writes that "radio was heard before it was invented". He goes on to describe how the first person to listen to radio was Alexander Graham Bell's assistant Thomas Watson. He tuned in with a telephone receiver "during the early hours of the night on a long metal line serving as an antenna before antennas were invented." Other telephone users also listened to radio for two decades before Marconi made his first transmission. Watson enjoyed listening to the natural VLF signals given off by the earth, though he did not know it's origin or that it was even radio at all. The natural signals were picked up on the telephone line acting as an extremely long wire that was resonant in the VLF range, from around 3 kHz to 30 kHz and corresponding to wavelengths of 100 to 10 kilometers. Watson's own line from the lab stretched a half mile down the street. Since he wasn't transmitting it didn't have to be fully resonant to pick up the VLF signals. I like to think of these long antenna wires as a type of terrestrial monochord that tunes in to the harmony of the Earth.
Watson did not try to do anything about the noises he heard on the line, as they did not interfere with voice communication. In fact he actually enjoyed listening to spherics, whistlers, dawn chorus and other VLF phenomenon he likely picked up, even as he didn't know or understand their cause. I like to listen to this form of natural radio myself. There are a number of live internet streams from people who have set up VLF listening posts, such as those found at http://abelian.org/vlf/. I think those sounds are as relaxing as listening to the surf of the ocean or a gentle breeze in the trees. Kahn goes on to write that nature "has always been the biggest broadcaster, bigger than all governments, corporations, militaries, and other purveyors of anthropic signals combined." May it remain so.
Fludd's image of the celestial monochord was made famous in 1952 when it came to adorn the cover of The Anthology of American Folk music compiled by Harry Everett Smith and released by Smithsonian Folkways. I think some divine inspiration was passed on to Harry Smith, from the same hand that tunes the instrument, and from him it passed on to all the lives his massive compilation touched. The six-album set brought new levels of cultural awareness to musicians such as Blind Lemon Jefferson, the Carter Family and Mississippi John Hurt and went on to kick start the folk music revival of the 50's and 60's. It had a strong influence on Joan Baez and Bob Dylan, who are acknowledged as disciples of the anthology. It continues to touch new generations of musicians today.
Avant-garde composer and father of minimalism La Monte Young found early inspiration from another type of electrical monochord. He recalled as a child listening to the droning sound of the power plant next to his Uncle's gas station. He became fascinated by the 60-cycle hum of electricity as it moved along the lines. This inspired such pieces of music as "the Second Dream of the High Tension Line Stepdown Transformer". John Cale and the late Tony Conrad are among the many influenced by Young's work. Both were involved in Young's Theatre of Eternal Music. Cale went on to a long and varied career and is notable for being a founding member of the Velvet Underground. During rehearsals with Young, Cale and Conrad would tune their instruments to the 60-cycle electrical hum, what Young called the "underlying drone of the city".
In the late 70's composer Alvin Lucier started working with physicist John Trefny on a musical acoustics course they were teaching at Wesleyan University. They had set up a monochord and placed an electromagnet over one end while an audio oscillator drove the wire. This created an interaction between the flux field of the magnet and the frequency and loudness of the oscillator, causing the stretched wire to be observed vibrating by the naked eye. This demonstration captivated Alvin's imagination and he started thinking about building a monochord to be used on the concert stage or in galleries. After getting some metal piano wire, clamps and a horseshoe magnet he had a built a portable version whose length could be varied depending on the size of the space. This became his classic piece Music on a Long Thin Wire. What he did was extend the wire across a room, clamping it to tables at either end. The ends of the wire were connected to the speaker terminals and a power amplifier placed under the table. The amplifier in turn had a sine wave oscillator connected to it, and a magnet straddled the wire at one end. Wooden bridges with embedded contact mics were put under the wire at both ends, and these were routed to a stereo systems. This electrified monochord is played by varying the frequency and loudness of the oscillator to create slides, frequency shifts, audible beat frequencies and other sonic effects. Lucier eventually discovered that the instrument could be left to play itself by carefully tuning the oscillator. Air currents, human proximity to the wire, heat or coolness and other shifts in the environment all caused new and amazing sounds to be heard, sometimes spontaneously erupting into triadic harmonies. This electric monochord is an instrument that can play itself just as the long thin wires of the early telephone and telegraph system tuned into the terrestrial harmonies continuously being broadcast by Mother Earth.
Earth Sound Earth Signal: Energies and Magnitude in the Arts by Douglas Kahn
The Hum of the City: La Monte Young and the Birth of NYC Drone by Alan Licht
The Anthology of American Folk Music compiled by Harry Everett Smith
Alvin Lucier, Music on a Long Thin Wire, Lovely Music LCD 1011
Justin Patrick Moore
Husband. Father/Grandfather. Writer. Green wizard. Ham radio operator (KE8COY). Electronic musician. Library cataloger.