June 2020

Note From President Dave

Greetings to All!

As we enter the fourth month of lock-down or limited activity, I am getting anxious to return to what we used to call normal.  I sincerely hope all of you and your families are safe and healthy. It seems that everyone I have spoken with is making the best of these trying times. It has at least been a time for many to spend quality time with family and working on projects. Most of us can find plenty to do with this extra time.

Some of us visit the shop from time to time to check on things. Everything is in good shape there. It seems strange to see only seven cars in the parking lot on Tuesday.  I want to express my appreciation to Boyd Bailey for making the class available to all members on Zoom.  We have continued to receive donations during this time including some very nice items, many will be available for our next auction. Thanks to those of you who have picked up these items or have assisted in any way. If any of you have problems with your radio projects and need help, please call me (205) 999-7178 I always enjoy talking with you radio guys about the problems you encounter.  So until we can meet again at the shop, I wish the very best to all of you and MAY GOD BLESS!!!

See you at the Shop – when we can?


What's happening at the Society

Leon Theremin

By Steven Westbrook, Dave Cisco & Kyle Owen

Here is a person every self-respecting radio and electronics person needs to know something about. Versions of his electronic, musical and radio related inventions are all around us and a part of our everyday lives.

Lev Sergeyevich Termen (Leon Theremin) born August 28, 1896, was a Russian and Soviet inventor, most famous for his invention of the theremin, one of the first electronic musical instruments and the first to be mass-produced, He also worked on early television research, clandestine listening devices and what was later called RFID (Radio Frequency Identification).

By the age of 17, and in his last year of high school, he had his own laboratory at home for experimenting with high-frequency circuits, optics and magnetic fields. On May 9, 1913 Theremin and his cousin, Kirill Fedorovich Nesturkh, then a young physicist, attended the defense of the dissertation of Abram Fedorovich Ioffe. Ioffe's. Kyrill introduced Theremin to Ioffe as a young experimenter and physicist, and future student of the university. Ioffe's subject was the elementary photoelectric effect, the magnetic field of cathode rays and related investigations. In 1917, Theremin wrote that Ioffe talked of electrons, the photoelectric effect and magnetic fields as parts of an objective reality that surrounds us every day, unlike others that talked more of somewhat abstract formulae and symbols. Theremin wrote that he found this explanation revelatory and that it fit a scientific – not abstract – view of the world, Theremin became fascinated with this concept and later endeavored to study this segment of physics in detail.

World War I and Russian Civil War

Although only in his second academic year, the deanery of the Faculty of Physics and Astronomy recommended that Theremin go to the Nikolayevska Military Engineering School in Petrograd (previously Saint Petersburg), which usually only accepted students in their fourth year. Theremin recalled that Ioffe reassured him that the war would not last long and that military experience would be useful for scientific applications.

Beginning his military service in 1916, Theremin finished the Military Engineering School in six months, progressed through the Graduate Electronic School for Officers, and attained the military radio-engineer diploma in the same year. In the course of the next three and a half years he oversaw the construction of a radio station in Saratov to connect the Volga area with Moscow, graduated from Petrograd University, became deputy leader of the new Military Radiotechnical Laboratory in Moscow, and finished as the broadcast supervisor of the radio transmitter at Tsarskoye Selo near Petrograd (then renamed Detskoye Selo).

During the Russian civil war, in October 1919 White Army commander Nikolai Nikolayevich Yudenich advanced on Petrograd from the side of Detskoye Selo, apparently intending to capture the radio station to announce a victory over the Bolsheviks. Theremin and others evacuated the station, after sending the equipment east on rail cars. Theremin then detonated explosives to destroy the 120-meter-high antennae mast before traveling to Petrograd to set up an international listening station. There he also trained radio specialists but reported difficulties obtaining food and working with foreign experts whom he described as narrow-minded pessimists.

Theremin recalled that on an evening when his hopes of overcoming these obstructing experts reached low ebb, Abram Fedorovich Ioffe telephoned him. Ioffe asked Theremin to come to his newly founded Physical Technical Institute in Petrograd, and the next day he invited him to start work at developing measuring methods for high-frequency electrical oscillations.

Under Ioffe

The day after Ioffe's invitation, Theremin started at the institute. He built a high-frequency oscillator to measure the dielectric constant of gases with high precision; Ioffe then urged him to look for other applications using this method, and shortly made the first “motion detector” for use as what he called a "Radio Watchman".

While adapting the dielectric device by adding circuitry to generate an audio tone, Theremin noticed that the pitch changed when his hand moved around. In October 1920 he first demonstrated this to Ioffe who called in other professors and students to listen. Using the newly discovered vacuum tube technology he designed and built the first musical instrument that relied on electronic oscillation to produce sound; furthermore, his invention remains the only instrument that is played without actual human contact. By November 1920 Theremin had given his first public concert with the instrument, now modified with a horizontal volume antenna replacing the earlier foot-operated volume control. He named it the "etherphone", to be known as the Терменвокс (Termenvox) in the Soviet Union, as the Thereminvoxin Germany, and later as the "theremin" in the United States.

In 1925 Theremin went to Germany to sell both the Radio Watchman and Termenvox (theremin) patents to the German firm Goldberg and Sons.

During this time Theremin was also working on a wireless television with 16 scan lines in 1925, improving to 32 scan lines and then 64 using interlacing in 1926, and he demonstrated moving, if blurry, images on June 7, 1927. His device was the first functioning television apparatus in Russia.

United States

After a lengthy tour of Europe starting 1927 – including London, Paris and towns in Germany – during which he demonstrated his invention to packed concert halls, Theremin found his way to the United States, arriving on December 30, 1927. He performed the theremin with the New York Philharmonic in 1928. He patented his invention in the United States in 1928 and subsequently granted commercial production rights to RCA.

Theremin set up a laboratory in New York in the 1930s, where he further refined the theremin and experimented with other inventions and new electronic musical instruments.

n 1930, ten thereminists performed on stage at Carnegie Hall. Two years later, Theremin conducted the first-ever electronic orchestra, featuring the theremin and other electronic instruments including a "fingerboard" theremin which resembled a cello. (Theremin was a cellist)

Theremin's mentors during this time were some of society's foremost scientists, composers, and musical theorists, including composer Joseph Schillinger, physicist (and amateur violinist) Albert Einstein and fellow Soviet émigré and theremin virtuoso Clara Rockmore (née Reisenberg).

Theremin was interested in a role for the theremin in dance music. He developed performance locations that could automatically react to dancers' movements with varied patterns of sound and light.

During this period, the United States Federal Bureau of Prisons hired Theremin to build a metal detector for Alcatraz Federal Penitentiary in San Francisco, California.

Rock Musicians Revived Interest

In the 1950s, the theremin was used in horror and science-fiction movies, including The Day the Earth Stood Still and It Came from Outer Space. Youngsters who were fans of the genre grew into the rock music innovators of the 1960s and 1970s. The inventor of the first synthesizer, Robert Moog, built his own theremin as a teenager from a how-to kit he bought out of a magazine. The most universally familiar theremin sound, however, remains the introduction to the 1966 Beach Boys hit, "Good Vibrations", though was actually performed by an Electro-Theremin, which used knobs for more precise control.

Return to the Soviet Union

Theremin was reported kidnaped by Soviet agent and returned to the Soviet Union in 1938. At the time, the reasons for his return were unclear; some claimed that he was simply homesick, while others believed that he had been kidnapped by Soviet officials.

Many years later, it was revealed that Theremin had returned to his native land due to tax and financial difficulties in the United States. However, Theremin himself once told Bulat Galeyev that he decided to leave because he was anxious about the approaching war. Shortly after he returned he was imprisoned in the Butyrka prison and later sent to work in the Kolyma gold mines. Although rumors of his execution were widely circulated and published, Theremin was, in fact, put to work in a sharashka (a secret laboratory in the Gulag camp system), together with Andrei Tupolev, Sergei Korolev, and other well-known scientists and engineers. The Soviet Union rehabilitated him in 1956.


"The Thing"

During his work at the sharashka, where he was put in charge of other workers, Theremin created the Buran eavesdropping system. A precursor to the modern laser microphone, it worked by using a low-power infrared beam from a distance to detect sound vibrations in glass windows. Lavrentiy Beria, the head of the secret police organization NKVD (the predecessor of the KGB), used the Buran device to spy on the British, French and US embassies in Moscow.

Theremin invented another listening device known as “The Thing”. This Soviet device was disguised in a replica of the Great Seal of the United States carved in wood. On August 4, 1945, Soviet school children presented the Seal, with the concealed “bug”, to U.S. Ambassador W. Averell Harriman as a "gesture of friendship" to the USSR's World War II ally. It hung in the ambassador’s residential office in Moscow and intercepted confidential conversations there during the first seven years of the Cold War, until it was accidentally discovered in 1952.

“The Thing”, also known as the Great Seal bug, was one of the first covert listening devices or “bug” to use passive techniques to transmit an audio signal. Because it was passive, needing electromagnetic energy from an outside source to become energized and activate, it is considered a predecessor of radio-frequency identification (RFID) technology. This technology is used today for everything from tracking inventory in warehouses to tracking your packages through the postal system, “chipping” our animals and many other applications.

“The Thing” consisted of a tiny capacitive membrane connected to a small quarter-wavelength antenna; it had no power supply or active electronic components. The device, a passive cavity resonator, became active only when a radio signal of the correct frequency was sent to the device from an external transmitter. This is referred to in NSA (National Security Agency) parlance as "illuminating" a passive device. Sound waves (such as voices inside the ambassador's office) passed through the thin wood case, striking the membrane and causing it to vibrate. The movement of the membrane varied the capacitance "seen" by the antenna, which in turn modulated the radio waves that struck and were re-transmitted by the device. A receiver demodulated the signal so that sound picked up by the microphone could be heard, just as an ordinary radio receiver demodulates radio signals and outputs sound.

Theremin's design made the listening device very difficult to detect, because it was very small, had no power supply or active electronic components, and did not radiate any signal unless it was actively being irradiated remotely. These same design features, along with the overall simplicity of the device, made it very reliable and gave it a potentially unlimited operational life.

The device consisted of a 9-inch (23 cm) long monopole antenna (quarter-wave for 330 megahertz (MHz) frequencies, but able to also act as half-wave [at 660 MHz] or full-wave [at 1320 MHz], the accounts differ—given the radio technology of the time, the frequency of 330 MHz is most likely)—a straight rod, led through an insulating bushing into a cavity, where it was terminated with a round disc that formed one plate of a capacitor. The cavity was a high-Q round silver-plated copper "can", with the internal diameter of 0.775 in (19.7 mm) and about 11/16 inches (17.5 mm) long, with inductance of about 10 nanohenry. Its front side was closed with a very thin (3 mil, or 75 micrometers) and fragile conductive membrane. In the middle of the cavity was a mushroom-shaped flat-faced tuning post, with its top adjustable to make it possible to set the membrane-post distance; the membrane and the post formed a variable capacitor acting as a condenser microphone and providing amplitude modulation (AM), with parasitic frequency modulation (FM) for the re-radiated signal. The post had machined grooves and radial lines into its face, probably to provide channels for air flow to reduce pneumatic damping of the membrane. The antenna was capacitively coupled to the post via its disc-shaped end. The total weight of the unit, including the antenna, was 1.1 ounces (31 grams).

The length of the antenna and the dimensions of the cavity were engineered in order to make the re-broadcast signal a higher harmonic of the illuminating frequency.

The original device was located with the can under the beak of the eagle on the Great Seal. Accounts differ on whether holes were drilled into the beak to allow sound waves to reach the membrane. Other sources say the wood behind the beak was undrilled but thin enough to pass the sound, or that the hollowed space acted like a soundboard to concentrate the sound from the room onto the microphone.

The illuminating frequency used by the Soviets is said to be 330 MHz.

The existence of the bug was discovered accidentally by a British radio operator at the British embassy who overheard American conversations on an open radio channel as the Soviets were beaming radio waves at the ambassador's office. An American State Department employee was then able to reproduce the results using an untuned wideband receiver with a simple diode detector/demodulator, similar to some field strength meters.

Two additional State Department employees, John W. Ford and Joseph Bezjian, were sent to Moscow in March 1951 to investigate this and other suspected bugs in the British and Canadian embassy buildings. They conducted a technical surveillance counter-measures "sweep" of the ambassador's office, using a signal generator and a receiver in a setup that generates audio feedback ("howl") if the sound from the room is transmitted on a given frequency. During this sweep, Bezjian found the device in the Great Seal carving.

The Federal Bureau of Investigation set about to analyze the device, and hired people from the British Marconi Company to help with the analysis. The “bug” was called the “The Thing” by the CIA until Marconi technician Peter Wright, a British scientist and later MI5 counterintelligence officer, figured out how it worked. Before he figured out how it works he repaired damage to the extremely thin membrane, damaged during handling by the CIA. Finally, he was able to get “The Thing” working reliably with an illuminating frequency of 800 MHz. The generator which had discovered the device was tuned to 1800 MHz.

The simplicity of the device caused some initial confusion during its analysis; the antenna and resonator had several resonant frequencies in addition to its main one, and the modulation was partially both amplitude modulated and frequency modulated. The team also lost some time on an assumption that the distance between the membrane and the tuning post needed to be increased to increase resonance.

Later life

After his "release" from the sharashkain 1947, Theremin volunteered to continue working with the KGB until 1966.

Theremin worked at the Moscow Conservatory of Music for 10 years where he taught, and built theremins, electronic cellos and some terpsitones (another invention of Theremin). There he was discovered by Harold Schonberg, the chief music critic of The New York Times, who was visiting the Conservatory. But when an article by Schonberg appeared mentioning Theremin, the Conservatory's Managing Director declared that "electricity is not good for music; electricity is to be used for electrocution" and had his instruments removed from the Conservatory. Further electronic music projects were banned, and Theremin was summarily dismissed.

In the 1970s, Leon Theremin was a Professor of Physics at Moscow State University (Department of Acoustics), continued developing his inventions and supervised graduate students.

After 51 years in the Soviet Union, Theremin started travelling, first visiting France in June 1989 and then the United States in 1991. Theremin was brought to New York by filmmaker Steven M. Martin where he was reunited with Clara Rockmore. He also performed a demonstration concert at the Royal Conservatory of The Hague in early 1993 before dying in Moscow in 1993 at the age of 97.

Theremin died on Wednesday November 3, 1993 in Moscow.

Sources: Wikipedia, Spycatcher: The Candid Autobiography of a Senior Intelligence Officer by Peter Wright, 1987 and many other sources

Radio History Contest

Submitted by Steven Westbrook

Below are both sides of a July 6, 1973 Northern Ireland postcard commemorating  the 75th Anniversary of Marconi’s first wireless signal from Rathlin Island, off the northern coast of Northern Ireland, to Ballycastle, County Antrim, Northern Ireland. Marconi had been tasked by Lloyds of London to report to London on shipping in the North Channel.

We are going to have a contest. The first person who can correctly define what is meant by “mostly red each way” will win a coupon to check out a history book from the AHRS library at no additional charge.  (The truth is - ARHS does not charge anyway… so much for truth in advertising) Please send your correct answer  to me at spwestbro@bellsouth.net  Please see Librarian Dave Cisco for contest rules and for details about checking out books from our wonderful library. The winner will be announced in the July Superflex newsletter.