The Cold War spy technology which we all use - Theremin
 

I've not come accross this intersting story before, maybe I'm not the only one so thought I'd share it.

https://www.bbc.co.uk/news/business-48859331#

John

Re: The Cold War spy technology which we all use - Theremin
 

I read that article with interest.

It worked on about 1GHz and used a cavity resonator with an audio diaphram as one side of the cavity, audio would phase modulate the reflected signal and be demodulated with what was effectively a direct conversion rx.

I experimented with and worked on a very similar system.

These days any high power illumination signal instantly raises attention from counter espionage types - plus you can determine exactly where the illuminating signal is coming from.

Mods - please delete this if not considered appropriate.

Re: The Cold War spy technology which we all use - Theremin
 

I knew about that object, but I didn't know it was designed by Theremin.

Re: The Cold War spy technology which we all use - Theremin
 

I have seen a photo of it some years ago. It looked pretty simple inside.

Re: The Cold War spy technology which we all use - Theremin
 

I remember reading about that bug in the seal - presumably in 1960 but didn't realise how old it was. If it only took seven years before it was found and was presented in 1945, presumably it was discovered on 1952.

So why didn't we hear about it for another 8 years? Is it possible that, having discovered what was inside it, they used it to plant false information and didn't tell anybody about it until the USSR finally realised that they had been tricked.

Re: The Cold War spy technology which we all use - Theremin
 

I'd heard of similar chicanery involving IR lasers being reflected off the windows of embassies and similar premises. Don't doubt for a moment that every possible (and some impossible!) means of finding out what the other side is saying has been thoroughly and expensively investigated and much of it won't escape into the public domain for decades.

Re: The Cold War spy technology which we all use - Theremin
 

"The Conversation"...8-o

Gene Hackman.

Lawrence.

Re: The Cold War spy technology which we all use - Theremin
 

lasers off windows doesn't work too well far too much external noise - much better to focus on something inside the room, but net curtains are pretty good as a counter measure - or so I'm told ;-)

Re: The Cold War spy technology which we all use - Theremin
 

I bought a really interesting book about the subject a few months ago, essentially a history of the CIA's Office of Technical Services, 'Spycraft' by Melton, Schlesinger and Wallace. It goes into some detail (but not too technical unfortunately for us) about the items used during the cold war and how they were inserted into walls, rats, tables etc etc. The transition from valves to transistors was the big game changer evidently. I really recommend it.

Andrew

https://www.amazon.co.uk/Spycraft-H-...=UTF8&qid=&sr=

Re: The Cold War spy technology which we all use - Theremin
 

In essence, that was the main story-line of a "The Avengers" episode called "All Done with Mirrors" that was first shown in 1968.

At the time me and my friend across the road had a modulated-light-beam telephone operating between our houses. Inspired by the episode, I noticed that each evening the sun reflected from the louvered glass windows in the shopfront of a nearby launderette into my bedroom so I turned my device towards it to see if I could hear the voices of those inside. There was plenty of noise from the vibration of the machinery, but that's all.

As for the American embassy incident, I was aware of it, but I had no idea that Theremin was involved. I suppose it's logical that detail like that wasn't available till after the fall of the Soviet Union.
One thing the BBC article doesn't mention and was alleged in the reports that I read, is that the the staff at the embassy suffered adverse health effects from the powerful non-ionising radiation beamed towards them.

Theremin died in 1993 according to his wiki entry, and according to the same source he devised the principle of raster interlace for television, I imagine like most television developments, there will be other contenders.

Re: The Cold War spy technology which we all use - Theremin
 

Sanabria was using an interlaced raster from 1929, on the Western Electric television system. I wonder if Theremin was earlier than that?

Re: The Cold War spy technology which we all use - Theremin
 

I know that in the 80's we were interested in using lasers to measure water waves. The people trying to sell use the system claimed that it had been used to eavesdrop in the Iranian Embassy seige - the one problem they had was that they didn't want anyone inside to see the spot on the glass and so they had to try and attach a what looked like pigeon droppings to the window for something to aim the laser at.

Re: The Cold War spy technology which we all use - Theremin
 

I have a service manual for the 1929 Theremin musical instrument, quite a simple device. The most famous use of it was for the eerie soundtrack to "Forbidden Planet" in the late 1940s.

Cheers

Roger

Re: The Cold War spy technology which we all use - Theremin
 

I highly recommend ‘Theremin: Ether Music and Espionage’ by Albert Glinsky for an outstanding history of Theremin. Available on Amazon. There is a lot more to the story on Theremin than generally known.

Re: The Cold War spy technology which we all use - Theremin
 

Dr David Maddison just created a detailed article published in Silicon Chip here in AU.

It is all about cyber espionage & bugs, with quite a lot of detail on "The Thing" designed by Leon Theremin and placed in a hand crafted carved timber seal. A type of cavity resonator modulated by acoustic waves, that works by illuminating it at 300MHz. Click on item 4 on the list of articles:

http://www.siliconchip.com.au/Issue/...tober/Contents

Re: The Cold War spy technology which we all use - Theremin
 

Sorry, but I beg to differ, Bebe and Louis Barron, the composers of the "electronic tonalities" (they were not permitted to call it music since the musicians union in the USA objected, this cost the Barrons their oscar) did not use a Theremin.

See the Wikipedia entry:
"While the theremin (which was not used in Forbidden Planet) had been used on the soundtrack of Alfred Hitchcock's Spellbound (1945), the Barrons' electronic composition is credited with being the first completely electronic film score"
and
"Using ideas and procedures from the book Cybernetics: Or Control and Communication in the Animal and the Machine (1948) by the mathematician and electrical engineer Norbert Wiener, Louis Barron constructed his own electronic circuits that he used to generate the score's "bleeps, blurps, whirs, whines, throbs, hums, and screeches". Most of these sounds were generated using an electronic circuit called a "ring modulator". After recording the basic sounds, the Barrons further manipulated the sounds by adding other effects, such as reverberation and delay, and reversing or changing the speeds of certain sounds."

Forbidden Planet is my favourite ever Sci-Fi film, way ahead of its time. I was fortunate enough to see it on the big screen when it was shown, at my request, at the old market cinema club in Brighton.

Peter

Re: The Cold War spy technology which we all use - Theremin
 

Glinksy's biography of theremin is the definitive writing on the man himself. Should be on anybody's bookshelf if they're even remotely interested in vintage electronics, mad inventions or cold war espionage.

https://www.amazon.co.uk/Theremin-ET...0984063&sr=8-2

Re: The Cold War spy technology which we all use - Theremin
 

I tend to agree with you about the quality of the Forbidden Planet film, I saw it at our local ABC cinema when still at school. I found out several years later why it was so good a narrative - it is based on "The Tempest" by our own William Shakespeare. Think about it...
Incidentally, the stage-play which was shown some time ago was equally as good.

To keep this a bit more on-topic, the "Ondes Martenot" was a similar-sounding device, but used a cable with a finger-ring to select the note(s) and apply tremelo. I can't recall any use of it in films, though.
Colin.

Re: The Cold War spy technology which we all use - Theremin
 

Maybe not in movies, but the Ondes Martenot have a good history of use in classical music: Olivier Messiaen's Turangalila-symphonie being probably the best-known instance.

I was lucky to see the late lamented Jeanne Loriod perform as the Ondes-Marteniste in this at the Royal Festival Hall in the early-80s.

Re: The Cold War spy technology which we all use - Theremin
 

I wish I had been there! Interestingly, the character on Futurama called "Leela" is named from that piece by Messaien - her full name is "Turanga Leela".
Colin.