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There is wealth of devices that are powered by radio waves. Every receiving antenna could be said to be powered by radio waves since it converts radio waves to
by lmilcin 7y ago
There is wealth of devices that are powered by radio waves.
Every receiving antenna could be said to be powered by radio waves since it converts radio waves to signal (albeit typically quite faint) and antennas were known way before The Thing.
The difference between The Thing and other devices is that it modulated and reflected the signal at different frequency all without use of any electronics. Every RFID chip is a bit of electronics but The Thing actually is an analog device without anything that could be recognized as electronic circuit at first sight.
As far as I understand it used some kind of resonant cavity an some kind of change in capacitance dependant on the geometry of the device. The sound waves would cause the physical setup to vibrate and the vibration would change geometry of the device causing modulation of the reflected signal.
- Zenst 7y agoCrystal radios are probably the earliest case of devices powered by radio waves. https://en.wikipedia.org/wiki/Crystal_radio https://en.wikipedia.org/wiki/Crystal_radio
- 52-6F-62 7y agoAh that brings back fond memories. I built one of those as a kid (from a kit). You had to wind your own coil and everything. It was thrilling to get it working.
- iNate2000 7y agoThat's my biggest complaint about digital broadcast. On the other hand - AM broadcast is still totally analog, so a crystal radio should still work! I should order a kit right now!
- tyingq 7y agoA "foxhole razor blade" crystal radio kit is an interesting offshoot.
- felipemnoa 7y agoThanks for this. I had no idea this was possible. Nice little project to try.
- laumars 7y agooh likewise. I remember being completely amazed by the thing. To extend the other comment about FM being digital (in the UK): so much tech we take for granted now is built upon layers upon layers of underlying technology. Devices have never been better but at the same time it's a real loss that we can't build stuff from scratch any longer. I learned so much as a kid from building - often bad - things.
- cbpowell 7y agoWikipedia has a very nice writeup on the device: https://en.wikipedia.org/wiki/The_Thing_(listening_device) https://en.wikipedia.org/wiki/The_Thing_(listening_device) They stress it had no active electronics. The imagery in the article clearly shows it had some metallic innards, presumably these are passive electronics for modulating the illuminating signal.
- kevin_thibedeau 7y agoIt's just an antenna and resonant cavity. No wires involved. The modulation was performed by the mechanical vibration of the diaphragm.
- yesenadam 7y agoMaciej Ceglowski has an illustrated page + talk Our Comrade The Electron about Termen's life and inventions (The Theremin, The Thing etc) and much more. Highly recommended! I love how he presents his talks on the web. https://idlewords.com/talks/our_comrade_the_electron.htm https://idlewords.com/talks/our_comrade_the_electron.htm
- nuxi 7y agoThat was a fantastic read, thank you.