3 ms·

Also see CuriousMarc's companion video, which shows how the spark gap works with a coherer for primitive radio transmissions. https://www.youtube.com/watch?v=9z

• makomk 7y ago
  Spark-gap transmitters are of course technically illegal to operate pretty much everywhere on the planet - by international treaty, even! - but in practice I guess a short-range device like this isn't going to do much more than maybe piss off the neighbours.
  • segfaultbuserr 7y ago
    > but in practice I guess a short-range device like this isn't going to do much more than maybe piss off the neighbours. Don't forget the option to transmit into a dummy load (or to a radio receiver and/or a spectrum analyzer with a 30 dB in-line attenuator). It allows one to experiment with "illegal" radio setup. Although the transmitter itself still has RF leakage and may still violate radio regulations, it's much less disruptive (and technically you can make it perfectly legal if good shielding is added).