4 ms·

60kHz isn't really an audio source, at that frequency it would (or used to be, anyway) be classified as an RF source. Marconi operated in frequencies even lowe

60kHz isn't really an audio source, at that frequency it would (or used to be, anyway) be classified as an RF source. Marconi operated in frequencies even lower, 14-30kHz, at many thousands of watts from Alexanderson alternators[0]. Dogs were not happy near these stations. https://en.wikipedia.org/wiki/Alexanderson_alternator https://en.wikipedia.org/wiki/Alexanderson_alternator edit: added link, lowered frequency range.

tomxor 7y ago
> 60kHz isn't really an audio source, at that frequency it would (or used to be, anyway) be classified as an RF source. It would not be classified as an RF source. Frequency does not redefine the medium. Sounds waves above 20KHz are usually referred to as ultrasound, but it is still sound. More specifically, it is still a compression wave in matter. EM waves are a completely different medium. I presume you are conflating the two through the existence of this machine, the mechanical nature of it's source of oscillation no doubt created compression waves in the air of the same frequency as a side effect (Pretty sure Dogs don't have RF receivers). Whereas now we use solid state oscillators, and so your dog doesn't care about your various RF devices.
- creeble 7y ago
  I conflate the two because I was temporarily nuts. Doh! Of course ultrasound exists, and can exist in air up to the GHz range (not for very far). Anyway, sorry for misinfo and thanks for the correction.
  - tomxor 7y ago
    No worries. It's probably not helped by the fact that RF starts at around 20 KHz in EM at the same frequency where human hearing range ends in sound waves. So it's fairly easy to read a bunch of statements about frequency ranges and then mix up mediums, especially when EM contains a bunch of seemingly very different things, light, RF, xrays etc.

4 ms·

60kHz isn't really an audio source, at that frequency it would (or used to be, anyway) be classified as an RF source. Marconi operated in frequencies even lowe

by creeble 7y ago

tomxor 7y ago
> 60kHz isn't really an audio source, at that frequency it would (or used to be, anyway) be classified as an RF source. It would not be classified as an RF source. Frequency does not redefine the medium. Sounds waves above 20KHz are usually referred to as ultrasound, but it is still sound. More specifically, it is still a compression wave in matter. EM waves are a completely different medium. I presume you are conflating the two through the existence of this machine, the mechanical nature of it's source of oscillation no doubt created compression waves in the air of the same frequency as a side effect (Pretty sure Dogs don't have RF receivers). Whereas now we use solid state oscillators, and so your dog doesn't care about your various RF devices.
- creeble 7y ago
  I conflate the two because I was temporarily nuts. Doh! Of course ultrasound exists, and can exist in air up to the GHz range (not for very far). Anyway, sorry for misinfo and thanks for the correction.
  - tomxor 7y ago
    No worries. It's probably not helped by the fact that RF starts at around 20 KHz in EM at the same frequency where human hearing range ends in sound waves. So it's fairly easy to read a bunch of statements about frequency ranges and then mix up mediums, especially when EM contains a bunch of seemingly very different things, light, RF, xrays etc.