4 ms·

On a similar note, I remember the FCC ordering a Bitcoin miner to turn off mining hardware that was emitting 700MHz and disrupting T-Mobile’s network.[1] [1] h

On a similar note, I remember the FCC ordering a Bitcoin miner to turn off mining hardware that was emitting 700MHz and disrupting T-Mobile’s network.[1] [1] https://arstechnica.com/information-technology/2018/02/bitcoin-miner-in-nyc-home-interfered-with-t-mobile-network-fcc-says/ https://arstechnica.com/information-technology/2018/02/bitco...

brutusborn 6y ago
I wonder if it would be feasible to build a faraday cage around the miners. A few sheets of metallic cloth and a wooden frame wouldn't be too expensive. https://www.ebay.com.au/i/184562911018?chn=ps&norover=1&mkevt=1&mkrid=705-139619-5960-0&mkcid=2&itemid=184562911018&targetid=920064925573&device=m&mktype=pla&googleloc=9070553&poi=&campaignid=10101785231&mkgroupid=102311926940&rlsatarget=pla-920064925573&abcId=9300368&merchantid=7364522&gclid=CjwKCAiAoOz-BRBdEiwAyuvA653zbutoU2N-8z9tnGow3nHDk3oEv_pXul4us8X9Mxtzd47xVB8LbhoC9SMQAvD_BwE https://www.ebay.com.au/i/184562911018?chn=ps&norover=1&mkev...
- Johnythree 6y ago
  Faraday cages are a bit of a myth. Unless the metal sheet is continuous with no gaps, and there are no wires passing through the sheet, they will be ineffective. It means that all joints must be screwed or soldered, all doors to have tight joints, and low-pass filters fitted to all power leads, comms leads, etc. And often you need two completely independent layers (connected at only one point) to achieve sufficient attenuation.
  - EarthIsHome 6y ago
    > Faraday cages are a bit of a myth. Unless the metal sheet is continuous with no gaps, and there are no wires passing through the sheet, they will be ineffective. Your microwave oven's cage would like to have a word with you. You can have an effective faraday cage using a metal fence/mesh depending on the frequency you're trying to attenuate and the thickness of the metal. [0] [0]: https://www.quora.com/What-size-of-mesh-should-I-use-to-build-a-Faraday-cage?share=1 https://www.quora.com/What-size-of-mesh-should-I-use-to-buil...
    - im3w1l 6y ago
      So from what I understand an important part of microwave operation is food soaking up the waves. Never heard any other faraday cages use absorption. Kinda wonder why not.
      - skykooler 6y ago
        Not really. You can test this by running the microwave with no food in it and noting that you don't lose wifi connection while that happens.
        im3w1l 6y ago
        I heard it will damage the microwave. My current one detects the situation and refuses to start actually. And my old one would glitch the wifi with or without food lol.
      - throwaway09223 6y ago
        Have you never wondered why there is a metal mesh across the glass in your microwave? The microwave's faraday cage is visible.
    - ThrowawayR2 6y ago
      The GP poster is actually correct; I work with RF engineers. Yes, Faraday cages work but, having tried it, my colleagues have attested that it's much harder to homebrew a fully effective Faraday cage than the average HNer would think, at least in the frequency range we work in. The types of mitigations described by the GP poster are also correct: see, for example, the description of issues for EMI shielding at https://celectronics.com/training/learning/basics/Noise-Propagation.md.html https://celectronics.com/training/learning/basics/Noise-Prop... > "These imperfections are: (1) openings (2) conductors going in or out and (3) finite thickness of the shield"
      - throwaway09223 6y ago
        Faraday cages are imperfect and designing a high quality cage does take work but GP is absolutely incorrect in that they are a "myth," or that they would be ineffective without precision engineering. 700MHz is a 42cm wave. A hole 1/10th of the wavelength is about an inch and a half. Not exactly tight tolerances. Perfection generally isn't necessary - mitigation is usually sufficient. Reducing the interference signal by some percentage (likely a very, very high percentage) goes a long way. Dropping a wire cage around a device broadcasting in the 700MHz band is going to very significantly reduce the signal.

brutusborn 6y ago

I wonder if it would be feasible to build a faraday cage around the miners. A few sheets of metallic cloth and a wooden frame wouldn't be too expensive. https://www.ebay.com.au/i/184562911018?chn=ps&norover=1&mkevt=1&mkrid=705-139619-5960-0&mkcid=2&itemid=184562911018&targetid=920064925573&device=m&mktype=pla&googleloc=9070553&poi=&campaignid=10101785231&mkgroupid=102311926940&rlsatarget=pla-920064925573&abcId=9300368&merchantid=7364522&gclid=CjwKCAiAoOz-BRBdEiwAyuvA653zbutoU2N-8z9tnGow3nHDk3oEv_pXul4us8X9Mxtzd47xVB8LbhoC9SMQAvD_BwE https://www.ebay.com.au/i/184562911018?chn=ps&norover=1&mkev...

Johnythree 6y ago
Faraday cages are a bit of a myth. Unless the metal sheet is continuous with no gaps, and there are no wires passing through the sheet, they will be ineffective. It means that all joints must be screwed or soldered, all doors to have tight joints, and low-pass filters fitted to all power leads, comms leads, etc. And often you need two completely independent layers (connected at only one point) to achieve sufficient attenuation.
- EarthIsHome 6y ago
  > Faraday cages are a bit of a myth. Unless the metal sheet is continuous with no gaps, and there are no wires passing through the sheet, they will be ineffective. Your microwave oven's cage would like to have a word with you. You can have an effective faraday cage using a metal fence/mesh depending on the frequency you're trying to attenuate and the thickness of the metal. [0] [0]: https://www.quora.com/What-size-of-mesh-should-I-use-to-build-a-Faraday-cage?share=1 https://www.quora.com/What-size-of-mesh-should-I-use-to-buil...
  - im3w1l 6y ago
    So from what I understand an important part of microwave operation is food soaking up the waves. Never heard any other faraday cages use absorption. Kinda wonder why not.
    - skykooler 6y ago
      Not really. You can test this by running the microwave with no food in it and noting that you don't lose wifi connection while that happens.
      - im3w1l 6y ago
        I heard it will damage the microwave. My current one detects the situation and refuses to start actually. And my old one would glitch the wifi with or without food lol.
    - throwaway09223 6y ago
      Have you never wondered why there is a metal mesh across the glass in your microwave? The microwave's faraday cage is visible.
  - ThrowawayR2 6y ago
    The GP poster is actually correct; I work with RF engineers. Yes, Faraday cages work but, having tried it, my colleagues have attested that it's much harder to homebrew a fully effective Faraday cage than the average HNer would think, at least in the frequency range we work in. The types of mitigations described by the GP poster are also correct: see, for example, the description of issues for EMI shielding at https://celectronics.com/training/learning/basics/Noise-Propagation.md.html https://celectronics.com/training/learning/basics/Noise-Prop... > "These imperfections are: (1) openings (2) conductors going in or out and (3) finite thickness of the shield"
    - throwaway09223 6y ago
      Faraday cages are imperfect and designing a high quality cage does take work but GP is absolutely incorrect in that they are a "myth," or that they would be ineffective without precision engineering. 700MHz is a 42cm wave. A hole 1/10th of the wavelength is about an inch and a half. Not exactly tight tolerances. Perfection generally isn't necessary - mitigation is usually sufficient. Reducing the interference signal by some percentage (likely a very, very high percentage) goes a long way. Dropping a wire cage around a device broadcasting in the 700MHz band is going to very significantly reduce the signal.