6 ms·

Even better: some crazy Russian/Ukrainian kids listening to the local radio station through weeds (and occasionally getting some minor RF burns): https://www.yo

Even better: some crazy Russian/Ukrainian kids listening to the local radio station through weeds (and occasionally getting some minor RF burns): https://www.youtube.com/watch?v=82s5Q3GIO9I https://www.youtube.com/watch?v=82s5Q3GIO9I

voltagex_ 11y ago
I don't think I'd want even minor RF burns - nasty nasty stuff.
- therein 11y ago
  What makes it worse than just a burn or a burn due to an electrical shock?
  - voltagex_ 11y ago
    I can't find the reference but a ham operator once told me they can be imperceptible while they're happening.
  - tjohns 11y ago
    Normal burns are usually localized to the surface of your skin. RF burns conduct all the way through your tissue, heating from the inside. It's a much deeper, more painful burn that takes an abnormally long time to heal. (Or so I'm told. So far I've been able to avoid experiencing one myself.)
    - jacquesm 11y ago
      Unfortunately I wasn't able to avoid the experience, I hit the screw on a silver trimmer in an end stage while looking at another one. Nasty little burn with dead tissue in the center and living tissue all around it. 35 years later it is still there, I don't expect that it will ever properly heal, it's a dead bit in the middle of a living finger.
      - scruple 11y ago
        Yep, I have a RF burns on 2 of my finger tips that I sustained between 5 and 10 years ago... They are dead little bits of flesh. Discolored a deep yellow, there is no feeling left and they feel, I guess I'd describe it as, quasi-numb when touched. I was an embedded engineer at an RF company and it sort of comes with the territory. We had technicians who had lasted 4+ decades in RF (same company, actually) with scars to show for it. Same story, mostly on their fingers from accidentally hitting hot spots.
        HeyLaughingBoy 11y ago
        What was the power level? We do a lot of RF stuff here and it would be good to know that we're safe.
        jacquesm 11y ago
        I got mine at about 100W from a Tronser trimmer.
        scruple 11y ago
        It really depends on a lot of different factors. Single-digit Watt levels can burn you under the right conditions, though obviously it wouldn't be as severe as at higher power levels. I was burned by ~300W in the specific cases I mentioned. I think it probably classifies as second-degree burns and (because I was young and dumb) I never did anything to help prevent scarring or heal the tissue besides basic first-aid. Safety first, everything else is secondary.
    - derefr 11y ago
      You mean they conduct from the entry-point to ground, similar to a lightning strike or electrical burn? Or is this more like a radiation burn? Actually, now that I think about it, it'd actually be most similar to how a microwave heats meat, wouldn't it? Microwaves being within the RF part of the EM spectrum and all. (Though not quite the same, given the lack of dipole interaction with water molecules outside of the particular part of the spectrum microwaves sit on.)
      - 50CNT 11y ago
        That reminds me of an urban legend regarding microwaves, which doesn't seem entirely infeasible. It involves a man working at a small fast food stand, who worked next to his microwave. Now his microwave was used often, and it had a small hole in the metal screen allowing microwave radiation to leak out. The man slowly starts to feel abdominal pains after a while, goes to his doctor, who diagnoses it as liver problems and recommends drinking less. A couple of months later, the man has died, and the autopsy reveals that parts of his liver were cooked. I was told this story by my grandmother to prevent me from watching food cook in the microwave. That and cataracts, which can also be caused by heating up things that shouldn't be heated.
        runarb 11y ago
        There is also the story of Anatoli Bugorski. He was debugging the worlds most powerful particle accelerator when he managed to look into the beam: http://www.strangerdimensions.com/2014/01/13/anatoli-bugorski-man-survived-proton-beam/ http://www.strangerdimensions.com/2014/01/13/anatoli-bugorsk...
        kuschku 11y ago
        And he’s become part of popular culture due to the annual satirical year in review panel at the C3 congress giving out the fictional "Anatoli Bugorski Award for applied nuclear safety".
        StavrosK 11y ago
        That doesn't sound very feasible. Microwaves work by standing waves, the magnetron doesn't just cook things when outside the oven.
  - topspin 11y ago
    Disclaimer: I am not a doctor or burn expert of any sort. I am an extra class ham. An RF burn will penetrate more deeply than a "conventional" burn of similar degree, possibly burning nerve cells, circulatory and other structures that an external burn would not. RF burns typically heal very slowly. I can't compare RF burns to burns caused by electrical current, except to say that electrical current will follow some path of least resistance while RF energy will heat flesh in a pattern corresponding to the field of the radiator and the impedance of the whatever matter absorbs it, so these types of burns will have different patterns.
    - tyingq 11y ago
      Also, RF energy is more damaging to tissues that lack blood flow to control heat. Like eyeballs, and testicles.
      - Florin_Andrei 11y ago
        Right, but for that to happen you'd have to stick your... uh... various balls directly into the path of the RF field. Like at the business end of a big RF horn antenna.
    - cocoablazing 11y ago
      The skin effect should result in a high-frequency AC current propagating at lower tissue depths than a lower-frequency AC current. Why would RF AC propagating in flesh not follow this general rule?
      - topspin 11y ago
        We're getting beyond my depth here, but a few things occur to me. First, I know microwaves `work'; the optimal frequency at which water exhibits the skin effect is about 10GHz, so at 2.45GHz the energy from a microwave oven penetrates meat effectively instead of only frying the surface, as one would expect if the skin effect dominated. Also, I suspect the skin effect could actually cause internal burns; an internal organ that exhibits a strong skin effect at some frequency will cause localized heating on its surface, burning tissue internally.
  - raverbashing 11y ago
    It's basically like putting your hand inside a microwave oven
batat 11y ago
It's abandoned radio station in Brovary, Ukraine, I've been there several times. There were two antennas — 180 m and 270 m with 100 and 150 kwt transmitters (later up to 250 kwt). Until 1988 they were used for radio jamming (BBC, Voice of America, Deutsche Welle), later for radio broadcasting [1] AFAIK you could get serious burns [2][3] even when antenna was not powered any more. In this case it works just like huge receiving antenna, getting kilowatts of RF energy directly from atmosphere. Before the thunderstorm ropes holding the antenna literally glowed due to corona discharge effect. A few years ago both antennas were demolished [4][5] [1] http://vk.cc/4LQeGa http://vk.cc/4LQeGa (wiki, Ukrainian) [2] http://io.ua/20405915p http://io.ua/20405915p [3] http://io.ua/20405932p http://io.ua/20405932p [4] https://www.youtube.com/watch?v=j6NgzzFrCv4 https://www.youtube.com/watch?v=j6NgzzFrCv4 [5] https://www.youtube.com/watch?v=Pn6sLpDS0Ks https://www.youtube.com/watch?v=Pn6sLpDS0Ks
- hippich 11y ago
  Regarding "AFAIK you could get serious burns [2][3] even when antenna was not powered any more", does it mean I can get "free" electricity from "thin air"? Did someone try this already?
  - upofadown 11y ago
    You sure can. The normal fair weather voltage gradient in the atmosphere is around 100V per metre. When there are close thunderstorms this increases. Unfortunately for energy collection air is quite insulative. That's also fortunate in that we don't get shocks all the time just from standing around in an environment where your head is 200V different than your feet. Popular Science once ran an article that showed how to build an electrostatic motor that ran off the atmospheric electricity you could get with something like a wire used as a kite string. * https://en.wikipedia.org/wiki/Atmospheric_electricity https://en.wikipedia.org/wiki/Atmospheric_electricity
    - jonahx 11y ago
      What's required for a tower to become electrified from the air? I feel like I've played on other metal towers in my life that were inert...
StavrosK 11y ago
Wait, is that thing just lightly fenced and casually has this much current flowing through it? Isn't that basically a death trap?

voltagex_ 11y ago

I don't think I'd want even minor RF burns - nasty nasty stuff.

therein 11y ago
What makes it worse than just a burn or a burn due to an electrical shock?
- voltagex_ 11y ago
  I can't find the reference but a ham operator once told me they can be imperceptible while they're happening.
- tjohns 11y ago
  Normal burns are usually localized to the surface of your skin. RF burns conduct all the way through your tissue, heating from the inside. It's a much deeper, more painful burn that takes an abnormally long time to heal. (Or so I'm told. So far I've been able to avoid experiencing one myself.)
  - jacquesm 11y ago
    Unfortunately I wasn't able to avoid the experience, I hit the screw on a silver trimmer in an end stage while looking at another one. Nasty little burn with dead tissue in the center and living tissue all around it. 35 years later it is still there, I don't expect that it will ever properly heal, it's a dead bit in the middle of a living finger.
    - scruple 11y ago
      Yep, I have a RF burns on 2 of my finger tips that I sustained between 5 and 10 years ago... They are dead little bits of flesh. Discolored a deep yellow, there is no feeling left and they feel, I guess I'd describe it as, quasi-numb when touched. I was an embedded engineer at an RF company and it sort of comes with the territory. We had technicians who had lasted 4+ decades in RF (same company, actually) with scars to show for it. Same story, mostly on their fingers from accidentally hitting hot spots.
      - HeyLaughingBoy 11y ago
        What was the power level? We do a lot of RF stuff here and it would be good to know that we're safe.
        jacquesm 11y ago
        I got mine at about 100W from a Tronser trimmer.
        scruple 11y ago
        It really depends on a lot of different factors. Single-digit Watt levels can burn you under the right conditions, though obviously it wouldn't be as severe as at higher power levels. I was burned by ~300W in the specific cases I mentioned. I think it probably classifies as second-degree burns and (because I was young and dumb) I never did anything to help prevent scarring or heal the tissue besides basic first-aid. Safety first, everything else is secondary.
  - derefr 11y ago
    You mean they conduct from the entry-point to ground, similar to a lightning strike or electrical burn? Or is this more like a radiation burn? Actually, now that I think about it, it'd actually be most similar to how a microwave heats meat, wouldn't it? Microwaves being within the RF part of the EM spectrum and all. (Though not quite the same, given the lack of dipole interaction with water molecules outside of the particular part of the spectrum microwaves sit on.)
    - 50CNT 11y ago
      That reminds me of an urban legend regarding microwaves, which doesn't seem entirely infeasible. It involves a man working at a small fast food stand, who worked next to his microwave. Now his microwave was used often, and it had a small hole in the metal screen allowing microwave radiation to leak out. The man slowly starts to feel abdominal pains after a while, goes to his doctor, who diagnoses it as liver problems and recommends drinking less. A couple of months later, the man has died, and the autopsy reveals that parts of his liver were cooked. I was told this story by my grandmother to prevent me from watching food cook in the microwave. That and cataracts, which can also be caused by heating up things that shouldn't be heated.
      - runarb 11y ago
        There is also the story of Anatoli Bugorski. He was debugging the worlds most powerful particle accelerator when he managed to look into the beam: http://www.strangerdimensions.com/2014/01/13/anatoli-bugorski-man-survived-proton-beam/ http://www.strangerdimensions.com/2014/01/13/anatoli-bugorsk...
        kuschku 11y ago
        And he’s become part of popular culture due to the annual satirical year in review panel at the C3 congress giving out the fictional "Anatoli Bugorski Award for applied nuclear safety".
      - StavrosK 11y ago
        That doesn't sound very feasible. Microwaves work by standing waves, the magnetron doesn't just cook things when outside the oven.
- topspin 11y ago
  Disclaimer: I am not a doctor or burn expert of any sort. I am an extra class ham. An RF burn will penetrate more deeply than a "conventional" burn of similar degree, possibly burning nerve cells, circulatory and other structures that an external burn would not. RF burns typically heal very slowly. I can't compare RF burns to burns caused by electrical current, except to say that electrical current will follow some path of least resistance while RF energy will heat flesh in a pattern corresponding to the field of the radiator and the impedance of the whatever matter absorbs it, so these types of burns will have different patterns.
  - tyingq 11y ago
    Also, RF energy is more damaging to tissues that lack blood flow to control heat. Like eyeballs, and testicles.
    - Florin_Andrei 11y ago
      Right, but for that to happen you'd have to stick your... uh... various balls directly into the path of the RF field. Like at the business end of a big RF horn antenna.
  - cocoablazing 11y ago
    The skin effect should result in a high-frequency AC current propagating at lower tissue depths than a lower-frequency AC current. Why would RF AC propagating in flesh not follow this general rule?
    - topspin 11y ago
      We're getting beyond my depth here, but a few things occur to me. First, I know microwaves `work'; the optimal frequency at which water exhibits the skin effect is about 10GHz, so at 2.45GHz the energy from a microwave oven penetrates meat effectively instead of only frying the surface, as one would expect if the skin effect dominated. Also, I suspect the skin effect could actually cause internal burns; an internal organ that exhibits a strong skin effect at some frequency will cause localized heating on its surface, burning tissue internally.
- raverbashing 11y ago
  It's basically like putting your hand inside a microwave oven

batat 11y ago

It's abandoned radio station in Brovary, Ukraine, I've been there several times. There were two antennas — 180 m and 270 m with 100 and 150 kwt transmitters (later up to 250 kwt). Until 1988 they were used for radio jamming (BBC, Voice of America, Deutsche Welle), later for radio broadcasting [1] AFAIK you could get serious burns [2][3] even when antenna was not powered any more. In this case it works just like huge receiving antenna, getting kilowatts of RF energy directly from atmosphere. Before the thunderstorm ropes holding the antenna literally glowed due to corona discharge effect. A few years ago both antennas were demolished [4][5] [1] http://vk.cc/4LQeGa http://vk.cc/4LQeGa (wiki, Ukrainian) [2] http://io.ua/20405915p http://io.ua/20405915p [3] http://io.ua/20405932p http://io.ua/20405932p [4] https://www.youtube.com/watch?v=j6NgzzFrCv4 https://www.youtube.com/watch?v=j6NgzzFrCv4 [5] https://www.youtube.com/watch?v=Pn6sLpDS0Ks https://www.youtube.com/watch?v=Pn6sLpDS0Ks

hippich 11y ago
Regarding "AFAIK you could get serious burns [2][3] even when antenna was not powered any more", does it mean I can get "free" electricity from "thin air"? Did someone try this already?
- upofadown 11y ago
  You sure can. The normal fair weather voltage gradient in the atmosphere is around 100V per metre. When there are close thunderstorms this increases. Unfortunately for energy collection air is quite insulative. That's also fortunate in that we don't get shocks all the time just from standing around in an environment where your head is 200V different than your feet. Popular Science once ran an article that showed how to build an electrostatic motor that ran off the atmospheric electricity you could get with something like a wire used as a kite string. * https://en.wikipedia.org/wiki/Atmospheric_electricity https://en.wikipedia.org/wiki/Atmospheric_electricity
  - jonahx 11y ago
    What's required for a tower to become electrified from the air? I feel like I've played on other metal towers in my life that were inert...

StavrosK 11y ago

Wait, is that thing just lightly fenced and casually has this much current flowing through it? Isn't that basically a death trap?