Results 1 to 15 of 15

Thread: How powerful would a radio signal have to be to feel it as vibrations on the skin?

  1. #1

    Default How powerful would a radio signal have to be to feel it as vibrations on the skin?

    Hi,

    How powerful would a radio signal have to be to feel it as vibrations on the skin?

    Is there a way to measure the presence of any radio signals in a given area i.e. the room of a house?


  2. #2
    Super Moderator 5B4AJB's Avatar
    Join Date
    Mar 2008
    Location
    Meneou, Cyprus
    Posts
    2,068

    Default

    Quote Originally Posted by Health&Footwear View Post
    How powerful would a radio signal have to be to feel it as vibrations on the skin?
    It really depends on the frequency - it'd have to be pretty high, say, microwave and also pulsed to feel like vibrations.

    Quote Originally Posted by Health&Footwear View Post
    Is there a way to measure the presence of any radio signals in a given area i.e. the room of a house?
    Yes, it's called a field strength meter, an incredibly simple circuit you can make for next to nothing...
    Last edited by 5B4AJB; Tue 6th Feb 2018 at 19:48.

  3. #3

    Default

    I agree a field strength meter would do it.
    Every ham who homebrews ought to have one, that in conjunction with an antenna analyzer is essential to really know what your antenna is doing. IMO

  4. #4

    Default

    I'm assuming you are asking because you believe you can feel it, and suspect it might be high in your room, maybe because of a local source?

    Radio waves will either pass through you, or be absorbed. If they are absorbed the energy has to go somewhere and it gets converted to heat - this is how your microwave works. 700W of radio energy gets squirted into your oven, and that's what cooks the food. If you were stupid enough to punch a hole in the door, it would escape, but it disappears quickly - If it measured as 10 units a foot away from the oven, if you move the meter to 2 feet, it would be 2.5, and then at 4 ft it's down to .625, and at 8ft it less than .2 - so it runs out of steam very quickly.

    Radio waves less than 600MHz or so are not considered capable of heating unless they are VERY strong, like standing next to the antennas of a Radio 2 transmitter. Above 600MHz you would feel it heating you - so standing in front of a 10MEGA Watt radar would be toasty very quickly, but living across the road from the Radio 2 transmitter would be hard to measure.

    RF will burn if very strong, which obviously hurts but you do not feel pulsing, or tingling - or at least, I never have when working with it. It's essentially electrical AND magnetic energy - so metallic objects can be affected. Humans are mostly water, so we are pretty good at stopping radio waves passing through us. Certain parts of your body can be damaged by microwave , or close to microwave energy - your eyes, in particular, but people who work with this kind of thing use distance as their first line of defence - but its standard to power transmitters down when working ion aerial systems unless they are low power. Low power in this context is linked to frequency. 400W from a radio hams HF radio wouldn't bother me too much, although some of the antenna parts can be quite high voltage, and the chances of a shock are certainly possible. 400W from a microwave oven with the hole in the door would have me avoiding being in the room. The high power signals from cellphone towers is not something to be happy with climbing up a ladder, but across the rd? No problem.

    What's the background to your question - sounds interesting?

  5. #5
    K7KBN's Avatar
    Join Date
    Jul 2008
    Location
    Bremerton WA USA
    Posts
    1,326

    Default

    To feel it "as vibrations on the skin", you wouldn't have to go much above a few kilohertz. Even then, it wouldn't be a "radio" signal but an audio frequency generator source. Unless I'm completely misunderstanding what you want.

    Do you want to be able to feel the individual "vibrations"?
    73
    Pat K7KBN
    Semper ubi sub ubi.

  6. #6

    Default

    I'm thinking he feels vibrations on the skin and wishes to link this to the possibility of radio waves causing it - which of course is something quite different.

  7. #7

    Default

    Sounds like another one of those hippies from California.

    If RF bothers you, my advice is to get rid of your cell phone, because it is more harmful then RF from say a 50 watt / 2 meter radio.

    That is why there is RF limits imposed when near human exposure. That is why a 2m mobile is only 50 watts, so you don't have to take exposure measurements and keep a log of when you operate. The only RF other than microwave that will harm you is 30 and 60 meters - since it can couple with your body and stop your heart or cause irregular rhythm.

  8. #8

    Default

    eh? two specific danger bands? How does this work then? Please explain the coupling and heart impact. Never heard this before.

  9. #9

    Join Date
    Nov 2017
    Location
    With my wife
    Posts
    73

    Default

    Quote Originally Posted by Sixmeters View Post
    Sounds like another one of those hippies from California.

    If RF bothers you, my advice is to get rid of your cell phone, because it is more harmful then RF from say a 50 watt / 2 meter radio.

    That is why there is RF limits imposed when near human exposure. That is why a 2m mobile is only 50 watts, so you don't have to take exposure measurements and keep a log of when you operate. The only RF other than microwave that will harm you is 30 and 60 meters - since it can couple with your body and stop your heart or cause irregular rhythm.
    Citations please.

  10. #10

    Default

    A heavy truck driving by your home/house/apartment or a mini-earthquake is more likely to cause such vibrations than a radio.
    --
    73, Jim/N4AAB/AE got my Extra class license in Aug 10, 2017. Vanity call in Oct, 2014.
    Ham radio site has no popups, no music, no huge banners.
    'Through the thorns to the stars' from Ghost-in-the-Shell anime.

  11. #11

  12. #12

  13. #13

  14. #14

    Join Date
    Nov 2017
    Location
    With my wife
    Posts
    73

    Default

    That's nice, but nowhere did I see 30 or 60 meters singled out as "coupling with your heart rhythm".

  15. #15

    Default

    "Despite the advent of numerous additional research studies on RF fields and health, the only established adverse health effects associated with RF field exposures in the frequency range from 3 kHz to 300 GHz relate to the occurrence of tissue heating and nerve stimulation (NS) from short-term (acute) exposures. At present, there is no scientific basis for the occurrence of acute, chronic and/or cumulative adverse health risks from RF field exposure at levels below the limits outlined in Safety Code 6. The hypotheses of other proposed adverse health effects occurring at levels below the exposure limits outlined in Safety Code 6 suffer from a lack of evidence of causality, biological plausibility and reproducibility and do not provide a credible foundation for making science-based recommendations for limiting human exposures to low-intensity RF fields".


    The above are quotes from the articles you listed....there is nothing contained in the articles to support the health risks you claimed...
    and it is also interesting to note that in any of the listed field strength testing, the max distance one needed to be from the transmitting antenna at 50 KW was around 10 meters....so it would appear that to run any risk at all one would basically have to be a professional working at a station that produced over 50 KW and stand less than 10 meters away from a transmitting antenna for long periods of time to run any risk....and of course from reading your previous posts I would believe that if the antenna were truly resonant the health risk would be virtually eliminated.

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •