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B Frequencies -- what is the average frequency for the human body?

  1. Dec 25, 2016 #1
    Hi all,

    Would anyone be able to let me know what the average frequency is for the human body?

    Also, what is the average frequency of a home? What would be considered abnormal?

    According to the Ofcom UK Frequency Allocation Table it notes different frequency uses e.g. a frequency of 1,600 MHz is for certain military/research purposes only.

    It also notes that 0-8,000 Hz is unallocated. Does anyone know why this is or what this means?

    Thank you in advance.
     
  2. jcsd
  3. Dec 25, 2016 #2

    Orodruin

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    Frequency of what in the human body? Frequency of what in a home?

    A frequency tells you very little without reference to what it is the frequency of.
     
  4. Dec 25, 2016 #3

    davenn

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    Hi susan

    welcome to PF :smile:

    as was hinted at in the previous response .... neither of these comments of yours make any sense


    1,600 (1.6GHz) may well be used for that purpose in the UK and maybe world wide.
    Most countries have frequency allocation tables and again in MOST cases they fall into line with other countries around the world
    that is because they all fall under the banner (leadership) of the ITU so that there is a standard use of the radio spectrum world wide
    On the whole, it works well with only a few variations in uses between different countries.

    https://en.wikipedia.org/wiki/International_Telecommunication_Union


    Frequencies below around 10 kHz are full of manmade and natural environmental radio noise. This makes their use for communications almost impossible because of all that background noise


    Dave
     
  5. Dec 25, 2016 #4

    Drakkith

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    A big, huge, very important note: this refers to the frequency of the electromagnetic radiation used in modern electronic devices. This EMR is mostly used in communications but also includes things like radar.

    Neither your house nor your body is an electronic device and as such cannot be placed anywhere on the frequency allocation table. Any references you find in papers or articles about the frequency of the human body are either talking about something else other than EMR, perhaps the resonant mechanical frequency, or are crackpot papers/articles trying to get you to believe in their pet theory.

    At that low of a frequency, the wavelength of the EMR becomes enormous and it becomes extremely difficult to efficiently generate or use this EMR. The frequency is also too low to use for almost all communications, as you can't even fit a single voice channel on an 8 kHz carrier signal. I believe they can use this band for submarine communication, as it will penetrate far enough into the water for a sub to detect, but the data rate is abysmal and only used for text-based communication.
     
  6. Dec 26, 2016 #5

    CWatters

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    There are quite a lot of web sites that make out everything has a "natural frequency" or "vibration". If you have been reading those then I'm afraid 99% of it is total nonsense.

    Parts of the radio frequency spectrum are allocated to particular users or uses for many reasons. For example you wouldn't want a pop radio station interfering with Air Traffic Control or the ambulance service so these typically all have their own allocated frequencies.

    Unallocated frequencies are either free for anyone to use or aren't allocated because they are virtually impossible to use. As Drakkith said it can be very hard to transmit a signal in the 0-8,000 Hz band. Typically to transmit or receive a signal you need an aerial that is around 1/4 of the wavelength or larger and the wavelength of an 8000Hz signal would be something like 37 kilometers. Typical radio stations use frequencies around 100MHz and their wavelength would be about 3 meters and the aerial less than 1m long.
     
  7. Dec 26, 2016 #6

    CWatters

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    One advantage of extremely low frequency radio signals is that they penetrate water to a usable depth. This makes them potentially interesting for communicating with submarines..

    https://en.wikipedia.org/wiki/Communication_with_submarines#Extremely_low_frequency

    These days they use satellites and the submarines send up an antenna on a buoy if they want to remain submerged.
     
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