RF diffraction and wind turbine

Discussion in 'Wireless & RF Design' started by Allumiin, Jun 16, 2016.

  1. Allumiin

    Thread Starter New Member

    Jun 5, 2016
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    Hello everybody, speaking on behalf of someone I know.
    He has a question regarding RF diffraction and wind turbines. Specifically a wind turbine cannot be built near a radio station (or vise versa), if the turbine total height and station antenna height dont heed to a formula. The formula is in the attachment.
    Where N-minimum distance between wind turbine and radio station, in kilometers
    h1- length of the radio station antenna, in meters
    h2- length of the maximum turbine height (including the blade), in meters
    His question is: does this formula hold any scientific merit, or is this something made up randomly ?
    Thank you for reading
     
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    This could be a spoof, since why not use the simpler factor 2.06 instead of 4.12/2? Also, plug in some numbers and see if the answer is reasonable: I don't think it is. For example, if you built a 1m high mini-turbine, would it really have to be 4.12 kilometres from a 1m high antenna?
    Can you post a link to the source including the formula?
     
  3. Allumiin

    Thread Starter New Member

    Jun 5, 2016
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    I'm afraid thats about it, this is sort of taken from a certain law and regulations page in my country, the one who I speak for has a suspicion that this formula is pretty much made up by someone at some time and has no right to exist in the regulations. He just wants a second opinion, if this formula holds any sort of merit, at all.
     
  4. BR-549

    Well-Known Member

    Sep 22, 2013
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    Contact your windmill permitting agency. I'm quite sure they know the requirements. Ask for the engineer in charge.
     
  5. nsaspook

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  6. Alec_t

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    Sep 17, 2013
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    It would be interesting to see the page.
     
  7. DickCappels

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    Aug 21, 2008
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    The concept has merit. Cannot comment on the formula.
     
  8. GopherT

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    Nov 23, 2012
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    There is plenty of information on-line about wind turbines interfering with radar and radio communications. Qinetic (UK) and Lockeed-Martin have done research about masking / absorbing radar signals to prevent false signals from wind turbines on air traffic control radar systems. A major problem before regulations were put in place. So many permanent false echoes were a real distraction for air traffic controllers.

    Similar strobing of signals can occur on the broadcast side of EM signals. As said above, the formula is open for debate.
    A 60m wind turbine and 100m tower produce laughable results.
     
  9. GopherT

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    Nov 23, 2012
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  10. tcmtech

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    Nov 4, 2013
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    Either it's not an issue or the people here don't know about it being we have a wind farm with a number of cell phone towers around it plus a number of our primary local radio and TV transmitter towers a few miles off from it as well.
     
  11. BR-549

    Well-Known Member

    Sep 22, 2013
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    tcmtech, do you notice problems with your signals?
     
  12. markdem

    Member

    Jul 31, 2013
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    I just had to post this...

    windmill_small.jpg
     
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  13. tcmtech

    Well-Known Member

    Nov 4, 2013
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    No.

    I see no reason they would interfere. The blades are largely fiberglass which is transparent to RF signals and the towers are of no major difference in size or spacing than common steel HV power line towers.
     
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  14. GopherT

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    Nov 23, 2012
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    I d.....erstan....ay you....ound....at..interes...
     
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