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does wavelength determine height of antenna

Discussion in 'Radio and Communications' started by bhuvaneshnick, Jun 18, 2014.

  1. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Yes, I used a couple of 2M rigs for doing a TV aerial job once (we had to fit the aerial at the top of a hill and cable down through an old quarry and a wood, so communications was helpful) :D

    I simply stripped 19 inches off the end of a piece of coax, and separated the inner and screen to make a simple dipole :p
     
  2. magvitron

    magvitron Active Member

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    From experience a micro strip patch antenna with center frequency 866 Mhz with 10 mhz bandwidth was about 20 cm by 20cm @~8 dBm directive.:confused:
     
  3. JimB

    JimB Super Moderator Most Helpful Member

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    Please explain what that statement means.
    JimB
     
  4. dave

    Dave New Member

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  5. magvitron

    magvitron Active Member

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    The antenna has got a "directive" gain of about 8 Decibel meter. The simulation result of that particular antenna is attached.
    A quick goog-fu had this , thank god for google, else I would have to get down with the latex editor.

    antenna.jpg
     
  6. JimB

    JimB Super Moderator Most Helpful Member

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    OK, but what is a decibel meter ?
    JimB
     
  7. magvitron

    magvitron Active Member

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    I confused dBi with some other term dbm, what I meant was the forward gain for the antenna. The thing was that , 36dBm was the power we are delivering to the antenna .
     
  8. HiTech

    HiTech Well-Known Member

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    ... and on the lighter side of the topic:

    A certain ethnic technician was seen trying to measure the height of an antenna mast. The bystander saw the technician repeatedly climb the mast, attach the tape measure end and slide back down to the ground whereby every time the tape measure unhooked and fell to the ground. The bystander approach the technician and suggested that he remove the mast, lay it on the ground and take a measurement. The technician very wisely replied, "You wise guy, I'm trying to measure the height not the length!"
     
  9. davenn

    davenn Active Member

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    LOL no such thing as a decibel metre ( or meter)

    as you will be probably aware Jim, but magvitron doesn't appear to be, dBm is dB related to 1mW ( one milliWatt)
    his 36 dBm = 4 Watts

    cheers
    Dave
     
  10. magvitron

    magvitron Active Member

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    :( Yeah I messed up there.
     
  11. davenn

    davenn Active Member

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    no probs .... we all do that occasionally :)
     
  12. magvitron

    magvitron Active Member

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    Thanks mate :) Goodday!
     

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