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What type of antenna is this?

  1. Jul 12, 2018 #1
    Hello everyone,
    for health reason, I just need to know from you what kind of antenna is the one in the photo attached, if it is a receiver or a transmitter and if it is safe enough.

    I will have to move on the first floor of a house right under that building (which is a police station if it can be useful to know) and I am a bit concerned. Many thanks.
     

    Attached Files:

  2. jcsd
  3. Jul 12, 2018 #2

    anorlunda

    Staff: Mentor

    :welcome:
    Those appear to be VHF radio antennas of the type used by fire, police, pilots and taxi drivers.

    I never heard of a health hazard associated with VHF radio antennas. I would not worry.
     
  4. Jul 12, 2018 #3

    berkeman

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    Staff: Mentor

    And on the first floor of the building below the antennas, you are out of the transmit antenna pattern anyway. There is very little RF energy below vertical antennas like that. :smile:
     
  5. Jul 12, 2018 #4
    Thanks to both of you, so I guess I shouldn't worry.
     
  6. Jul 12, 2018 #5
    Just in case, this is an other view, with the house and the police station with the antenna.
     

    Attached Files:

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  7. Jul 12, 2018 #6

    berkeman

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    Staff: Mentor

    You are still well below the main Tx pattern, and are pretty far away. I wouldn't worry about it.
     
  8. Jul 13, 2018 #7
    That's good to know, thanks again.
     
  9. Jul 13, 2018 #8

    Tom.G

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    Science Advisor

    What is the dish antenna, aimed horizontally, in the planter at the front of the house? Not many satellites viewable in that direction!
     
  10. Jul 13, 2018 #9

    berkeman

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    Staff: Mentor

    Looks like a hummingbird director. Or reflector, it's hard to tell.

    Or staging for the rubbish collectors. Maybe he didn't pay his bill...
     
  11. Jul 14, 2018 #10

    davenn

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    Science Advisor
    Gold Member
    2017 Award

    you may not be familiar with offset feeds ?

    It's an offset fed satellite dish. The beam direction with the current mount would be up over that blue wall

    dish.JPG

    if you notice, the arm out to the feed point is near horizontal (maybe a few deg above the horiz.), this means the beam angle will be a good few degrees above the horizontal

    in this pic is yours truly repurposing an offset fed sat dish for use on the 10GHz ham band
    NOTE the angle of the feed boom … it is angled down from the horizontal and as a result the radiated signal is beaming out at a horizontal angle

    091002-IMG_2226 Dave and Paul at La Perousesm.jpg



    Dave
     
    Last edited: Jul 14, 2018
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