Is the Offset Fed Satellite Dish on the Police Station Safe?

  • Thread starter Thread starter phys86
  • Start date Start date
  • Tags Tags
    Antenna Type
AI Thread Summary
The discussion centers on the safety of a VHF radio antenna located on a police station, particularly for someone moving into a house directly beneath it. Participants confirm that VHF antennas, commonly used by emergency services, do not pose health hazards, especially when positioned below the main transmission pattern. Concerns about a horizontally aimed satellite dish are also raised, with suggestions that it may be an offset-fed dish designed for specific signal directions. The overall consensus is that there is minimal risk associated with living under the antenna. The conversation concludes with technical insights regarding the satellite dish's orientation and potential uses.
phys86
Messages
4
Reaction score
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.
 

Attachments

  • antenna.png
    antenna.png
    68.4 KB · Views: 548
Engineering news on Phys.org
: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.
 
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:
 
Thanks to both of you, so I guess I shouldn't worry.
 
  • Like
Likes berkeman
Just in case, this is an other view, with the house and the police station with the antenna.
 

Attachments

  • view.png
    view.png
    115.1 KB · Views: 509
phys86 said:
Just in case, this is an other view, with the house and the police station with the antenna.
You are still well below the main Tx pattern, and are pretty far away. I wouldn't worry about it.
 
  • Like
Likes dlgoff
berkeman said:
You are still well below the main Tx pattern, and are pretty far away. I wouldn't worry about it.
That's good to know, thanks again.
 
What is the dish antenna, aimed horizontally, in the planter at the front of the house? Not many satellites viewable in that direction!
 
Tom.G said:
What is the dish antenna, aimed horizontally, in the planter at the front of the house? Not many satellites viewable in that direction!
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...
 
  • #10
Tom.G said:
What is the dish antenna, aimed horizontally, in the planter at the front of the house? Not many satellites viewable in that direction!

you may not be familiar with offset feeds ?

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

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
 

Attachments

  • dish.JPG
    dish.JPG
    55.1 KB · Views: 436
  • 091002-IMG_2226 Dave and Paul at La Perousesm.jpg
    091002-IMG_2226 Dave and Paul at La Perousesm.jpg
    64.3 KB · Views: 444
Last edited:
  • Like
Likes TechTree, dlgoff, Tom.G and 1 other person
Back
Top