this post was submitted on 30 Jun 2024
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[–] [email protected] 36 points 5 months ago* (last edited 5 months ago) (4 children)

Ackshually, being too close to high power radio frequencies isn't safe. I remember at one base I was stationed at in Afghanistan, there was a smoke spot we all used to take breaks at. For some reason, I started developing really bad headaches and feeling kind of nauseous. I figured I was just acclimating to the local climate or something. After a few weeks, I was up on our building installing one of our satcom dishes on top of it when I noticed something. Right on the other side of the fence of that smoke area, was a ~2m high powered dish pointing just above above where the smoke area was. I pointed this out to the Norwegians that ran the camp and the break area was promptly moved, lol.

But seriously, I do not understand the anti-5G nutters.

[–] [email protected] 13 points 5 months ago

FCC already has regulations on maximum power. These emitters are usually dozens of feet off the ground as well.

[–] [email protected] 6 points 5 months ago (3 children)

Hell the high power WiFi equipment^‡^ I installed at my Grandma's house had warnings about keeping a few feet clear of it when powered on due to health concerns and that's just WiFi equipment. I can't imagine the dosage of gnarly from a 2m powered dish.

‡ I installed that equipment because she wanted WiFi on all 10 acres of her property and she didn't want me to install more stations around her property. Now she has the broadcast equipment in her garage with a tape line on the floor like it's a Goddamned radiation research facility lol

[–] [email protected] 15 points 5 months ago* (last edited 5 months ago)

WiFi emissions are tightly regulated and there are no “high power” WiFi equipment unless you flash custom firmware and break the law. The link you posted below is the same power as anything else, up to the maximum allows by law. This is not uncommon, every router / AP does this unless it’s some special low power model.

[–] [email protected] 2 points 5 months ago (1 children)

Yeesh, I didn't even know there were consumer grade WiFi transceivers that were strong enough to cover such a massive area. Was it a small farm or just a big property? That had to have been a pretty expensive WiFi system regardless. Did you use Ubiquiti directional access points or something?

I have a sister that runs a small family farm and she asked my brothers and me (3 of us have IT backgrounds/careers) for viable coverage solutions to their various livestock areas. We settled on just running copper to one barn from her house and broadcasting from there with a few repeaters equipped with trunk channels in order to maintain full duplex.

[–] [email protected] 5 points 5 months ago (1 children)

It's a small farm and yeah it's Ubiquiti hardware though I don't think they sell it anymore. The last time I looked through their website I couldn't find it again.

Though here's the Amazon link

Basically this thing is located on one end of the property and on the other end there's a nano station hooked up to a router because there was still a WiFi dead zone that she wanted covered. But given that that spot was inside a metal barn on the otherside of another metal barn I wasn't surprised.

[–] [email protected] 15 points 5 months ago* (last edited 5 months ago)

There’s nothing high power about that, It’s the same as everything else. Maximum 30dBm, about a watt.

[–] [email protected] 2 points 5 months ago (2 children)

Does it work? I'd be surprised her phone can transmit loud enough to reach the base station.

[–] [email protected] 2 points 5 months ago

It works great

Literally able to us the WiFi in a metal barn 50 yards away on the otherside of a garage

It doesn't faff about

Mowing the field at her place my phone will stay connected to the WiFi basically the whole time, the only WiFi blind spot that I had to fix was on the far side of her property where there's 2 metal barns, a garage, and a wall of her house between you and the broadcast equipment.

[–] [email protected] 1 points 5 months ago

If your antenna is strong enough, you can pick up a lot of lower power devices from a long ways off.

[–] [email protected] 5 points 5 months ago (1 children)

The higher the frequency, the worse that is. So standing very close to an HF antenna that only broadcasts up to like say 30 megahertz is different than standing next to a 700 megahertz cell phone antenna, which is different from standing next to a 2.5 gigahertz cell phone antenna. The reasoning for that is due to power levels and wavelength of the radio signal itself.

[–] [email protected] 19 points 5 months ago* (last edited 5 months ago) (1 children)

Humans are most sensitive to EM radiation between 30-300 MHz. It tapers off after that, it’s not linear where higher = worse for you across the entire spectrum.

https://www.fcc.gov/engineering-technology/electromagnetic-compatibility-division/radio-frequency-safety/faq/rf-safety

In the case of exposure of the whole body, a standing ungrounded human adult absorbs RF energy at a maximum rate when the frequency of the RF radiation is in the range of about 70 MHz.  This means that the "whole-body" SAR is at a maximum under these conditions.  Because of this "resonance" phenomenon and consideration of children and grounded adults, RF safety standards are generally most restrictive in the frequency range of about 30 to 300 MHz.

[–] [email protected] 2 points 5 months ago (2 children)

What about those military things that they use to disperse crowds? Where it makes you feel like your skin is cooking, but it's actually not. I feel like that uses high power and high frequency radio waves to accomplish that.

[–] [email protected] 8 points 5 months ago (1 children)

This? it says that uses 95ghz which seems to be another frequency that is absorbed well. It’s not just because it’s cb high frequency, there’s specific frequencies that resonate with different things. Also it is definitely cooking your skin and you would be burned if you were hit long enough

[–] [email protected] 2 points 5 months ago* (last edited 5 months ago)

Won't that increase probability of skin cancer?

Edit: yes:

there is an extremely low probability that scars derived from such injury might later become cancerous

[–] [email protected] 6 points 5 months ago (1 children)

Those are 95 GHz but very high power and focused as well.

It's not that high frequency can't hurt you, what I'm trying to say is for a given power level, 30-300 MHz is the most risky to humans. That's why the FCC regulates this band the most stringently.

[–] [email protected] 3 points 5 months ago

Fair enough, there's some really golden information in this thread.