Do I want a cellphone tower on my property?

On a sunny day (Sun, 9 Jun 2019 10:33:42 +0100) it happened Piglet wrote in :

It is close to the same frequency that heats stuff in your microwave.

Reply to
Jan Panteltje
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On a sunny day (Sun, 09 Jun 2019 11:55:21 +0300) it happened snipped-for-privacy@downunder.com wrote in :

Come on ;-) I a did hang out one level lower for almost an hour without problems before going up to the dishes.

Yes, and beaming 2.4 GHz up to oscar 100 I have about 75 Watts max available, will be experimenting with several feeds. It is circular polarized so will also try to point a helical at the offset dish, large part of it goes past the dish ..

Many different waveguide types possible, This is a nice site:

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No space for a large prime focus dish here, wind load would blow it away anyways.

Now when weather gets better an some much needed parts coming in, i tis more fun. Just put the garden furniture back in place, some blew away in the storm yesterday. Even the sun shines here today ... Coming week rain rain rain predicted.. that is good weather to test that coil project stuff.

Reply to
Jan Panteltje

It is more the power that causes the heating than hitting the "right frequency". Industrial microwave ovens use other frequencies too. I'd be just as worried being near 800W at L or C band.

piglet

Reply to
Piglet

On a sunny day (Sun, 9 Jun 2019 11:44:18 +0100) it happened Piglet wrote in :

Interesting, so better stay away from those dishes!

Reply to
Jan Panteltje

None of this radiation exposure stuff matters.

In the United States, FCC Licensee, including AT&T and all the other carriers, are REQUIRED BY LAW to protect the public from the potential effects of human exposure to non-ionizing RF radiation.

Furthermore, the carriers have risk management departments in place that would make sure the public is never exposed beyond what the regulations mandate.

And at these frequencies, you'd basically have to climb the tower and hug the antenna to exceed the occupational exposure limits. It's a non-issue for wireless towers. Broadcast FM & TV, and high-power radar/microwave are another story.

Reply to
mpm

With all due respect, these two statements demonstrate a fundamental misunderstanding of how modern-day LTE networks operate in the downlink.

Reply to
mpm

Actually, it's more about resonance. The average adult human body is a reasonably good RF absorber at frequencie s about 80 to 100 MHz. And nothing beats resonance, and proximity, for goo d power transfer!

So keep your distance from 100 kW ERP FM broadcast antenna arrays. And even then, the safe distance is something on the order of 20-feet under the typical antenna for occupational exposure.

Short towers with high-power broadcast (FM & TV), with homes built nearby, are a legitimate concern for RF exposure (although the vast majority are fi ne). But it's rare (I've never heard of a legitimate case) involving a mon opole & cellular / PCS configuration being a problem. Other than a hyped-u p, baseless one, that is. It's a non-issue.

Reply to
mpm

ut for.

Um... microwave ovens have a lot higher peak power, and the energy is conce ntrated into a cavity. Not exactly the same thing as an outdoor cell site. Plus, the distances involved from emitter to absorber are magnitudes apar t in these two scenarios. Again, non-issue.

Microwave ovens typically operate on ISM band frequencies (FCC Rules Part-1

8).
Reply to
mpm

The tower may get taller or perhaps turn into multiple units. So the terms should be subject to re-negotiation with changes to the tower(s). What ab out an access route? Will the phone company take care of the taxes for the tower? Talk with a realtor about how this will affect your property value a nd desireability in future markets.

Reply to
alan.yeager.2013

Does that mean avoid vertical polarized VHF when standing and horizontal polarized VHF when lying down ? :)

piglet

Reply to
Piglet

Jan Panteltje wrote in news:qdimtv$rqc$ snipped-for-privacy@dont-email.me:

But nowhere near the power level or proximity.

Reply to
DecadentLinuxUserNumeroUno

Apparently that US figures refers to some general public IEEE

10-400 MHz. At lower and higher frequencies, the limits are higher.

It is interesting to note that while Russian standards allow similar power densities for 6 minutes, the limit for 8 hour occupational

I saw an interview with a former antenna installer who was climbing the tower containing a high power UHF TV antenna. The transmitter was supposed to be off during the installation, but it was on. The installer was able to climb down but was unable to continue his job as a tower installer.

Reply to
upsidedown

Yes, the human length or limb length are at 1/4, 1/2 or 1/1 wavelength resonance and this is the reason why the IEEE standard specifies 27.5 V/m for 10 to 400 MHz. The IEEE standard is also used by a multitude of national standards.

Reply to
upsidedown

I like investing the $9600 a year, Stock Market say 9% over 20 years compounded $538,316. 30 years $1,475,529. That's not accounting for taxes or any inflation increase or loss of value because of inflation.

Mikek

Reply to
amdx

Nope. What you want is an RF absorber, not a reflector. Tin foil and aluminum are reflectors and simply reflect the signal in another direction. While that would be effective if the entire house were shielded on all sides, it doesn't do much good if RF leaks into the house through an opening, such as a door or window, and then bounces around. At microwave frequencies, such the new 5G 24 to 40GHz frequencies, RF can wiggle through small (half wave) cracks in the metal wall. Incidentally, AT&T is testing at 38GHz. At best, reflective shielding only extends the path loss by the distance of each reflection. At worst, if one lives in a circular house, reflections concentrate the RF.

What he really needs is an RF absorber as used in an anechoic RF test chamber: The pyramid shaped structures are made from carbon impregnated foam. The pyramid shape avoids any resonances and allows the foam to absorb a wide range of frequencies. As an added bonus, if there's any nearby street noise, the foam cones really quiet down the house. Most anechoic RF test chambers use both metal reflective shielding and absorbers as well as metal finger stock around all the doors to totally seal the chamber. If the home owner has lots of money, such overkill might be appropriate.

Incidentally, the predicted useful range of mm wave 5G is rather short. See table at:

Drivel:

If the owner really wants to reduce RF exposure inside his house, he should ask AT&T to build a macrocell monster tower that straddles his house. Directly under the antenna has the lowest RF exposure.

Typical RF exposure report required for building a cell site. Associated lease agreement (for $1,752/mo plus 4% annual increases). Proposed site plan:

"FIELD INTENSITY and POWER DENSITY"

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

I don't see a problem:

Due to the need for more bandwidth than a point to point microwave link can provide, and to avoid difficulties with frequency coordination and FCC licensing, most backhauls are moving to fiber optic. At this time, my guess(tm) is about 40% use microwave, 40% use some form of fiber, and the remaining 20% use copper (usually supplied by the local telco). As additional bandwidth is needed at the larger sites, the limited throughput microwave radios are being replaced by fiber. Microwave will still be used where the terrain or lack of infrastructure makes fiber impractical.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

Hey Jeff, how would I find out where my local 5G tower fits in the chart you posted here,>

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the pole,

The Building permit,

Not worried about RF, just want to know if it will be of use to me. I suspect it will be, I'm 1450ft away. Mikek

PS, the next closest 5G tower I'm aware of, is 1.9 miles away.

Reply to
amdx

Perhaps purchasing a "personal RF safety monitor" such as: Version 2 is only $600. Carry one of these and you don't need to guess if that nearby antenna will turn your brain to mush. I don't climb towers any more, but if I did today, I would probably purchase or build something similar.

You can probably use a much cheaper 3 axis RF field strength meter: However, you might need to do some calculations and graph reading to determine if you're safe. You will also need to know the frequencies involved in order to make the determination.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

On a sunny day (Sun, 09 Jun 2019 09:03:42 -0700) it happened Jeff Liebermann wrote in :

Yes, indeed there is a tendency towards fiber, and the future 5G also needs that but over here in the country that part of the infrastructure is not there yet. I do have 3 cellphone towers to chose from at home...

Would not you be just as worried if a 24 GHz antenna was on a street light next to your bedroom window? I have a street light on a high pole in front of the house...

Personally I think 5G is largely a hype. I use internet extensively, and do not feel the need for higher speed really. OTOH some people think it is cool to put HD movies on youtube with no other content than them babbling along. That would be better in a postage stamp size low resolution window... It is the same with ultra HD TV, it is the content that counts, not the resolution! But then a new standard every few year sells new stuff.

Reply to
Jan Panteltje

On a sunny day (Sun, 09 Jun 2019 09:35:24 -0700) it happened Jeff Liebermann wrote in :

I have one of these (apart from all the real RF stuff I have)

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adjustable sensitivity, 1MHz to 6.5 GHz cannot beat the 7$ free shipping price, goes wild near a PC or raspberry or monitor or anything that radiates RF. Very useful thing really. And has a compass too :-)

Reply to
Jan Panteltje

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