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Shielding home from radio waves - experiment


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#1 kodama

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Posted 9 January 2010 - 01:03 AM

Greetings all, my first post here is a topic of great personal interest originating from a movie. It's something I have struggled to find online and it's either very simple or very complex. Either way I haven't found links about it which tells me I'm looking for the wrong thing, no-one cares or it simply isn't possible.

We've probably all seen Gene Hackman and Will Smith in Enemy of the State. 'Brill' used a copper mesh cage to shield himself from external radiation. This made me wonder if this would actually work?

Stop cell phones having reception.Prevent harmful radio waves passing through (eg. GSM, Radar, Television, satellite, appliance etc..)
We weren't always exposed to this level of radiation, could it be shielded, could it be measured? - (beside a cell phone not having a signal).

If it would work how would it work, a simple earthed mesh? Would it have to be copper?

Found this site.
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#2 Externet

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Posted 9 January 2010 - 03:34 AM

A metal box and also a mesh can greatly reduce the passing of radiofrequency, as the window your microwave oven has.
Wrapping a house would not be simple. And 'grounding' such may not be fully effective. Having it laid all even under the house may be better.

Some people is more sensitive to become paranoic to the subject.
Years ago I read research took place by placing very high AC voltage plates directly above and below a large amount of eggs in an incubator, full time during 3 weeks the process takes.
No defects were found on the chicks. :eek: :eek:

Yesterday I heard on Public Radio, that Alzheimer disease was reduced and eliminated in laboratory rats exposing them to 4 daily hours of cell phone radiation, and examination showed that some sort of harmful chemical 'dentrites' in the rats brain were dissolved by the 'treatment' :confused: :confused:

Personally, have no opinion on EMF effects, other than microwaves do cook whatever is nearby.

On a very recent post of some forum; a guy placed his cordless phone inside an off microwave oven, and called to it.
It rang !!! Some debate about the shielding facts, led nowhere.

Edited by Externet, 9 January 2010 - 03:41 AM.

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Abolish the deciBel !

#3 StringJunky

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Posted 9 January 2010 - 03:56 AM

Kodama: They are snake oil merchants in that link ....it's pseudoscientific rubbish, trying to feed peoples latent anxieties and in the process make some money.

I think your question about blocking radio waves is ok. You might find this article informative at practical experiment level:

http://www.madsci.or...62213.Eg.r.html

As to the potential health risks of radiowaves in general, I'll leave that to a more informed person to put you right.

Edited by StringJunky, 9 January 2010 - 03:59 AM.
Consecutive posts merged.

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" In the absence of data, we have more degrees of freedom to wave our arms."- Anon.

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#4 mooeypoo

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Posted 9 January 2010 - 03:59 AM

  • Prevent harmful radio waves passing through (eg. GSM, Radar, Television, satellite, appliance etc..)

Sorry, but why do you assume that all of the above are harmful? Radar I can understand, but Television? Satellite? Appliances? ...
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No trees were harmed in the creation of this post.
But billions of electrons, photons, and electromagnetic waves were terribly inconvenienced during its transmission.

 

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#5 Cap'n Refsmmat

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Posted 9 January 2010 - 04:41 AM

This may be of interest:

http://news.thomasne...ullstory/459490

However, you could just get a full chain-mail outfit. That would block everything but the really short wavelengths.
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#6 kodama

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Posted 9 January 2010 - 11:30 AM

Thanks for your responses. The link I posted was an example of all I could find on the web, not my personal preferences, but you get the idea.

I tried calling my cell phone in my microwave and had no signal; interesting, perhaps the 'tyre kickers' way to shop for a safer microwave!

This is part of a larger experiment and I'm only loosely drafting the framework. Current considerations are does it work or would it be possible, and how would you measure it?

It's really to see how much of the surrounding environment is saturated by modern radio waves (since the first broadcast on December 24, 1906 from Brant Rock), and look at how much effort is required to shield it. Whether it's pointless or redundant isn't the point in this instance, it's a controlled experiment to see if it's possible and measure the difference between them.

Disappointingly, a frequency is a measurable dimension and depending on wave frequency and mesh size, some will fit through larger meshes and be stopped by smaller ones accordingly. Besides a metal box, the alternative is to stop all radio waves above and below the visible range of the Electromagnetic Spectrum.

Posted Image


Or click here for a more enjoyable version.

With emphasis on the modern waves, it would be interesting to better understand the frequencies in use above, from 1900 to 2010.

Edited by kodama, 9 January 2010 - 12:05 PM.

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#7 Moontanman

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Posted 9 January 2010 - 09:28 PM

I think it's interesting that my cell phone messes up my computer monitor when it rings, every time with out fail, even if the phone is 18" away from the monitor. Occasionally my computer monitor reacts the same way even if the phone doesn't ring as though a random signal is moving past. Sorry if this is off topic.
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#8 Klaynos

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Posted 9 January 2010 - 11:29 PM

There are three options for shielding from mm -> m wavelength EM waves.

Faraday cages, this is IIRC what your microwave uses, you have to be mindful of the skin effect (check wp as a starting point for what that is).

Microwave absorber/absorbing cones, these are very very narrow bandwidth.

Anechoic chamber, it is similar to faraday cages but far easier to do on a large scale and broad bandwidth even for things with long wavelengths without having to have very complicated structures/walls.

Merged post follows:

Consecutive posts merged

I think it's interesting that my cell phone messes up my computer monitor when it rings, every time with out fail, even if the phone is 18" away from the monitor. Occasionally my computer monitor reacts the same way even if the phone doesn't ring as though a random signal is moving past. Sorry if this is off topic.


This is probably the wire acting as an aerial. The seemingly random occurrences will be your phone handshaking, the phone network going "hello are you still there Moontanman's phone" and your phone reply "Yo! How's it flying, I'm still here all tickety boo"
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Klaynos - share and enjoy.

#9 needageek

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Posted 1 February 2010 - 04:18 PM

HELLO ALL DOG LOVERS!

I have a related question to blocking radio waves.

I have a situation where a lady hates me --I did not want to be involved in her political gatherings--her home office is 10 feet from where I come and go. She is taking it out on my lovely dogs who enjoy playing chase and running hard in a figure 8.

It appears that they are being distracted by some ultrasound device.

This person has a regular whistle which I have heard her use from inside her house but now seems to have jumped to using this cruel tool.

The dogs stop and stand like statues with their ears twitching. They are not exercising properly. They pee in the house at night. Even though I ask one to go out she looks at me in fear.

I am losing my mind because my one female will not go out sometimes to eliminate waste. This is bad for her health.

I probably have to move but that is a long way off and I would like to document by recording the use of this and videotaping my dogs at the same time. Ideallly I would have the strength to move and to organize a class action law suit against the manufacturer of these devices.

Anyone have an idea on how to record ultrasound. Thank you so very much.

I am so upset that I can not seem to help myself. In addition my ears are ringing.
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#10 Cap'n Refsmmat

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Posted 1 February 2010 - 04:23 PM

Get yourself a bat detector. They're designed to make the echolocation signals of bats (which are ultrasound) audible to humans.

http://www.econvergence.net/batdet.htm

or just Google around for other kinds. Dogs can only hear up to 40kHz or so, so the whistle should be 20kHz-40kHz. Get a bat detector that can operate in that range.
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#11 swaha

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Posted 6 February 2010 - 05:53 PM

bats can help. Batman brother!
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