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Science Forum Index » Physics - Electromagnetic Forum » Copper and mobile phone radiation
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| Man-wai Chang ToDie |
 Posted: Sat Nov 24, 2007 11:50 pm |
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Is a sheet of copper good enough to block mobile phone radiation?
--
@~@ Might, Courage, Vision, SINCERITY.
/ v \ Simplicity is Beauty! May the Force and Farce be with you!
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| Benj |
| Posted: Sat Nov 24, 2007 11:50 pm |
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On Nov 24, 10:50 pm, Man-wai Chang ToDie <toylet.toy...@gmail.com>
wrote:
Quote: Is a sheet of copper good enough to block mobile phone radiation?
Yes, if it's thick enough! And oh, yeah, it has to be formed into a
completely closed container.
Benj |
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| Man-wai Chang ToDie |
| Posted: Sun Nov 25, 2007 4:07 am |
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Quote: Is a sheet of copper good enough to block mobile phone radiation?
Yes, if it's thick enough! And oh, yeah, it has to be formed into a
completely closed container.
Just wanna place a sheet (about 0.5mm thick) of copper between my body
and the phone in the waist bag.... my father makes brasswares.
--
@~@ Might, Courage, Vision, SINCERITY.
/ v \ Simplicity is Beauty! May the Force and Farce be with you!
/( _ )\ (Xubuntu 7.04) Linux 2.6.23.8
^ ^ 16:06:01 up 6 days 20:28 0 users load average: 1.00 1.02 1.03
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| Wimpie |
| Posted: Sun Nov 25, 2007 8:34 am |
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On 25 nov, 09:07, Man-wai Chang ToDie <toylet.toy...@gmail.com> wrote:
Quote: Is a sheet of copper good enough to block mobile phone radiation?
Yes, if it's thick enough! And oh, yeah, it has to be formed into a
completely closed container.
Just wanna place a sheet (about 0.5mm thick) of copper between my body
and the phone in the waist bag.... my father makes brasswares.
--
@~@ Might, Courage, Vision, SINCERITY.
/ v \ Simplicity is Beauty! May the Force and Farce be with you!
/( _ )\ (Xubuntu 7.04) Linux 2.6.23.8
^ ^ 16:06:01 up 6 days 20:28 0 users load average: 1.00 1.02 1.03
$B\#1g(B (CSSA):http://www.swd.gov.hk/tc/index/site_pubsvc/page_socsecu/sub_addressesa/
Hello,
The thickness of the copper sheet is not of importance as the
penetration depth for 900 MHz is just 2.2um (and even less for higher
frequencies). The size does matter. A piece of 0.5*0.25 lambda (900
MHz) does already work as a reflecting sheet. It does not block the
radiation, but will reduce it. For virtually blocking it, you need a
larger size.
It is also not safe to have a large piece of copper/bras sheet on your
body, it could penetrate your body in case of certain mechanical
impact.
Note that if you want to turn this into product, you should
demonstrate the effect under real circumstances.....
Best regards,
Wim
PA3DJS
www.tetech.nl |
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| Wimpie |
| Posted: Sun Nov 25, 2007 11:18 pm |
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On 26 nov, 08:51, Man-wai Chang ToDie <toylet.toy...@gmail.com> wrote:
Quote: It is also not safe to have a large piece of copper/bras sheet on your
body, it could penetrate your body in case of certain mechanical
impact.
Seldom happen...
Note that if you want to turn this into product, you should
demonstrate the effect under real circumstances.....
No... personal use only. I think lead is a better blocker.
Strictly spoken no, lead is not a better blocker, we are not in the
radio active range of radiation. Just conductivity and permeability is
of importance, and of course the size/shape of the metal. For this
application you can use lead foil because of skin depth << material
thickness. You could use every metal available at your location.
Quote:
--
@~@ Might, Courage, Vision, SINCERITY.
/ v \ Simplicity is Beauty! May the Force and Farce be with you!
/( _ )\ (Xubuntu 7.04) Linux 2.6.23.8
^ ^ 15:50:01 up 1:06 1 user load average: 1.05 1.18 1.08
?? (CSSA):http://www.swd.gov.hk/tc/index/site_pubsvc/page_socsecu/sub_addressesa/
best regerds,
Wim
PA3DJS
www.tetech.nl |
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| Wimpie |
| Posted: Mon Nov 26, 2007 3:21 am |
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On 26 nov, 11:06, Man-wai Chang ToDie <toylet.toy...@gmail.com> wrote:
Quote: Strictly spoken no, lead is not a better blocker, we are not in the
radio active range of radiation. Just conductivity and permeability is
of importance, and of course the size/shape of the metal. For this
application you can use lead foil because of skin depth << material
thickness. You could use every metal available at your location.
How could I ground that piece of metal while wearing sport shoes?
The concept of a ground doesn't hold at 30cm wavelength as the earth
is in the far field with respect to your cell phone. You could define
a local ground (the metal plate) if you like. Attenuation of the
metal is caused by destructive interference of incident and reradiated
fields and not by electrostatic or magnetostatic phenomena. So don't
worry about ground to mother earth.
best regards,
Wim
PA3DJS
www.tetech.nl |
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| Man-wai Chang ToDie |
| Posted: Mon Nov 26, 2007 3:51 am |
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Quote: It is also not safe to have a large piece of copper/bras sheet on your
body, it could penetrate your body in case of certain mechanical
impact.
Seldom happen...
Quote: Note that if you want to turn this into product, you should
demonstrate the effect under real circumstances.....
No... personal use only. I think lead is a better blocker.
--
@~@ Might, Courage, Vision, SINCERITY.
/ v \ Simplicity is Beauty! May the Force and Farce be with you!
/( _ )\ (Xubuntu 7.04) Linux 2.6.23.8
^ ^ 15:50:01 up 1:06 1 user load average: 1.05 1.18 1.08
?? (CSSA):
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| Man-wai Chang ToDie |
| Posted: Mon Nov 26, 2007 4:18 am |
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Quote: It is also not safe to have a large piece of copper/bras sheet on your
body, it could penetrate your body in case of certain mechanical
impact.
It could be used as a weapon on the other hand. :)
--
@~@ Might, Courage, Vision, SINCERITY.
/ v \ Simplicity is Beauty! May the Force and Farce be with you!
/( _ )\ (Xubuntu 7.04) Linux 2.6.23.8
^ ^ 16:17:01 up 1:33 1 user load average: 1.56 1.66 1.47
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| Man-wai Chang ToDie |
| Posted: Mon Nov 26, 2007 6:06 am |
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Quote: Strictly spoken no, lead is not a better blocker, we are not in the
radio active range of radiation. Just conductivity and permeability is
of importance, and of course the size/shape of the metal. For this
application you can use lead foil because of skin depth << material
thickness. You could use every metal available at your location.
How could I ground that piece of metal while wearing sport shoes?
--
@~@ Might, Courage, Vision, SINCERITY.
/ v \ Simplicity is Beauty! May the Force and Farce be with you!
/( _ )\ (Xubuntu 7.04) Linux 2.6.23.8
^ ^ 18:05:01 up 3:21 1 user load average: 1.00 1.04 1.04
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