Can copper wire mesh really keep radio signals out?

Question

I just wanted to know.

Answer 1

If it is joined electrically all over (soldered with no gaps) it makes a Faraday cage that is used for exactly that. The higher the frequency the more you have to worry about gaps since the wavelength is shorter.

Answer 2

Tin foil hats are better... just kidding.

:-)

You will find a home made or bought mesh or grid insulated room in pretty much every lab which makes equipment using electromagnetic waves or very low noise amplifiers. Often it is nothing but a cube made of wood with chicken wire all over. Just enough to put a desk with test equipment and one or two people in there. The difference between being inside and outside is amazing. I regularly pick up radio-stations and the radar of the local airport with my amplifiers. On the inside it is all quiet and I can actually measure the noise floor of the amplifier rather having to guess if its an artifact of the circuit or an external noise source.

Answer 3

Yes, it can; provided the following conditions are met: there must be solid electrical connectivity between the mesh elements at every junction, and the mesh must be significantly finer than the wavelength of the signals you wish to block. If those conditions are met you have a Faraday cage, which is (for example) the device that contains the microwaves inside your microwave oven while allowing you to look through the glass to see what's happening inside. (Microwaves are much, much longer wavelength than visible light.)

Answer 4

I don't believe thats true, unless its energised by electricty in which case it will act like a coil. Copper is good for the garden to keep the snails at bay.