Posted by bbin37 on
URL: https://www.es-forum.com/shielding-Notebook-tp1536902p1536911.html

Hi Glenn & Randolf,

If we can take the computer's CPU clock speed as its highest frequency
component then the aperture/mesh size below which shielding for the
computer will begin is:

(0.3 m)/(CPU speed in GHz) or
(300 m)/(CPU speed in MHz)

Smaller aperture sizes than this work much better. For typical square
mesh, divide by the square root of 2 to account for the diagonal of
the mesh being its largest aperture width.

For example, if we had a 1 GHz CPU, then square mesh below (30
cm)/(sqrt 2) ~ (21 cm) will begin to confine the transverse EM
radiation. A 1/4" square mesh has as its largest aperture width
(0.25") * (1.414) ~ (0.35") ~ (0.89 cm) which should readily shield the
transverse emissions in the above example.

Beau

--- In [hidden email], "Glenn Coleman" <glennhcoleman@h...>
wrote:
> Hello,
>
> I have thought of something similar, but to hook an external
keyboard, and
> use a wire-mesh fence between me and the notebook. I figure if wire
mesh
> works on microwaves it may work here too. I may even make a whole
box
> around my notebook with notebook sitting in cage.
>
> If it does work, then I can find a finer quality mesh so I can see
monitor
> better. I was going to start with some wire fencing with 1/4"
holes to But I do
> not know If there can occur problems when I do it.
>
>
> Randolf Weinand