archiv~1: Re: SETI Re: Argus: CPU Lead Shielding

Re: SETI Re: Argus: CPU Lead Shielding

David Woolley ( david@djwhome.demon.co.uk )
Mon, 9 Nov 1998 23:13:32 +0000 (GMT)

>
> As I understand it, any conductor, especially a good one, will block out
> EM radiation. For radio frequencies, you would only need some wire with
> holes no larger than the wavelength.

They need to be no more than about a 10th or 12th of the wavelength, and
preferably smaller (satellite dishes don't have to attenuate the ground
noise through the back that much, so their mesh is probably not optimum
for really low noise operation in the presence of an active source, which
may be extremely hot in terms of an equivalent thermal source).

In practice, I think this is an area where there is probably more art
than science.