[Gllug] entropykey: why did nobody ever mention this thing before?

[Andrew Back]

On (10:32 02/08/10), Richard Jones wrote:

<<SNIP>>

> This was about the point where we stopped, but only after ascertaining
> that the way to do this was to put the whole device inside a half inch
> thick, earthed copper box.  Put a battery inside there, so there's no
> power supply interference.  Then run the output cable through a narrow
> hole in the metal box.  The problem _then_ is that the output cable
> carries environmental RF back into the box, and really the only way
> around that would be some sort of metalized window with an opto
> coupler.  I guess you can probably see why we didn't build the final
> device in the end.

I'm not sure you'd need such an expensive enclosure and imagine that a 'can'
of the sort generally used in RF screening would suffice. Employing
feedthrough capacitors for taking bits out and possibly power in, with
ferrite cores on the leads to further suppress RFI.
 
Cheers,

Andrew

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