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<TITLE>RE: [Beowulf] Re: Not all cases need be metal</TITLE>
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<P><FONT SIZE=2>You are right, of course. This also explains why all laptops have metal lining behind their funky (or not) plastic cases.<BR>
<BR>
In my experience of running with cases open, no case at all, or even using a cardboard boot box as a case (yep, a student brought that in once :D) , the worst interference is with loudspeakers. Nothing much is detected with TV sets, radios or cell phones. I guess it's just that loudspeaker wires are so much longer than other equipment.<BR>
<BR>
On the other hand, metal cases that are not appropriately isolated from the inboard electronics may act as emitting antennae, actually increasing interference with other equipment. Seen that mainly with some low-end tower boxes.<BR>
<BR>
Cheers,<BR>
-Alan<BR>
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<BR>
<BR>
-----Original Message-----<BR>
From: beowulf-bounces@beowulf.org on behalf of David Mathog<BR>
Sent: Tue 10/28/2008 12:32 AM<BR>
To: beowulf@beowulf.org<BR>
Subject: [Beowulf] Re: Not all cases need be metal<BR>
<BR>
I missed most of this thread, so somebody may have already pointed this<BR>
out, but cases are metal not just for fire safety reasons. The case is<BR>
usually made of a good conductor so that it will also shield the radio<BR>
emissions from the electronics housed inside. Failure to do so could in<BR>
theory bring the wrath of the FCC down on you (in the U.S.), or at least<BR>
make you really unpopular with your neighbors. I wonder if the new<BR>
digital TV tuners are more or less sensitive to this sort of thing than<BR>
were the old analog tuners? I'm thinking they are likely to be more<BR>
sensitive, since weak channels we could pick up with varying amounts<BR>
of "snow" and multipath using an analog tuner tend to be a big nothing<BR>
with a digital tuner.<BR>
<BR>
David Mathog<BR>
mathog@caltech.edu<BR>
Manager, Sequence Analysis Facility, Biology Division, Caltech<BR>
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