Internetworkers: http://www.ibiblio.org/internetworkers/

[Jeremy Portzer <jeremyp AT pobox.com>]

On Wed, 2004-01-07 at 13:35, Tanner Lovelace wrote:
> Mark Turner wrote:
> 
> > <radio geek talk>
> > 
> > It's quite possible that his phone was being used close to the CAT5 
> > cable my phone was using, since he was working in the ceiling. His phone 
> > may have interfered with the frequencies on the Ethernet cable.
> > 
> > </radio geek talk>
> 
> Ah, that makes a lot more sense.  I hadn't realized he was in the
> ceiling near the ethernet cable.  Of course, since we're using
> a weird form of VoE (voice over ethernet, since we didn't by
> the voice over IP module), it probably messed up the ethernet
> transmissions.

Ethernet cables normally don't emit or accept any radiation, the
"twisted pair" nature of the cables dampens most radiation emission (and
also acts as a shield).  The more twists, the better.  Not saying it
isn't possible, but it's not likely.

Here are some much more likely sources of interference:
Ballasts from flourescent light fixtures
El-cheapo light dimmer switches (not as likely to be found in offices)
UPS equipment
Improperly shielded CRTs (Computer monitors, TVs, etc)
Improperly shielded industrial equipment of many different types

> Sure.  Just make sure you don't miss out on something worthwhile
> while being careful.

Agreed with that.  Note that the interference that Mark was receiving
was interfering with his *reception* of the cell phone signal from the
tower.  It had nothing to do with the transmitting circuit which is the
circuit that could possibly cause any harm to human health.

--Jeremy  (not an e.e. but working in that direction one of these days)
-- 
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| Jeremy Portzer        jeremyp AT pobox.com      trilug.org/~jeremy     |
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