Well, but
Most PC designs use phase lock techniques which keep external
signals way below the CPU operating frequency
There are legal limits for radiation; most laptops and all
PDA devices are "Class B" which is a pretty low level.
The real issue I suspect is that there is no practical way to test
what the effect of a whole planefull of "at-the-limit" devices do
to the plane's systems. It is very reasonable to design the avionics
to be hardened against this sort of thing, but the older planes wouldn't
have such avionics.
I expect we will see some lessening of the rules as the experience
and turnover of the airframes proceeds. We already have the
"mobile use okay until pushback" which is a real change.
Brian
-----Original Message-----
From: Harald Alvestrand [mailto:Harald(_at_)alvestrand(_dot_)no]
Sent: Tuesday, March 20, 2001 5:24 PM
To: RL 'Bob' Morgan; ietf(_at_)ietf(_dot_)org
Subject: Re: presentation-prep as safety hazard
At 19:11 19/03/2001 -0800, RL 'Bob' Morgan wrote:
On the plane last night, flying in to Minneapolis:
"We're now starting our descent, please return your tray
tables and seat
backs to their upright and locked position, and turn off any
electronic
equipment."
2 minutes later:
"People! We really need you to turn those laptops off NOW ..."
note that having a PC with a 500 MHz clock means that there is an
oscillator in there running at some hundreds of megahertz,
attached to a
nest of wires of uncertain shape.
this particular setup WILL transmit energy in the radio bands
below 500 MHz.
--
Harald Tveit Alvestrand, alvestrand(_at_)cisco(_dot_)com
+47 41 44 29 94
Personal email: Harald(_at_)Alvestrand(_dot_)no
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