At 1:11 AM -0500 11/5/98, Jim Choate wrote:
Forwarded message:
Date: Wed, 4 Nov 1998 21:45:29 -0800 From: Tim May <tcmay@got.net> Subject: Re: TEMPEST laptops
Radio waves scatter...they don't just travel in pure line of sight. And even if they travelled only in line of sight, the reflections from inside the box and then into the room and then off surfaces....
It depends on the frequency. Last time I checked a laser or a maser (both are radio waves strictly speaking) travel LOS. The scattering comes from beam divergence and incidental refractions and reflections from the molecules in the air and supported detritus.
And both Lasers and Masers scatter under certain conditions. If you can see the laser, it is scattering a bit of [energy light photons] That is what Mr. May is talking about. I was under the (apparently false) impression that things like animal bodies, and ordinary building materials (like wood, Lathe & plaster/drywall) wouldn't stop or significantly bounce the beams back the way you didn't want them to go. I was thinking more of controling the direction of the RF, rather than trying to completely supress it. It doesn't appear that will work.
Microwave ovens work by having the waves bounce around inside a box. Any significant hole or crack (up to roughly half the wavelength) would let the waves out.
Depends on the size of the hole and location. In most microwave ovens there are definite dead-spots (corners and the exact center of the area are notorius).
We're not cooking Hotdogs here, and we aren't using (for the most part) microwaves. Yes, you can heat a hotdog on a PII, but that is more from heat radiation than RF. Microwave ovens also leak RF. -- "To sum up: The entire structure of antitrust statutes in this country is a jumble of economic irrationality and ignorance. It is a product: (a) of a gross misinterpretation of history, and (b) of rather naïve, and certainly unrealistic, economic theories." Alan Greenspan, "Anti-trust" http://www.ecosystems.net/mgering/antitrust.html Petro::E-Commerce Adminstrator::Playboy Ent. Inc.::petro@playboy.com