At 08:02 PM 5/11/96 +0000, Jean-Francois Avon wrote:

Or, to the contrary, is it reasonable to assume that modern Tempest equipment can work around theses impediments almost all of the time, therefore making any attempts at this futile?

It's probably worth investigating. Chances are good that as long as the total beam current remains as constant as possible, the signal will be much harder to interpret. One way to investigate this comparatively easily is to measure the total power consumption of a monitor when the screen is filled with different colors at different saturations, etc. Supply the AC to the monitor through a 1-ohm resistor, measure the AC voltage across the resistor to 1 mv accuracy or better, and you have a pretty good way to distinguish different beam currents. I'm waiting for cheap flat-panel displays for desktop computers to arrive, because they will probably be almost impossible to detect usably by Tempest systems. Jim Bell jimbell@pacifier.com