On Mon, 9 Feb 1998, Dave Emery wrote:
On Tue, Feb 10, 1998 at 03:03:53AM +0100, Lucky Green wrote:
Now all this was done without the use of a DSP. I can only imagine what one could capture after adding a DSP to the setup.
Miles...
Given static screen images and thousands of repetitions in a few seconds the processing gain from integration of the signal verus the uncorrelated noise over thousands of cycles gets quite interesting. And add to that the tricks one can do with comb filters and combining together the correllated energy from several harmonics of the dot clock one can see that getting signal out from under the trash is easy even at considerable distances.
That would be my analysis as well. Note that the van Eck demonstration I
saw didn't even make use of the common analog tricks, such as using a
super heterodyne receiver. Not to mention the near magical capabilities of
a few Fourier transforms for pulling a nice, fat signal spike out of all
that "white noise".
There wasn't a single person watching said demonstration in that brutally
hot tent at HIP'97 that didn't walk away impressed. And I can off the top
of my head come up with a design that would improve the gain by at least
20dB over what was used there..
-- Lucky Green