[RFI] AST Research

[Cortland Richmond]

I did some fairly basic, not to say
fundamental, work on monitor EMI, years ago at
Tandy.

By way of demo, I set up something a computer
for conducted emissions, and then showed the
boss. Turning a nearby monitor on would cause
the computer, which was turned OFF, to exceed
the FCC limit. Heh!

The solution was all too familiar to EMI
engineers; shorten the return loop! I did it
with metal; adding capacitance so more of the
local field was returned on the cathode video
amps. Didn't take much, either. The vendors
already knew they had trouble, but I think they
were hoping we would finesse their way around
it (larger H's on the screen, etc) as a favor.
They started to worry when we bought other
monitors!

Then I showed them how to fix it.

Cortland