The equation for cable shielding effectiveness
SE [dB] = 36 - 20 log(Zt)
where Zt is the total frequency dependent transfer impedance has
been around for a number of years.
Does anyone out there have a good derivation or reliabe source for
it?
Or for that matter what are the limitations of the equation?
MIL-C-24640 specs Zt as 700 milliohms per meter which implies a
90 meter cable, which is not unheard of, has zero dB of shielding.
(Does a 100-meter cable have gain?)
Jim Sketoe
Boeing Company - St. Louis
[email protected]
