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December 23rd 03, 05:25 AM

On 22 Dec 2003 21:06:44 -0800, (Art Unwin KB9MZ)
wrote:

Richard
I think you are confusing low frequency aplications with
high frequency aplications. A flat sheet allows formation of
ground loops that then form their own emissions.
This is not desirable in high frequency aplications and
thus a common short circuit to ground for discharge is required.
Best regards
Art

Hi Art,

I am confusing nothing. A current cannot be induced without a path,
if you do not provide any more than one terminus, there is no path
EXCEPT TO GROUND and it is a common shared by both halves of the
magnetic linked circuits (read your Terman). This means the circuits
on both sides of the shield are electrically decoupled from each other
and are driving ground directly - capacitively (the electric field).
The sole purpose of the Power Transformer's Faraday Shield is EXACTLY
for snubbing VLF/MF/HF/VHF/UHF coupling (there's no purpose to killing
50/60 Hz fields with a Faraday Shield, that just doesn't make sense in
the first place).

The guff you are repeating is the ill-understood concepts of UHF/SHF
circulating currents that could only be developed if the wavelength
scale can support it. Are you talking about 900 MHz applications with
3 inch Faraday screens? I think not.

There's no mystery about this, dimension and frequency drive all such
issues.

73's
Richard Clark, KB7QHC