[TowerTalk] Faraday Cage

[warrenwolff at aol.com]

Hi again folks,

Wow, I surely do stir up a hornet's nest when I pose some of my 
questions to this group.

This subject of a Faraday?Shielded Room came up when I was
trying to get this new house as protected as possible.? The almighty
dollar interfered with some of my thoughts, this being one of them.

I was suspecting that a bit less than 1/4 wave at 2 meters would have
been sufficient for such a room.

Now David has dug up a reference:


- Aperture
Aperture
An opening in a shielded enclosure that may become the source of leakage for electromagnetic energy. This is

most common in joints, seams and penetrations such as switches, connectors, and lamps/LEDs. Typically, the

maximum dimension of an aperture should be less than 1/20 wavelength of the highest frequency of interest in

order to avoid emissions.

Interesting, to say the least.

The comments re: air conditioning resurrected an old experience(s).? When I was an OIC of a STRATCOM
Receiver Site in Hawaii, we had a all copper screen room.? As Program Manager of a Comm System in
Kuwait, we also had one.? In both cases, we did not close the door unless absolutely necessary because
of poor air conditioning.

Then it hit me; my project engineer from USAF days has a PhD in Physics.? Think I will
ask him if 1/20 or 1/10 is overkill.? The idea of something less than the tightly closed
copper mesh room still intrigues me - - IF the spacing is not too small.? Doorways and
A/C ducts probably pose the biggest problem to a "cheapo" room.

I appreciate all of the interest and the well-founded references provided so far.

Warren; W7WY