On Fri, 13 Feb 2004 13:38:42 -0500, Mike Coslo wrote:

Thanks very much, Richard and Ed, I'm doing a search at our University
Lib right now.

- Mike KB3EIA -

Hi Mike,

Add:
"Grounding And Shielding Techniques in Instrumentation,"
Ralph Morrison

"Noise Reduction Techniques in Electronic Systems,"
Henry W. Ott

Two slim volumes with more practical information than a thousand EE
books.

73's
Richard Clark, KB7QHC

Hi Mike:

I have those books if you can't find them. Many shield rooms also have a
shield of soft iron as well as the copper. The soft iron shields against
magnetic fields.


--
John Passaneau W3JXP
State College Pa

This mail is a natural product. The slight variations in spelling and
grammar enhance its individual character and beauty and in no way are to
be considered flaws or defects.



"Richard Clark" wrote in message
...
On Fri, 13 Feb 2004 13:38:42 -0500, Mike Coslo wrote:

Thanks very much, Richard and Ed, I'm doing a search at our University
Lib right now.

- Mike KB3EIA -

Hi Mike,

Add:
"Grounding And Shielding Techniques in Instrumentation,"
Ralph Morrison

"Noise Reduction Techniques in Electronic Systems,"
Henry W. Ott

Two slim volumes with more practical information than a thousand EE
books.

73's
Richard Clark, KB7QHC

"John Passaneau" wrote in message
...
Hi Mike:

I have those books if you can't find them. Many shield rooms also have a
shield of soft iron as well as the copper. The soft iron shields against
magnetic fields.


The traditional modular shielded enclosure has become standardized to a
design of 4' x 8' x 3/4" panels, held with a "hat & flat" clamping rail
system. Each panel is a sandwich of a sheet of galvanized steel, plywood and
another layer of galvanized steel. The steel is often about 24 gauge. This
is a trade-off between weight, manufacturing ease, and durability. The
galvanizing ensures good conductivity at the joints. The steel does give you
a bit of LF H-field SE, but the real reason for the steel is that it's just
a whole lot cheaper that copper screen, and lasts better, since the SE
doesn't degrade and it isn't nearly so vulnerable to puncture.

If you want serious H-field shielding, you need to go to thick steel
(welded) chambers, or employ exotic alloys (expensive, and physically &
magnetically vulnerable).


Ed
wb6wsn