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 "Quitt, Walter" wrote:
 >
 > If it were fine mesh and all bonded together and grounded
 > it might work.  Go look at things called:
 > Screen Rooms
 > They are basically a big cube of very fine copper mesh,
 > soldered together at the seams with the doors having
 > mesh RF gaskets.
 > Such rooms can be seen in military installations,
 > communications repair shops and places where they
 > do CE or other emmissions testing.
 >
 > Been there and done that, an RF tight room is a hard thing to make.

  Atleast 10-15 years ago my dad did worked on atleast two project that
 required RF shielded enclosures. One was a 3x3x6 foot (1x1x2 metre) box
 (for whatever reason) and the other was a semi-tractor trailer that was
 RF shielded for a contract for the Saudi government that was to be
 positioned out in the desert for intelligence purposes. (Or so I was told..)
 Before the trailer was sent off my dad gave me a tour of it. It had
 steel plated walls, no normal seems anywhere from what I remember
 (all welded seems.) There was a subfloor where all the wiring was run but
 below the subfloor was all steel. The room had some massive airconditioners
 (that had to be shielded as well) to keep the room from baking in Saudi desert
 heat. The entrance to the trailer was double-sealed doors. I.E. You had to
 enter one door & seal it off before you were allowed entrance to the other
 room. (I think there were even solenoids to prevent both doors being open
 at once but I can't remember. But an alarm would definitely go off if both
 doors were opened simultaneously.) The airduct vent into the room was designed
 to shield many different wave lengths as well. I remember dad showing me LED
 Xmtr/Rcvr pairs that were used to send data into & out of the room because
 standard wire pairs were not allowed due to there "alternate signal" carrying
 characteristics. The actual piece of equipment that allowed in the raw
 power needs for the trailer dad mentioned were atleast US$100 each and were
 designed specifically to pass AC current but shieled out almost every other
 frequency.
    Hmmm... I hope the saudi government isn't watching this list
 and targeting me for termination... ;)


  An Adept Rocketry PIC-based (16c54) model rocket schematic is now online
 that I reverse-engineered back in 1993. They now appear to be out-of-business
 so I decided to post the schematic for learning purposes:

  http://www.devrs.com/       (Select NEWS or PIC to see the schematic.)

  Jeff