Not quite. What happens is that the surfaces parallel to the incident wave behave as capacitance and the surfaces perpendicular to the incident wave behave as indictors. The initial pulse sets this LC circuit resonating much like a struck bell and creates it's own internal EM field as the energy dissipates in the resistance. This can be effectively damped by placing low value resistors, 50 to 100 ohms, across surfaces to reduce the Q of the shield and absorb the energy. Similar damping Rs are used in high power Tx equipment to stop parasitic resonance in structural parts. It's not uncommon to see a couple of 700W 68ohm resistors bolted to the anode boiler of an HF output tube. Without them the boiler suffers greatly from burnt supports and melted bolts. Lee. . ___________________________________________________________ How much free photo storage do you get? Store your holiday snaps for FREE with Yahoo! Photos http://uk.photos.yahoo.com