> So the purpose of the noise probe (on my circuit at least) would be to > deliberately cause interference, i.e. to test the reliability of my circu= it? Yes. The small probe coil allows you to do this in a targeted manner. Alternatively, you can spend some serious bucks illuminating your PCB in a chamber at various frequencies. I have a PDF that I can email you directly, but I don't have a way to post it anywhere convenient. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .