On Wed, Aug 18, 2010 at 11:00 PM, Forrest W Christian wrote: >... > =A0 Pulled > the scope probe out of it's 'grabber clip thingy (yes technical I > know)', and touched the tip to the grounding clip (you know, the one > with about 3 inches of wire attached directly to the probe itself). > Amazingly, the spikes were *still* there. =A0 Ended up disconnecting all > the other grounds on the other probes and referencing only to that one > to verify that signal was clean. =A0Of course, then all the other signals > weren't clean anymore - at least not on the scope. > If you're using the ground clip with its attached wire you will not get a clean signal. The inductive loop is too large. If you look at the end of the scope probe with the grabber removed you will see a little ring of ground near the end of the probe. Somewhere under the debris at back of your workbench you will find the little plastic bag of accessories that came with your scope probe. One of them is a little clip that goes on the end of the ground ring. You can also take some solid wire and wrap it around the ground on the end of the probe. The idea is to reduce the area of the loop formed by the probe and its ground. Regards, Mark markrages@gmail --=20 Mark Rages, Engineer Midwest Telecine LLC markrages@midwesttelecine.com --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .