On 7/6/06, Martin Klingensmith wrote: > I can't believe you thought of that! > But yes, interestingly it was. > I don't remember if I moved my cell phone when the problem went away, > but it's possible that I did. > Cell phones cause all sorts of interference around analog electronics > that I've noticed occasionally. I have some computer speakers that "burp > and fart" when a cell phone is close by. > I'll see if I can replicate this next time I'm using the scope. Boy, does that remind me of some debugging sessions: * Back in college, in a physics lab, my partner and I were doing coupled oscillators (magnetic induction coupling via torroids). At one point, we saw the oscillators coupling, displayed on an oscilloscope, "bouncing" between two values. It turns out that the "bouncing" was due to the error display (flashing numbers) on my calculator, which used a DC-DC converter (and thus it's own oscillating magnetic field). We wound up re-doing the entire experiment with my calculator safely placed far away. * A friend asked me to look at his monitor, thinking something was wrong. It would work fine in text mode, but display wavy lines when doing games or graphics like Windows (back in the 3.1 days). I looked at the wavy screen, thought for a second or two, then reached up and turned off the "clip-on" fan on the top of the monitor. The lines disappeared... Bill -- Psst... Hey, you... Buddy... Want a kitten? straycatblues.petfinder.org -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist