Paul Haas wrote: ===Now I'm going Way Way Off Topic, but I can't help myself.===== >I want the thread to die, so I shouldn't mention this. But it was too cool not to note. With the meter hooked up to the foil, I could detect a running cat at 15 feet. It is dry here this time of year, and he is a long haired cat. I imagine he is really charged up. He enjoys chasing the dot from a laser pointer. So even though he is a cat, I could get him to run anywhere I wanted, when I wanted, to do experiments. >If I was still, and the cat was far away, the voltmeter showed a few millivolts. If I had the cat run towards the negative meter lead, the meter would register a few volts. When he ran away, it would go negative. At longer distances, I'd see smaller changes, but he could still change that last digit at about 15 feet. Since the measured voltage went up as he approached the negative probe, and down when he went away, he's got a significant negative charge. >I can't repeat the experiment with my other cats, they don't chase the laser dot. This is better than the lawn mowing goats thread. Long live OT!! Meanwhile, to continue the static thread, on a dry day a large elevated conductor that is very well insulated from ground can accumulate a sizeable charge - enough to give you a real jolt if you touch it while grounded. I once read of a farmer who strung a wire from his house to the barn for an AM radio antenna (this was long ago). The wire was insulated on each end. He got called into dinner before he connected the lead in wire, so the wire sat there twenty feet off the ground and completely insulated for about an hour. When the farmer went back to work, he touched the antenna wire and got such a bad shock that he fell off the ladder and broke his neck. I used to have a "Big Stick" CB antenna many years ago. It was essentially an eleven foot long piece of 1-1/4" pipe bolted vertically to a second floor balcony. An 11 foot long fiberglass "whip" with a wire inside was attached to the top of the pipe. Coaxial cable ran up the pipe. Its center conductor was attached to the vertical "whip" and its shield was attached to the top of the pipe. There was _NO_ DC continuity between the whip and the pipe. When thunderstorms were in the area, fat blue sparks would jump from the center conductor to the outer conductor of the PL-259 connector at the CB end of the coax. I hooked up a switch box so I could switch the coax over to an NE-2 neon bulb when thunderstorms were coming. As the storms got nearer, one of the two electrodes would start to flash, first once every few seconds, then faster and faster until it appeared to be continuously lit when the storms were very near. One interesting effect I noticed was that after a nearby lighting stroke, the voltage on the antenna would switch polarity, as indicated by the lit electrode going out and the other starting to glow. This would doubtless have an interesting effect on any model airplanes using the atomospheric electric field to maintain level flight. On a larger scale, a friend was visiting at a local AM broadcast station one day just before a thunderstorm hit. There had been no rain for weeks and everything was dry. AM broadcast band stations (non-US: 550 - 1600 kHz) insulate the whole tower from the ground and use it for the antenna. The guy wires that support the tower are broken every few meters and insulators are inserted so that they don't mess up the antenna tuning. My friend was just walking out to his car, before any rain had fallen, when he heard snapping noises coming from the tower. He looked up and saw large blue sparks jumping across the insulators on the guy wires! He didn't stick around long enough to check for polarity changes! Anyway, watch out for big elevated conductors that are isolated from ground, make sure all the pieces of your outdoor antennas have DC continuity to ground (a small coil will let the DC charge flow through while keeping the RF where it should be) and long live the OT portion of the PIC List! Sorry I couldn't write anything about goats. Dave "OT" Mullenix, N9LTD (and KAEZ-2705)