Posted: 7/30/2014 5:26:30 PM EDT
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Know when to disconnect the antennas!
http://www.lightningmaps.org/realtime?lang=en The strike patterns are interesting. Several seconds with nothing, then a rapid series of strikes. |
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Quoted:
Know when to disconnect the antennas! http://www.lightningmaps.org/realtime?lang=en The strike patterns are interesting. Several seconds with nothing, then a rapid series of strikes. Thanks for that link. Gives me one more tool for my weather watching during our stormy weather seasons in DFW. |
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Know when to disconnect the antennas! My rule, any time I am not on the air, I disconnect the coax from the radios, lay it across the bench with the ends hanging free, and unplug power supply and anything else radio from the AC sockets. Even if no direct strike, you can get static discharges on the plug and start fires. This is why some old time hams put the end of the coax in a Mason jar. They know that won't stop lightning, but at least they won't burn down the house from static discharges lighting up the note pad on the desk. There used to be a Youtube video showing the disconnected coax sparking during a storm. |
Love my M38.
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Lightning up on the hill where I live sometimes takes on the proportions of Dr. Frankenstein's laBORatory. Whenever I'm not using the station, I disconnect the feedline at the base of the antenna, roll it up, and place the reel in the carport where the feedline enters the house. There's about 40' between the two points.
I had some minor damage happen years ago when I just pulled the end of the coax back, leaving a loop that stretched about 20' from the house. Lightning hit a nearby tree about 50' away and charge dissipating through the ground induced enough voltage in the loop of coax to jump to an AM/FB BC on the workbench bench and kill it. Nothing else was damaged. |
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Which led me to another video connecting this thread to the S9 antenna thread.
Lighting 1, S9 antenna 0 |
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Quoted:
Which led me to another video connecting this thread to the S9 antenna thread. Lighting 1, S9 antenna 0 Interesting video I 'may' have posted in the s9 sale thread, (or maybe the 60 mph wind) Some good comments following video, if you have time, read the comments. |
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Cool Video.
30+ years ago I lived on high hill top, had long wire several hundred feet long. (was into LF, had tapped coils ,amps, etc) Had excellent ground system, enjoyed placing Simpson 260, as well as a Gould strip recorder between ant. and gnd. Measured hundred if not more V. Was fun having AM radio on, hearing static crash, then, counting down to the 'BOOM'. And ( 'whistlers') |
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Note to self: get a lightning arrester. The power in a lightning stroke is unimaginable.
I saw a similar result from an assumed direct strike many years ago of the NC coast. My group maintained a waverider buoy about 1/2 mile off the beach, it is a spherical stainless buoy 1 m diameter, in those days we used HF to telemeter data ashore. The antenna was a fiberglass tube, similar to a marine VHF antenna. A big storm came up over the weekend and the waverider went silent. We went out to recover it and found the antenna had disappeared. Only the spring base remained. Actually, a good bit of it was still there, in the form of carbon tracks along the exposed parts of the buoy hull. The electronics inside were undamaged, I suspect the lightning traveled on the surface of the buoy due to skin effect. That same storm took out an instrument sled deployed under some high tension lines. The sled's mast protruded above the water about 10 ft, and it got its power from a bank of car batteries on one of the HT line towers. We figure lightning hit the ground wire on the HT line, jumped to the tower, down our cable, into the instrument housing. Voltage regulators inside the housing exploded. It also killed several instruments through indirect coupling. We had a lot of buried cables leading to remote instruments, all were protected by transzorbs but a few went dead during the storm. Bear in mind, these were buried cables leading out into the ocean. |