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| uk.tech.digital-tv (Digital TV - General) (uk.tech.digital-tv) Discussion of all matters technical in origin related to the reception of digital television transmissions, be they via satellite, terrestrial or cable. Advertising is forbidden, with no exceptions. |
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#1
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"Wrightsaerials" wrote in message
... Here's what happenned yesterday. Lightning hit the end of the roof of a block of flats. The milk lady was stood just below and she was knocked against a wall by the pressure wave, breaking several bottles. The building has a conventional roof with a loft space, Later we found the loft was brightly lit thanks to the hole in the roof. The end of the roof apex near the gable had disappeared, and about a dozen tiles were smashed or missing. The woodwork in that area was charred. In the flat immediately below, all the nails in the ceiling were protruding about 10mm, suggesting that the plaster board had had been pushed down. The TV system in that block serves 14 flats. Amongst these there were four dead TV sets and one dead VCR. One flat at the opposite end to the strike had no mains power at the incoming supply. Bill Shocking! ;o) --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.497 / Virus Database: 296 - Release Date: 04/07/03 |
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#2
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"Wrightsaerials" wrote in message
... Here's what happenned yesterday. Lightning hit the end of the roof of a block of flats. The milk lady was stood just below and she was knocked against a wall by the pressure wave, breaking several bottles. I almost hate to spoil this thread with a sensible question... Should aerial downleads be earthed? ie connecting the coax screen to ground or mains earth, in an effort to reduce the risk of lightning strike? Or would this, in fact, make it more likely for the aerial to suffer a strike, being such a low resistance circuit to ground? And would it affect reception? I've often pondered this. Back to the silly stuff : When lightning strikes nearby, I get a mettalic taste in my mouth. --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.476 / Virus Database: 273 - Release Date: 24/04/2003 |
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#3
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"Ian" wrote in message ... "Wrightsaerials" wrote in message ... Here's what happenned yesterday. Lightning hit the end of the roof of a block of flats. The milk lady was stood just below and she was knocked against a wall by the pressure wave, breaking several bottles. I almost hate to spoil this thread with a sensible question... Should aerial downleads be earthed? ie connecting the coax screen to ground or mains earth, in an effort to reduce the risk of lightning strike? Perhaps Bill can enlighten us, I'm almost certain that in some countries the earthing of aerials and satellite dishes is a legal requirement therefore it would be interesting to know how this is achieved.. i.e. type of conductor etc.. I would be surprised if it doesn't add to a pretty penny or two to the price of an installation. Or would this, in fact, make it more likely for the aerial to suffer a strike, being such a low resistance circuit to ground? And would it affect reception? I've often pondered this. Back to the silly stuff : When lightning strikes nearby, I get a mettalic taste in my mouth. --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.476 / Virus Database: 273 - Release Date: 24/04/2003 |
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#4
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Should aerial downleads be earthed? ie connecting the coax screen to
ground or mains earth, in an effort to reduce the risk of lightning strike? In a direct strike the aerial and cable are vapourised. Even a strike nearby can melt the cable. As far as I can see the only thing that would make any difference would be to install a proper lightning conductor (you know, copper strip 1.5 inch x three sixteenths). And what difference would it make? The telly would still be blown up. I suppose there would be less chance of a fire starting inside the building. Big buildings generally have all the aerials and other metal appendages bonded to to the lightning conductor system, but I wonder if this is wise. Maybe it would be better to keep aerials and their downleads isolated from the lightning conductor. I just dunno! Bill |
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#5
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"Wrightsaerials" wrote in message ... Should aerial downleads be earthed? ie connecting the coax screen to ground or mains earth, in an effort to reduce the risk of lightning strike? In a direct strike the aerial and cable are vapourised. Even a strike nearby can melt the cable. As far as I can see the only thing that would make any difference would be to install a proper lightning conductor (you know, copper strip 1.5 inch x three sixteenths). And what difference would it make? The telly would still be blown up. I suppose there would be less chance of a fire starting inside the building. Big buildings generally have all the aerials and other metal appendages bonded to to the lightning conductor system, but I wonder if this is wise. Maybe it would be better to keep aerials and their downleads isolated from the lightning conductor. I just dunno! Bill It would be interesting for someone from somewhere [USA, Germany?] where earthing is a requirement, to let us know how it works in their particular country. |
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