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#1
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I got a YAGI antenna and put it in my attic -- helped me get rid of FM
static problem I had been experiencing with just the basic dipole antenna I was using. But I was wondering ... is there any issues with lightning like if the antenna was outside or is the fact that the antenna is in the attic and covered completely by roof make that a non-issue Thanks for any info (p.s. I know some people are probably laughing at this as a dumb question -- but I figure better to ask then take a chance on toasting my house!) Thank you |
#2
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![]() mBird, The likelihood of your antenna in the attic being hit by lightning is about the same as winning the lottery. Not impossible, but don't hold your breath. 'Doc |
#3
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Treat it like an outside antenna.
Wise words, up to a point. 1) Hardly any difference in the face of a near hit. EMP will hit the antenna through non-conducing roof. 2) No problem with static accumulation, though. That is due to the direct interaction of wind / rain / snow and outside metal. 3) Also, IMO, reduced risk of direct hit. Old fashioned lighting rods featured tall spikes to provide a preferental path to ground for a lightning. Today's standard solution is a set of flat conductors that still provide a preferential path, but do not stand up "inviting" bolts, thus reducing somewhat the likelihood of a hit. (They also affort little or no protection to nearby property, unlike the older design). This in not so clear cut though. If grounded, an attic antenna will become statically loaded anyway as the bolt potential builds up. The point effect will be there, leading to a potential dielectric-perforation risk. The roof will indeed afford additional isolation, depending on how much material (roof + DRY air) is between the antenna and the moist outside air in an electrical storm _with_ rain. I don't know the exact figures, but I think rainstorm bolts are more common that dry air bolts. Take your precautions! Filippo |
#4
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Must agree, as , in my youth, had neighabor liveing across the street, in
Portland, OR., this on the valley floor, had her Electric Range struck by lightning, tho, must also agree with Doc, the odds are not much better (or worse, depending on your outlook!) of hitting the lottery. and, if your home is serviced by power lines on poles, there is USUALLY a GROUND WIRE , at the top of the pole line, and, as lightning USUALLY takes the path of least resistance, would be the object struck by lightning. It never hurts, tho to provide lightning protection, just for general safty. Jim NN7K "CW" wrote in message news:aMDpb.72275$mZ5.450665@attbi_s54... Not at all a dumb question. There are many people that think if it's inside you don't have anything to worry about (the ostrich syndrome). Lightning doesn't care much about your roof nor does static. Treat it like an outside antenna. "mBird" wrote in message |
#5
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Jim wrote:
... must also agree with Doc, the odds are not much better (or worse, depending on your outlook!) of hitting the lottery. ... Actually, I read somewhere that you're about 1000 times more likely to be hit my lightning than to win the PowerBall. I would imagine it would vary considerably depending on which state lottery you're comparing it to, but I'd also imagine that lottery odds are in general much longer than being hit by lightning odds (i.e. winning the lottery is much less likely). |
#6
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On Wed, 05 Nov 2003 02:22:29 GMT, asdf wrote:
Jim wrote: ... must also agree with Doc, the odds are not much better (or worse, depending on your outlook!) of hitting the lottery. ... Actually, I read somewhere that you're about 1000 times more likely to be hit my lightning than to win the PowerBall. I would imagine it would vary considerably depending on which state lottery you're comparing it to, but I'd also imagine that lottery odds are in general much longer than being hit by lightning odds (i.e. winning the lottery is much less likely). Guess I'm gonna have to ask for better odds as my tower gets hit bout 3 times a year on average. http://www.rogerhalstead.com/tower.htm There are taller towers around, but it's two miles to the nearest one. Considering I never disconnect the gear I've had very little damage. One direct hit really frazzled the end of the big 144/440 vertical, blew off all the coax seal and tape, and even removed the plating from all the connectors at the top of the tower. I did lose the front end out of the 2-meter rig on that one. The water running out of the 9913 after the lightening removed the coax seal was at least as big a problem. One-of-these-days I'm going to get some static balls up there to see if they make a difference. Roger Halstead (K8RI EN73 & ARRL Life Member) www.rogerhalstead.com N833R World's oldest Debonair? (S# CD-2) |
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