<br><br><div class="gmail_quote">On Mon, May 4, 2009 at 3:49 PM, Zachary Kotlarek <span dir="ltr"><<a href="mailto:zach@kotlarek.com">zach@kotlarek.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
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On May 4, 2009, at 3:38 PM, Tim Wilson wrote:<br>
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<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
've heard that what you have to protect against the most is not lightning, but static electricity. Wind blowing particles across the antenna can build up static electricity, which will travel down the wire and into your sensitive components. I've had installers tell me that if (in my case) the dish were to get a direct strike, the lightning would likely travel the cable, regardless of grounding. I don't know if that's true, but more than one person has told me this. My guess is that in the case of a direct strike, enough electricity would still flow through the cable to fry components.<br>
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I think that's probably true -- there's a good chance a direct strike will blow out your electronics no matter what. But hopefully you can mitigate the damage and go from "my VCR exploded and started the house on fire" to "the VCR blew a few capacitors and needs to be replaced". And there's certainly a better chance your equipment will survive if the line is properly grounded than if it's not.</blockquote>
<div><br>Oh yeah, I'm definitely for grounding, I'm just saying that a lightning strike could still take out your equipment. Don't count on nearby objects attracting the lightning. There still might be enough of a charge left in the air to zap your gadgets.<br>
<br> <br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="im"><br>
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I've also heard to put a gentle curve in the cable coming down from the antenna similar to a drip curve. The thought is, lightning (or at least some of it) will travel in a straight line, and will not follow the curve.<br>
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That's about inductance. You're supposed to install grounding wires with no small-radius turns to minimize the inductance of the grounding path. There's a very large, near-instantaneous current change related to a lightning strike, so even minor curves can have a large impact on the effectiveness of a grounding wire. There's probably some benefit to adding inductance to the signal wire, but I don't know that it would provide any practical amount of protection beyond the existing high impedance of the signal path versus the grounding path.</blockquote>
<div><br>I was meaning a curve in the actual cable, not the grounding wire. Like a half-loop, where the cable comes down, and curves back up with a gentle radius. But I guess the same could work for grounding wires. <br>
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Zach<br>
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