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#41
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Honus wrote:
Let's stay on topic, shall we? Back to cuhulin: The pervert's puny pecker porked a pretty pudgy Pekingese. With his habits, that's NOT alliteration. It's alimenterycanalation. I'm starting to think 'hulin means something disgusting in Celtic. Mcmike II |
#42
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The Tips can be Elevated above ground or
the Tips can be at/near ground level and a Ground Rod placed at both ends (Tips) with a Lightning Aresster (GDT) mounted on each. .................................................. ....... The higher the ends above ground, the better. You have less earth loss. There is no need to use lightning arresters at the tips of the dipoles to ground. If the wire were actually close enough to ground to arc to ground, it will do it, arrester, or not. Being as you are not protecting any devices at the ends, there is no real point in using arresters. The arrester should be in the feedline leading to the radio. If the inv vee is supported by a tree or mast, the lightning is more likely to take that path to ground, than the path of perpendicular antenna wires to ground. Lightning doesn't like to take sharp turns. So you should always ground the supporting mast well, if it's metal. It's gonna take the brunt of the strike to ground... Horizontal wire antennas are not near as prone to be a lightning target, as say a vertical, or other tall mast. IE: a dipole, or inv vee hung in a tree will add little to the overall likelyhood of that tree being struck. It would probably be struck anyway, antenna or not, if lightning was that close, to choose that target. I bet in most cases, the antenna would basically be untouched, unless the strike found the feedline running down the tree, and decided to use it....You can always snub the feedline to ground at the base of th tree in a case like that. I know I have had two direct strikes to my mast supported my various dipoles, and have never had any indication of wire, or coax damage. That tells me most of the strike is carried to ground by the mast, which does stick up about a foot above my antenna apex. "I currently have 160/80/40 dipoles on one feedline...Appx 440 ft of wire in the air...The apex about 42 ft high supported by a metal mast. So far, in 35 years of hamming, SWLing, I've never had a horizontal wire dipole be a lightning target. But mine are never higher, than surrounding objects, trees, etc unless supported by a mast, or tree, which then becomes a more preferred target than the dipole itself... Not saying it can't happen. It surely can. But not near as often as vertical targets. Even at 42 ft, I've still got trees taller than that in the yard... That helps...The last strike hit the tree in the front yard.... If the vertical target is well above the house, other objects, you can bet on it taking a zap sooner or later. Most people don't have wire antennas higher than the surrounding trees, etc, unless they have a vertical support to support it...When they get above the surroundings, is when their chance of a strike goes up sharply. Even horizontal metal can be a problem if it's really high...IE: beams, etc..MK |
#43
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Dr, Artaud,
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#44
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![]() From: "RHF" Organization: http://groups.google.com Newsgroups: rec.radio.shortwave Date: 22 Apr 2005 07:18:06 -0700 Subject: Antenna Suggestions and Lightning Protection Dr, Artaud, . You are interested in installing a 'shallow' Inverted "V" Antenna that would be center over your House; and you want to improve your Lightning Protection at the same time. (Snip) RHF - I don't recall Dr. Artaud's particular circumstance, but here is mine: My radio table faces an inside wall. The widow is across the room. Under the window is a long concrete patio. So I can't have an earth ground nearby. I can put up an antenna as you describe. My question: Is it safe to disconnect the antenna input (center of coax) from the radio and switch it to the household AC ground for lightning protection? Greg |
#45
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I told y'all before Greg doesn't know ****.There are such things as
drill bits made for drilling through concrete.(I own several different sizes of them) Drill a hole through the concrete patio and then hammer a six foot long ground rod down into the ground. cuhulin |
#46
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Lightning doesn't start at the top and travel down.Lightning starts at
the bottom and travels up. cuhulin |
#47
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![]() "Greg" wrote From: "RHF" Organization: http://groups.google.com Newsgroups: rec.radio.shortwave Date: 22 Apr 2005 07:18:06 -0700 Subject: Antenna Suggestions and Lightning Protection Dr, Artaud, . You are interested in installing a 'shallow' Inverted "V" Antenna that would be center over your House; and you want to improve your Lightning Protection at the same time. (Snip) RHF - I don't recall Dr. Artaud's particular circumstance, but here is mine: My radio table faces an inside wall. The widow is across the room. Under the window is a long concrete patio. So I can't have an earth ground nearby. I can put up an antenna as you describe. My question: Is it safe to disconnect the antenna input (center of coax) from the radio and switch it to the household AC ground for lightning protection? Greg Greg, before you entertain such suicidal thoughts again, please browse my website explanation of why your home's electrical wiring and ground system are not meant to handle lightning surges. While Cuhulin entertains us with his every post, his comment is nonetheless correct that a patio ground is possible. So is drilling a hole and sinking a ground rod through your radio room floor. But if renting a Hilti hammer-drill and concrete drill bits isn't your cup of tea, then consider coming through a different wall of the radio room that does have a short path to deep earth ground. The very best plan, no matter what room in your home you want to connect and listen from, would be to route all antenna feedlines to the AC service entrance ground FIRST, (shield grounding the coax at the base of the antennas and at the service entrance, install lightning arrestors on the coax at the same ground rod, then snake them into your radio room any way/direction you have to. It would be safer if your radio room was also right next to the AC service entrance ground, but you will see options on the website to deal with that problem if it's not close. http://members.cox.net/pc-usa/station/ground0.htm Best regards, Jack Painter Virginia Beach, Virginia |
#48
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Alternately,if a woman is the manager of the complex you live in,make
love to her every night and she just might let you run a ground wire wherever you want to. cuhulin |
#49
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![]() wrote Alternately,if a woman is the manager of the complex you live in,make love to her every night and she just might let you run a ground wire wherever you want to. cuhulin We used to call that "thinking out of the box" ;-) Jack |
#50
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Greg,
=2E If you build the Shortwave Listener (SWL) Antenna as described in my post. 1=2E The Shortwave Listener (SWL) Antenna which is a basic [Horizontal] Random Wire Antenna will be 'remote' from your house. 2=2E The Primary Ground for your Shortwave Listener (SWL) Antenna will be 'remote' from your house. 3=2E The Matching Transformer will provide some 'isolation' between the Shortwave Listener (SWL) Antenna and the Coax Cable Feed-in-Line. 4=2E Burying the Coax Cable near the 'remote' Shortwave Listener (SWL) Antenna and Ground Point will 'improve' the Lightning Protection of the system. 5=2E Using a Coax Cable Feed-in-Line with the Outer-Shield Grounded and Buried at the Far-End near the 'remote' Shortwave Listener (SWL) Antenna; will 'improve' the Lightning Protection of the system. 6=2E Using a Commercial Heavy Duty Antenna Switch that 'facilitates' the Connection of the Shortwave Listener (SWL) Antenna to your Radio Equipment when "In-Use" and Disconnecting the Shortwave Listener (SWL) Antenna and Grounding-the Antenna-Out when Not-In-Use. =2E -IF- You do not have a Ground for your Shack's Radio Equipment that is "Bonded" to your House's Electrical System : Then the above 'remote' Shortwave Listener (SWL) Antenna and Grounding Point will provide you some level of Lightning Protection that is "Better-Than" NO Ground at All when you use Using a Commercial Heavy Duty Antenna Switch. =2E WARNING "DO NOT" 'connect' the Center-Wire of the Coax Cable to the House's Electrical System via one of the little Round Holes or one of the little Screws of a common Three-Prong Electrical Box. Caution - This is NOT Good or Smart Lightning Protection for your Radio Equipment; your House; and you and your Family and Loved Ones. =2E HOUSEHOLD GROUNDING "A PROJECT" {In and of Itself} : Building a 'reasonable' Household Safety GROUND for your Shack's Radio Equipment that is "Bonded" to your House's Electrical System is a Project in and of itself. Somewhere between Nothing (No Ground) and a "Certified" Grounding System is a 'reasonable' Household Safety GROUND that meets and satisfies your expectations for your personal level of Electrical Safety comfort and Local Lightning Conditions. =2E =2E iane ~ RHF =2E =2E All are WELCOME and "Invited to Join" the Shortwave Listener (SWL) Antenna eGroup on YAHOO ! http://groups.yahoo.com/group/=ADShortwave-SWL-Antenna/ =2E Some Say: On A Clear Day You Can See Forever. http://groups.yahoo.com/group/=ADSho...message/=AD502 =2E I BELIEVE: On A Clear Night . . . You Can Hear Forever and Beyond, The BEYOND ! With a Shortwave Listener SWL Antenna of your own making. "If You Build It {SWL Antenna} You Will Hear Them !" =2E . . . . |
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