Lightening damage
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Bingo!
Of course the tower is not immune from lightning. Mine has taken many direct strikes and it has a number of ground rods. The ground system gives it a path that is not though your equipment. Also a single point ground and proper bonding as K9YC mentioned will keep everything at the same potential, minimizing damage. Back to the Elecraft net John KK9A Nr4c wrote: Sent from my iPhone ...nr4c. bill > On Nov 7, 2017, at 11:58 AM, <john at kk9a.com> <john at kk9a.com> wrote: > > Why would lightning avoid striking a grounded tower? > > John KK9A > Richard Fjeld rpfjeld at outlook.com > > I'm trying to avoid taking anyone's side on this discussion. I wanted to > say that I worked for a company that had towers throughout the state which > were several hundred feet tall. Over the years, I only saw one that took a > hit. The company was so certain their grounding specs had not been > followed, that they made the contractor dig up the entire grounding layout. > It revealed the specs had not been followed. > > Certain radio and TV services need to operate 24/7 and can't shut down when > lightening threatens. Their grounding methods apparently prevent the towers > from being hit . > > Rich, n0ce ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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Likewise - 3 direct hits to the tower and nothing in the house damaged.
Radios always plugged in. Do it properly (don't trust me - google it). Lots of buried ground rods and copper strap and a single point of ground connection for the radio bench (only). Gas arrestors across all the aerial and rotator connections (and MOV's etc where appropriate). Radio bench isolated from house mains and all other electronic devices (optic fibre to PC). All the lightning arrestors (and MOV's) bolted to a single copper ground bus bar - the single point ground connection is from here to the tower ground system. This keeps the differential voltage across all the radio connections to a minimum. The caveat is - don't operate the radio (manually) in thunderstorms. Of course it's fine via the optic fibre. One lightening hit shook my teeth and made me jump a couple of feet into the air. Most things in the house with running software just crashed. All came good when the power was cycled - nothing was permanently damaged. To say I was relieved is quite an understatement. The 2m collinear at the top of the tower didn't survive. Shame the phone guys don't so it as well. If I get a tree hit by lightning in the front paddock the phone stops working (either immediately or the next time it rains). They replace the gas arrestors and dig up the cable. 73's Peter VK4JD -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of [hidden email] Sent: Wednesday, 8 November 2017 8:12 AM To: [hidden email] Subject: [Elecraft] Lightening damage Bingo! Of course the tower is not immune from lightning. Mine has taken many direct strikes and it has a number of ground rods. The ground system gives it a path that is not though your equipment. Also a single point ground and proper bonding as K9YC mentioned will keep everything at the same potential, minimizing damage. Back to the Elecraft net John KK9A ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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Hi Peter,
Sounds like we have a similar setup for lightning protection. I wound up using 23 ground rods all cadwelded together with solid #4 copper wire. Everything coming into the house and leaving the house is all tied together to one point common ground. I never disconnect and most of the time I don't turn off equipment. For sure I saw two direct hits. And on one I was in the yard coming towards the house as a store approached. It hadn't started raining yet so thought I was safe. Took a tower hit that knocked me to the ground. The one difference is I took off the MOV's and use gas arrestors. When the MOV's took a hit they would short and take out the driver IC's in the SteppIR controller. I do have a ground position for the cable coming into the shack for the SteppIR controller. 73, N2TK, Tony -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Peter Lambert Sent: Tuesday, November 07, 2017 5:57 PM To: [hidden email] Subject: Re: [Elecraft] Lightening damage Likewise - 3 direct hits to the tower and nothing in the house damaged. Radios always plugged in. Do it properly (don't trust me - google it). Lots of buried ground rods and copper strap and a single point of ground connection for the radio bench (only). Gas arrestors across all the aerial and rotator connections (and MOV's etc where appropriate). Radio bench isolated from house mains and all other electronic devices (optic fibre to PC). All the lightning arrestors (and MOV's) bolted to a single copper ground bus bar - the single point ground connection is from here to the tower ground system. This keeps the differential voltage across all the radio connections to a minimum. The caveat is - don't operate the radio (manually) in thunderstorms. Of course it's fine via the optic fibre. One lightening hit shook my teeth and made me jump a couple of feet into the air. Most things in the house with running software just crashed. All came good when the power was cycled - nothing was permanently damaged. To say I was relieved is quite an understatement. The 2m collinear at the top of the tower didn't survive. Shame the phone guys don't so it as well. If I get a tree hit by lightning in the front paddock the phone stops working (either immediately or the next time it rains). They replace the gas arrestors and dig up the cable. 73's Peter VK4JD -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of [hidden email] Sent: Wednesday, 8 November 2017 8:12 AM To: [hidden email] Subject: [Elecraft] Lightening damage Bingo! Of course the tower is not immune from lightning. Mine has taken many direct strikes and it has a number of ground rods. The ground system gives it a path that is not though your equipment. Also a single point ground and proper bonding as K9YC mentioned will keep everything at the same potential, minimizing damage. Back to the Elecraft net John KK9A ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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Not lightening, LIGHTNING!
-- Scott K9MA [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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