Keith, Did you also lose your TV's and other electronics? Did you lose any transceivers not connected to your mains? The fact is that a lightning strike on or very near your house is going to impress current on any antenna system, or analogue thereof, in the near field, and the amount of energy carried by that antenna system is directly proportional to wire length to that antenna or antenna analogue. The largest antenna analogue in our houses is the wiring system of the house itself, and a residential ground, while being a good short path, is not usually very efficient compared to the ground system of a commercial building or a broadcast tower. That being said, the odds of taking such a hit are small by ground area and reduced exponentially by the relative heights of the surroundings. The object lesson being that if you have the highest thing in large square footage connected electrically to your equipment, you are increasing your odds of a strike significantly. Unfortunately, the best thing for getting a great signal on radio is the worst thing to do for protecting yourself from lightning strikes, which makes perfect sense if you realize that we are in the hobby of taking a small powered sine wave electrical signal from the atmosphere and responding to it using a slightly higher powered electrical sine wave :-) The folks of us that do that most efficiently are the most likely to be the victims of the fact that the system is, by definition, very good at attracting a tens billion times higher potential static DC capacitive discharge.
Ron KE4DRF On Wed, May 26, 2021 at 7:16 PM Keith Dutson via BVARC <[email protected]> wrote: > Some useful info in this post, but shows lack of facts. For example, it > is well known and documented that lightning can strike from cloud to ground > and vice versa. > > My station has been damaged by lightning several times. The worst damage > was in May, 2019, when a large bolt struck my 150 foot tower. This was > witnessed by my daughter and her husband who were outside at the time. The > station furniture in the shack was being moved at that time and there were > no antennas connected. However, all units were plugged into power and > connected to computers. ALL computers and transceivers were destroyed, and > the linear amplifiers were damaged in the power supply section. There were > several signs of lightning flashover at signal and power connections. I > was standing in the shack at the time of the strike, and there was no > sound, but it felt like the time in military basic combat training where > I felt the concussion of dynamite blasts. > > Now I have relay controlled disconnect of power and antennas for all > stations. The disconnect grounds antennas and rigs. > > I did collect insurance. The claim was for about $25,000, and I got about > $22,000 after deductible. > > 73, Keith NM5G > > On Wednesday, May 26, 2021, 09:40:06 AM CDT, Will Gray via BVARC < > [email protected]> wrote: > > > There are lots of books on the subject and plenty of examples > visible around major electrical installations of how to prevent damage by > lightning. Lightning occurs when there is a large charge difference > present, normally caused by rain carrying electrons from clouds to ground. > If there is no path to deplete the charge and when the charge is great > enough, the electrons go back to the more positively charged area of the > clouds above. The strike is from ground to cloud. The use of several > ground rods tied together and connected to power grounds, water pipes, gas > pipes, and the antenna system tends to deplete the charge to the earth, > preventing the strike. Unplug, disconnect and ground your equipment. > During an electrical storm stay away from doors, windows and chimneys. Get > in your vehicle and close the doors. > > Safety! > Will Gray, KB7QL > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > Publicly available archives are available here: > https://www.mail-archive.com/[email protected]/ > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > Publicly available archives are available here: > https://www.mail-archive.com/[email protected]/ >
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