I’ll throw my $0.02 in (truly all it’s worth): I have a similar setup at my house - power lines through the back yard at about 30’ high, probably 60’ or so laterally from my chimney; single-story house; 10-foot dual-band vertical mounted on chimney, extending above it.
We love building big, blazing, masonry-melting fires in the wintertime (which is any time it dips into the 40s, in these parts). My antenna’s been up there for about 6 years now, and it still works fine. I’d suspect your J-Pole is even hardier than my fiberglass groundplane. As far as lightning, your latter comments are key. Lightning will go where it wants to. I don’t think power lines are any more of a magnet than every single tree, light pole, chimney, or other rooftop around you. Enjoyed your stories too. Really amazing what lightning can / will do. 73, N5OL Sent from my iPhone > On Apr 8, 2020, at 6:16 AM, Mark Brantana via BVARC <[email protected]> wrote: > > Since folks are hunkered down anyways, here is a problem. I am improving my > emergency radio capability by adding a 2-m radio to my home office. Who knows > where this thing is going, and I think this is a good time to prepare. I > would like your thoughts or experience with the following. > > I am looking to mount a 2-m antenna on my roof. Currently I have a TV > antenna attached with a j-pole just below the chimney output. I have a > single-story house. My plan has been to extend the j-pole about 4 ft higher > to get better TV reception, and mount the antenna just above it. I do have > to watch out for offending the HOA. > > My property has power lines running parallel with the back of the house, and > these power lines are about 35 feet high and 35 feet laterally away from the > chimney. > > I am concerned about a couple of things: > Some day I may want to start a fire in the fireplace, and I do not want the > heat to get to the antennas. This is why I have the TV antenna mounted below > the top of the chimney. > I would like to avoid arching or lightning strikes, though I think it is > quite common for most of us to have power lines around to contend with. Two > thoughts here: > Of course, I will ground it all. > I wonder if the power lines might protect the lower antennas since lightning > may hit them first. I mention this since the first thought was that the > power lines might add to the lightning risk, not detract. > That said, lightning does what it wants, and even a nearby lightning strike, > as opposed to a direct strike, will do significant damage. > > On that last point, I will share a short story. When in Louisiana many years > ago, we got into a discussion about how lightning had destroyed a lot of > equipment in a member’s shack. This included, as I recall, about 3-5 > computers, and about as many radios. This was all sitting on a metal table. > Due to the lightning storm, the Ham had disconnected all of the antennas. > Lightning hit his tower and made the 2” jump to the table. The rest was > history. But, that was not the story I wanted to tell. That was the > discussion we were having. Another Ham broke in and told us that he had a > tower at one end of his house which was operational, and he had just that day > mounted a short marine antenna at the other end of the house on his chimney. > It was a dark and stormy night the previous evening, and the lightning passed > the tower to hit the yet unconnected marine antenna. So, lightning does not > follow the rules. > > OK, so I diverged. I really would like to know what experience and advice > you can offer me on my project. The power lines make me nervous, and I > really wish my best mounting option were not in the heat zone of the chimney. > > Mark > N5PRD > > > > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org
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