HFU HF Underground
Technical Topics => Equipment => Topic started by: Treehouse SWL on January 30, 2019, 2016 UTC
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Hoping to elicit some informed advice here:
Since I started listening to shortwave again last year, I've just had a longwire antenna strung out of my window, which means the window stays a tiny bit open, which is not ideal for heating bills, etc. I found a long-forgotten cable TV hookup in our room, so I'm in the process of rewiring my feed line through there, which led me to wonder if I should also relocate my antenna. My options:
1: Keep my existing longwire antenna, which is about 50 feet long, running west-east along a wood fence (5-6 feet off the ground) from the top of our backyard to the bottom of it.
2: Run the wire, 40-50 feet long, a few inches above the roofline on the back of our house. That would put it approx. 30 feet above the ground, though running north-south instead of east-west.
3: Do both.
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Do you have any trees anywhere from 30ft to 75ft from your house? I would run the long wire out to them. Why??? Better height, and get some distance from the house, which is usually the generator of various noises, electrical, computer, TV spurs, etc. If possible, try to run the long wire on the side of your house, away from where the power lines, phone, cable TV, come in. Try this also, if you have a portable shortwave radio, take it outside and walk the whole outer perimeter of your house to find the quietest, least noisy, spot, to run the long wire out. Hope that helps.
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I'd recommend the fence line, as it keeps the antenna away from the house (assuming not near any power lines for safety as well as RFI issues).
If you can run to a tree as ThaDood suggests, that would also be good.
You may want to consider a loG (Loop on Ground) antenna as well, if you have limited space for in the air antennas.
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So, we actually have a near-perfect tree to which I could run a longwire across the backyard from the house, but there are two major problems:
1> My three kids throw balls and such right in that part of the yard, and it would inevitably get hit down.
2> More importantly, my wife does not approve. And I have to admit it would mar our Cascade Mountain views (https://imgur.com/a/zY0DB8s).
There is a closer tree to my house, but I could only run that wire about 20 feet through the air. That tree is pictured here, along with the fence I'm currently running a wire on: https://imgur.com/a/G8JiHil.
My worry about a LoG is the kids messing with it. However, right outside where the feeder lines will enter the house is a patio roof created by the bottom of the deck. It extends out a good 10 feet from the house. Maybe hanging an outdoor-rated loop antenna there would work there.
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Oh, I forgot to answer the RFI question. We're lucky to live in a neighborhood with no overhead power lines, and my house has no cable TV or landline phone, etc. We run our Wi-Fi network via a cellphone dedicated for our VoIP phones, video streaming, internet, etc.
So I've been happy to find that, except for RFI from one particular exhaust fan, the noise level's not too bad here. Even the nearest legal marijuana grow facility (I hear those lights can give off interference) is at least a 1/2 mile away.
Like most DX'ers, I'm just seeing if I can improve on my reception without spending big $$. When I got back into this last summer, I literally just threw a long wire on my fence without any separate feeder line, grounding (I know, I know), etc., and that's brought in stations from 53 countries, as well as about two dozen different pirates within six months. So I can't complain too much. And, yes, I'm finally getting a real feeder line and grounding set up in the coming weeks.
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Keeping the antennas conformal with the surrounding environment is a great idea. I propose a vertical strung up to the top of the tallest tree, made of insulated wire of course, and a number of radials placed in the thatch so the new growth this spring will cover them and keep them in place. All fed with coax that can likewise be held in place. Some folks use old wire coat hangers to hold down the wire, just cut a length off and bend it in a U shape and pin the wire to the ground every few feet with your coat hanger U's. That way everything should stay in place for mowing and etc activities.
Neighbors and wife will be none the wiser.
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My daughter and the neighbor kids used the low ends of my longwires/inverted vee's to play badminton over. It's why I switched to Dollar Store speaker wire for antennas until they were grown
Eight feet is my minimum height for any longwire. You don't want to clothesline a tall meter man.
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My daughter and the neighbor kids used the low ends of my longwires/inverted vee's to play badminton over. It's why I switched to Dollar Store speaker wire for antennas until they were grown. Eight feet is my minimum height for any longwire. You don't want to clothesline a tall meter man.
Lol when I had a sloper going from the second story br to the mailbox at the end of the drive, the mailmen finally asked wtf it was, on hearing it's a shortwave antenna, a sloper to be precise, they laughed and said we all thought it was some kind of earthquake seismic sensor thingy. It was red insulated wire so everyone saw it, had a white porcelain insulator at the end. Reason no one ever walked into it or complained about it is we had the last house on that side of the street and the sidewalk ended a foot on the other side of the mailbox.
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I'll ask an add-on question:
So far, my longwire antenna stretches about 50 feet (west to east) down to the far end of my yard along a wooden fence. There, at the corner, is a metal fence that separates us from the school field below and runs about 50 feet to the north, where it meets up with another 50-foot-long wooden fence that runs east to west to separate our yard from the neighbor.
In other words, it's like a big squared-off U shape of fences. So far, I've just used the once fence for my wire. Would there be any advantage to running an antenna wire all 150 feet or so? Would the metal fence just increase interference noise (my wire antenna is insulated)?
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Try hooking your wire to it and see how it fares, or run additional wire along it. Also, it offers the option to use the fence as a ground to make your wire a beverage antenna.
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I used a chain link fence as a counterpoise/ground for a BoG for the funny bands during the summer for a number of years. It worked surprisingly well and was all inside the same fence. Don't use the chain link fence as an antenna, they just don't get it done.
Use a spring loaded battery clip. An alligator clip moves around too much on the heavy gauge fence wire. Otherwise you'll be walking out to reconnect several times a listening session if there is any kind of wind.
Coming up with antennas is low cost, fun hobby that will let you save money for better radios. With knobs, of course.
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A HAM I know had a wire loop inside his chain link fence and worked Europe on 20m with 100w ssb on that thing. Prolly wasn't even 300ft of wire.
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Use a spring loaded battery clip. An alligator clip moves around too much on the heavy gauge fence wire.
Agreed. I also recommend burnishing to clean off the oxidation in the area of the fence that you plan to connect the clip to. Use some sandpaper or perhaps a file. Yes, the oxidation will come back.
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Oh, I forgot to answer the RFI question. We're lucky to live in a neighborhood with no overhead power lines, and my house has no cable TV or landline phone, etc. We run our Wi-Fi network via a cellphone dedicated for our VoIP phones, video streaming, internet, etc.
So I've been happy to find that, except for RFI from one particular exhaust fan, the noise level's not too bad here. Even the nearest legal marijuana grow facility (I hear those lights can give off interference) is at least a 1/2 mile away.
Like most DX'ers, I'm just seeing if I can improve on my reception without spending big $$. When I got back into this last summer, I literally just threw a long wire on my fence without any separate feeder line, grounding (I know, I know), etc., and that's brought in stations from 53 countries, as well as about two dozen different pirates within six months. So I can't complain too much. And, yes, I'm finally getting a real feeder line and grounding set up in the coming weeks.
The marijuana growth facility lights give off interference? Thats nothing - try talking to those that use the stuff! :D