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#1
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Antenna recommendation needed
Hi all,
I've had a planning application for a tower turned down which is a real pain. My options are now very limited. I'm in a bungalow with a roof apex height of 18 feet and I'm not allowed to put up anything much above this roof line it transpires, so inverted vees that need to be mounted high up at the feed point like G5RVs are not possible for me. My garden boundaries limit the length of any wire antenna I might wish to put up to about 120 feet overall. On the plus side, though, the QTH is several hundred feet ASL close to the top of the hill and am not overshadowed by any trees or buildings to speak of. What's my best choice for an HF antenna under these circs? (I mostly do CW on 20m & 40m, but would like a bit more band choice ideally if poss). Many thanks. Many thanks. |
#2
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Antenna recommendation needed
Bruno wrote:
Hi all, I've had a planning application for a tower turned down which is a real pain. My options are now very limited. I'm in a bungalow with a roof apex height of 18 feet and I'm not allowed to put up anything much above this roof line it transpires, so inverted vees that need to be mounted high up at the feed point like G5RVs are not possible for me. My garden boundaries limit the length of any wire antenna I might wish to put up to about 120 feet overall. On the plus side, though, the QTH is several hundred feet ASL close to the top of the hill and am not overshadowed by any trees or buildings to speak of. What's my best choice for an HF antenna under these circs? (I mostly do CW on 20m & 40m, but would like a bit more band choice ideally if poss). Many thanks. Many thanks. Verticals; if you have a lot of area, phased vertical arrays. -- Jim Pennino |
#3
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Antenna recommendation needed
On Sun, 18 Jan 2015 21:28:07 +0000, jimp wrote:
Verticals; if you have a lot of area, phased vertical arrays. Aren't verticals more inclined to generate interference? BTW, my plot is 120' by 90' so I think an array at HF will be impossible. The feed point will be pretty much central to the plot, though. |
#4
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Antenna recommendation needed
"Bruno" wrote in message ... Hi all, I've had a planning application for a tower turned down which is a real pain. My options are now very limited. I'm in a bungalow with a roof apex height of 18 feet and I'm not allowed to put up anything much above this roof line it transpires, so inverted vees that need to be mounted high up at the feed point like G5RVs are not possible for me. My garden boundaries limit the length of any wire antenna I might wish to put up to about 120 feet overall. On the plus side, though, the QTH is several hundred feet ASL close to the top of the hill and am not overshadowed by any trees or buildings to speak of. What's my best choice for an HF antenna under these circs? (I mostly do CW on 20m & 40m, but would like a bit more band choice ideally if poss). Many thanks. You may want to put up an off center fed antenna. Good for most all bands except 15 meters. Whatever, stick up something and get on the air. While it might not be the best, anything to get on the air with to start and later you can refine the antenna system for what you have. If you do put up a vertical, most of them will need to have radials burried just under the ground. The main thing is not to overthink things to start with. Start simple, get on the air and if it doesn't work well, put something else up when you have time. There was something in QST magazine a few months ago. They were vertical loops. I tried them for the 18 and 24 mhz band, but they did not work nearly as well as my OCF and dipoles cut for those bands. I have a coax switch so I could switch the antenas in just a fraction of a second. However the other antennas are at 50 feet high on the ends and the loop was only about 5 feet off the ground at the bottom. |
#5
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Antenna recommendation needed
Bruno wrote:
Hi all, I've had a planning application for a tower turned down which is a real pain. My options are now very limited. I'm in a bungalow with a roof apex height of 18 feet and I'm not allowed to put up anything much above this roof line it transpires, so inverted vees that need to be mounted high up at the feed point like G5RVs are not possible for me. My garden boundaries limit the length of any wire antenna I might wish to put up to about 120 feet overall. On the plus side, though, the QTH is several hundred feet ASL close to the top of the hill and am not overshadowed by any trees or buildings to speak of. What's my best choice for an HF antenna under these circs? (I mostly do CW on 20m & 40m, but would like a bit more band choice ideally if poss). Many thanks. Many thanks. I think Ralph Mowery is right -- get on the air with almost anything you canfind including just a hunk of wire, and while you are having the fun of operating you can decide on something that meets your desires. Radiating comes first -- the rest later! Irv VE6BP RADIATE OR DIE TRYING! |
#6
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Antenna recommendation needed
Bruno wrote:
On Sun, 18 Jan 2015 21:28:07 +0000, jimp wrote: Verticals; if you have a lot of area, phased vertical arrays. Aren't verticals more inclined to generate interference? No. BTW, my plot is 120' by 90' so I think an array at HF will be impossible. The feed point will be pretty much central to the plot, though. A 40M four square would be a push, but a 20M a slam dunk. DXEngineering has a lot of stuff and info for building various vertical arrays with phased feeding. The simplest array is 3 verticals about .23 lambda tall spaced at about ..34 lambda with just the center one fed. With the other two undrounded, you get a typical, omnidirectional vertical pattern. If you ground the outer two (think remote relays) you get a broadside pattern like a dipole with about 3.5 dBi gain. Of course your ground will make a difference and likely the more radials you can bury the better it will be unless you live in a swamp. Verticals want a good ground, horizontals want a better than .5 lambda height. -- Jim Pennino |
#7
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Antenna recommendation needed
Ralph Mowery wrote:
snip There was something in QST magazine a few months ago. They were vertical loops. I tried them for the 18 and 24 mhz band, but they did not work nearly as well as my OCF and dipoles cut for those bands. I have a coax switch so I could switch the antenas in just a fraction of a second. However the other antennas are at 50 feet high on the ends and the loop was only about 5 feet off the ground at the bottom. In my adventures of modeling loops close to ground, I've found them lacking except in the case of the hentenna; They work very well as close as one foot to the ground. A 17M hentanna is going to be a bit tall though. -- Jim Pennino |
#8
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Antenna recommendation needed
On Sunday, January 18, 2015 at 4:08:31 PM UTC-6, Bruno wrote:
On Sun, 18 Jan 2015 21:28:07 +0000, jimp wrote: Verticals; if you have a lot of area, phased vertical arrays. Aren't verticals more inclined to generate interference? BTW, my plot is 120' by 90' so I think an array at HF will be impossible. The feed point will be pretty much central to the plot, though. I would probably string up parallel coax fed dipoles and have them at the low height. IE: 18-20 feet off the ground if that's all you can do. They will still work fairly well overall. Say if you can stick a short 1-2 ft stub mast on the roof, run dipoles from it, and feed with a single coax for both bands. Run the legs out to wherever you can tie them off. IE: trees, or short masts in the back yard/garden, etc. Won't be a gang buster DX setup, but plenty good enough for general use. With 40 and 20 dipoles, you would also have 15 meters, running the 40 legs. And you can feed more dipoles from the same coax if you want more bands. Using the coax as a feed line, no tuner required and low system losses. And also no need to worry about laying out radials. |
#9
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Antenna recommendation needed
"Bruno" wrote in message ... Hi all, I've had a planning application for a tower turned down which is a real pain. My options are now very limited. I'm in a bungalow with a roof apex height of 18 feet and I'm not allowed to put up anything much above this roof line it transpires, so inverted vees that need to be mounted high up at the feed point like G5RVs are not possible for me. My garden boundaries limit the length of any wire antenna I might wish to put up to about 120 feet overall. On the plus side, though, the QTH is several hundred feet ASL close to the top of the hill and am not overshadowed by any trees or buildings to speak of. What's my best choice for an HF antenna under these circs? (I mostly do CW on 20m & 40m, but would like a bit more band choice ideally if poss). Many thanks. Many thanks. For many years, my antenna space has been restricted or limited. I favor verticals in those circumstances. I used a ground mounted Butternut for many years and it was OK. The grounding system was five heavy insulated wires, each five feet long and terminated in 6 foot ground rods. The idea for that grounding configuration came from a study by E-Systems done in the 1970s. Currently I use a 16 foot vertical mounted on a rather large metal patio cover. I feed it with 20 feet of coax and do the ATU inside the shack. I'm currently thinking about adding a remotely controlled ATU at the base of the antenna. For mobile use I have an Outbacker, and I have tried it on the metal patio cover. It works, but is marginal. If you get stuck with a mobile sized antenna, I'd recommend a bugcatcher. If you can handle a 30 foot vertical (advertised by MFJ and others) it might work well with a good ground. If the real estate is limited for ground wires, just do the best you can, and live with it. If your restrictions do not allow a permanent 30 foot vertical, you might get permission to tilt it down when not in use. Good luck! Wayne W5GIE |
#10
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