Anyone have any experience with this antenna on the flat. The wifes really against a beam. Just wondering how it would compare to my ground plane in dx.
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sirio sd-27 mounted flat
- Thread starter canoe
- Start date
I had one mounted for east/west Tx/Rx at 20 ft (about half way up my tower) in the horizontal config.
I was able to work skip with it and it did seem directional.
I would recommend mounting the antenna at least 36 feet off the ground and then use a simple tv antenna rotor to turn it.
When mine was up it was mounted in a fixed location so if the conditions were not running to the east or west of me I had no use for it.
The antenna is very light and simple to construct.
Just be careful with the small tuning element that has to be adjusted for optimal swr. The tuning element is very easy to snap in the middle.
I had one break and had to wait for Sirio to send me a replacement.
I was able to work skip with it and it did seem directional.
I would recommend mounting the antenna at least 36 feet off the ground and then use a simple tv antenna rotor to turn it.
When mine was up it was mounted in a fixed location so if the conditions were not running to the east or west of me I had no use for it.
The antenna is very light and simple to construct.
Just be careful with the small tuning element that has to be adjusted for optimal swr. The tuning element is very easy to snap in the middle.
I had one break and had to wait for Sirio to send me a replacement.
on the flatside it would be better than any stick type antenna. you,l only need a tv rotar
to turn it. nice choice imho
I wonder how it would work mounted on my tower at about 40'. My tower is 50' but my Imax is on top. I was thinking of maybe a 6' pipe mounted off the side of the tower facing south, with the antenna mounted to that. So the middle of the antenna would be 6' from the tower. Do you think the tower would cause some sort of reflect or interference.
Yes; it would interfere.
Kinda makes having a beam lot less useful if you can't rotate it. You can put it flat on the top of the tower and then put the Imax on top of it w/o the Imax ground planes. You won't need them.
Sounds like you need to get a decent rotor; you already have everything else . . .
Sd-27 is a dipole ? Imax mounted at 50 ft (70 feet odd overall height) is going to work better that that horizontal dipole at 40 ft on most occasions . Dipole may have lower noise though and will pickup horizontal local signals better. On dx ,signals arrive at all sorts of polarization and changes constantly, at times the dipole may be stronger .Why not put a reflector on that 6 ft boom and make it a 2 el beam .
Actually its 74'. The imax works excellent at the height. I only talk dx aind believe me it talks. i havent bought anything yet. I agree for 50 more why not a 3 element. Theses are just thoughts and ideas.
I have found that a dipole is a surprisingly agile DX antenna.
I have a choice of a 4 element rotatable beam, an EFHW vertical, a fixed east/west EDZ, an attic mounted west oriented Moxon, and an attic mounted full wave loop with the twist of a switch. The 4 element beam is without doubt the king of the antennas most of the time, however, when DX roles in this can change and any other might be the antenna of choice of the moment.
When I consider the best of several worlds I would have a beam under a vertical, as I do. If a beam is not a choice, it would be the dipole horizontal directly under the vertical Omni-directional with rotatable ability.
Seeing I enjoy DX more than the limited local chatter, if I were reduced to a single antenna choice where a beam was not possible, and it needed to be not so much a visual intrusion, the horizontal dipole would be it in one or the other of its iterations.
They are great for their size and simplicity.
I have a choice of a 4 element rotatable beam, an EFHW vertical, a fixed east/west EDZ, an attic mounted west oriented Moxon, and an attic mounted full wave loop with the twist of a switch. The 4 element beam is without doubt the king of the antennas most of the time, however, when DX roles in this can change and any other might be the antenna of choice of the moment.
When I consider the best of several worlds I would have a beam under a vertical, as I do. If a beam is not a choice, it would be the dipole horizontal directly under the vertical Omni-directional with rotatable ability.
Seeing I enjoy DX more than the limited local chatter, if I were reduced to a single antenna choice where a beam was not possible, and it needed to be not so much a visual intrusion, the horizontal dipole would be it in one or the other of its iterations.
They are great for their size and simplicity.
I'm the same. Love dx and not so much on the local. Actually there are no locals up here. I can't take my tower down to mount the horizontal antenna (whichever it may be) because there is a pool now in its path. And I don't think I'm that interested in climbing up 50' to try and mount a rotor and what have you. The wife feels very strong about no " stupid 1970's looking antenna ". ( Her words not mine). That's why when I saw the Sirio sd-27 it got may attention. Mount it off the side of the tower, point it south west and enjoy was my first thought. But now after asking around, that wont work either, because the tower will cause reflect with the antenna radiating north east as well.
Now, I do have another 36' tower I was going to mount on my shed, but I'll need about 150' of coax. I don't think she'd mind the dipole there, but will it work that well to warrant $150 for coax and another $75 - $100 for dipole.
I can see spending that kind of money for an actual beam, but is it really worth it for a one element.
Now, I do have another 36' tower I was going to mount on my shed, but I'll need about 150' of coax. I don't think she'd mind the dipole there, but will it work that well to warrant $150 for coax and another $75 - $100 for dipole.
I can see spending that kind of money for an actual beam, but is it really worth it for a one element.
Canoe, we all can assume that a tower will effect an antenna if located off to the side like you describe, and not well enough above the entire tower well away from anything that can cause reflections.
But IMO the bad effects of this particular antenna install are minimal at worst and maybe good at best in one very broad direction. You will likely see a bit of directionality is true. But, IMO it will probably be about as hard to detect as the same difference being added to the gain in the desired direction you install it. At least you might have to check really close to see either difference occur, but that doesn't mean they are not real effects...they just don't make much difference. The lesser power to the back of the tower will be a bit more noticeable maybe, but IMO it might be hard to tell. I think the engineers at Sirio know more that most of us here.
Ask HomerBB, I think he built one of these and had it stuck out about 3' from a mast support. As I recall, it worked find even though he didn't have it mounted too high. Sure we give up a little, but the big question is always how much difference does this really make?
CBr's read something technical that is generally based on theory, where the idea is set to perfection and the experimenter finds differences in his comparisons, usually small differences to be noted. But, let's say such differences were in the range of a 1/4" or 1db as an example. O'boy O'boy when the CB'r gets through with his looking at pictures mostly and maybe reading a bit...all of a sudden the difference in his mind are closer to a foot or two of difference or a' whole Sunit or two.
I could be wrong about HomerBB's experience on this subject, but he could guide you better. I wouldn't be so persuaded by "wolf taking BS" without testing the idea myself, or getting the straight poop from a reliable source you really trusted first.
The install you described is probably used in 1000 of installations all over the World and that would not likely be the case if it did not provide a benefit in some directions.
This is just my opinion.
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get either a pushup pole and mount the sd-27 on it or another tower. i wouldnt mount the antenna on the shed if your actually gonna need 150 feet of coax to make it to the radio.
your coax loss will be large at that lenth. if you can get a bucket truck and get to the top of your tower you could easyily mount the dipole just below the imax
As Marconi said, I put one up about 3' - 4' off the mast to one side. I tried it both vertical and horizontal, and I found no noticeable ill effects from the install. Whet I did miss was having it higher up as I had put it before. This particular antenna was on,y 12' up to the bottom tip of the dipole when it was vertical, and 20' or so when horizontal. I had been running it around 35' feet previously. Directionality seemed a non-issue at those low heights and on the side of the mast.
Thanks for everyones replies. So what I think your saying HommerBB is that you did have this dipole mounted of to the side of your tower with very little swr reflect from the tower. Correct?
So, like I posted earlier. I'd like to mount it off the south/west side of the tower around 36'. I think I might actually try this. I'll need about 50' of coax for this application.
So, like I posted earlier. I'd like to mount it off the south/west side of the tower around 36'. I think I might actually try this. I'll need about 50' of coax for this application.