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Outdoor Loop
- Thread starter HomerBB
- Start date
w8jitom is a smart guy but i dont agree with him alot. i read elsewhere on the web where other guys have had totally different experiences and calculations then tom says is right and they argue like rival scottish clans. ui think sometimes he counts to heavily on calcs instead of real world experience. the well known saying "quads open and close the band' is out there for a reason. i remember back in the 90s a guy ran a 5 el quad and allways heard dx first. then about 5-10 minutes later a guy with a 3 el quad would start to hear it. then about 10 min later the rest of us yagi users would hear it. i was made a quad beleiver when i was still runing a yagi but its allways the guys runing a yagi that say quads are no better
I hear ya.
I will get it read, and then look around for other points of view.
I enjoyed the 2 el quad I had up, and want to do it again.
This one is flat, and is doing an admirable job. Sometimes I do better than the Sigma4 with it DX-wise, anfd then it changes around. . . conditions make it hard to say anything definitive the way things are. I must say that in virtually every case I ask switching back and forth I get similar/same results on the other end.
Noticeably, the flat lying quad is much quieter in terms of white noise.
If I stood it on its edge then the comparison to the vertical would be apples to oranges more so than it is because of the directional aspect of the quad. I will report that the horizontal mounted quad has receive and transmit to every place the vertical omni has. This leads me to accept it has omni characteristics that are valid.
It comes down to what one experiences within certain limits. Still listening and talking.
I think this antenna definitely has a noticeable TOA difference. I am not through deciding in what way, and without field testing it will once again be anecdotal observations, and like every fish story, antenna stories tend to grow with every telling.
I will get it read, and then look around for other points of view.
I enjoyed the 2 el quad I had up, and want to do it again.
This one is flat, and is doing an admirable job. Sometimes I do better than the Sigma4 with it DX-wise, anfd then it changes around. . . conditions make it hard to say anything definitive the way things are. I must say that in virtually every case I ask switching back and forth I get similar/same results on the other end.
Noticeably, the flat lying quad is much quieter in terms of white noise.
If I stood it on its edge then the comparison to the vertical would be apples to oranges more so than it is because of the directional aspect of the quad. I will report that the horizontal mounted quad has receive and transmit to every place the vertical omni has. This leads me to accept it has omni characteristics that are valid.
It comes down to what one experiences within certain limits. Still listening and talking.
I think this antenna definitely has a noticeable TOA difference. I am not through deciding in what way, and without field testing it will once again be anecdotal observations, and like every fish story, antenna stories tend to grow with every telling.
Well sure you can. Here it is:
The dimensions are dictated by the length of the wire, which is viewable in the photo of the calculator I used to determine the wire length, spreaders, etc.
The parts in the above photos are:
two sets of 2" x 8-32 SS screws and nuts with washers.
3/4" soc PVC caps qty 3
3/4" tee all soc
2 feet long 1-1/2" PVC tube
3" x 1-1/2" adapter
6 inch length of 3" PVC tube
one stick of 10' x 3/4" PVC
2 sticks of 1/2" x 10' EMT (conduit)
prepared 6' piece of 75 Ohm coax
some tape to wrap around the EMT to take out slack between its diameter and the ID of the 3/4" PVC.
1. Take the 3 x 1.5 adapter and remove the stop inside the 1.5" end so the 1-1/2" PVC tube can go all the way through a couple inches. This is to make it sturdier than if the stop is in place. Glue the two pieces together as shown in the photos. I used self-drilling screws also for reinforcement.
2. Glue the 6" x 3" PVC tube into the adapter. I used self-drilling screws for reinforcement.
3. Drill two sets of holes into the 3" x 6" PVC tube at 90° to each other offset from each other.
4. Insert the two joints of EMT through the offset holes. Be sure they are inserted half way their lengths. This will form the characteristic cross shape of Quad spreaders. Secure them to each other in the center as you see done in the above photo. This provides stability and assures the spreaders remain in place.
5. Cut the 10' joint of 3/4" PVC into 4 equal parts - 2.5' each. Place caps on three of them, and the tee on the fourth.
6. Drill holes through the ends/caps of the three capped pieces of PVC so the wire can pass through them. Drill two holes, one in each end of the tee for the connector end of the loop as shown in the photos above.
7. Wrap sufficient amount of tape around the EMT spreaders to remove slack between the 3/4" x 2.5' sections when they are slipped onto the spreaders. Do this near the end of the EMT, and at 49" out from the outside edge of the 3" PVC center tube.
8. Slide the PVC sections onto the four EMT spreaders. Thread the pre- measured, pre-cut wire through the holes of the three caps securing the ends of the loop wire with the SS screws on the two sides/ends of the tee. Slide the four PVC sections out equally from the center until the wire is taut.
9. attach 6' piece of 75 Ohm coax. Tape or zip-tie this along the spreader . Done.
Thank You Homer BB your so professional !!!
:w00t:
Some have said it's hard to tell whether the loop is mounted vertical or horizontal. I hope this helps:
Some things are so lovely it almost makes you cry . . .
Some things are so lovely it almost makes you cry . . .
can you turn it? i imagine its a figure8 pattern that favors directions perpendicular to the feed line spreader?
Homer BB,
Well done !
The loop you have now has a impedance around 110/150 ohms depending on heigth ground. So it migth not have a perfect 1;1 reading. (besides the 1/4 wave matching section)
Now, thats not a bad thing as SWR isnt everything as you know...
But your present loop has a issue with the radiation pattern.
The loop you use now is commenly used on low HF bands and is sometimes called "skyloop" wire. The radiation plot tends to be more straigth up with the minor lobs under a "skip" angle.
It is quite well known for so called "NVIS" use. Not a really good DX antenna for us on folks on 27Mhz.
You migth investigate similair omnidirectional horizontal antennas like "halo or cobwebb" these have are small in turning radius and or known to have a better "skip" angle.
If you would take for example the cobwebb with only half the size compared to the quad on say 20..25 feet heigth it would already beat the horizontal quad loop with over 3dB on skip situations
Hope it helped,
Kind regards,
Henry HPSD
19sd348
www.dx-antennas.com
Well done !
The loop you have now has a impedance around 110/150 ohms depending on heigth ground. So it migth not have a perfect 1;1 reading. (besides the 1/4 wave matching section)
Now, thats not a bad thing as SWR isnt everything as you know...
But your present loop has a issue with the radiation pattern.
The loop you use now is commenly used on low HF bands and is sometimes called "skyloop" wire. The radiation plot tends to be more straigth up with the minor lobs under a "skip" angle.
It is quite well known for so called "NVIS" use. Not a really good DX antenna for us on folks on 27Mhz.
You migth investigate similair omnidirectional horizontal antennas like "halo or cobwebb" these have are small in turning radius and or known to have a better "skip" angle.
If you would take for example the cobwebb with only half the size compared to the quad on say 20..25 feet heigth it would already beat the horizontal quad loop with over 3dB on skip situations
Hope it helped,
Kind regards,
Henry HPSD
19sd348
www.dx-antennas.com
B
BOOTY MONSTER
Guest
Some have said it's hard to tell whether the loop is mounted vertical or horizontal. I hope this helps:
Some things are so lovely it almost makes you cry . . .
if it can out do the v4k sometimes at the lower feed-point , imagine what it could do at the same tip height . :drool: it would require a few sets of guys though
Lots of input here, and everyone supplying food for thought.
Needle Bender,I could turn if I wished.
Henry, it has done remarkably well on DX, but perhaps you are right, and as well as it is something better in the way of a loop may be more useful.
Booty, I've considered raising it to see if things changed, However, I am inclined to agree with Doc that there may not be enough advantage in doing so to be worthwhile.
Should I do so, it would go up where the Sigma4 is.
Needle Bender,I could turn if I wished.
Henry, it has done remarkably well on DX, but perhaps you are right, and as well as it is something better in the way of a loop may be more useful.
Booty, I've considered raising it to see if things changed, However, I am inclined to agree with Doc that there may not be enough advantage in doing so to be worthwhile.
Should I do so, it would go up where the Sigma4 is.
hey homer i got one for you. try building another one and put one about 5/8 above thais one and use a pair of 75ohm matching lines to a coax t connecter tomatch them. i bet you get awesome horiz performacne with gain off the sides of the figure8 pattern
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