-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
Outdoor Loop
- Thread starter HomerBB
- Start date
'zactly correct,..... I don't care what the computerized verticle radiation pattern is,..... just because there is a verticle lobe does not make it NVIS. ie : a "cloudwarmer" antenna that sends the signal almost straight up (not "high angle") and then the signal is reflectd almost straight back down.
NVIS on the high bands just doesn't happen.
Last edited:
Homer's cophase quad idea.
Homer, I'm not sure about this model. I added a sources for each radiator and made the feed point at the bottom of both radiators, but I don't know why the match is so bad, even not-withstanding it has no harness. So it is what it is. The match shows to be terrible, >100 SWR.
I also added a view from the top.
I recall that Signal Engineering made a wire antenna that looks similar, but it was fed in the middle of the wires...instead of at the bottom. It also used some kind of short wire and a decoupler on each harness, and all of that is a mystery. I'll have to tinker and think about this one a bit. Were you expecting this to be omni directional and show some quad gain? I was surprised the angle was so high.
View attachment Homer's cophase quad idea..pdf
Sorry, the model above is in error. I placed the two feed points on the same radiator at wires 1 and 2. I will post the correction in another post below. The antenna will still basically look the same, but the two small red circles should be on wires 2 and 6 instead.
View attachment Homer's quad looking down on the top..pdf
Homer, I'm not sure about this model. I added a sources for each radiator and made the feed point at the bottom of both radiators, but I don't know why the match is so bad, even not-withstanding it has no harness. So it is what it is. The match shows to be terrible, >100 SWR.
I also added a view from the top.
I recall that Signal Engineering made a wire antenna that looks similar, but it was fed in the middle of the wires...instead of at the bottom. It also used some kind of short wire and a decoupler on each harness, and all of that is a mystery. I'll have to tinker and think about this one a bit. Were you expecting this to be omni directional and show some quad gain? I was surprised the angle was so high.
View attachment Homer's cophase quad idea..pdf
Sorry, the model above is in error. I placed the two feed points on the same radiator at wires 1 and 2. I will post the correction in another post below. The antenna will still basically look the same, but the two small red circles should be on wires 2 and 6 instead.
View attachment Homer's quad looking down on the top..pdf
Last edited:
Robb, More than likely the loop will become a quad beam, but there is no harm looking at all the possibilities.
I am just curious about the potential of the Quad element done as the illustration shows. Maybe an octopus, who knows.
NB, you deserve your pat on the back.
I am also aware of the nature of DX propagation. I agree with Doc, and HO6 that it is unreliable, and that NVIS is not reliable on 11 meters.
I also see the possibilities of playing with a Moxon. Just too easy now. Slide the feed point around to one side, and then sever the wire on two other sides at the right spot and it's done.
Then there is just the single loop stood up vertical, or a dozen other things.
One item that has been mentioned is that the contacts posted were only USA/North American.
I would challenge one to overlay a map of Europe centralized to my location in nearly the center of the USA and compare some of the distances I talk to some of the international distances from similar point in the EU. Most of the EU will fit inside of Texas.
If I was surrounded by an ocean instead of these rocky Ozarks no telling where I'd consistently get out to. . .
All that said, I am merely going back to Doc's point that DX is its own animal, and like every junkyard dog, will escape the fence every chance it gets no matter what address is on the collar tag.
Everything respectfully stated.
:closedeyes:
BM,
I am just curious about the potential of the Quad element done as the illustration shows. Maybe an octopus, who knows.
NB, you deserve your pat on the back.
I am also aware of the nature of DX propagation. I agree with Doc, and HO6 that it is unreliable, and that NVIS is not reliable on 11 meters.
I also see the possibilities of playing with a Moxon. Just too easy now. Slide the feed point around to one side, and then sever the wire on two other sides at the right spot and it's done.
Then there is just the single loop stood up vertical, or a dozen other things.
One item that has been mentioned is that the contacts posted were only USA/North American.
I would challenge one to overlay a map of Europe centralized to my location in nearly the center of the USA and compare some of the distances I talk to some of the international distances from similar point in the EU. Most of the EU will fit inside of Texas.
If I was surrounded by an ocean instead of these rocky Ozarks no telling where I'd consistently get out to. . .
All that said, I am merely going back to Doc's point that DX is its own animal, and like every junkyard dog, will escape the fence every chance it gets no matter what address is on the collar tag.
Everything respectfully stated.
:closedeyes:
BM,
marconi are you feeding one side of each loop in parallel with the center and the other 2 with the shieild? 2 100ohm loops in pairalel should be close to 1:1swr
homer, how hard would it be to just stand it up with the feed point on the bottom and play horiz dx?
thank you homer and thanks for helping to keep me so humble
homer, how hard would it be to just stand it up with the feed point on the bottom and play horiz dx?
marconi are you feeding one side of each loop in parallel with the center and the other 2 with the shieild? 2 100ohm loops in pairalel should be close to 1:1swr
thank you homer and thanks for helping to keep me so humble
homer, how hard would it be to just stand it up with the feed point on the bottom and play horiz dx?
NB, thanks for asking about how I handled the feed points. When I opened the file and enlarged the antenna view to really see the feed point area, I saw right away that I had placed the 2 feed point sources on the same radiator, wires 1 and 2. I fixed it and the pattern is much better, in fact Homer might even be encouraged somewhat not-withstanding the high angle lobe. The match is also much better.
Sorry! :blushing:
View attachment Homer's quad corrected source points.pdf
Needle Bender, this is not precise, but the source in Eznec5 does not work exactly like a feed point with the center and the shield. This is probably why the author refers to the feed point as the source.
The source is probably a virtual type of mathematical function and I think the location may be all that is physical within some limitations. We do have some range in which to place the source anywhere along a wire, but Eznec assigns the source to the middle of a wire segment for the antenna view and that is what you are able to see.
So E5 assigns the final placement within some limits and that function is buried in the code. Eznec calculates a percentage and a segment for how close the user's selected location is from the nearest end of the wire, and that is the actual feed point, not the 50% location shown in the Antenna View between the little green dots on the wires.
So we can only get so close. You can see this in the blow up model posted below, but the real location in this instance is 1% from end 1 of wire 1.
There is a E5 feature noted as a "split" that allows us to place a source at the junction of two wires, again under certain conditions, but with 4 wires all terminating at the same spot in this model, Eznec will not allow the use of the split. The split is what Henry used in his stacked co-phased model he posted above. You do not have to include the coax or a phase line for the model to work, so the model will reflect the condition without matching for this co-phase setup.
View attachment Homer's quad corrected source points.pdf
The source is probably a virtual type of mathematical function and I think the location may be all that is physical within some limitations. We do have some range in which to place the source anywhere along a wire, but Eznec assigns the source to the middle of a wire segment for the antenna view and that is what you are able to see.
So E5 assigns the final placement within some limits and that function is buried in the code. Eznec calculates a percentage and a segment for how close the user's selected location is from the nearest end of the wire, and that is the actual feed point, not the 50% location shown in the Antenna View between the little green dots on the wires.
So we can only get so close. You can see this in the blow up model posted below, but the real location in this instance is 1% from end 1 of wire 1.
There is a E5 feature noted as a "split" that allows us to place a source at the junction of two wires, again under certain conditions, but with 4 wires all terminating at the same spot in this model, Eznec will not allow the use of the split. The split is what Henry used in his stacked co-phased model he posted above. You do not have to include the coax or a phase line for the model to work, so the model will reflect the condition without matching for this co-phase setup.
View attachment Homer's quad corrected source points.pdf
Well, that is more interesting. There is that big blob striaght up, though. I've seen this antenna configuration dicussed, but I fail to see why one would do it given most of the power goes straight up into that Elmer Fudd head shaped pattern.
Thanks for doing it.
So, will E5 allow us to split and feed the two wires at two of the corners on the sides?
Sorry about the 'NVIS'/'Nevis' thingy, even misspelled you get the idea.
I used an antenna called a NVIS to do phone patches during 'Desert Storm'. That 'short range' type of qualification/classification is very vague to say the least. Admittedly, the propagation was much 'better' than now, but still, that 'straight up' thingy isn't as sure a bet as you might think.
About that 'diamond' shaped quad thingy. Yes, it can work and be directional. There are several antennas of that sort. Would two quads be better than using two other types of antennas (or more than two)? I don't know, but I sort of doubt it. It would be the equivalent of two single element quad antennas pointed in different directions. Using dipoles instead of a loop means that the resulting antenna would be a two element directional antenna (Super Scanner??). Different shaped/styles of antennas have different characteristics in them selves. I like loops, but they get sort of bulky/cumbersome, you know?
- 'Doc
I used an antenna called a NVIS to do phone patches during 'Desert Storm'. That 'short range' type of qualification/classification is very vague to say the least. Admittedly, the propagation was much 'better' than now, but still, that 'straight up' thingy isn't as sure a bet as you might think.
About that 'diamond' shaped quad thingy. Yes, it can work and be directional. There are several antennas of that sort. Would two quads be better than using two other types of antennas (or more than two)? I don't know, but I sort of doubt it. It would be the equivalent of two single element quad antennas pointed in different directions. Using dipoles instead of a loop means that the resulting antenna would be a two element directional antenna (Super Scanner??). Different shaped/styles of antennas have different characteristics in them selves. I like loops, but they get sort of bulky/cumbersome, you know?
- 'Doc
So, will E5 allow us to split and feed the two wires at two of the corners on the sides?
Homer, I'll try this one tomorrow, but I don't think it will be a true quad when finished, like 'Doc suggested.
Check this out.
http://www.signalengineering.com/Th8.jpg
no no no, you have to look at the green dot! you would have a 12 degree angle at the highest gain lobe of 5.56dbi or about 3.5dbd!
hey marconi, can you do that model looking straight down on it from space? i want to see the polar pattern.