The biggest advantage of a diamond over a square is simply strength. The vertical spreader and top two wires support the horizontal spreader much better than with everything at a 45 degree angle. A vertical spreader will take a huge vertical load.
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quad reflector versus yagi reflector
- Thread starter smokercraft
- Start date
One person's anecdotal perspective IS interesting but what was it he said in the article based on him actually using them both, a Quad & a Yagi..?
Oh yeah,
- Quad was 20% shorter,
- Quad is only 26' wide vs 33' for the Yagi,
- Quad had better F to B,
- Quad had better side rejection (which translates into more forward gain & a tighter pattern.)
...and had noticeably less local static/ QRN.
OK, well I also have an anecdotal experience to share:
Some years ago I had an opportunity to compare my home-built, meticulously well-tuned, 3-el Quad at 40' & 75w pep
against
another local operator with a 5-el Yagi at 60' with TWICE THE POWER of 150w pep.
Into Aussieland he was S-9,
I was 20-over S-9.
Oh I know, his coax must've been bad, no, his gamma was bad, wait, he had it turned the wrong way.
Oh yeah, his mic gain was down.
blah blah blah...
He was a watch maker/ watch repairer and a meticulously detailed gentleman, no doubt his station was dialed in.
The vast majority of Quad users I've spoken with and whom have had both Yagi and Quad antennas, have told me they, "Will never go back to a Yagi".
I agree.
http://lists.contesting.com/_towertalk/2002-11/msg00427.html
https://www.w8ji.com/quad_cubical_quad.htm
I have used both type of antennas here at my QTH.
No major difference between them as far as I can tell. Nor could any of the receiving stations tell which antenna I was using.
As any informed operator should know DX is not a good source for comparisons of antennas. Your neighbor was 20' higher in elevation that your antenna?? The DX was favoring the higher angle of arrival due to your antenna being lower, or your neighbor being that high AGL may have had a null in his antenna pattern, so many variables.
I like a quad, but the yagi is easier to construct, less likely to have mistakes in constructions, and a heck of a lot easier to keep in the air in high wind areas.
I do not know ANY QUAD owner who has not had to repair, or replace his quad due to mother natures vengeance.
If you find faults in any of the articles, then email the authors, I could personally care less which one you prefer as the articles were referenced so the thread initiator could get different point of views from different sources on quads vs yagis.
https://www.w8ji.com/quad_cubical_quad.htm
I have used both type of antennas here at my QTH.
No major difference between them as far as I can tell. Nor could any of the receiving stations tell which antenna I was using.
As any informed operator should know DX is not a good source for comparisons of antennas. Your neighbor was 20' higher in elevation that your antenna?? The DX was favoring the higher angle of arrival due to your antenna being lower, or your neighbor being that high AGL may have had a null in his antenna pattern, so many variables.
I like a quad, but the yagi is easier to construct, less likely to have mistakes in constructions, and a heck of a lot easier to keep in the air in high wind areas.
I do not know ANY QUAD owner who has not had to repair, or replace his quad due to mother natures vengeance.
If you find faults in any of the articles, then email the authors, I could personally care less which one you prefer as the articles were referenced so the thread initiator could get different point of views from different sources on quads vs yagis.
A comment on the first of Wavrider's links, then a response to some assumptions.
The article talks about adjusting the quad for maximum forward gain, but does not mention the same for the yagi. As they can be configured with other primary effects, better F/B radio as an example, I guess I am to assume that the Yagi was tuned to maximum forward gain? I don't like assumptions, but the best I can come up with is he put the yagi antenna up to however it was set up and continued to use it with that tune. It was mentioned that the quad, on the other had, was adjusted several times. It would have been nice if he mentioned more on this aspect of the yagi.
You used said article to support your opinion, and that is fine, but there are also good points mentioned for the yagi as well, and said points should be considered when choosing the best antenna for the individual. If you want to say that you think the quad is superior, thats fine, and for the most part I agree with you, although for very different reasons. However, that isn't necessarily the case for everyone. If you were in an area that gets high winds often, as well as certain other weather conditions, the yagi's stronger design may well be key. From multiple reports I have read from multiple sources, the difference in raw strength between the two is quite high. The yagi was also apparently more lightening resistant than the quad, for those that live in areas that get lots of electrical storms.
Both of your items I quoted above could lead to more forward gain, but in reality there are other factors that are also in play, so this is really nothing more than an assumption. Just because one antenna has less power in undesirable directions does not automatically mean that it has more power going in a desirable direction.
I'm not for a minute going to say that these aspects aren't desirable in their own right. I, personally, prefer more side and rear rejection over additional forward gain, so these are not necessarily a bad thing, and these aspects lead me to prefer the quad as well. However, there are other things to consider.
One thing to consider is the difference in efficiency between the antennas. By the article, and your own post, the elements are closer together on the quad, in addition, the quad elements are in the range of twice as long (all the way around the loop, near 1 wavelength, as opposed to straight near half wavelength elements). Both of these will cause more interaction between elements on the quad, and by extension potentially greater loss/less efficiency. This potential lower efficiency can negate some, if not all, of the potential additional gain that you are expecting to see, and have other effects, such as...
Of course, the quad was designed to be more use-able in high static environments, so that is also helping with this, so that isn't to say that all of the lower QRM/QRN is from losses, and there is another possibility in play...
There is also evidence of a potentially wider forward beam width with the quad, which would spread the potential additional power in that forward direction out a bit more, so instead of more gain you might simply have a wider beam width/height. Where does this evidence come from? The numbers the author presented in his article, more people were in the quads stronger signal range than the yagi's. This, to me, suggests that the quad's signal is possibly covering more area, and thus it gets more better reports than the yagi. While this isn't definite proof, it is evidence that you would be wise to consider. However, it could also have been random chance that more of his contacts just happened to be in the quad's lobe as well, with the limited number of contacts we simply don't have a large enough sample size to be absolutely sure.
Something that you specifically (Needle Bender) have mentioned multiple times in the past is that the quad opens and closes the band. I don't think that the small amount of additional gain that you think would be present would be responsible for this effect. I think that the wider beam width/height would be far more likely to cause such an effect than the insignificant (if any) amount of extra forward gain that you might get with one of these antenna designs over the other.
The DB
The article talks about adjusting the quad for maximum forward gain, but does not mention the same for the yagi. As they can be configured with other primary effects, better F/B radio as an example, I guess I am to assume that the Yagi was tuned to maximum forward gain? I don't like assumptions, but the best I can come up with is he put the yagi antenna up to however it was set up and continued to use it with that tune. It was mentioned that the quad, on the other had, was adjusted several times. It would have been nice if he mentioned more on this aspect of the yagi.
You used said article to support your opinion, and that is fine, but there are also good points mentioned for the yagi as well, and said points should be considered when choosing the best antenna for the individual. If you want to say that you think the quad is superior, thats fine, and for the most part I agree with you, although for very different reasons. However, that isn't necessarily the case for everyone. If you were in an area that gets high winds often, as well as certain other weather conditions, the yagi's stronger design may well be key. From multiple reports I have read from multiple sources, the difference in raw strength between the two is quite high. The yagi was also apparently more lightening resistant than the quad, for those that live in areas that get lots of electrical storms.
Both of your items I quoted above could lead to more forward gain, but in reality there are other factors that are also in play, so this is really nothing more than an assumption. Just because one antenna has less power in undesirable directions does not automatically mean that it has more power going in a desirable direction.
I'm not for a minute going to say that these aspects aren't desirable in their own right. I, personally, prefer more side and rear rejection over additional forward gain, so these are not necessarily a bad thing, and these aspects lead me to prefer the quad as well. However, there are other things to consider.
One thing to consider is the difference in efficiency between the antennas. By the article, and your own post, the elements are closer together on the quad, in addition, the quad elements are in the range of twice as long (all the way around the loop, near 1 wavelength, as opposed to straight near half wavelength elements). Both of these will cause more interaction between elements on the quad, and by extension potentially greater loss/less efficiency. This potential lower efficiency can negate some, if not all, of the potential additional gain that you are expecting to see, and have other effects, such as...
Of course, the quad was designed to be more use-able in high static environments, so that is also helping with this, so that isn't to say that all of the lower QRM/QRN is from losses, and there is another possibility in play...
There is also evidence of a potentially wider forward beam width with the quad, which would spread the potential additional power in that forward direction out a bit more, so instead of more gain you might simply have a wider beam width/height. Where does this evidence come from? The numbers the author presented in his article, more people were in the quads stronger signal range than the yagi's. This, to me, suggests that the quad's signal is possibly covering more area, and thus it gets more better reports than the yagi. While this isn't definite proof, it is evidence that you would be wise to consider. However, it could also have been random chance that more of his contacts just happened to be in the quad's lobe as well, with the limited number of contacts we simply don't have a large enough sample size to be absolutely sure.
Something that you specifically (Needle Bender) have mentioned multiple times in the past is that the quad opens and closes the band. I don't think that the small amount of additional gain that you think would be present would be responsible for this effect. I think that the wider beam width/height would be far more likely to cause such an effect than the insignificant (if any) amount of extra forward gain that you might get with one of these antenna designs over the other.
The DB
Here are three models that might help show the differences being discussed here.
1. is a 4 element diamond shaped quad with 180" inch boom, and is noted in blue on the overlay. I don't remember the source of the design but I did tweak it to show the best rejection without loosing too much gain.
2. is the Moonraker made to specs as noted in the manual with a 186" inch boom. No tweaking with this model. Noted in green. The cursor (*) is on this antenna so the gain and angle data to the right of the image is what is noted.
3. is the Maco M-104c made to specs as noted in the manual with a 195" inch boom. No tweaking with this model either. The Maco is noted in red.
All models are set to horizontal. They all show almost identical beam widths
IMO, this shows what the chatter about a quad does vs. the yagi and a quagi. The two antennas with quad element(s) show a 1* degree less maximum radiated angle. There is definitely an advantage difference in gain for the full quad, but I'm not sure we could see the difference just using our radio.
The models were mounted at 36' feet to the boom. They were modeled above what Eznec's table shows as Average Earth. All models were tested in Free Space showing 0.10 db or less Average Gain Results before the model was setup over Real Earth.
DB, I disagree with the your idea the quad has a wider beam width...even when modeled in Free Space the beam width shows to be less when compared to the yagi, so I added a Free Space overlay in case the idea for which antenna has a better beam width comes into question again. As noted above my Real Earth models don't suggest there is any difference in beam width either.
If you have a model that shows a different beam width with the Quad compared to the yagi...I sure would like to see it.
1. is a 4 element diamond shaped quad with 180" inch boom, and is noted in blue on the overlay. I don't remember the source of the design but I did tweak it to show the best rejection without loosing too much gain.
2. is the Moonraker made to specs as noted in the manual with a 186" inch boom. No tweaking with this model. Noted in green. The cursor (*) is on this antenna so the gain and angle data to the right of the image is what is noted.
3. is the Maco M-104c made to specs as noted in the manual with a 195" inch boom. No tweaking with this model either. The Maco is noted in red.
All models are set to horizontal. They all show almost identical beam widths
IMO, this shows what the chatter about a quad does vs. the yagi and a quagi. The two antennas with quad element(s) show a 1* degree less maximum radiated angle. There is definitely an advantage difference in gain for the full quad, but I'm not sure we could see the difference just using our radio.
The models were mounted at 36' feet to the boom. They were modeled above what Eznec's table shows as Average Earth. All models were tested in Free Space showing 0.10 db or less Average Gain Results before the model was setup over Real Earth.
DB, I disagree with the your idea the quad has a wider beam width...even when modeled in Free Space the beam width shows to be less when compared to the yagi, so I added a Free Space overlay in case the idea for which antenna has a better beam width comes into question again. As noted above my Real Earth models don't suggest there is any difference in beam width either.
If you have a model that shows a different beam width with the Quad compared to the yagi...I sure would like to see it.
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You think I came to that conclusion based on modeling? If you did you should re-read my last post, I tell you where I got the idea from, and a potential problem with the idea. Not everything I mention is solely based on modeling, and some things not based on modeling at all.
Question, Eddie, did you confirm that both of these antenna models are in fact tuned to produce the maximum forward gain as opposed to other possible configurations? If the answer to this is no then I have the same complaint with your models as I had with one of the antennas used in the article my post was in part responding to. That, to, is written about in my previous post.
The DB
Obviously, I'm seldom sure what your intentions might be DB. I read the bold type above as you're being positive in what your meant. I got the impression you supported the numbers in the article and where suggesting to NB that he might give these ideas some serious consideration.
So. I figured you had probably modeled the antennas in question here and found the quad with greater beam width, and I just wanted to see what evidence you had. In the first sentence, you did say there is evidence.............let us see your evidence or give us a link to the article where it says a quad has a wider beam width, OK?
Your second sentence in bold type in the same paragraph is for me another categorical comment by you supporting your comments again. I read you saying "...the quad signal covers more area."
So, I just assumed you were agreeing and basically substantiating the claims of something you read in Wavrider's links.
I don't know, but I did wonder how you would go about making such a conclusions with out depending on the pure physics or an antenna model. I know you are a math man, to quote your own description of yourself, but determining the beam width would seem to me to be a very arduous task, to-say-the-least, and I don't think for one minute you're about doing that.
I agree you did not start the point about beam width here, but you did talk about what somebody else said on the matter and in the end I don't think you voiced any disagreement about the idea concerning the quad.
Why not just show us a model or some other evidence that says the quad produces a wider beam width than a yagi, like I did to support my opinion. That ought to be pretty easy.
Here you go DB! I included the overlay I posted above and I added the individual results of each antenna in the overlay. Maybe this will clear up any confusion you might have.
I prefer to try and produce some evidence for my claims...when I can.
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Seriously? Wow, at this rate I am going to spend more time explaining what I did to you, something that you should be able to figure out on your own with the information at hand, than it would actually take for me to make the models and compare them...
On referring to the quad's signal covering a larger geographic area, in the same paragraph, I also said this...
Do these bold statements make it sound like I was absolutely sure? Did you even consider them when writing your response? I simply followed the evidence found in the article to a logical conclusion, then made statements intended to imply that said that conclusion wasn't the only possible explanation. I am happy to admit that with regards to the statements on beam width, after applying the new evidence of your models, that I was apparently mistaken.
I'm gong to have to address these later, I have things to say and don't have time to make a proper response right now.
The DB
On referring to the quad's signal covering a larger geographic area, in the same paragraph, I also said this...
Do these bold statements make it sound like I was absolutely sure? Did you even consider them when writing your response? I simply followed the evidence found in the article to a logical conclusion, then made statements intended to imply that said that conclusion wasn't the only possible explanation. I am happy to admit that with regards to the statements on beam width, after applying the new evidence of your models, that I was apparently mistaken.
I'm gong to have to address these later, I have things to say and don't have time to make a proper response right now.
The DB
It all started with the comparison information between antennas that the author of the article provided. One group of people had a stronger signal from the quad, and the other with the yagi. Further, one of the antennas has noticeably more higher s-meter results than the other, however, the other still had a significant amount of higher s-meter readings, to many to just brush off as random chance. So essentially, it all started with statistics.
All of the authors data was collected with long haul skip, and he stated that there is little to no difference between the two when it comes to local contacts, and single hop skip.
What would cause one antenna to be able to communicate with more people with a stronger signal strength than the other? The first thought that came to mind was that it was likely that the stronger part of one of the antennas was covering a larger geographic area, and thus more people reported a stronger signal. This is a possibility that made sense, and I determined that it was most likely the case, barring more evidence that told me otherwise, which if anyone has I am willing to look at.
Next, I wondered what would cause one antenna to reach a larger geographic area than the other. An antenna with a wider beam width/height would have a signal that would cover a larger geographic area, and by extension, more reports for this antenna would show as stronger than the other antenna. See, application of logic, and finding a possibility that makes sense. That is how I came up with the possibility of one of the antennas having a different beam width than the other.
Then their was the wording, something I took care to be specific with, and you ignored any part of it that might suggest that what I said was only a possibility that should be considered. This wasn't the first time you seemed to only look at part of what I said, ignored another part, and based an opinion on only some of what I said, this is in fact a re-occurring problem with you, and is a big reason why I get frustrated with you as much as I do.
So I am to say absolutely nothing, withdraw all help, and ignore everything until I make and post a model?
Three reasons for you.
- Not everything requires a model for an explanation, especially when I am just talking about a possibility as I clearly stated above.
- I don't always have time to make models for every antenna I look at or talk about. I actually have a life and responsibilities outside of posting on this forum, and sometimes I am very busy, which also applied to my time this morning.
- Modeling isn't the end all and be all of my knowledge when it comes to antennas, to me it is just another source of information. I don't rely on it nearly as much as you seem to.
Eddie, I have a question for you.
You regularly take things I say out of context, you ignore parts of what I say that you think are inconvenient even though they are often key to what I am talking about, on multiple occasions you made accusations about my models that had no basis in reality and in some cases someone with nothing more than rudimentary modeling experience could clearly see was incorrect (you claiming I was using a perfect ground once when I clearly wasn't comes to mind). I can go on here. You also seem to home in on me, how about this example from above, Needle Bender made a statement that someone with your experience in modeling should quickly determine was not necessarily true, and he actually mentioned it as a fact (unlike what you got on me about). This isn't the first time that you ignored things like that and homed in on me instead.
Are you targeting me?
That is what it feels like and I really don't like this feeling. There are a lot of models I don't post simply because I am under the impression that you are more interested in trying to say I am wrong about whatever it is I am talking about and that you often don't even try to understand. It is almost like you see me as a threat for some reason.
To those on topic, I apologize for my part in hijacking this thread.
The DB
I would prefer to discuss antenna ideas rather than the differences in our personalities, DB.
I don't have my sights set on you and I'm not after you. I do read your posts however, but that is because we have modeling in common. I believe you understand modeling and figure I may learn something reading your words and checking out your models.
I try my best to understand your words, and in this particular case, I simply felt you left us with the wrong impression on the subject of beam width regarding the Quad vs. Yagi...a subject that is not talked about very much. IMO it is an important characteristic to consider if one is interested in antenna responses at modest heights.
I accept your admission, but I'll still hope to voice my opinions and ideas.
I don't have my sights set on you and I'm not after you. I do read your posts however, but that is because we have modeling in common. I believe you understand modeling and figure I may learn something reading your words and checking out your models.
I try my best to understand your words, and in this particular case, I simply felt you left us with the wrong impression on the subject of beam width regarding the Quad vs. Yagi...a subject that is not talked about very much. IMO it is an important characteristic to consider if one is interested in antenna responses at modest heights.
I accept your admission, but I'll still hope to voice my opinions and ideas.
I don't want to sound out if hand. I would like to ask a question (s).
In a nut shell so to say....for 11 meters, over all, and at 12-15 ft. over a house roof ( 3 tab comp), and 36 - 39 ft. off of the earth which, on average would work "best", talk, hear,
a 2el (wire) Quad, over a 2el (tube) Yagi ?
Or
A 3el (wire) Quad, over a 3el Yagi ?
Thank you for your time...
Quads are of internist to me...I don't know why but am "pulled" to them.
I do have a "bambi" Quad cut for .555 I set up at times for SB work but not now....It's put up for the lack of dx now.
Thank you.
In a nut shell so to say....for 11 meters, over all, and at 12-15 ft. over a house roof ( 3 tab comp), and 36 - 39 ft. off of the earth which, on average would work "best", talk, hear,
a 2el (wire) Quad, over a 2el (tube) Yagi ?
Or
A 3el (wire) Quad, over a 3el Yagi ?
Thank you for your time...
Quads are of internist to me...I don't know why but am "pulled" to them.
I do have a "bambi" Quad cut for .555 I set up at times for SB work but not now....It's put up for the lack of dx now.
Thank you.
The differences between a yagi and a quad are minimal. On air tests and modeling has proven that over and over. Any differences in favour of one over the other can often be traced back to initial construction parameters. The differences are so small that it is pointless to argue one over the other. What difference does it make if one has a 10-15 degree wider beamwidth when one is 60 degrees and the other 70 degrees? Same for elevation angle. If one is 10 degrees and the other 12 degrees you will not see a difference 99% of the time.
Thank you.I am interested in Quads....but I can realy see what a mees it is to put one up, and care for it. At one time I had a 3el Yagi and loved it, ease up ease to care for. I'm setting up a base soon and will run a Sirio 2016 (5/8 wave), and I was thinking about a Quad....but common sense tells me to run a3el Yagi flat side.
And for my HF rig(after I test) I want to put up a lone wire or 80 meter loop.