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sigma4 article is online
- Thread starter bob85
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DB, I already complained that the model was useless for this report IMO, because probably you were the only one that might appreciate a model that does not comport with any known dimensions for the antenna under discussion in Henry's report on the Sigma4. Just show us what you have and forget about my problems. If I have any questions, I will ask.
That will not be a new revelation from you Donald, since I don't agree with you on this antenna anymore...you disregard my post anyway, that is obvious you just like being personal and ill at easy with any new ideas...that is obvious.
Thanks Bob, but I went to bed.
It did get heated yesterday, and I'm sorry I even got back into the fray. If I know Henry, he will not be pleased either. I saw nothing fruitful in the discussion going on at some point...and I think it was yesterday or Saturday, and I made a post.
Donald is right about one thing. In my mind, I don't understand what is going on, nor why all the personal attacks. This arguing all the time about seeming-less chatter is not good for me. I saw it starting over again, but this time Henry was the target.
I think these guys should be able to discuss and argue some sensible differences without getting personal, but noooo. So, I lost it again and got back into the fray.
I just got tired of hearing the onslaught of stuff being said to and about Henry, and it looked to me like nobody was even considering any of his details for discussion on his report...just getting down and dirty with words...so I popped up again and again it is fruitless.
I started with just a point of view and a image I posted of my S4 cone. It was the radial cone view describing the Eznec's current pattern for the radials compared to the image that Donald posted...where he referred to it as being crescent bowed like a 1/2 wave pattern looks, and that is all it took and the words were on.
It did get heated yesterday, and I'm sorry I even got back into the fray. If I know Henry, he will not be pleased either. I saw nothing fruitful in the discussion going on at some point...and I think it was yesterday or Saturday, and I made a post.
Donald is right about one thing. In my mind, I don't understand what is going on, nor why all the personal attacks. This arguing all the time about seeming-less chatter is not good for me. I saw it starting over again, but this time Henry was the target.
I think these guys should be able to discuss and argue some sensible differences without getting personal, but noooo. So, I lost it again and got back into the fray.
I just got tired of hearing the onslaught of stuff being said to and about Henry, and it looked to me like nobody was even considering any of his details for discussion on his report...just getting down and dirty with words...so I popped up again and again it is fruitless.
I started with just a point of view and a image I posted of my S4 cone. It was the radial cone view describing the Eznec's current pattern for the radials compared to the image that Donald posted...where he referred to it as being crescent bowed like a 1/2 wave pattern looks, and that is all it took and the words were on.
Yes, you complained the model was useless, however, most of your claims on it are strictly based on opinion and your broken version of the model, and the rest have nothing to do with the model itself (for example, the high segment count complaint that had nothing to do with the model in question as it didn't have nearly that many segments). You have not demonstrated that the model is useless in any way, shape, or form. There is a difference. Apparently, you think you can demand proof from others and only accept it if it meets a very stringent set of standards, but when the same is demanded from you, your opinion about something you know less than nothing about is a good substitute. You have shown that you have a clear double standard in this regard.
So I should just give you the models I come up with? I tried that, and instead of working with it properly you broke it by making changes to it without compensating it for said changes, which gave you results that were not accurate in any way, and then you tried to use your broken results against the model's relevance.
Ordinarily I would give the info on my models to anyone for the asking, but your reputation now precedes you, and that reputation was reinforced by your inability to use the GHZ24 model as it was intended. Two models you were given access to and refused to use properly... and you call yourself a modeler. Tell me, why should I give you model data when you not only refuse to properly examine the model in the context given, but then break the model and use the broken results to try and discredit the model?
If you want anything from me, especially relating to this antenna, you will have to find a way to change my opinion of you...
The DB
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You guys are eager, your supposed to wait for the bell,
Yes Eddie,
Unlike me who does not mind a brawl if somebody is winding me up,
Henry is not into that kind of thing, he's polite and likes to stick to the topic and facts that can be proven,
He's made his view clear, I don't have a problem understanding , at least i don't think im not understanding,
If somebody disagrees the onus is on them to post proof that its wrong so we can all look at the evidence,
That's how a debate is normally conducted, If we ever hope to bring the debate to a conclusion.
DING DING
Yes Eddie,
Unlike me who does not mind a brawl if somebody is winding me up,
Henry is not into that kind of thing, he's polite and likes to stick to the topic and facts that can be proven,
He's made his view clear, I don't have a problem understanding , at least i don't think im not understanding,
If somebody disagrees the onus is on them to post proof that its wrong so we can all look at the evidence,
That's how a debate is normally conducted, If we ever hope to bring the debate to a conclusion.
DING DING
There are clear problems with Henry's theory. His theory relies on 5 rotating fields taking place at the cone. The 4 radials and the inner monopole. He sees these fields as separate and therefore able to severely interact with each other, causing almost complete cancellation of constructive fields radiating from the cone. If that's the case why do 4 radial versions work better than 3? We don't need more conductors to create a situation where cancellation improves. One leg on the side of the monopole can do that. On the other hand more radials does improve the effects of confinement or shielding.
If the effects were caused by confinement each additional radial would improve performance but the benefits of each one added would become less as the number of radials increases. That is exactly what takes place in the field with very little improvement noticed going beyond 4 radials all the way up to a complete wire mesh cone.
I see this as evidence there are only 3 rotating fields at the base of this antenna. One around the monopole itself. One around the inside surface of the cone and most important is the one spinning around the outside of the entire cone that has been effectively isolated from the fields within.
We are also told there are no constructive currents left on the outside of the cone while we are left with the most unusual 1/2 wave shaped field emitting from this 1/4 wave radiator. Not only are there currents present here, there has to be a pair of them in order to make that shape field. I tend to believe my eyes over my ears. I see the outside near field on the cone as isolated from the field within just like CST shows it, just like the engineer explained it and just like the performance in the field suggests.
If the effects were caused by confinement each additional radial would improve performance but the benefits of each one added would become less as the number of radials increases. That is exactly what takes place in the field with very little improvement noticed going beyond 4 radials all the way up to a complete wire mesh cone.
I see this as evidence there are only 3 rotating fields at the base of this antenna. One around the monopole itself. One around the inside surface of the cone and most important is the one spinning around the outside of the entire cone that has been effectively isolated from the fields within.
We are also told there are no constructive currents left on the outside of the cone while we are left with the most unusual 1/2 wave shaped field emitting from this 1/4 wave radiator. Not only are there currents present here, there has to be a pair of them in order to make that shape field. I tend to believe my eyes over my ears. I see the outside near field on the cone as isolated from the field within just like CST shows it, just like the engineer explained it and just like the performance in the field suggests.
Donald
Any time you have current flowing in a conductor you have an electric E-field measured in V/M and a magnetic H-field measured in A/m
CST can show either of those fields, as can FEKO,
I don't model and can't afford CST to find out, i would not bet my life on what the CST animation is showing,
whatever it is showing is clearly measured in A/M so its not the electric E-field,
Henry tells us its the magnetic H-field with colors to indicate direction of rotation with a comparison to FEKO that uses arrows to indicate direction of rotation of the magnetic H-field,
and that he's compared the gain against other antennas in field tests,
You claim its showing us radiation currents and their phase,
and that its backed up with field tests done independently by some of your customers,
We don't have any more evidence such as FEKO to back the animation up, or confirmation of field tests done by the guys you tell us did the tests,
Those tests would be one way to lead us to question what Henry is telling us about the antennas gain,
Another way would be for one of you modelling guys
(independent of Henry) to contact somebody at CST and ask exactly what the animation is showing us to remove any doubt,
Does that sound reasonable ?
Any time you have current flowing in a conductor you have an electric E-field measured in V/M and a magnetic H-field measured in A/m
CST can show either of those fields, as can FEKO,
I don't model and can't afford CST to find out, i would not bet my life on what the CST animation is showing,
whatever it is showing is clearly measured in A/M so its not the electric E-field,
Henry tells us its the magnetic H-field with colors to indicate direction of rotation with a comparison to FEKO that uses arrows to indicate direction of rotation of the magnetic H-field,
and that he's compared the gain against other antennas in field tests,
You claim its showing us radiation currents and their phase,
and that its backed up with field tests done independently by some of your customers,
We don't have any more evidence such as FEKO to back the animation up, or confirmation of field tests done by the guys you tell us did the tests,
Those tests would be one way to lead us to question what Henry is telling us about the antennas gain,
Another way would be for one of you modelling guys
(independent of Henry) to contact somebody at CST and ask exactly what the animation is showing us to remove any doubt,
Does that sound reasonable ?
Does someone have a link to that cst model that is on page 14 of henry's report?
somewhere that i can get a better look at it and a basis of what it is...
somewhere that i can get a better look at it and a basis of what it is...
it kind of looks like this one
http://www.gain-master.it/vsconventional.php
but from the reading on henry's report the numbers are different, so i think it's a different model.
http://www.gain-master.it/vsconventional.php
but from the reading on henry's report the numbers are different, so i think it's a different model.
It doesn't sound unreasonable but still leaves me with serious questions regardless of what field the model is showing. Everyone accepts the fact the field shown in the top 1/2 wave of the model makes it into the far field. The only difference I see with the field around the cone is its shape (which may be key to solving the cone mystery but seems to be overlooked regularly) and magnitude being less. Those issues have no ability to prevent the near field from combining with the far field. So why should we expect the lower exposed field to behave any differently than the upper 1/2 waves field? It's not showing us the H field for the bottom and the E field for the top.
Therefore the only remaining difference is the field we see inside the cone. Henry's theory is suggesting that the field inside the cone is interacting with the outside field in such a way that it cancels the far field radiation from the cone. That's a bit hard to swallow when I see near perfect isolation between these "confined" fields in the model and there is obviously in phase radiation remaining on the outside of the cone.
Regardless of how we interpret the model, the entire issue seems to pivot on whether the cone functions as individual elements or one broadband flared element. If Henry's theory of operation were correct, then the entire principle of operation and performance characteristics should change once the cone is replaced with a solid structure.
That would eliminate any chance of individual rotating fields around each radial and force us to recognize the cone is a single element. The mesh cone had been tried as early as 1939 and as recently as a few years ago by myself. Once we have 4 evenly spaced radials the benefits of a solid cone are minimal. Take one of the 4 away and you can see distant performance degrade. That leans more towards confinement rather than cancellation.
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I think the main problem is you claim the field inside the cone is opposite in phase to the field outside the cone because the colors are at opposite ends of the A/M scale,
as if the monopole was one phase and the radials act like a mirror keeping the field from the monopole inside the cone while allowing an opposite phase current to flow outside the cone,
That’s not how i see it,
let me explain what i think is going on until somebody proves otherwise,
The monopole and radial are in opposite phase with fields from both rotating in opposite directions, as seen in Henry’s FEKO plot,
That causes the fields between the radials and monopole to be either moving away from you or moving towards you depending on which side of the monopole we are looking at,
in the same way rollers on an old mangle rotate in opposite directions but from your perspective looking between the rollers they both move towards or away from you depending on which direction you crank the handle or which side of the mangle you look at ( mind you don’t trap your fingers )
The field seen on the outside of a radial is the same field as on the inside of a radial but moving in the opposite direction from your perspective like a single mangle roller,
The field seen on the outside is the leftover radiation after cancellation due to the opposite rotating fields interacting and cancelling and maybe some small leakage due to the radials not been parallel with the monopole,
The magnitude of that radiation is highest towards the top of the cone where the radials are furthest away from the monopole ( at a voltage not current maxima ) and lowest towards the base ( current maxima ) where the radials are closest and cancellation is more complete,
its not a 1/2wave current pattern on a 1/4wave radial caused by a current source at each end of the 1/4wave radial as you imagine,
Its clear to see that the magnitude of the radiation is only a small fraction of the radiation from the upper 1/2wave,
Which gets us back to gain,
Think about a collinear, say 2x 1/2wave phased with a 180 degree stub like the collinear j-pole,
You will never get close to the theoretical 3db over a dipole unless you put significant distance between the two 1/2wave radiators, and that’s using two radiators with very similar radiation field strengths,
As you reduce the separation between the two 1/2wave elements gain drops towards 2dbd,
How is it possible to have 2dbd from a vector when you have 1x 1/2wave radiator and only some very small magnitude of radiation from the cone that is in no way comparable to radiation from a second 1/2wave radiator?
That seems to defy the laws of physics,
Not only that but extending the radiator causes current phase in the cone area to shift resulting in a reduction in low angle radiation and an increase in high angle radiation just like a 5/8wave j-pole,
http://www.hamradio.me/antennas/58-wave-j-pole-vs-12-wave-j-pole-eznec-shootout.html
giving us less signal where we want it on the horizon,
You already told us peak signals come when the hoop is close to the zero crossing point using 1/4wave radials which is when you have an electrical 1/2wave above the cone, that gives us the best balance at the top of the cone, least radiation from the cone,
Its clear as mud that Avanti and the 90” radial clones did not optimise the design,
Its also clear the 7/8 monopole versions with 90” radials were even further from optimal,
That’s why we can adjust our antennas and make them perform better out towards the horizon than any of the versions seen on the market before,
And why sirio have updated their vector to have 1/4 wave radials with a 1/2wave upper monopole claiming improved low angle radiation,
Does that sound crazy to you Donald?
Can we honestly expect 2dbd from a 1/2wave + a sniff of radiation from the cone?
As Henry pointed out other factors can also contribute to the signal received at distance and we cannot ignore those possible effects as we adjust our antennas.
That's how it looks to me,
Id like to hear other peoples view if mine makes no sense to them,
thanks.
as if the monopole was one phase and the radials act like a mirror keeping the field from the monopole inside the cone while allowing an opposite phase current to flow outside the cone,
That’s not how i see it,
let me explain what i think is going on until somebody proves otherwise,
The monopole and radial are in opposite phase with fields from both rotating in opposite directions, as seen in Henry’s FEKO plot,
That causes the fields between the radials and monopole to be either moving away from you or moving towards you depending on which side of the monopole we are looking at,
in the same way rollers on an old mangle rotate in opposite directions but from your perspective looking between the rollers they both move towards or away from you depending on which direction you crank the handle or which side of the mangle you look at ( mind you don’t trap your fingers )
The field seen on the outside of a radial is the same field as on the inside of a radial but moving in the opposite direction from your perspective like a single mangle roller,
The field seen on the outside is the leftover radiation after cancellation due to the opposite rotating fields interacting and cancelling and maybe some small leakage due to the radials not been parallel with the monopole,
The magnitude of that radiation is highest towards the top of the cone where the radials are furthest away from the monopole ( at a voltage not current maxima ) and lowest towards the base ( current maxima ) where the radials are closest and cancellation is more complete,
its not a 1/2wave current pattern on a 1/4wave radial caused by a current source at each end of the 1/4wave radial as you imagine,
Its clear to see that the magnitude of the radiation is only a small fraction of the radiation from the upper 1/2wave,
Which gets us back to gain,
Think about a collinear, say 2x 1/2wave phased with a 180 degree stub like the collinear j-pole,
You will never get close to the theoretical 3db over a dipole unless you put significant distance between the two 1/2wave radiators, and that’s using two radiators with very similar radiation field strengths,
As you reduce the separation between the two 1/2wave elements gain drops towards 2dbd,
How is it possible to have 2dbd from a vector when you have 1x 1/2wave radiator and only some very small magnitude of radiation from the cone that is in no way comparable to radiation from a second 1/2wave radiator?
That seems to defy the laws of physics,
Not only that but extending the radiator causes current phase in the cone area to shift resulting in a reduction in low angle radiation and an increase in high angle radiation just like a 5/8wave j-pole,
http://www.hamradio.me/antennas/58-wave-j-pole-vs-12-wave-j-pole-eznec-shootout.html
giving us less signal where we want it on the horizon,
You already told us peak signals come when the hoop is close to the zero crossing point using 1/4wave radials which is when you have an electrical 1/2wave above the cone, that gives us the best balance at the top of the cone, least radiation from the cone,
Its clear as mud that Avanti and the 90” radial clones did not optimise the design,
Its also clear the 7/8 monopole versions with 90” radials were even further from optimal,
That’s why we can adjust our antennas and make them perform better out towards the horizon than any of the versions seen on the market before,
And why sirio have updated their vector to have 1/4 wave radials with a 1/2wave upper monopole claiming improved low angle radiation,
Does that sound crazy to you Donald?
Can we honestly expect 2dbd from a 1/2wave + a sniff of radiation from the cone?
As Henry pointed out other factors can also contribute to the signal received at distance and we cannot ignore those possible effects as we adjust our antennas.
That's how it looks to me,
Id like to hear other peoples view if mine makes no sense to them,
thanks.
Here is what you did Bob. You got me to clearly understand the rotating field theory Henry is presenting. It now makes sense how well defined the fields appear on each side of the cone due to it being an indication of direction. I get that but why are you ignoring the fact this same CST image could easily be representing the cone as one element with confined fields rotating inside and outside?
Why is everyone so resistant to the fact the antenna demonstrates the same characteristics when the cone is solid??? Can't you see if you make the cone solid (and it's been done in the past) that makes Henry's theory IMPOSSIBLE? If the cone were solid and CST were giving us the same view, what do you think would look different?
If one field was traveling around the inside surface of the cone and the same thing was happening on the outside surface that was isolated, wouldn't you see the same thing in CST? The inside field would still be rotating the same way, going away from you on one side and coming towards you on the other. The exact same thing would be happening on the outside.
It seems to me you're forgetting the claims you made about this antenna hearing stations others couldn't and noticing an improvement going from 3 to 4 radials. That adjusting radiator lengths peaked distant signals beyond what you could see in other designs. How much improvement is required before you can notice these things? Could you notice that with less than 2 db? That doesn't make sense either.
I've been suggesting for years since we have two radiators that we can manipulate the pattern on the distant horizon through electronic beamtilt between the two radiators in such a way that it beats the most efficient center fed broadcast dipoles made today on a regular basis. Not that we magically came up with impossible gains but that existing gain has been more effectively focused in comparison to a dipole.
When I told you peak gain occurs with the loop "close" to the zero crossing point, how do you think I determined that? That was mostly with measurements and experimenting with the models. I don't have a current probe to place on that radiator and never claimed to do so. You know tiny changes in these lengths effect performance in the distance so we don't know for sure how "close" to perfect this alignment is when far field gain peaks.
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Im pretty sure ccm built a wire mesh version and noticed very little change too,
nor could he measure increased gain with the vector,
Henry's cst model does not show the gain either, it shows similar gain to models done with other software,
His field tests confirm about the same gain as a j-pole,
He has also shown that the design can put more signal at distance than other antennas,
i wonder why sirio never gave you the full cst information backing up their 2dbd claim?
Maybe you can get one of your customers to confirm the measured gain?
That seems like the logical thing to do since you keep telling us some of the engineers took measurements,
With regards to the mesh vs radials,
you will have some current on the outside of the mesh due to unbalanced current at the top of the cone but not much if the antenna is adjusted correctly in my humble opinion,
The mesh version modeled in CST could not have the same magnetic H-field as seen in your animation its confined inside the coax,
The H-field displayed is not current, its the magnetic field caused by current,
Im not ignoring my years of experience with the antenna,
i just can't agree with a frespace gain that cheats the laws of physics,
Having similar freespace gain to a dipole does not mean the design can't put more signal on the horizon than other antennas, it does,
its taller and sees a further horizon with more signal at low angles than a 5/8wave
my 5/8waves at the height they are used have their major lobe up at high angles as Cebik explains, jay told me the same thing years ago,
That's not ideal for my situation here, i have no interest in talking to clouds,
I have never once seen a local swap any other antenna for a sigma or vector and not have better results except me when i swapped to the BIG-MAC.
nor could he measure increased gain with the vector,
Henry's cst model does not show the gain either, it shows similar gain to models done with other software,
His field tests confirm about the same gain as a j-pole,
He has also shown that the design can put more signal at distance than other antennas,
i wonder why sirio never gave you the full cst information backing up their 2dbd claim?
Maybe you can get one of your customers to confirm the measured gain?
That seems like the logical thing to do since you keep telling us some of the engineers took measurements,
With regards to the mesh vs radials,
you will have some current on the outside of the mesh due to unbalanced current at the top of the cone but not much if the antenna is adjusted correctly in my humble opinion,
The mesh version modeled in CST could not have the same magnetic H-field as seen in your animation its confined inside the coax,
The H-field displayed is not current, its the magnetic field caused by current,
Im not ignoring my years of experience with the antenna,
i just can't agree with a frespace gain that cheats the laws of physics,
Having similar freespace gain to a dipole does not mean the design can't put more signal on the horizon than other antennas, it does,
its taller and sees a further horizon with more signal at low angles than a 5/8wave
my 5/8waves at the height they are used have their major lobe up at high angles as Cebik explains, jay told me the same thing years ago,
That's not ideal for my situation here, i have no interest in talking to clouds,
I have never once seen a local swap any other antenna for a sigma or vector and not have better results except me when i swapped to the BIG-MAC.
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