Battle of the Ground plane #2

[Marconi]

Guess what? I think you are correct and I should have stuck with my original thoughts that the CST model showed an individual radial current that was 4 times less than the total sum. That is the is the main reason I was excited to see the very first computer simulated model of this antenna that actually did reflect what I was seeing in the field for what was 13 years when I first received the CST model. It is also going to be a key point in my final attempt to convince you that your thoughts on this antenna are incorrect my friend.

Don't be offended either. I know where you're at with the time invested in EZNEC and how difficult or convenient you may think it is that I say no other program has demonstrated an ability to model the antenna that I have seen, other than CST. It costs something like $2,500 for some reason. Maybe because when you throw that 1 out of 100 designs at it that requires tons more software programming code to handle correctly, it doesn't get confused?

Rather than look at the pretty colors the CST model shows and applying opinion to what it all means. I'm going to try and show you why it's the "goose laying the golden egg" here. Maybe you'll see why it explains with a blink of an eye what took well over an hour to say in words. Lets break the color shades down into "units" so that we have something to compare.

If you look at the bottom of CST video frame #21 you will see 5 lines dividing 4 "units" that are fairly close in size. The first line is the beginning of the intense red shades emitted from the top half wave. The second line is the beginning of those same shades from one cone radial. The third is the end of the red shades for one cone radial. The fourth line is simply an equal spacing between the last two lines. The fifth line is the end of red radiation from the top 1/2 wave.

See anything interesting yet? Knowing that the individual radial current that we are looking at is multiplied by 4 times makes those combined radial currents almost equal to the upper 1/2 wave. I say "almost" because the unit that represents the radial currents is slightly smaller than the others. Almost equal in CST is vastly different than 10 times less in EZNEC. CST replicates what I see in the field with my clients every day. EZNEC did so poorly on this design I gave up trying to figure out why. That's Roy's job.

I know the cone currents don't cancel for many reasons. There is no other place for the gain to come from. CST clearly shows it is the source of this 2 dbd. The engineer that built the model in CST and the new Vector specifically said the cone "confines radiation from the vertical" and did not say it cancels. More evidence of this is when remove some of the radials, gain goes down. If cancellation was the dominant factor here, one radial with all the current on it would produce the effect you're thinking of.

The word "confine" is more like "shield" or "block" than it is "canceling". Shielding like you might put over the VFO tube in a transmitter rather than canceling in a parallel ladder line of equal lengths. That is an entirely different effect causing the same collinear result and is why Cebik called it "non apparent collinear". It removes the unwanted currents from the vertical by blocking them so the cone energy is not wasted in cancellation and allowed to contribute significantly to the upper 1/2 wave.

This is why I say you'll probably have to forget about most of these cheaper programs if you want to learn anything about the Sigma.

Donald nothing in your words are offensive to me. We are discussing our opinions, and this is the way we learn about other ideas.

Until you showed us this image Donald, I did not understand what or how you were seeing what you were telling us.

I am still puzzled however, that you consider the magnitude in this way. This is just a guess on my part, but are you visualizing the red indicator from the outer edge back to the radiator itself (the four lines) as the indication for current magnitude? Should we not consider the magnitude of any current to be relative to the source element or wire only?

If I'm right above, with your idea in mind I could only consider your idea as speculation, and that puts us both even. Reason being IMO, the relative magnitude associated with Eznec and CST is represented by the distance the red line in my case, and the red color in your case, is physically away from the element or source wire in question. The currents on the radials are measured out from the radial, and not out from the radiator like you are suggesting...me thinks.

Also it is my opinion that the red and blue colors only represent the sign (+-) of the phase, and the width (thickness) of the red gives us an idea of the magnitude...just like Eznec does. Excepting that Eznec's Antenna View does not give us an indication of phase here...that is what the tabular currents log is for.

Do you see the thickness of the red current indicator on the radial edge being thicker at the base and thinner at the top...just like Eznec shows? This situation with the color in the CST model follows the current distribution to some degree...just like my Eznec does, so I still don't get your thinking here.

Do you think if I produce the evidence I mentioned to Bob, that you can give an objective look as what I think it tells us, these two models are producing very similar results?

Said another way, do you think if my Eznec model of the NV4k shows the same/similar maximum current in my currents log as CST indicates in their color/phase table...that will be suggestive of the fact that my model is pretty much spot on with the CST model...at the very least?

 

[Marconi]

i don't know how much in phase current flows eddie,
enough current flows on the wide spaced j-pole to skew the pattern in the direction of the short leg,
enough current flows on the open sleeve antenna to compress the pattern from the upper 1/2wave,
if the vector manages a 360 degree version of that id be happy,

sirio claim 2dbd for all their sleeve type antennas and at lower radiation angles than a 5/8wave, i can live with that claim, i doubt the sirio engineers are far from the truth.

Well Bob, that question I asked Donald was to see if he had some idea how much current was flowing in the bottom of the Vector that was effective in the far field. He did say earlier that the current was significant.

All I've ever said in this regard was that I don't see that much current flowing into the far field from the base of the S4/NV4K antenna and that consideration from me has always been due to what I see in the Eznec models I've made.

I further say that if there was more balance in the currents in the radial cone area...there would likely be no currents flowing, and that would be due to complete cancellation...something that Donald seems to want to disregard as happening at all in this antenna.

I don't see how we can get around the fact that Sirio refers to their NV4K as a coaxial j-pole, which pretty much describes cancellation at the very least. This is also how the argument came to be with the j-pole, some saying that the 1/4 tuning stub did not radiate, while others argue that it did. This is exactly why you say here that the j-pole skews the pattern, because some RF is excaping the cancellation process going on the the out of phase bottom of that antenna.

It is not fair to have your argument work one way with an out of phase j-pole, and then NOT argue the same with an out of phase Vector.

My idea here does not say we see no currents flowing in the bottom, it says there are very little currents flowing. As to whether these currents are beneficial or not depends on whether the phase of the element with the greatest magnitude is equal to the phase of the upper radiator or not.

If Donald is right and there is no cancellation going on with the out of phase condition in the radial area for the Vector...then my idea is dead.

 

[Shockwave]

Donald nothing in your words are offensive to me. We are discussing our opinions, and this is the way we learn about other ideas.

Until you showed us this image Donald, I did not understand what or how you were seeing what you were telling us.

I am still puzzled however, that you consider the magnitude in this way. This is just a guess on my part, but are you visualizing the red indicator from the outer edge back to the radiator itself (the four lines) as the indication for current magnitude?

That is what the scale at the top right of the plot represents. The color represents amps per meter (measurement of intensity with RF fields) and how far away from the element it is able to maintain that field is directly related to it's strength. That's why the top of the antenna has almost no red extending outwards.

Should we not consider the magnitude of any current to be relative to the source element or wire only?

If you are trying to compare the magnitude of the cone against the source element, then yes.

If I'm right above, with your idea in mind I could only consider your idea as speculation, and that puts us both even. Reason being IMO, the relative magnitude associated with Eznec and CST is represented by the distance the red line in my case, and the red color in your case, is physically away from the element or source wire in question.

So if the currents are equal why does your EZNEC model show .35 dbd and CST shows 2 dbd? Why does EZNEC have you tricked into thinking constructive currents from the cone are only a tiny fraction of the vertical and CST shows the combined currents of all four radials are nearly equal or about 1 db less than the vertical? Why does EZNEC miscalculate the radiated phase angle by a 1/4 wavelength or 90 degrees?

The currents on the radials are measured out from the radial, and not out from the radiator like you are suggesting...me thinks.

That's why the unit that represents the current for a single radial is approximately 1/4 the size of the one for the upper 1/2 wave. It is measured with respect to the radial and not the vertical radiator. Just follow the lines and you'll see.

Also it is my opinion that the red and blue colors only represent the sign (+-) of the phase, and the width (thickness) of the red gives us an idea of the magnitude...just like Eznec does. Excepting that Eznec's Antenna View does not give us an indication of phase here...that is what the tabular currents log is for.

Do you see the thickness of the red current indicator on the radial edge being thicker at the base and thinner at the top...just like Eznec shows? This situation with the color in the CST model follows the current distribution to some degree...just like my Eznec does, so I still don't get your thinking here.

Do you think if I produce the evidence I mentioned to Bob, that you can give an objective look as what I think it tells us, these two models are producing very similar results?

Said another way, do you think if my Eznec model of the NV4k shows the same/similar maximum current in my currents log as CST indicates in their color/phase table...that will be suggestive of the fact that my model is pretty much spot on with the CST model...at the very least?

Nothing I have ever seen in EZNEC is remotely similar to how the antenna works or how CST models it. EZNEC is wrong on phase, gain and currents in the Sigma model. That's 3 strikes and covers just about every area of importance in computer modeling and is why I don't even consider EZNEC any use at all with the Sigma. If you're trying to learn about the Sigma, EZNEC will just make you stupid if you believe it and frustrated if you don't.

 

[Marconi]

Neither one of you have acknowledged my offer of more proof that my model shows almost exactly the same current distribution condition noted at the radiator's current maximum as the CST model.

All I did to my Vector model that I posted here earlier is to change the default power to 500 watts the same as Sirio tested for.

So, if ya'll check the current maximum amps/m at segment #73, for wire #2, you will see -2.3038 amps/m, compared to the CST model which shows -2.37 amps/m for the same maximum.

Is this close enough to be convincing that my model is very close to the model that CST made for the Sirio New Vector 4000.

I also made some notes that speak to my idea that there is cancellation in the radial cone area, and the net effect is -.4714 amps/m radiation that is in phase with the top 1/2 wave radiator and this is constructive addition to gain.

I was surprised this showed as much current as it did at about 20% of the maximum, but guys the way I see it the S4/NV4K does show some radiation into the far field from the the radial cone area.

Bob you were right all along. It has always been my goal to try and prove your idea correct, but I believe you felt me your enemy at times too.

I don't know if this is what Donald wanted to hear, but maybe this amount of current is significant enough to do what he sees in the field. I have never once claimed his field work was in question or wrong. I don't do that to my friends.

Now I also think I know why Cebik, W8JI, and others often report model results at legal limits, so that the currents they complain about being errant and troublesome don't look so small...like my original model showed at -.12368 amps/m difference that was radiating in the far field.

Before I go though, let me call attention to another fact. This difference at -.4714 amps/m, is just a little bit larger than the minimum current at the tip of the radiator which is -.33260 amps/meter, and Donald again that ain't much.

If you guys consider all of this, then you'll know as much about currents as I do and I learned what I did through careful consideration and observations. Nobody ever managed to really and effectively help, except the guy I don't even remember that sent me his simple model of an old Starduster, and I saw the light.

Donald if you still disagree with me, then come up with some real proof like I show here, right or wrong, and I'll consider anything you can show us.

Do you know or recall that Henry at one time some months ago promised me to model the NV4K using CST, but that just never happened and I wasn't surprised for some reason.

If I was you, I would consider checking in with him...he seems to have a good handle on modeling and has lots of knowledgeable contacts regarding modeling. So, you won't have to continue asking your friends at Sirio. Personally I don't think we can ever ask too many questions.

View attachment Vector set at 500 watts.pdf

Eddie

 

[Marconi]

Thanks Donald, we just don't see things the same, not even close and my words are in vain.

 

[Shockwave]

Well Bob, that question I asked Donald was to see if he had some idea how much current was flowing in the bottom of the Vector that was effective in the far field. He did say earlier that the current was significant.

All I've ever said in this regard was that I don't see that much current flowing into the far field from the base of the S4/NV4K antenna and that consideration from me has always been due to what I see in the Eznec models I've made.

The longer you work with software that happens to be riddled with inaccuracies for the particular design you're working with, the longer you will draw inaccurate conclusions.

I further say that if there was more balance in the currents in the radial cone area...there would likely be no currents flowing, and that would be due to complete cancellation...something that Donald seems to want to disregard as happening at all in this antenna.

I would not say there is no cancellation at all and CST does not say that either. From what I see there is perhaps up to 1 db of cancellation.

I don't see how we can get around the fact that Sirio refers to their NV4K as a coaxial j-pole, which pretty much describes cancellation at the very least. This is also how the argument came to be with the j-pole, some saying that the 1/4 tuning stub did not radiate, while others argue that it did. This is exactly why you say here that the j-pole skews the pattern, because some RF is excaping the cancellation process going on the the out of phase bottom of that antenna.

You're placing way too much emphasis on the name. They had to call a it something and since the only previously produced model only called it a Sigma IV, we have the Coaxial J-pole. Shakespeare called the Big Stick a collinear. Was that accurate? With respect to how it works, you just won't admit the inexpensive EZNEC program could be wrong 1 out of 100 designs or you're summer of testing one Sigma with questionable methods could fail.

It is not fair to have your argument work one way with an out of phase j-pole, and then NOT argue the same with an out of phase Vector.

It's not fair to put so much weight on opinion founded on inaccurate software and testing while you ignore more advanced software or someone else's daily experiences in hundreds and hundreds of locations who puts his money where his mouth is and guarantees noticeable gain with every install or a refund.

My idea here does not say we see no currents flowing in the bottom, it says there are very little currents flowing. As to whether these currents are beneficial or not depends on whether the phase of the element with the greatest magnitude is equal to the phase of the upper radiator or not.

Ideas are great. Unfortunately we must learn to abandon them once proven wrong. The earth is flat sounded like a good idea at one time. It's as silly to me as the Sigma's cone done not contribute significantly to the radiation pattern.

If Donald is right and there is no cancellation going on with the out of phase condition in the radial area for the Vector...then my idea is dead.

Some cancellation is taking place Marconi. If you reversed the amount of cancellation and radiation in your mind, you'd probably be closer to accurate.

 

[Marconi]

The longer you work with software that happens to be riddled with inaccuracies for the particular design you're working with, the longer you will draw inaccurate conclusions.

Well Donald, I know that is your opinion, and I do find things using Eznec that I don't understand and can't explain, but I'm not nearly as categorical about Eznec being riddled with inaccuracies as you.

My model of the Vector shows almost the same maximum current at the top 1/2 wave current maximum with 500 watts input as the CST model does, and I don't think if the model was riddled with errors...we would see my Vector manifest this same value at the CST current maximum which is clearly noted in the animated image you posted. I ran similar scans on several of my other high gain CB models, and I find every one showing differences that we don't see in my presentation above.

As I read the Sirio tech sheet for the Gain Master the other day I saw where the power was set at 500 watts. I tried doing that on the Vector model, and if you bothered to check my evidence you will clearly see where the amps/meter was almost the same...for my model as noted in the animated image you posted at 2.37 amps/m. That does not smack of errors to me.

Respectfully I think you look here to only pick and choose the facts and figures you see that support you beliefs concerning Eznec. Donald, did you ever consider that you could be wrong about Eznec?

Think about what you reminded of the other day, when you told me that Sirio makes the "Coaxial J-Pole" notation in their specs, and that was done solely out of convenience, or for some long standing tradition.

I think you and Bob both found that use of the statement offensive as though it is untrue. IMO I think you just decided to NOT argue the reference as though if wasn't there...basically saying that it don't mean anything.

I think the idea is perfectly appropriate for a general description, and that is why I believe the bottom cone radiates minimally and that is based on how and what I see in my Eznec model. That said, I also see the same in your CST model.

I would not say there is no cancellation at all and CST does not say that either. From what I see there is perhaps up to 1 db of cancellation.

This has to be another assumption, because no where does Sirio state this fact and we don't see it noted in the image.

You're placing way too much emphasis on the name. They had to call a it something and since the only previously produced model only called it a Sigma IV, we have the Coaxial J-pole. Shakespeare called the Big Stick a collinear. Was that accurate? With respect to how it works, you just won't admit the inexpensive EZNEC program could be wrong 1 out of 100 designs or you're summer of testing one Sigma with questionable methods could fail.

Back in those days when Shakespeare was a big dog selling CB antennas, that collinear idea came out about the advent of the CB version of the 5/8 wave antenna too. Would you say the 5/8 wave is also a collinear, because it also shows a smaller portion of the bottom of the monopole being out of phase with the top 1/2 wave radiator...or do we see a destructive result there also due to cancellation. CBr's have been know to buy anything that used buzz words to peak their interest. We use to call these claims "fish bait" when I was in the CB business back in its heyday.

It's not fair to put so much weight on opinion founded on inaccurate software and testing while you ignore more advanced software or someone else's daily experiences in hundreds and hundreds of locations who puts his money where his mouth is and guarantees noticeable gain with every install or a refund.

All modeling needs follow up testing, just like Sirio does with their in house testing facility. You keep trying to conflate these two tools. CST may well be technically way ahead of Eznec, because it is designed for the professional. Roy also has a version of Eznec for the professional I think, but I'm not sure about all the differences.

You told us the story about your lack of success with Eznec, and your idea for the Dominator was jeopardized because of your use of Eznec, right? I believe your story, and as I recall that seems to go back in time some 15 years ago, right?

CST looks to have started up around 2008 at trade shows with their new animated or simulated antenna design ideas, right? If you were using Eznec 15 years ago to design and test your Dominator idea, and you didn't get the right results until you had a redesign using CST, then what does that suggest happened with you antenna design all the years before CST came on the scene?

Ideas are great. Unfortunately we must learn to abandon them once proven wrong. The earth is flat sounded like a good idea at one time. It's as silly to me as the Sigma's cone done not contribute significantly to the radiation pattern.

I do agree times and ideas do change over time in the minds of men, but I show you what and why I believe what I think. You show what and why you believe what you think...isn't that fair for men to do?

Some cancellation is taking place Marconi. If you reversed the amount of cancellation and radiation in your mind, you'd probably be closer to accurate.

You're asking me to change the rules of physics, doing so will prove me wrong and you right. That is not logical Donald. I just showed you evidence for what and how I see what I think. If you don't understand that then ask me some questions. I asked you about your new sill image of the CST pattern with the lines. We talked about it, but just didn't get any where yet.

Could you try and describe that image again in some different words maybe. I would like to fully understand what you see. Hey Bob, I think you made a comment about that new image, but it was more like tongue in cheek, and was not very descriptive. Why don't you try and describe what you see in that image. If we can't still talk about this idea...then who will talk about it. You both see all the looks and interest being made. There are curious minds out there wanting to know more I think, but they just seem to me to be afraid to say anything.

Both you and Donald talk like you fully understand completely how the S4/NV4K works, or at the very least know enough to argue that my model is wrong. So, I am confused and have questions. Why can't you both together convince me of what you know? You both seem pretty clear in you conviction that you're both right.

I think there are plenty of guys out there that would like to be convinced too.

Bob what is your opinion about the cancellation ideas that I presented?

What significance do you place on the accuracy of my Vector model, considering I showed evidence that the maximum current at the center of the top 1/2 wave is almost the same as noted on the CST model that Donald posted?
So, who else is there Bob?

 

[Shockwave]

Well Donald, I know that is your opinion, and I do find things using Eznec that I don't understand and can't explain, but I'm not nearly as categorical about Eznec being riddled with inaccuracies as you.

My model of the Vector shows almost the same maximum current at the top 1/2 wave current maximum with 500 watts input as the CST model does, and I don't think if the model was riddled with errors...we would see my Vector manifest this same value at the CST current maximum which is clearly noted in the animated image you posted. I ran similar scans on several of my other high gain CB models, and I find every one showing differences that we don't see in my presentation above.

As I read the Sirio tech sheet for the Gain Master the other day I saw where the power was set at 500 watts. I tried doing that on the Vector model, and if you bothered to check my evidence you will clearly see where the amps/meter was almost the same...for my model as noted in the animated image you posted at 2.37 amps/m. That does not smack of errors to me.

EZNEC is perfectly accurate at modeling the Sigma as a 1/2 wave. I never said anything that should make you think the error in EZNEC had anything to do with the currents in the upper 1/2 wave. Why would you even be looking here when I said dozens of times EZNEC is dead wrong about the cone?

Respectfully I think you look here to only pick and choose the facts and figures you see that support you beliefs concerning Eznec. Donald, did you ever consider that you could be wrong about Eznec?

Don't put your shoe on my foot Marconi. It don't fit. I'm may be the only one you'll ever meet that has conclusive proof that EZNEC mistakenly identifies the Sigma as a 1/2 wave based on the phasing network it requires to add another 1/2 wave element. You don't understand that concept so you revert back to what is a useless piece of software. Why don't you present what I'm saying to Henry? I'm fairly confident he will understand that to build a working collinear phase delay, you must identify all of the radiation currents below the delay first. Without that knowledge there is no way to bring the top into phase with the bottom.

You need to understand this concept desperately to move on. Nothing screams louder that EZNEC is garbage when used on the Sigma design more than it mistakenly adding 100% extra length in a collinear phase delay. This completely proves EZNEC calls the Sigma a 1/2 wave. The fact it really requires 90 degrees of phase shift, completely proves the antenna has developed a significant in phase radiation current over a 270 degree or 3/4 wavelength radiator. If you don't get this, STOP EVERYTHING until you do. You'll never understand if you don't.

That little piece of proof is so powerful to those who understand it that it stopped Roy from conversing with me about the subject dead in his tracks. He tried to convince me I must have made a mistake in calculating the electrical length of my phase delay in the field test. When I told him it was just a folded wire with a complete length of 1/4 wavelength he never responded. There is no wiggle room in this type of phase delay like in some helically wound coil designs. What it measures physically is what it is electrically within a very tinny percentage and never off by 100% like EZNEC is.

If you can't respond to this or at least tell me you are going to seek help understanding what I'm talking about, I'll just be comfortable letting you make the same mistake EZNEC does on the Sigma and call it a 1/2 wave. Show us your want to learn is as big as your want to be right and I'll be impressed. For your own benefit, if you believe Henry has CST ask him for help because he's about the only one who might be able to help you understand.

If he builds an accurate model of the NV4K in CST it could only reproduce the same video you've not taken seriously for the last 2 years. Yes, he will have access to the tabulated data at this point but if you think it will be anything other than in full agreement with its video representation, you're fooling yourself.

Think about what you reminded of the other day, when you told me that Sirio makes the "Coaxial J-Pole" notation in their specs, and that was done solely out of convenience, or for some long standing tradition.

I think you and Bob both found that use of the statement offensive as though it is untrue. IMO I think you just decided to NOT argue the reference as though if wasn't there...basically saying that it don't mean anything.

I think you forget how many years Sirio has been making the Sigma IV design in Europe and that they had it named years before CST was invented. We have the new Vector because of CST and if they had the chance to pick the name for the first time again today, it might be different. That's as far as I'll go with opinion.

I think the idea is perfectly appropriate for a general description, and that is why I believe the bottom cone radiates minimally and that is based on how and what I see in my Eznec model. That said, I also see the same in your CST model.

If you think CST agrees you need to stop ignoring post #71 with respect to breaking the field strength down into units so you could understand. I knew you missed the entire thing as soon as you didn't read what each of the four units divided by the 5 lines represented. Sadly that's about as simple as any of this is going to get so there has to be something like denial blocking your ability to proceed here.

This has to be another assumption, because no where does Sirio state this fact and we don't see it noted in the image.

Back in those days when Shakespeare was a big dog selling CB antennas, that collinear idea came out about the advent of the CB version of the 5/8 wave antenna too. Would you say the 5/8 wave is also a collinear, because it also shows a smaller portion of the bottom of the monopole being out of phase with the top 1/2 wave radiator...

Absolutely not! In order to use the term "Collinear" in good faith the antenna must contain more than one source of significant radiation that combine constructively in the far field to produce more gain. Not simply extending a free standing radiator to the point where phase inverts. Collinears must deal with this issue of phase correction that you ignore because EZNEC tricked you.

or do we see a destructive result there also due to cancellation.

The destructive result is not due to the same type of effect in the Sigma. The only part cancellation plays in the deconstructive currents on the 5/8 wave groundplane are in the far field. When the lower 1/8 wave that is out of phase combines with the upper 1/2 wave. Shielding action is the primary confinement method in the cone of the Sigma. That why the Vector with 4 radials has more gain on the distant horizon than the 3 radial Sigma that I think you were using for tests.

If the main effect in the cone were cancellation of equal but opposite currents, it would not change with the ratio of elements. Cancellation of equal but opposite currents only requires equal lengths of parallel transmission line. This effect can be accomplished with as little as one radial. The Sigma design drops to unity gain with a skewed pattern similar to a J-pole when you do this.

CBr's have been know to buy anything that used buzz words to peak their interest. We use to call these claims "fish bait" when I was in the CB business back in its heyday.

All modeling needs follow up testing, just like Sirio does with their in house testing facility. You keep trying to conflate these two tools. CST may well be technically way ahead of Eznec, because it is designed for the professional. Roy also has a version of Eznec for the professional I think, but I'm not sure about all the differences.

It's not me trying to "conflate" CST with field results. That is the result of what testing in a scientific manner produces in this case. The fact the two can be combined simply means they are in agreement with each other. The fact I can prove EZNEC ignores 1/4 wavelength of effective radiation through phase delay experiments in collinear prototypes debunks EZNEC more then Roy wanted to hear about too.

You told us the story about your lack of success with Eznec, and your idea for the Dominator was jeopardized because of your use of Eznec, right? I believe your story, and as I recall that seems to go back in time some 15 years ago, right?

CST looks to have started up around 2008 at trade shows with their new animated or simulated antenna design ideas, right? If you were using Eznec 15 years ago to design and test your Dominator idea, and you didn't get the right results until you had a redesign using CST, then what does that suggest happened with you antenna design all the years before CST came on the scene?

Are you serious Marconi???????????????????????????? Do you read anything I have posted in direct respect to this question you have to ask again? You're not respectful at all when you don't read and twist your misconception into implying I've lied. Now I'm taking it personal because you're acting ignorant again in the same exact way. Please take a quote from any post I've made that says anything close to the words you just fabricated here.

Anyone who has followed this knows where and when the first mention of the CST models originated. They know that came about when Sirio published the CST data for the new GM about 2 years ago. As soon as I saw the CST model for the GM I had to know if they ever used this powerful software to model the Vector design. The response was an email back with the first photo that I posted here the same day.

So eager to share with you guys that I forgot to brand the image so the thieves would find it and copy it like all the other material on the company website. One of the site moderators provided the info needed to get that updated here.

I told you that EZNEC screwed up my accuracy in drawings filed with the PTO (Patent and Trademark Office) with regards to the collinear phasing. That this took place what has to be at least 2 winters ago when I filed based on the EZNEC results and had not built a prototype for field testing.

Later that spring when the prototype was tested I had to rip out 1/4 wavelength of phase delay or the equivalent of 8 feet conductor on this band to see gain over the stock antenna. Once again that is 100% proof that EZNEC is ignoring the magnitude of in phase radiation emitted from the cone.

I do agree times and ideas do change over time in the minds of men, but I show you what and why I believe what I think. You show what and why you believe what you think...isn't that fair for men to do?

You're asking me to change the rules of physics, doing so will prove me wrong and you right. That is not logical Donald. I just showed you evidence for what and how I see what I think. If you don't understand that then ask me some questions. I asked you about your new sill image of the CST pattern with the lines. We talked about it, but just didn't get any where yet.

Very little of what you have misconstrued has been fair Marconi. I'm questioning if you're of sound mind to have reached some of these conclusions. How much time do you want to waste by asking to see the proof when you don't understand the proof and think your opinion is valid instead? I'm tired of the way you hijack sound logic combined with scientific method and replace it with your opinion.

Don't just look at the new image, read post #71 so you know what the lines mean. Do you think I just posted a picture without any explaination? We don't get anywhere because you keep your breaks on all throughout the learning process and keep saying "look what I found, look what I found". All the while you're using software that can't teach you a damn thing about this antenna to drag the forum through the same nonsense again.

Could you try and describe that image again in some different words maybe. I would like to fully understand what you see. Hey Bob, I think you made a comment about that new image, but it was more like tongue in cheek, and was not very descriptive. Why don't you try and describe what you see in that image. If we can't still talk about this idea...then who will talk about it. You both see all the looks and interest being made. There are curious minds out there wanting to know more I think, but they just seem to me to be afraid to say anything.

I'm not falling for it again. Looks more like you're trying to play me for a fool at this point and I can't waste more time with it. I suggest you find another teacher in this matter because it's become clear I can't make any progress with you. Start with reading post #71 this time. I'm also not surprised you're finding it difficult to find anyone willing to say anything in support of your ideas or posts with this antenna.

Both you and Donald talk like you fully understand completely how the S4/NV4K works, or at the very least know enough to argue that my model is wrong. So, I am confused and have questions. Why can't you both together convince me of what you know? You both seem pretty clear in you conviction that you're both right.

I think there are plenty of guys out there that would like to be convinced too.

Bob what is your opinion about the cancellation ideas that I presented?

What significance do you place on the accuracy of my Vector model, considering I showed evidence that the maximum current at the center of the top 1/2 wave is almost the same as noted on the CST model that Donald posted?
So, who else is there Bob?

Stop waging the dog Marconi. You showed evidence that EZNEC gets ONE current close to right on the entire antenna. Not even the current in dispute yet you wag it around like it was the holly grail CST actually is in this case. I've met many skeptical people in discussing this design and heard many ideas. Not one of them even tried to use the top 1/2 wave section of this antenna as though it were in dispute at all.

Get back to the bottom 1/4 wave radiator where EZNEC is just about totally wrong and why 90 degree phase delays are needed to stack another 1/2 wave on top of a Sigma.

PS: If you ever have any model of the Sigma you think is worth anyone viewing, make sure you can add an electrical 1/4 wavelength horizontal "U" shaped phase delay to the top with another 1/2 wave vertical on top of the phase delay and see gain over the stock antenna. Until you have a model that can do what we see in the field on this particular issue, they aren't even worth looking at much less trying to extrapolate any specific information. Unless you want to know how a 1/2 wave works.

We are not smarter than Cebik who said it would be difficult to model this antenna in EZNEC. We don't know more about the program than Roy, who refuses to even consider the fact that his program could make a mistake analyzing any radiation current. You have never seen an accurate computer simulation of this antenna in EZNEC so you shouldn't say another word in support of modeling this antenna in that program until your model can pass the constructive radiation phase test I've outlined above.

 

[bob85]

have a look at this thread, theres a guy adding a 3rd wire to transmission-lines in eznec
so that nec recognises the outside of the coax as a conductor otherwise transmision-lines won't radiate in eznec, could it be whats missing in the vector nec model?

http://www.eham.net/ehamforum/smf/index.php?topic=32091.0

im wondering if eznec does not see the lower 1/4wave as a coaxial transmission-line and only deals with antenna mode currents in the lower 1/4wave,

donald are afaik to phase 1/2wave above another 1/2wave needs 180 degree phase shift such as a 90 degree 1/4wave shorted stub, are you saying eznec shows gain to peak with a 1/2wave shorted stub?

 

[Shockwave]

donald are afaik to phase 1/2wave above another 1/2wave needs 180 degree phase shift such as a 90 degree 1/4wave shorted stub, are you saying eznec shows gain to peak with a 1/2wave shorted stub?

That is exactly what the results are Bob. To phase a 1/2 wave over a 3/4 wavelength radiator that already has strong in phase radiation over it's entire length, only requires half the phase shift EZNEC says for the Sigma.

In a CB example EZNEC peaks its free space gain when the phase delay is twice as long as it should be for the Vector. The shorted stub EZNEC wants to see to make it happy is made from 18 feet of wire, folded over on top of itself so it's physically 9 feet long and shorted at the far end with an overall shift or delay in phase of 180 degrees.

For that to be the case EZNEC absolutely views the constructive currents from the cone as insignificant to the point they are ignored in the construction of a collinear. That produces disastrous results in the field because the phase has been delayed to the point where the where the collinear top section only combines with the phase of the stock top 1/2 wave. Not with the phase corrected 1/4 wave current on the cone. The result is a reduction in gain compared to the stock antenna.

Cut the phase delay in half to compensate for the significant cone radiation and the fact the cone has delayed any radiation in the bottom of the vertical by its 1/4 wavelength of shielding, and the collinear 1/2 wave top now adds almost 2 db to the stock antenna! Walla, we have just proved EZNEC misses 1/3 of the constructive wavelength in the Sigma design.

 

[Marconi]

Donald, I know it is frustrating, and my not being sure is even more frustrating for me, but I refuse to let that stop my efforts to try and understand.

You and Bob are apparently confident that you're right, and you have testing to back this all up.

I'll read that post #71 again, and see what I can figure out.

Regarding my asking Henry about considering to model the Vector with his CST software. I reminded him about his promise to do that for several months after he made the promise to me. He let me know, because he wanted my Eznec model of the Sigma4. I think I talked him into doing the New Vector 4000, instead...just because it was an antenna still being produced.

We've also had a long drawn out discussion right here on the forum, where I asked him for advice about how Eznec handled currents, and that turned out less than informative for me. He had a totally different point of view on currents, and I never understood what he was trying to explain either.

So, I think if you would really like some CST modeling done on the Vector, you might be better off asking him youself...he might think I'm just like you described Donald...without a clue.

I'm sorry I upset you again.

 

[mr_fx]

what about a j pole on 11 meters?

 

[Marconi]

what about a j pole on 11 meters?

Mr_Fx, I appreciate your question, but could you be a bit more specific as to what you are thinking.

I think Donald suggested something similar earlier with his idea of the Vector with only 1 radial. He may have however meant something entirely different in that comment.

have a look at this thread, theres a guy adding a 3rd wire to transmission-lines in eznec
so that nec recognises the outside of the coax as a conductor otherwise transmision-lines won't radiate in eznec, could it be whats missing in the vector nec model?

http://www.eham.net/ehamforum/smf/index.php?topic=32091.0

im wondering if eznec does not see the lower 1/4wave as a coaxial transmission-line and only deals with antenna mode currents in the lower 1/4wave,

donald are afaik to phase 1/2wave above another 1/2wave needs 180 degree phase shift such as a 90 degree 1/4wave shorted stub, are you saying eznec shows gain to peak with a 1/2wave shorted stub?

Bob, in order to use this transmission line feature with Eznec, IMO one must have a wire to install the feed line or the feature will not work. The added wire is part of the description for the feature.

I think we often don't get the word pictures in our minds correctly placed when, as CBr's, we read stuff that is typically related to ham operators. I am not saying that the theory is different, just the real world experiences are worth considering.

The subject of your link is some hams talking about a wire dipole and usually they are strung between two points, and there is hardly ever a mast involved. In CB we hardly ever install a vertical CB antenna without using a mast, and that is my only point here...we have the necessary wire if we inclued a mast in our model.

This is a distinction I make not to be contentious, but hopefully for a better understanding for what Eznec does and doesn't do in our situation with the Vector in mind. Also it is MO, when I consider a feed line then I'm doing a model over real Earth. When I include the feed line or mast and I want to see FS results, I remove the mast and the feed line...or else the FS results are skewed by all elements attached to the antenna. The idea for FS models is to remove all losses.

The only thing I see change when adding a feed line to my NV4K model that already has a mast is a little increase in gain, due to some in phase RF at some angle from the 32' foot mast, and the new feed line is the only thing changed in the model. If these guys are right, does this sound like the results we would expect to see simply by my adding a feed line that does not radiate?

What I've said here could be all wrong, and you and Donald can ignore it if the guys talking in that thread were right, but Bob what if this link suggest to us an apples and oranges idea?

IMO, I don't think this idea of adding a feed line, weather it radiates or not, is the answer to Donald's thinking about how badly Eznec works.

Just something to consider.

 

[Marconi]

Donald I told you I would study you image with the lines added. Could I ask you some questions?

Can I assume that each space is 1/16th of an inch, and the magnitude for the top of the radiator is indicated as 4/16th inches thick, starting at line #1, and terminating at the 5th line with 4 x 1/16 inch spaces according to your image?

I think you indicate the current on the radial starts at the second line and terminates at the 3rd line. So, the maximum current on each radial is approximately 1/16th or 25%. So, if the current for the maximum current point for the top 1/2 wave radiator is 4/16 then would the sum of the radials = 100% or a maybe a little less?

If I'm right, I think I can clearly see what you are suggesting in your example.

I will try the same and post my results, but I'm not sure about the perspective I'll be able to produce if I have to blow these images up so we can see the details.

From just looking at my model my reports for the red lines look pretty close to the same as your see, with about 1/16th on the bottom of the radials, and about 4/16th for the current on the base of the monopole.

However the current on the center of the 1/2 wave top portion of my radiator looks to be smaller by about 1/2, so you could be right, excepting you told me the following in regards to the top 1/2 wave radiator.

EZNEC is perfectly accurate at modeling the Sigma as a 1/2 wave. I never said anything that should make you think the error in EZNEC had anything to do with the currents in the upper 1/2 wave. Why would you even be looking here when I said dozens of times EZNEC is dead wrong about the cone?

To answer your question honestly...I was trying to answer my own questions about Eznec. Remember, this all started out with my hoping to have a discussion with that guy #24. I asked if he would talk to me about how he saw currents using 4nec2, but I think all this discussion has run him off. So, it's me and you my friend.

But let me do the model first and I'll post whatever it shows. Don't quite on me now. Now I see what you are talking about.

I tweaked my Vector model today and found out that the longer radials is what was preventing the gain my S4 shows at 4.06 dbi, and that one is not far from what Sirio posts for the Vector...if they are showing us real world results over real Earth, and not in Free Space.

If you're sure their reports are done in Free Space, then Eznec does have problems beyond the limitations, and it is not just a unique problem with the S4/Vector design. None of my CB vertical models show gain over about 2.70 dbi, in free space on my homemade Marconi 5x model. That really surprised me too when I did all my models in a compare, check, and recap project a couple of weeks ago. I've found some errors in some of my models since, and I also added free space reports to my new project, but that makes the report very long and I will have to break it down into maybe three files if I post it.

 

[mr_fx]

Mr_Fx, I appreciate your question, but could you be a bit more specific as to what you are thinking.

I just meant a traditional J pole like HAMs use on 2m, but scaled for 11m