GHZ24 what is your opinion of the Sigma 4?

[Marconi]

You made a post the other day and I got the impression you could do modeling. I responded to your comments, but I never heard back.

I looked at your album and see some models of a Sigma 4, that I don't recall ever seeing on WWDX before.

http://www.worldwidedx.com/members/ghz24-albums-sigma4-picture3179-sigma4-currents.html

I was wondering if you would consider a discuss about this model with me. I have an Eznec model and I have an original Antenna Specialists version.

IMO the way the currents flow in this antenna the currents on the mast inside of the cone are out of phase with the top 1/2 wave element. The combined currents on the 4 radials in this area are in phase with the top 1/2 wave and a bit more in magnitude than the bottom mast currents. Thus due to cancellation I see this difference radiating...as in phase currents with the top 1/2 and adding to far field radiation in a constructive way.

How say you?

 

[ghz24]

just my take

Hi Marconi,
Sorry late response I've been super busy lately.
When I first started to try to apply modeling to CB frequency antennas I read a long thread (somewhere ) with a heated debate about this very question.
Some regarding it as just a modified j-pole, others claiming an almost collinear gain from currents on the radials being in phase with the element and the basket/radials containing the out of phase signal from the bottom of the main element. Pretty much as you outlined here

The combined currents on the 4 radials in this area are in phase with the top 1/2 wave and a bit more in magnitude than the bottom mast currents. Thus due to cancellation I see this difference radiating...as in phase currents with the top 1/2 and adding to far field radiation in a constructive way

.

The picture you linked to is actually not to stock dimensions the radials are quite short. On the stock dimension model the out of phase part from the main element is contained (same height as) by the radials and ring.
I think a more telling picture is this one

Over all I think you got it right the radials are constructive and at least close to in phase with the main radial. A little out might even be beneficial.
This antenna (model) shows about 0.5 dBd gain, and more gain than any other single element vertical (that is not counting phased arrays) Ive modeled in free space.
0.5 dB may not sound like much but In the brutal realm of free space that is sizable, when few verticals can beat a dipole at all (gain wise) that is hard won gain
The pattern is aimed square at the horizon not skewed upward like destructive interference seems to cause. A 5/8th GP with horizontal radials has an innate take off angle even in free space.
I assume due to destructive interference.
I built the model to satisfy my curiosity but was hoping to get some feedback on what I think the model is telling me.
I think the "color as phase" picture above shows just what you said happening. Or am I missing something?
Without a lower mast and any gama match it is resonant at ~56 ohms SWR of 1.14.
Maybe the best omni out there for this band ,would love to test one out have intent to homebrew one eventually.
I think I can prep a descriptor file from any of my models so you could import them.

 

[Marconi]

Hi Marconi,
Sorry late response I've been super busy lately.
When I first started to try to apply modeling to CB frequency antennas I read a long thread (somewhere ) with a heated debate about this very question.
Some regarding it as just a modified j-pole, others claiming an almost collinear gain from currents on the radials being in phase with the element and the basket/radials containing the out of phase signal from the bottom of the main element. Pretty much as you outlined here
.

The picture you linked to is actually not to stock dimensions the radials are quite short. On the stock dimension model the out of phase part from the main element is contained (same height as) by the radials and ring.
I think a more telling picture is this one

Over all I think you got it right the radials are constructive and at least close to in phase with the main radial. A little out might even be beneficial.
This antenna (model) shows about 0.5 dBd gain, and more gain than any other single element vertical (that is not counting phased arrays) Ive modeled in free space.
0.5 dB may not sound like much but In the brutal realm of free space that is sizable, when few verticals can beat a dipole at all (gain wise) that is hard won gain
The pattern is aimed square at the horizon not skewed upward like destructive interference seems to cause. A 5/8th GP with horizontal radials has an innate take off angle even in free space.
I assume due to destructive interference.
I built the model to satisfy my curiosity but was hoping to get some feedback on what I think the model is telling me.
I think the "color as phase" picture above shows just what you said happening. Or am I missing something?
Without a lower mast and any gama match it is resonant at ~56 ohms SWR of 1.14.
Maybe the best omni out there for this band ,would love to test one out have intent to homebrew one eventually.
I think I can prep a descriptor file from any of my models so you could import them.

It is my current belief that the currents on the monopole inside the radial basket is producing (+) polarity currents, and the current for the first segment in my model is at the base of the antenna with a magnitude of +1.0861a.

It is also my current belief that the sum of the currents on the 3 projecting radials is producing (-) polarity currents, and the current for the first segment in the model is at the base of the antenna with magnitude of -1.04661a.

I further belief currents that are equal in magnitude with opposite phase will cancel, and if there is any magnitude of current difference between these two polarities then the phase with the maximum magnitude will radiate the difference. This results, depending on the sign of the phase, can be constructive or destructive to the primary radiating element.

In the case noted above for my Sigma 4, the radiator wire #2, shows (-) current phase, and the difference in the currents in the radial area is insignificant...so there is very little to no current radiating that will effect the far field radiation pattern IMO.

This idea for analyzing the currents here is based on my assumptions; that the current distribution for short straight wires is basically linear and proportional...from end #1 to end #2. So, a comparisons at segment #1, of two parallel wires can effectively be assumed and compared regarding magnitude, phase, and cancellation effects.

To ensure that these distributions are as noted, propotional, I set the segments in the related elements as close to the same segment length as possible.

I see no significant radiating currents flowing, constructive or not, with my Sigma 4 model. I therefore conclude that the only net advantage over any other vertical antenna is the result of the added (length) and the height attained for the current maximum...that this design has to offer a user if all models compared are set at the same height to the base.

I have not analyzed my New Vector 4000 model yet for comparative accuracy with the S4, but I think the segments lengths are basically the same length. The main difference I see in the NV4 is an approximate 17% increase in the (-) polarity current magnitude of the radials over the (+) polarity of the base of the main radiator. So, we do see some constructive addition to the far field gain in the New Vector 4000...which Sirio has suggested is the reason for their modification. Even though it looks better than the original Sigma 4, ever little bit helps.

24, I don't see the matching or the Free Space results you're seeing. In fact I see the same upward angle of FS RF you warrned against with all of your other FS models.

How much effort did you go to to try and get your model to specifications? I noticed you have your feed point set at the base, and I have mine feeding at a point very close to where the tap point is on my real S4. There is not much difference in the results because of this difference when applied to my models, but there is a difference in the currents as a result for sure. It looks like the longer radials on the NV4 are increasing the current flow in the radials...which are constructively in phase with the 1/2 wave maximum current lobe below the tip of the antenna.

I'll get my model together and post my usual layout. If you or any other member wants the description file...then PM me your email address.

Thanks for your response. It is refreshing to talk with someone that knows a little about the nitty gritty of modeling. Are you using 4nec2 in the model above?

 

[Shockwave]

It's not likely you'll see a better representation of the radiation currents in this antenna. You must click on the GIF image below to view the currents through one cycle of RF drive.

 

[Marconi]

It's not likely you'll see a better representation of the radiation currents in this antenna. You must click on the GIF image below to view the currents through one cycle of RF drive.

Donald I see exactly what you see, but what is it telling us in real values?

Are you claiming the current magnitude on the radials is approaching 2.37 amps due to the red line indicator noted, and the current is similar to the currents we see on the primary 1/2 wave lobe producing 2.37 amps...just because it is also noted in red?

What about the idea of current magnitude being the distance the red line is away from the element? Are we just going to forget that idea?

It is obvious these two red line indicators are no where near equal or even close. When I see this in Eznec I go to Eznec tabular currents log in order to see the real current data, phase, and sign.

I suggest that the currents left over from cancellation between two such out of phase elements in the radial area is all the current there is radiating in the far field for the Sigma4 and the Vector, and that the magnitude of these currents left over in my models show to be minimal at best.

Also IMO, what is left over to radiate may be constructive with the top 1/2 wave radiator, but in this case the contribution is next to nothing...so that does not matter.

IMO, this does not disagree with the idea presented as a notation on the old Sigma 4 box...that the whole antenna radiates either. I heard much less of an argument given as facts.

Although I have said this before, I also posted an argument for an idea how and why the Sigma 4 design makes a better signal...without all the hoc us poc us and mystery.

To me, the results are simple, it is a little better because the antenna is taller that all others, and if I raise another antenna, that is lesser by design, so that the maximum current lobes are equal...the models pretty much fits the idea that I suggest...it is just a little more height that matters when we compare these antennas.

Isn't the fact that the Sigma 4 design can produce a better gain and angle ENOUGH advantage, considering we mount both antennas at the same feed point height...where 90% of CBr's will probably agree...is the only fair way to compare antennas?

The Sigma 4 is not special, but it is the best big CB designed antenna in my opinion out there, bar none. Actually, according to my Eznec models my New Vector 4000 is the best, even when I remodeled it to .82 wave Donald, it was no way no.

Of course your real world testing is the final judge for a real report on the success of any model.

 

[Shockwave]

Donald I see exactly what you see, but what is it telling us in real values?

Are you claiming the current magnitude on the radials is approaching 2.37 amps due to the red line indicator noted, and the current is similar to the currents we see on the primary 1/2 wave lobe producing 2.37 amps...just because it is also noted in red?

Not exactly, but the fact there is red and blue present on the cone at all tells us there is significant, constructive radiation that has not been cancelled.

What about the idea of current magnitude being the distance the red line is away from the element? Are we just going to forget that idea?

I'm not forgetting this at all, being very much aware that intensity is also related to how far out these colors extend.

It is obvious these two red line indicators are no where near equal or even close. When I see this in Eznec I go to Eznec tabular currents log in order to see the real current data, phase, and sign.


I suggest that the currents left over from cancellation between two such out of phase elements in the radial area is all the current there is radiating in the far field for the Sigma4 and the Vector, and that the magnitude of these currents left over in my models show to be minimal at best.

Also IMO, what is left over to radiate may be constructive with the top 1/2 wave radiator, but in this case the contribution is next to nothing...so that does not matter.

IMO, this does not disagree with the idea presented as a notation on the old Sigma 4 box...that the whole antenna radiates either. I heard much less of an argument given as facts.

Although I have said this before, I also posted an argument for an idea how and why the Sigma 4 design makes a better signal...without all the hoc us poc us and mystery.

To me, the results are simple, it is a little better because the antenna is taller that all others, and if I raise another antenna, that is lesser by design, so that the maximum current lobes are equal...the models pretty much fits the idea that I suggest...it is just a little more height that matters when we compare these antennas.

Isn't the fact that the Sigma 4 design can produce a better gain and angle ENOUGH advantage, considering we mount both antennas at the same feed point height...where 90% of CBr's will probably agree...is the only fair way to compare antennas?

The Sigma 4 is not special, but it is the best big CB designed antenna in my opinion out there, bar none.

The rest of your post is just showing that we completely disagree on how effective the cone is. It also suggests you may not understand the model or function of the cone.

I'll simply state that the CST model I've posted is responsible for the Vector 4000's 2 dbd gain figure. I'm easily able to confirm this in the field.

This is only possible because the cone is not only producing significant radiation but it also redistributes much more energy from the secondary lobe, to the primary lobe over earth ground.

This is what makes it the only 3/4 wave radiator that can produce noticeable gain over any 1/2 wave or 5/8 wave ground plane. If you don't think that's something special, I have no more evidence to persuade you.

 

[Shockwave]

As a follow up I also have to add it has NOT been my findings that the extra height of this antenna is it's primary advantage. My lowest installations are 100 feet and the highest one is 750 feet AGL. That's the equivalent of 360 to 2722 feet on this band once you factor in the difference in wavelength between 27 and 98 Mhz.

In the .82 wavelength design we easily obtain the gain posted for the Vector at the above heights. Where the difference between a 5 foot radiator and a 9 foot radiators height amounts to nothing in terms of clearing more obstacles. On 11 meters with typical mounting heights of 30 to 40 feet on rooftops, you may see better results because the upper current maxima is clearing more obstacles.

 

[Marconi]

Not exactly, but the fact there is red and blue present on the cone at all tells us there is significant, constructive radiation that has not been cancelled.

I'm not forgetting this at all, being very much aware that intensity is also related to how far out these colors extend.

The rest of your post is just showing that we completely disagree on how effective the cone is. It also suggests you may not understand the model or function of the cone.

I'll simply state that the CST model I've posted is responsible for the Vector 4000's 2 dbd gain figure. I'm easily able to confirm this in the field.

This is only possible because the cone is not only producing significant radiation but it also redistributes much more energy from the secondary lobe, to the primary lobe over earth ground.

This is what makes it the only 3/4 wave radiator that can produce noticeable gain over any 1/2 wave or 5/8 wave ground plane. If you don't think that's something special, I have no more evidence to persuade you.

Donald, I don't consider it good discussion for me to claim what you know or don't know as my argument. Do we always have to get into the personal side to the issue?

I mentioned to GHZ24, that I was interested in his views on how currents were represented using the modeling product that he used and hopefully we could make some comparisons with my Eznec model. Among other members, I too have pleaded with you to do the same, and produce the current long information, with the CST model that Sirio did for their New Vector 4000.

Personally I think you must have access too to the Vector report from CST. If your story about the rejected application to the FCC or whoever you talked about...was due to your use of Eznec information as support and CST came to the rescue in that case, you at least have a record on your Dominator. That said, I understand why you would not wish to publish such.

I understand the risk you have if CST cannot prove their modeling product regarding currents or wishes not to publish for business reasons, but I didn't present the animated pattern for the CST model either...you did and both you and CST must have considered what you were doing if you let that the simulation out to the public. How could you not figure there would likely be some more questions? What does all the colors moving about really mean, and how do the number values for amps/meter relate to anything. I see the sign for the phase in the chart, but how does that relate. The image is fascinating to view, but how much info are you really getting from that image.

My questions are pretty simple questions about a complex subject...currents. I can produce the currents log numbers per segment that Eznec produces, and you can say I don't understand what my models are telling us, but then I have to ask why can't you do the same Donald? How do you really know what you describe is going on? Did you get a heads up for that specific understanding when you were given the image to publish?

This request seems pretty simple to me. IMO if Eznec can produce the currents log, with amp/segment, and the phase sign...then
why can't CST do the same or something similar?

Then maybe we would have something to compare and maybe we could together figure this all out what we are really seeing in the CST pattern.

I would be just as happy in your camp as I am out here in the wilderness, all alone, with my own ideas on the subject.

I use to believe what Bob told me about Cebik telling him that the Sigma4 idea used a non-apparent collinear scheme with its 3/4 wave radiator, and it did things that no other 3/4 wave element could do. We agreed until in 2009, I wasn't able to reproduce the long distance results that Bob reported.

That is when Bob informed me that I didn't succeed simply because the Simga4 was not capable of doing what he was talking about.

Then he published his report claiming to find similar ideas and testing that spoke to the 3/4 wave element virtues and limitations in a piece published in the ARRL Antenna Book, 19th edition, entitled "The Open Sleeve Antenna."

At the time this too sounded reasonable, and I believed the reported until I used the math presented on page 7-20, chapter 7, to test for the limitation as to length where constructive radiation for the top 1/2 wave worked along with the radiation from the bottom 1/4 wave, using a ratio of 3:1 for the max results, and then with a top limit of 3.2:1 ratio where the results would produce non-constructive results.

3:1 is 3/4 over 1/4 quarter, thus we get
36'/4=9' a 1/4 wavelength.
9'x3=27' over 9' equals what is said in the idea noted in the article so as to produce constructive radiation for the CB band.

If we use the limitation noted in the article instead we get the following results.

9'x3.2=28.8' and beyond this 3.2:1 ratio we see non constructive radiation.

Now all we have to do is consider what lengths of the radiators both Bob and Shockwave would use at 27.205 mhz, and if they're both longer than this 3.2:1 ratio limit suggests...then what has been told to us is in question according to Bob's supporting document noted in part below.

The important areas of text for this verification idea note above is the last paragraph on the 1st page, ant the top two paragraphs on the 2nd page that I marked off. Sorry the highliter didn't show up well.

View attachment The Open Sleeve Antenna.pdf

If however, Bob and Shockwave's ideas for their best Sigma lengths at the middle of the CB band were at or less than 28.8' feet...then Bob's idea with this link may have some real merit to consider. Let's see if both will own up to the lengths they claimed earlier were the best radiator lengths to use for reaching those really far off contacts, or be able to explain how this article does not apply to the ideas they both support here.

This doesn't address the currents in the bottom of the Sigma/Vector, but it is another issue in this discussion that I figured and tested that just didn't pan out so good. Now I could be proved to be in error, and that would be a horse of a different color. Then I would apologize, and accept the word of the powers that be.

 

[Shockwave]

Donald, I don't consider it good discussion for me to claim what you know or don't know as my argument. Do we always have to get into the personal side to the issue?

I mentioned to GHZ24, that I was interested in his views on how currents were represented using the modeling product that he used and hopefully we could make some comparisons with my Eznec model. Among other members, I too have pleaded with you to do the same, and produce the current long information, with the CST model that Sirio did for their New Vector 4000.

I'm not the one who takes these things to the personal level. That would be you who implies I've been dishonest or held back information. I saw this post directed to GHZ24 days before he did and stood by waiting for you to get your direct response before I said a word. It was only when you reverted back to the mistaken ideas that the cone wasn't special or all antennas work about the same when you have the SO-239 at the same height that I responded again. I wonder how quick you might let go of that idea if you tried free space models more? You've already seen everything I have from the CST model.

Personally I think you must have access too to the Vector report from CST. If your story about the rejected application to the FCC or whoever you talked about...was due to your use of Eznec information as support and CST came to the rescue in that case, you at least have a record on your Dominator. That said, I understand why you would not wish to publish such.

I understand the risk you have if CST cannot prove their modeling product regarding currents or wishes not to publish for business reasons, but I didn't present the animated pattern for the CST model either...you did and both you and CST must have considered what you were doing if you let that the simulation out to the public. How could you not figure there would likely be some more questions? What does all the colors moving about really mean, and how do the number values for amps/meter relate to anything. I see the sign for the phase in the chart, but how does that relate. The image is fascinating to view, but how much info are you really getting from that image.

This is exactly what I'm talking about when I say it is you that takes things to the personal level and as a result it causes the respect I've held for you to deteriorate to where I'll freely respond without holding back. I have made mistakes out here over the years but the one thing I have not done is to be dishonest. When I tell you I don't have the damn current logs in tabulated format for CST you can bet your ass I've never even seen them! If I didn't want to share something with you it would be much easier for me to ignore your question than to fabricate a "story" for you.

Bob has already explained that "amps per meter" is a measurement of intensity in RF fields. I've explained to you that the CST colors not only represent magnitude but also show phase as related to the chart. Once you grasp these concepts understanding why Cebik called it a "Non apparent collinear" is much more apparent in the CST model posted.

Remember when CDX-007 was acting much the same way you are now about seeing the entire CST radiation plot and not just one image? I originally only had the one still image of the CST model. It took a second request to obtain the video. I told him I'd share it publicly when I was ready and he implied I wasn't being honest and didn't have it.

Have you ever had anyone steal years of your work before Marconi? I have several times now over the years of doing business in an International market. You can't buy protection for designs, trademarks or any other type of patent that can guard you against unscrupulous countries like China. They thumb their noses at international laws and take whatever they want as if it were their own.

All of my published information has been taken off the website at one point to be used to market counterfeit products. I simply waited until my IT guy had the time to sit down and brand the video with our company logo so it was not as attractive to the thieves. It was you that is obsessed with seeing the CST current values. I'm able to extrapolate enough information from the model that was given to me that I deemed it not necessary. My obsession was in the field, confirming I could consistently reproduce the same results.

My questions are pretty simple questions about a complex subject...currents. I can produce the currents log numbers per segment that Eznec produces, and you can say I don't understand what my models are tell us, but then I have to ask why can't you do the same Donald?

This request seems pretty simple to me. IMO if Eznec can produce the currents log, with amp/segment, and the phase sign...then
why can't CST do the same or something similar?

Then maybe we would have something to compare and maybe we could together figure this all out what we are really seeing in the CST pattern.

Your questions relate to a specific area in which EZNEC has failed to produce any reliable data on with respect to this design and keep asking for something I don't have or need. The very root of the problem with modeling this antenna in EZNEC is this issue of current phase and radiation angle along the radiator. I've told you I now have a working collinear version of this antenna on file with the US PTO. That I built a previous model in EZNEC and that later in the spring when I tested the EZNEC model in the field, it failed miserably.

Weeks of work revealed that the problem was in the phasing section and caused by EZNEC's inability to correctly calculate the phase of the 270 degrees of radiation occurring below the collinear phasing network. EZNEC calculates that the next 180 degrees of radiation from the tip of the stock antenna will be deconstructive and should be within the phasing network. That's wrong by 90 degrees or 1/4 wavelength. That also happens to be the radiation length of the cone. This is why I had to refile with the PTO. Because EZNEC produced the inaccurate model that I filed with the first time. Not because CST revealed anything I didn't like or won't share publicly. I'm ecstatic about everything CST has revealed.


Due to that, I don't have any faith in models of this antenna built in EZNEC. I don't need to see the CST currents or phases because I already had to figure all of that out the hard way in the field in order to get the collinear prototype I mentioned to work. I know some of what I just typed may sound like gibberish. I'm sorry I don't have the time to explain each of these details in more depth. If you don't understand then you should take someone's word who does and trust that all of the EZNEC models I've seen thus far (including yours), do not accurately represent the fact that 270 degrees or 3/4 wavelengths of constructive radiation have taken place.

I would be just as happy in your camp as I am out here in the wilderness, all alone, with my own ideas on the subject.

I use to believe what Bob told me about Cebik telling him that the Sigma4 idea used a non-apparent collinear scheme with its 3/4 wave radiator, and it did things that no other 3/4 wave element could do. We agreed until in 2009, I wasn't able to reproduce the long distance results that Bob reported.

This is ludicrous to me. What went off in your head that makes you believe you have a deeper understanding of how antennas work than the late L.B. Cebik? I wish I had even 50% of this mans knowledge. On the other hand, are you implying Bob has lied too? If so, then as Bob would say "Not your finest hour". When are you going to own the fact that none of your tests have been conducted using a scientific method? No offense but your results are plagued with variables that make them almost useless.

You're trying to discern the difference in a third of an S-unit using SSB with completely different locations, coax, and mast. The fact you can't find any measurable difference between a 1/4 wave ground plane and anything like the Vector or Gain-Master should be the first clue you're doing something wrong. Yet you ignore the consistent advice of experts and complain you can't see the results so others must be wrong.

That is when Bob informed me that I didn't succeed simply because the Simga4 was not capable of doing what he was talking about.

You didn't succeed because you repeated the same mistakes Bob and many others have pointed out over the course of years now. It had nothing to do with the capabilities of the design and you were provided the correct information to improve your testing abilities.

Then he published his report claiming to find similar ideas and testing that spoke to the 3/4 wave element virtues and limitations in a piece published in the ARRL Antenna Book, 19th edition, entitled "The Open Sleeve Antenna."

This too sounded reasonable too, until I used the math presented on page 7-20, chapter 7, to test for the limitation as to length where constructive radiation for the top 1/2 wave worked along wit ht he radiation for the bottom 1/4 wave using a ratio of 3:1 for the max, with a top limit of 3.2:1 where the results would produce non-constructive results.

The open sleeve and skeleton monopole are not the same a the coaxial J-pole. There are NO published references to the Sigma design other than the original patent work. My testing shows that these designs do not perform as well as the Vector 4000 or Sigma. I do not have the answer as to why.

3:1 is 3/4 over 1/4 quarter, thus we get
36'/4=9' a 1/4 wavelength.
9'x3=27' over 9' equals what is said in the idea noted in the article so as to produce constructive radiation.

If we use the limitation noted in the article instead we get the following results.

9'x3.2=28.8' and beyond this 3.2:1 ratio we see non constructive radiation.

Now all we have to do is consider what lengths of the radiators both Bob and Shockwave would use at 27.205 mhz, and if they're both longer than this 3.2:1 ratio limit suggests...then what has been told to us is in question according to Bob's supporting document noted in part below.

The important areas of text for this verification idea note above is the last paragraph on the 1st page, ant the top two paragraphs on the 2nd page that I marked off. Sorry the highliter didn't show up well.

View attachment 11166

If however, Bob and Shockwave's ideas for their best Sigma lengths at the middle of the CB band were at or less than 28.8' feet...then Bob's idea with this link may have some real merit to consider. Let's see if both will own up to the lengths they claimed earlier were the best radiator lengths to use for reaching those really far off contacts, or be able to explain how this article does not apply to the ideas they both support here.

Here we go again. "Own up to the lengths they claimed"? How many years have I been saying .82 wavelength now? That won't change unless I see evidence that contradicts all previous field tests. I see no significant variation in Bob's findings with regards to radiator or cone length. We both have agreed for years that longer than 3/4 wavelength was beneficial and that modifying the cone dimensions could improve far field coverage.

I'd been using radials that were closer to 1/4 wavelength than the stock ones for years just like Bob. All I knew then was it made signals go up in the distance. Bob's mind went a little further to say it may be lowering the angle of radiation. I believe Bob was very close but the actual angle of radiation does not change. That is determined by height. What does change when you manipulate the ratio of cone to radiator length is the energy balance between the primary lobe and any secondary lobes.

Increasing the radial length that supports the loop towards 1/4 wave and lengthening the main radiator beyond 3/4 wave causes more energy to shift from the secondary lobes to the primary lobe. Remember what happens when you tilt these radials out or down from the main radiator? The vast majority of energy is focused in the secondary lobes with the 3/4 wavelength antenna and is wasted.

This doesn't address the currents in the bottom of the Sigma/Vector, but it is another issue in this discussion that I figured and tested that just didn't pan out so good. Now I could be prove in error and that would be a horse of a different color and I would apologize and accept the word of the powers that be.

When I've got collinear prototype in front of me that I can test in the field that shows a 2 db increase but the best models in EZNEC show it has a gain reduction, I have all I need to know Roy is wrong when he says "It's not possible for my program to miscalculate any radiation currents". I believe what I see and can repeat not dozens of times, but thousands of times over the last decade. The length of constructive radiation is off by 90 degrees or 1/4 wavelength in EZNEC.

Our testing methods are quite different too. While I think we both do testing in the receive mode, that's where the similarities end. I use FM and a field strength receiver that has been calibrated on a previous employers test bench where we had access to a fortune in laboratory grade test equipment. The network analyzer was used to look into the front end of the receiver and measure it's actual input impedance. The tuned front end was aligned to track a perfect 50 ohm input impedance across the band.

We attached a variable 50 ohm attenuator to the receivers input and a digital meter to measure the AGC voltage. We established the region where the signal and AGC voltage tracked most linearly and operate this field strength receiver in this range. Measurements of the voltage were taken as the signal level was precisely varied through the linear region and all values were recorded to confirm how much change in voltage was noted for a 1 db, 2 db and 3 db change in signal. When I could increase the generator by 3 db, add another 3 db of attenuation and return to the exact same AGC voltage on the digital meter, I knew it was working.

My clients don't just take my word for it when I tell them the antenna can produce the far field gain I claim. They have engineers on the payroll of companies like Clear Channel or CBC Canada. You can find them in broadcast forums where even in my field we have a "J-pole camp". My worse case scenario is one station engineer at KOLG has posted he only found a 2 dbd gain in his field measurements but was pleased to find that much.

I debate on other topics that I'm not personally involved with just as aggressively when it comes to debunking BS. For example you'll find just as many posts arguing that most solid state amps that produce abnormally high reflected power when switched on, do so because of oscillations within the amp circuit that are not on the fundamental frequency and have nothing to do with harmonic filtering.

Saying the cone does not contribute usable gain to the 3/4 or .82 wavelength radiator is as wrong as changing your jumper lengths to lower your VSWR. I apologize if anyone thinks I go too far. There are times when judgment or being easy to get along with go out the window in favor of technical accuracy. This is probably one of them.

 

[bob85]

what are the currents shown in the eznec tables?, im guessing they are antenna mode currents since there's only one current log, how do transmissionline mode currents figure into the nec logs?,

we know from the arrl article that the impedance of the transmissionline formed by the radials and central monopole is seen in parallel with the antenna mode impedance of the central monopole and that currents flow in transmissionline mode according to the impedance of the 1/4wave transmissionline,

i don't see those currents in the nec logs or current plot but i see them in cst, currents travelling opposite directions/phase on the same conductor if im understanding the plot correctly,

i don't know of another mode of radiation that the sigma could use other than how the arrl describes the open sleeve antena operates,
the tapered cone been wide at the top and high impedance MAY enhance radiation over a parallel sleeve with a smaller spacing due to the larger impedance imbalance at the top of the sleeve,

if anybody can come up with an alternative mechanism for the in phase radiation
from the sleeve im all ears?

 

[Marconi]

what are the currents shown in the eznec tables?, im guessing they are antenna mode currents since there's only one current log, how do transmissionline mode currents figure into the nec logs?,

we know from the arrl article that the impedance of the transmissionline formed by the radials and central monopole is seen in parallel with the antenna mode impedance of the central monopole and that currents flow in transmissionline mode according to the impedance of the 1/4wave transmissionline,

i don't see those currents in the nec logs or current plot but i see them in cst, currents travelling opposite directions/phase on the same conductor if im understanding the plot correctly,

i don't know of another mode of radiation that the sigma could use other than how the arrl describes the open sleeve antena operates,
the tapered cone been wide at the top and high impedance MAY enhance radiation over a parallel sleeve with a smaller spacing due to the larger impedance imbalance at the top of the sleeve,

if anybody can come up with an alternative mechanism for the in phase radiation
from the sleeve im all ears?

Bob, you ask; "what are the currents shown in the eznec tables?, im guessing they are antenna mode currents since there's only one current log, how do transmissionline mode currents figure into the nec logs?,"

What I say here are not facts, it is my idea of what I see and have been able to figure out, right or wrong, on my own.

I asked GHZ24 to join in because I saw a pattern of a model he did in his profile. I stated my intentions in the beginning of this thread.

I'll say this again. For a while now I have sought out someone to talk with about this issue of Eznec currents or currents in general. I've talked to Henry, I've talked to Donald, I tried to talk to Roy Lewallen, but I was thrown in the Brier patch at first mention of the words, "...could you help me a little." I've read as much Cebik stuff as I could, trying to find something specific on how we should view the currents noted on the tabular currents log...but I find zero information.

So, I do what looks right to me, right or wrong in this regard.

Before I posted this thread I determined the models that I wished to compare. The two models are set at 32' feet to the feed points, and I choose my Sigma4 and the New Vector 4000, for this project.

I used my best models for my Sigma4 and my New Vector 4000. I studied these two and tried my best to get them as close to the specs in their manuals as possible. For the New Vector 4000, I think I used your posted dimensions for the New Vector. Then I attempted to get all the Eznec settings, segment counts, source information as close together as I could. I also made sure the segments for the radials and the radiator were as close to the same as possible.

During the process I noticed that the Vector was not resonant where it should at the dimensions you posted and I re-checked the exhibit that you and a buddy did for the forum some time back. I did it right, according to your numbers, so I decided to use the dimension information that I had previously received from some body else. He gave me the overall height only, and I had to try and back into the tubing lengths. A little before you posted you numbers I posted my estimate as to the tapered lengths. Now the antenna shows to be resonant. I could not figure out how I messed up, but I got it straight. I probably screwed up somewhere on your image, and the dimensions ended up too long. I only found this out yesterday or the day before. This is not the only thing I discovered about my old Vector model that caused me to do the project over completely.

After I did these models I noticed that the NV4 model used tapper and the specified length and diameter for all tubing was skewing the model like it did with my Sigma4 model a year or two back. So, I made the NV4 radiator into a single wire a little thinner than I used on my S4. I also had my Sigma4 set that way at one point, but I changed that in light of the ideas I learned from a tip in a Cebik report...that talked about Eznec not handling tapper correctly. I now tend to agree, but I just forgot to change my New Vector.

I think understanding the currents noted by Eznec are vital to understanding how any of these models work if we really want to explain that process in some detail, but without help and advice that is not easy, and I surely could be mistaken. I'm sure Donald will be glad to hear that bit of testimony from me.

I had to redo all of my models, so I'll post them maybe tomorrow. I want to study them and try and make some notes to help describe what I see in the tabular currents log and how they relate to the elements in the antenna.

I do not know how currents actually work in Eznec. I assume that is part of the process that Method of Moments software handles. Personally, I don't even think that Eznec is involved in the computations at that level, but I really can't say for sure.

Personally I have the idea that the Sigma4, design being referenced as a coaxial J-pole by Sirio is probably pretty accurate. I think the up swept radials do for this antenna just like Jack use to tell us about the Sigma...those radials act like and extension of the feed line using cancellation of the currents flowing on the radiator and the radials, being parallel, pretty much out of phase, and with almost equal current magnitudes flowing. I have since added my own thinking to the ultimate conclusion in order to agree with the notion that this antenna radiates from top to bottom for the most part.

This idea relates to how I see cancellation working when the elements are not perfectly balanced and there is some difference in the currents. Where most of the currents are canceled out with the primary current phase either contributing to the top element if in phase, or else the currents are a bit destructive for the pattern if out of phase with the top 1/2 wave element.

For me what happens is we see something similar to common mode currents or antenna currents develop, or depending on the phase we could see transmission line currents, that don't radiate well.

Whatever the phase for the strongest current is after cancellation occurs, I call it the difference for lack of a better term, is what determines the addition or the subtraction that result...showing up in gain.

Bob maybe I can figure out a way to show arrows like EzBob Antenna Software does it, who knows?

BTW, I have never said the cone does not contribute to this antenna's functions. Without this function from the radials, in this case, we see a typical 3/4 wl radiator with RF at very high angles, and even a j-pole doesn't act that bad. What I say is this bottom area is a matching device and due to its large size effectively raises the primary radiating element up higher than the typical 1/4, 1/2, or 5/8 wave antennas when these antennas are mounted at the same feed point heights. Frankly this will get you where it hurts Bob, this idea sounds exactly like our old nemesis the Masterbater.

Bob, the two models below are my evidence, trying to explain why I claim the Sigma4 primarily benefits from being taller when mounted at the same feed points with other antennas. IMO it does not project a collinear effects like we would see with a true collinear design.

The Starduster and the Vector that are attached below are at the same height at the bottoms for both antennas noted. Does the SD'r also develop a collinear feature as well? Here we see the Vector is still about 8' feet higher at the tip, but the bottoms are both at the same height. I see this all the time, if you guys don't...then you just did something wrong is the way I see it.

I know this may seem silly to you and Donald and maybe to a lot of others, but this is why I have these ideas. I would have never known if I was not able to model. I have also claimed the same thing going on in the real word testing I have done for years too. I have even produced videos demonstrating this work, but I understand your disbelief.

I also agree with Sirio's description that the Sigma4, is a coaxial j-pole of sorts, but it works a whole lot better maybe. How do you guys get around this fact that all that know or care what is going on here is an in your face fact that nobody can argue...unless your minds just decide to ignore this simple fact...that Sirio describes the antenna they designed and build in a way that you and Donald refuse to accept. What does that say about being single minded? I that anymore bizarre than my idea?

My main idea here is that the Vector is coaxial, but not so much of a J-pole maybe. Bob, I think the sleeved idea you posted is also a good and clear demonstration of what is going on with the idea you have developed for this complex antenna, but you guys just didn't test the math the article presents as an important tipping point at 3.2:1 ratio. This is what the project I'm in the process of completing is hoping to demonstrate here, but I could be surprised and find that I am wrong too.

The attached two models show me that if you raise the Starduster up even close to the tip height of the Vector...the results noted for the models is not so dramatically different as everyone imagines. As noted above, I see this in my real world testing also, but some don't believe me in my words or my videos either.

View attachment Starduster vs. Vector.pdf

I will study more on these models I designed around the math ideas in the ARRL article I noted above, and I'll try and demonstrate what the currents log shows me. Hopefully I will see what I expect when I finish and make a recap. If you don't hear me talking to myself again about this topic, then just figure that things did not pan out for my ideas, and I've gone on to other subjects.

I would post the work for this project, but it will be a big file and no body would understand anyway. I might try and make notations and send it to you Bob, maybe I can do a better job of explaining to you.

The other day I was hopeful that GHZ24 and I could talk about this and get somewhere, but I think he is probably long gone by now. Who in their right mind would wish to get all snared up in this fruitless discussion...where only pride and animus is the result.

This is not personal Bob, this was only about my opinions and ideas. I put it out there for the consideration by others only. If it is not somehow convincing, then I just did a bad job of trying to explain that idea.

I do appreciate you questions.

 

[ghz24]

I knew it would be contentious

Started this 3 days ago so sorry if it reaches way back.
sleep, work, read latest posts, write a couple sentences, repeat.

That's a nice program there Shockwave wish I could play with it.
I tried to find an easy way of reproducing that very effect (only the wires would cycle through the colors) I could get it but wasn't motivated enough to make 360 models (or even 180) all with an extra degree (or 2) of phase lag.

Marconi wrote

Are you using 4nec2 in the model above?

Yes 4NEC2

Marconi wrote

How much effort did you go to to try and get your model to specifications?

Not much at all.
I built the model to help me understand how it works. Since 4nec2 allows variables in the geometry description a well designed model can show what ifs about dimensions and even angles Like 18 consecutive models with the ring diameter increasing from 30" to 48 "
Oh that's radius not diameter. That model had a 30 inch radius ring ...Should be 30" diameter right?
length of main element 324"
height of ring 108"
Maybe the ring should be 60". When I made the ring 30" across the impedance went to ~38 +j21 and SWR more in the 1.7 area but I haven't swept for resonance yet the gain dropped a little also.
Marconi wrote

24, I don't see the matching or the Free Space results you're seeing. In fact I see the same upward angle of FS RF you warned against with all of your other FS models.

The ring diameter explains the match ,but even correcting the ring diameter the up-tilt is only a degree or 2.
Does your mast extend below the radial attachment point?
including a mast (connected to the main element electrically) caused the mast below to be in phase with the mast within the radials and out of phase with the rest of the antenna.

Marconi wrote

Also IMO, what is left over to radiate may be constructive with the top 1/2 wave radiator, but in this case the contribution is next to nothing...so that does not matter.

The currents are higher in a end fed half wave (like the top part of the sigma) and a dipole but both have less gain.

shockwave wrote

I believe Bob was very close but the actual angle of radiation does not change. That is determined by height

Height is certainly the dominant factor but higher gain should translate to lower TOA, but 11 meters verticals are so close in gain that it is probably not significant.

shockwave wrote

The length of constructive radiation is off by 90 degrees or 1/4 wavelength in EZNEC.

What about the color as phase picture I posted is it 90 off as well?

Marconi wrote

Bob, the two models below are my evidence, trying to explain why I claim the Sigma4 primarily benefits from being taller when mounted at the same feed points with other antennas. IMO it does not project a collinear effects like we would see with a true collinear design.

Of course it's not a true collinear design but it gets more gain from some effect what do you propose is the source of this additional gain!
I'm pretty comfortable calling it collinear gain.
You guys ran right to ground, personally I always model in freespace first.
I understand the only real world measurements we have are over ground
but in freespace the mounting height of the feed point is... well pointless.

Marconi wrote

What I say is this bottom area is a matching device and due to its large size effectively raises the primary radiating element up higher than the typical 1/4, 1/2, or 5/8 wave antennas when these antennas are mounted at the same feed point heights

The basket does act as a matching device and a coax of sorts but it radiating almost has to be the source of the additional gain.

Marconi wrote

The other day I was hopeful that GHZ24 and I could talk about this and get somewhere, but I think he is probably long gone by now. Who in their right mind would wish to get all snared up in this fruitless discussion...where only pride and animus is the result.

Fools wade in .... I'm not gone yet!
regarding the different variants of this antenna I purposefully haven't paid attention to that at all. I made a generic model that can be quickly resized to any dimensions I want to investigate.
Tell me what dimensions you want to use and I'd be interested in replicating/comparing/confirming or refuting your results.
I have no axe to grind and no horse in this race just curiosity.
What do you have for a freespace gain?
BTW I'm pretty confident I'll see that 2 dB gain (over ground).

 

[bob85]

eddie we have been over this many times and so far nothing new has come from the j-pole camp,
i found a mechanism by which the cone can radiate in phase, the same mechanism found in the open sleeve article, the mechanism that CEBIK says causes radiation from the short leg of a wide spaced j-pole,

it is my belief until somebody comes up with a better explanation that the same currents are shown in the cst plot donald posted,
i don't see those currents in your nec model eddie, how does nec handle transmission line mode currents??,

maybe you can model the lower 1/4wave of an open sleeve antenna which the arrl says radiates about equal to a 1/4wave radiator alone, i think the spacing needs to be about 10 inches @cb frequencies

i don't know how much those currents contribute to the far field pattern but they are there radiating in phase, imho it validates what CEBIK told me,

nitpicking over the magnitude when we don't fully understand what we are looking at won't serve us well, a better understanding of how cst handles splitting current between radials is what we need,

im sure the extra height gives the sigma some of its benefit, in my yard i bet that's most of the benefit, since i have only tested as high as 73ft of mast i can't comment on donalds findings at much higher heights relative to wavelength,

putting a starduster at the same tip height as my vector means an extra 20ft of mast which is heavier with notably higher wind load and uglier,

im not sure about using an extension due to inadequate radiator length but i heard from mack that some merlin guys use that method,

3.2:1 is nothing new i went over that years ago, i don't think it means what you think it means so why don't you elaborate?


we did nothing wrong in our tests eddie, your "how NOT to do antenna tests" demonstration video's are cb classics and entertaining in a National Lampoons kinda way.

 

[Shockwave]

What about the color as phase picture I posted is it 90 off as well?

If I'm interpreting the model correctly, it appears that all exposed surfaces of the antenna are within about 25 degrees of matching phase. The only inverted phase is within the confined area inside the cone on the lower 1/4 wave of the main radiator. I see a similar thing in EZNEC as both of these programs seem to be addressing only one of the two currents present on the cone.

Much of this issue regarding current and phase drove me crazy trying to interpret what was going on with models in EZNEC. I became determined to devise a field test that could easily identify how many degrees of effective radiation the Sigma had.

Did it act like a 1/2 wave with an elevated feedpoint and only have 180 degrees of effective radiation or did it behave more like a phased 1/2 wave over a 1/4 wave? It occurred to me that this could be proven in the field simply by determining how much phase shift was required at the top of the stock antenna to bring another 1/2 wave element added on top, in phase with the rest of the antenna.

In other words, if it took a phasing section that was an electrical 180 degree wavelength to bring a second 1/2 wave radiator in phase with the rest of the antenna, the Sigma would be a glorified 1/2 wave J-pole.

On the other hand, if it only took a 90 degree or 1/4 wave phase delay to bring a second 1/2 wave section in phase with the rest of the antenna it absolutely proves Cebik's "non apparent collinear" analysis was 100% correct!

This would also prove radiation from the cone is a significant contributing factor to gain. If the cone were just a matching network or means of elevating the feedpoint, collinear versions would require the more common 1/2 wave delay line.

This only works when you use a 90 degree or electrical 1/4 wavelength phase delay between the two exposed 1/2 wave sections. With 90 degrees, gain goes up by nearly 2 db. With 180 degrees, gain is less than the stock antenna in field tests.

Unfortunately I can't just look at these models and determine what I need to know to see if it is more accurate in displaying the phase issues I've spotted. I need to know how the program will interpret the phase over the next 90 and 180 degrees, extending from the current main radiator.

The easiest way to spot this is to model another 1/2 wave collinear element on top of the Sigma with an insulator or gap between these elements. Make a simple folded phase delay line rather than a coil so it's very easy to keep track of the actual electrical length contained within the phase delay and see where the free space gain peaks.

Then you will know if this design confuses your software as much as us or if the program could actually shed light on the subject like CST has. I also believe whatever is responsible for making this design require a 90 degree phase delay is the same mechanism that is responsible for keeping the currents on the outside of the cone and top of the mast in phase with the rest of the Sigma.

 

[Marconi]

eddie we have been over this many times and so far nothing new has come from the j-pole camp.

Bob, I hardly ever hear anything from the “j-pole camp” anymore, and I’m the only one still trying to have a discussion on this enigma.

Do you really think an animated image is all that is necessary to explain away what we wonder about in this regard?

I’m trying to produce a different point of view. Take a different tack if you will, and all I get in return is no real discussion, just critiquing of what I’ve done in the past, with the tools I had available and trying to explain something in my experience, and in some limited way I've tried to produce some work that I think tries to help explain or demonstrate what I've experienced. Is that still alright on this forum?

You’re wrong though, there is something new on this issue, and that something is the image that Donald has posted. I’m looking to find an explanation of what we see, that can help me get some real answers to go along with the opinions you guys hold. What evidence is there in a picture that words can't explain? All that is said is look and you'll see...I say see what?

The Sirio image is new and there is not one shred of and other supporting evidence from Sirio to support the idea and Donald swears he has none.

The image just happens to have popped up and you guys get all excited. Just opinions and your words to supported it, and all of a sudden I’m to believe this is the answer to an issue that Cebik himself did not want to get involved with. Give me a break.

I like and respect Donald. I believe what he says about what he does, and who he is associated with. But bless his heart, all he is able to tell us regarding this CST image is here is the answer. I'm just not convinced it is that easy to bring the light of truth to any matter. Bob what convinces you beyond doubt?

How many times have you heard folks complain, and maybe even done it yourself, saying Solarcon’s claim that their entire A99 antenna radiates - 9.9 dbi gain is just CBBS and hog wash?

How about JoGunn claims? How about claims for the Merlin, the Coily antenna, the Avanti antennas. How about the claims by Jay in the Mojave? You and other's obviously pick and choose your winners, swear by them, and all the others are condemn to the BS bin out of hand. That does not make sense to me, and no wonder we hear so much CBBS.

Why are you willing to believe the word of one producer and not another?

i found a mechanism by which the cone can radiate in phase, the same mechanism found in the open sleeve article, the mechanism that CEBIK says causes radiation from the short leg of a wide spaced j-pole.

Yes it make sense to you does it not? It makes sense to me too. You were searching for an answer, and you found something that looked worth considering and you shared it. I believed it, and I tested it to the extent I could. The models seem to confirm what was claimed, and what I thought about those claims. My report shows some errant activity taking place at the precise points predicted in the report, and then you are prideful in telling me that you violated the very limits the report claims would produce bad results, and my models show that happens, and that you still believe this report supports your ideas on this subject. I had my doubts, and that is why I tested, and I sent you the recap for the work I believe.

it is my belief until somebody comes up with a better explanation that the same currents are shown in the cst plot Donald posted.

I told Donald I see what you both see, but

I’m not suggesting that CST is wrong, I’m not qualified to do that. The same is true for Eznec, but honestly I do have issues I can’t explain working… with my models. I’m just not comfortable saying I know best. So I’m honest in saying Eznec does things I don’t understand. I don’t hear one peep about questions understanding CST however. So Bob, I guess all you guys either have a lot of faith in the product, or you know how it works, and how to interpret what is reported.

i don't see those currents in your nec model eddie, how does nec handle transmission line mode currents??

Well, showing the currents are on a switch the user controls. You may have something you’re referring to where I did not show the red line for currents along the wires, or I printed the Antenna View before I scanned the model for reports, or I had the currents turned off.

I have the traditional looking images in my mind for what the currents look like along a ¼ wave wire, and a ½ wave. I have learned to recognize the currents for a 5/8 wave too, and I see that in many of my Eznec examples.

You posted your ideas about how these current formations look...right here on WWDX. Those images are in your photo software folder on Photobucket I think. To me they look pretty much the same way I see these red line images for currents in Eznec. So I'm surprised that you miss seeing what Eznec represents clearly as currents.

I think in your terms you would refer to such currents as Antenna mode currents mostly. This is what you would see on a ¼ wave or a ½ wave radiator, or a dipole in Eznec. You would also see similar red lined currents on the ¼ wave radials, if attached as ground radials. However I think radials often cancel-out and you could consider them Transmission line mode currents because they don't radiate much if any RF.

If I’m right, these are currents that are simply out of phase, and do not radiate into the far field. They too are noted as red lines in Eznec as noted above. I guess here you will complain, because I didn't give all the other characteristics for TM currents.

I don’t find any Eznec reference in the index or the list of topics that even mentions transmission line currents or antenna mode currents, so what does that suggest. These are just some words we use in discussing antennas that help us cut to the chase.

All I figure is; that these terms really mean is one radiates and one doesn't, and we have to understand the distinctions. But to be sure Eznec provides the user a tabular currents log list of values for every segment showing every wire #, the segment # on that wire, the magnitude in amps, and the sign and degree for the phase. This is like playing piano, the more you practice the more familiar the image of this list looks to users.

Some guys are likely able to describe an antenna just by looking at this list. But if the list does not seem important to you and you would rather look at some animation and some pretty bright colors that are also suggesting something going on...then so be it.

maybe you can model the lower 1/4wave of an open sleeve antenna which the arrl says radiates about equal to a 1/4wave radiator alone, i think the spacing needs to be about 10 inches @cb frequencies.

Give me more details for the dimensions and the results expected, and I will try that.

i don't know how much those currents contribute to the far field pattern but they are there radiating in phase.

I’ve said it before, I see the currents you see, and I agree there is current on the radials. To not acknowledge this would be foolish on my part. I want to know what it all means, and how much current is likely radiating into the far field. That is what matters. I think you believe there is considerable current radiating from the cone, and I see some, but very little compared to the radiator.

I see our differences as that simple.

I also see current on the radiator inside the radials. I can also see the implications that these currents on the radiator are not in phase with the top of the radiator. It also looks like the currents on the radials are in phase with the currents on the upper ½ wave radiator. But, like you I don’t know how much current is present. Donald is suggesting that these radiating currents on the radials are significant. You and Donald say I'm dead wrong and I don't know what I'm talking about. I say I disagree with your opinions and you disagree with mine.

Example: if the bottom of the radiator shows +1.0 amp and the upper ½ wave shows a maximum -2.0 amps, and the base cone area could works out as follows, a hypothetical. The bottom radiator, as noted, has +1.0 amp at the bottom. The sum of the currents on the bottom of the radials is -1.02 amps. Here we have some cancellation to consider due to a lack of balance. The radials radiating are max in magnitude, so we see we have -.02 amps available to radiate in phase with the -2.0 amps in the upper ½ wave potion of the radiator wire, and this arrangement would then be considered as constructive.

Visa-versa applies if the +1.0 amp of current on the bottom of the radiator were the maximum magnitude, and any difference after cancellation would then be considered destructive.

imho it validates what CEBIK told me,

nitpicking over the magnitude when we don't fully understand what we are looking at won't serve us well, a better understanding of how cst handles splitting current between radials is what we need.

I agree in principal, but I don't think it is nitpicking.

im sure the extra height gives the sigma some of its benefit, in my yard i bet that's most of the benefit, since i have only tested as high as 73ft of mast i can't comment on donalds findings at much higher heights relative to wavelength.

When I talked about the height of the Sigma4 design being the primary benefit to Donald, my point had nothing to do with the total overall installed height at 100’s of wavelengths like Donald was talking about. I was talking about the differnece in the height of the radial cone at the bottom of the Sigma4, for petesakes.

Bob, I take it for granted that you know what I was getting at when I commented about that. I said when both antennas were mounted at the same feed point height. Donald is just trying to put words in my mouth, because he can't discuss his idea or proof about the animation video.

putting a starduster at the same tip height as my vector means an extra 20ft of mast which is heavier with notably higher wind load and uglier.

That was only and example trying to show that the Sigma4 does not have collinear properties at least not any significant properties that really matter.
I have a stacked ½ wave collinear on the side of a tower. I will compare that bugger with the Starduster along-side, like I did with the Sigma4. I’m making a guess here, because I don’t know for sure, but I think we’ll see there is no comparison.

Do we have a deal?

im not sure about using an extension due to inadequate radiator length but i heard from mack that some merlin guys use that method,

Again Bob, I get your point here and the mounting height was not the height I was referring to.

This idea of setting both antennas closer to the same tip height was done just as an example to demonstrate whether the maximum current lobes at or near similar heights could mitigate any height advantage the Sigma4 design has.

It was my idea to see what the height advantage for the Sigma4 really had over other shorter antenna. You will also note I did not even raise it up as high as the S4, just to prove another point. I accept that you believe my models are misleading so this effort is not really that important.

IMO, this whole idea was a similar idea and story related to the AstroPlane design by Avanti, but you don’t believe that either, right?

I understand how comments are sometimes taken wrong in the reading. It also happens sometimes with me even in the writing process too.

I know you objections to my testing approach. I thought everybody tested the same way…sitting in front of their radio recording some signals if that is what they wanted to do.

This subject has all been well gone over and trashed for years like oh my God, we can’t have such efforts presented on this Forum. All of our reputations and good works are at stake. This has been going on ever since I first did a video…where I bared Ole Grampa out for all to see.

3.2:1 is nothing new i went over that years ago, i don't think it means what you think it means so why don't you elaborate?

I don’t remember the full story back then, but I know you were excited like you found the Holy Grail, and I was glad for you. I felt the words made sense and it explained a lot.

I also figured one day that I would have an idea to test the math and find out that the math did not agree with the reports you were making, with your Vector Hybrid set with a 31’ foot radiator. That was way beyond the limit of 3.2:1 ratio limit clearly noted in your own reference for what likely goes on in the Vector.

Bob, I hear the echo of your voice telling me another of your ideas that did not pan out when you advice me to make my Sigma4 longer. You said doing so would allow me to talk at longer distance.

But, when that did not work out, you then told me that the Sigma4 was not capable of performing in a manner, and I was trying to duplicate the same experiences that you claimed to me. I think you even went on to give me some reasons, but I don’t recall the details.

I don’t think I have ever told these stories before, but it is about time to let the cat out of the bag.

So now you’re telling me the math that the article suggested does not mean what they said it means, forget what I said it means. I haven’t got anything to do with the math, but I can calculate the math, and it flat out does’t support the reports you’ve made for years. The math suggested the limits, and my models support that what the math shows. Are you really trying to claim this report was not what you first claimed it was some time back?

Bob, I don’t think you are a stupid man by a long shot, but apparently you must think me a fool.

I would like to hear anything you have to say or show, trying to excuse the claims I’ve made using this math however. If I’m in error…I will apologize.

we did nothing wrong in our tests eddie, your "how NOT to do antenna tests" demonstration video's are cb classics and entertaining in a National Lampoons kinda way.

I laugh at your jokes Bob. I’ve always said you were a funny man in your own way. Being compared to National Lampoons could be good for credits in my line of work.

I don’t know for sure what test you’re talking about now. I had a test at the Doctor’s office the other day. Is that what you had in mind? You’ll have to elaborate with a little more detail, and then I will respond.