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Question on the Vector

Shockwave

Sr. Member
Sep 19, 2009
3,779
3,270
273
Since we are right back at step one in convincing Marconi CMC exists on the Sigma in a noticeably constructive manner, I say more of the same is just a waste here. Since no model has ever convinced Marconi the sigma is anything more than a 1/2 wave, I suggest nothing on paper is going to make a difference here.

It's simply too easy for him to ignore things he has never seen in his life like a 1/4 wave current with a peak in the middle as a mere anomaly. In order to fit his square peg theory into the round hole he must ignore many things that couldn't possibly explain what we see in CST or the field.

I suggest the ONLY way to convince anyone the cone is an effective radiator is to BUILD THE COLLINEAR test. That will end all debate for anyone with a basic understanding of antennas. There will be no possible way to argue the cone does not contribute to the gain once you find you MUST use a 90 degree phase delay.

The determining factor will boil down to if the phase delay that works is 100% too long as NEC says, or the antenna is a phase corrected 3/4 wave radiator making a 90 degree phase shift the ONLY possibility that works in the field.
I've been explaining the facts that CAN BE REPRODUCED for over two years and been called everything short of a liar the entire time by someone with nothing but a J-Pole opinion that has never stood up to a single field test.

Wanting DB to add the extra CMC wires as parasitic elements screams out that you don't understand the entire point of his model was to simulate the current and phase CMC would have to produce in this design. Something a parasitic element could never do since its phase must mimic that of the element which excited it.

How do you suppose DB was going to simulate a 1/2 wave CMC current that traveled from the bottom inside of the cone, folding over the top and back down? How would your idea be possible if the extra wires were simply 1/4 wave parasitic elements that could only be excited by the 90 degree 1/4 wave current on the outside of the cone?

These are the things that are pissing the people off that have done much more work to understand the antenna than you as well as the way you've managed to misinterpret or reconfigure the information we have told you.

It's almost amusing to see this "model" debate stretch on for years when the time required to prove this in the field would have been far less. Once you do this, I still doubt Marconi would believe it. He'll claim because you did it on 2 meters it's insignificant in some way. What's important is anyone who really wants to understand, can test it for themselves.

We don't need to struggle for years with models that the smartest people in this field have already claimed would be very difficult to reproduce using software. Once again this is why the software used to accurately model the design costs $2,500. On the other hand, all the parts you need to build a 2 meter field testable prototype can be had from Home depot's plumbing and hardware isles.

You could have your results in one weekend. At which point anything the J-Pole camp suggests will immediately become irrelevant. Someone please try this and spend less time with the software. It doesn't matter what the computer tells you if it can't get close to what we see in the field.
 

bob85

Supporting Member
Mar 30, 2005
3,479
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173
england
eddie,
im not dragging you anywhere, i want the truth of why i see what i see,

common mode radiation does not require coaxial cable, the currents exist in many places we don't want them, on poorly designed circuit boards, on 2 wire lines that are not balanced or have asymetry in the source placement ect,

i think i found what i was looking for with regards my question about method of moments and how it handles the two currents but i can't copy/paste it,

http://tinyurl.com/k55auvl

unlike the transmission-line equations numerical analysis of maxwells equations (MOM ) gives the complete solution to currents without presupposing only the existence of TEM mode,

so until i learn otherwise im fairly confident that MOM will show radiation from a transmission-line that is part of an antenna structure,
this seems to fit the radiation from the short leg of a j-pole seen in eznec & described by cebik as i noted earlier,

the issue could be no more than that of close spaced wires at accute angles as henry told us and is mentioned from multiple other sources,
im pretty sure if it was as simple as throwing some wires around a monopole cebik would not have told me it would be very difficult to get accurate results using eznec,

software using nec4 may give better results, especially if you include correct tube diameters and taper schedule, barkley says relative diameters are important to loss by radiation in the open sleeve antenna,

i don't know how nec4 handles flared radials and segment alignment, when you add the hoop i see things getting even more complicated,

have a look at the 5 wire cage monopole,
http://www.antennex.com/w4rnl/col0807/amod114.html

and TC2M terminated coaxial cage monopole,
http://www.tc2m.info/TC2M HF Vertical G8JNJ.pdf

see how they fit into your idea of what is coaxial and what will radiate,

a commonality of these antennas & the open sleeve articles that we don't have in the elevated vector is a groundplane and im not sure how that figures into the equation yet though i note that the open sleeve can be used in yagis which don't have a groundplane.
 

Marconi

Usually if I can hear em' I can talk to em'.
Oct 23, 2005
7,048
2,061
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Houston
Donald I will try and get back to your post soon, but I've basically heard and talked on most of these subjects already, and no matter what I say...you will likely disagree. I know you probably feel about the same of me. This means we have not discussed this to a conclusion that we both can agree on, that's all.

I decided to stop talking in general, but to try and have a conversation with DB about his ideas and his models...after which I was finally able to see what he was doing.

I, for one, have not seen his model where he claims to show the gains he posted early on...when I saw the pattern his model produced compared to a 1/2 wave. When I did, I said "...finally a NEC program was possibly showing the gains that you and Sirio have presented."

DB said that idea was his brain child, but he told us he had discussed the idea with both you and Bob, and that's OK.

However, I finally saw his modified model of his Vector where he added wires, and I was totally surprised as those results...which surprised me.

After he and I fussed and discussed this model a bit, in the last couple of days, DB finally gave me what I needed to understand what he was doing better, and now I see his purpose in that model. I just hope this does not come too late for him to continue with his ideas.

That said, this would not have happened without our talking and getting our ideas clear between us.

I'll get back to your post. You raise some new and interesting points that I don't think we've discussed before. I will have to analyze my model with these points in mind.
 

Marconi

Usually if I can hear em' I can talk to em'.
Oct 23, 2005
7,048
2,061
343
Houston
eddie,
im not dragging you anywhere, i want the truth of why i see what i see,

Maybe not physically Bob. I can only give you my opinion as to what the truth is, and maybe site a few examples to support what I think I see.

common mode radiation does not require coaxial cable, the currents exist in many places we don't want them, on poorly designed circuit boards, on 2 wire lines that are not balanced or have asymetry in the source placement ect,

Bob, I can agree, and I can site a few example, but I tend to refer this CMC's idea as coaxial. I will talk more about this below.

You know about circuits Bob, and you also know I can't comment on that subject...it's all Greek to me.

I consider 2 wire lines as coaxial, but they too have design requirements in order to work like a feed line. Again, my point is a distinction I try to make. When we start to change the structural design requirements of coax or twin lead wires, the line is no longer coaxial...it becomes a radiator of sorts. This is how I see the S4 cone. That said however, I don't consider this as a particular bone of contention to continually argue. We know that the cone on the Vector will radiate...just like we know the bottom elements for a J-Pole can radiate. Some swear the J-Pole is terrible in the regard, some say they don't see RF in their J-Pole. Donald made such a remark a while back in another thread possibly. When we get down to it, this radiation tends to be small, if Donald is right. I see the same with my S4 model...the RF is small. Some call this CMC, and some call it radiation or antenna mode currents. Like you've said, "...what is the difference..."

i think i found what i was looking for with regards my question about method of moments and how it handles the two currents but i can't copy/paste it,

http://tinyurl.com/k55auvl

I looked this over and it has a lot of empty pages at first. So we have to go down a bit, and there we see more Greek I don't understand. I did read some of the text however. If you find in this a solution to this seeming epic task, you will have to put it into simple words...for me to understand.

unlike the transmission-line equations numerical analysis of maxwells equations (MOM ) gives the complete solution to currents without presupposing only the existence of TEM mode,

so until i learn otherwise im fairly confident that MOM will show radiation from a transmission-line that is part of an antenna structure,
this seems to fit the radiation from the short leg of a j-pole seen in eznec & described by cebik as i noted earlier,

I can't understand the top comments you present from Maxwell, he is too complicated.

I don't deny the second part of you comments. I think this is what DB's project is all about.

Here is why Bob. The J-Pole seems to me to be a classic example where transmission type currents flow along, out of phase with the antenna mode currents on the radiator...a structural part of the antenna.

I figure the J-Pole and the S4 design are similar in this regard. The magnitude of the currents left over (the losses) after cancellation...typically determines how bad the problem of unwanted currents really is on our feed line. This is what we see in the case of the J-Pole, because when the CMC problem is on our feed line...the issue is quite often a problem for the antenna pattern, and for local electronics. The fact that the bottom of the J-Pole looks like a transmission like is irrelevant in my thinking, simply because typically there is not much radiation in this area. I say the same about the S4 design.

On the other hand we know the Gain Master works using coax to create constructive CMC's on its shield. IMO, Sirio uses the short sub to create as much current imbalance at the center point of the antenna, where the shield stops. IMO this is done in order to create as much CMC's to flow on the shield as possible and radiate constructively with the top section of this 5/8 wave wire.

To me this is done well, and I figure the net currents in these two elements on this 5/8 wave wire are pretty well balanced at the feed point as a result of Sirio's design. So, the GM produce a very good pattern on the horizon, or at least it appears to do so.

the issue could be no more than that of close spaced wires at accute angles as henry told us and is mentioned from multiple other sources,

im pretty sure if it was as simple as throwing some wires around a monopole cebik would not have told me it would be very difficult to get accurate results using eznec,

I also think that could have been a reason that Cebik made such comments to you. To bad he didn't explain. I can only guess that he knew you did not work with Eznec...and figured that would be wasted words.

I've tried to explain this issue before...when I recounted the gamma match problems that both Homer and Booty Monster experience building their first Vectors. This problem may also be a real world problem with connecting wires. This is why I add a hub to my model, you can't successfully just add radials at a steep angle to another wire, and we know that Eznec does not handle taper well either.

DB, just curious...what do you say happens with 4Nec2 regarding taper?


software using nec4 may give better results, especially if you include correct tube diameters and taper schedule, barkley says relative diameters are important to loss by radiation in the open sleeve antenna,

Nec4 may help to fix the problem, but I don't really know. This is just a guess, but maybe what Barkley says on the subject is why Homer and Booty had problems due to the lack of a hub too. I think the both had their radials way too close to the radiator.

i don't know how nec4 handles flared radials and segment alignment, when you add the hoop i see things getting even more complicated,

I see this issue as a problem if we don't try and get the segment lengths close to the same Bob, and I don't know if Nec4 fixes anything we are discussing here.

I've suggested to you already why I think the adding of the hoop with 4 radials is a problem of providing the Nec engine with proper wire connections or else complicating the currents data in the Current Log Report.


I'll check this out later and maybe I'll try and remember to respond, but I can imagine an explanation would be lengthy, and you already don't like long responses from me.

and TC2M terminated coaxial cage monopole,
http://www.tc2m.info/TC2M HF Vertical G8JNJ.pdf

Same here.

see how they fit into your idea of what is coaxial and what will radiate,

IMO, an actual coaxial element will radiate, among other things, if there is an imbalance at the actual feed point. If the design for the CMC's is to be beneficial, like the GM, then we want that imbalance at the shield termination to show as much current magnitude as possible...in order to balance the in phase currents with the other end of the antenna. In this case I site the Gain Master. I consider the actual feed point to be at the center of this antenna. But to be sure regarding your question...I need to check these articles out better.

a commonality of these antennas & the open sleeve articles that we don't have in the elevated vector is a groundplane and im not sure how that figures into the equation yet though i note that the open sleeve can be used in yagis which don't have a groundplane.

I might agree, but I have mixed opinions on whether the S4/NV4K does or does not have a ground plane. I've heard it argued both ways. I still refer to the cone as a radial cone, and I tend to see it as a GP using radials. IMO, they still provide the antenna with a return currents path to aid in balance an symmetry at the feed point. I consider this issue as arguing semantics.

The only advantage I see with a dipole inside of an open sleeve is to add strength to the antenna. The Eznec model that Roy added to his software package, as an example, shows very little performance difference in any way for the model.

Long, but here it is.
 

bob85

Supporting Member
Mar 30, 2005
3,479
1,433
173
england
"I consider 2 wire lines as coaxial, but they too have design requirements in order to work like a feed line. Again, my point is a distinction I try to make. When we start to change the structural design requirements of coax or twin lead wires, the line is no longer coaxial...it becomes a radiator of sort"

i dont consider a two wire line as coaxial eddie,
you don't need to change anything physical about a two wire line to cause some radiation,
terminating it with an unbalanced load or feeding it asymetrically or placing conductive objects in close proximity to the line causes common mode to rear its head,
read the link i posted again, you don't need to understand the math to get the gist of what clayton is telling us,

"On the other hand we know the Gain Master works using coax to create constructive CMC's on its shield. IMO, Sirio uses the short sub to create as much current imbalance at the center point of the antenna, where the shield stops. IMO this is done in order to create as much CMC's to flow on the shield as possible and radiate constructively with the top section of this 5/8 wave wire."

imho the stub in the gainmaster is there only to create an impedance match,
kirchhoff takes care of the cmc's since any current entering the upper section of the antenna must be returned on the outside braid,

i won't speculate on what cebik meant in his comments about eznec as im not 100% sure he did not mean just very difficult for a novice,

"I looked this over and it has a lot of empty pages at first. So we have to go down a bit, and there we see more Greek I don't understand. I did read some of the text however. If you find in this a solution to this seeming epic task, you will have to put it into simple words...for me to understand"

anything from respected sources is complicated eddie, its a long time since i was at colledge doing equations,
if you want to analyse all currents including radiation from common mode you use MOM as henry told us,

"Nec4 may help to fix the problem, but I don't really know. This is just a guess, but maybe what Barkley says on the subject is why Homer and Booty had problems due to the lack of a hub too. I think the both had their radials way too close to the radiator."

from what i have read nec4 handles taper and dissimilar diameter elements and close spaced wires,
i don't know about flared radials,
the radials on the vector are closer at the base than i remember in booty's antenna,

"I might agree, but I have mixed opinions on whether the S4/NV4K does or does not have a ground plane"

kirchhoff tells us if current flows into an antenna it must have a return path,
the elevated vector definately does not have a groundplane in the same manner as barkleys open sleeve paper or the cage monopoles in the links, check them out,

"The only advantage I see with a dipole inside of an open sleeve is to add strength to the antenna. The Eznec model that Roy added to his software package, as an example, shows very little performance difference in any way for the model"

im sure the sleeve is nothing to do with adding strength to the dipole eddie, stronger tubes would do that and look easier on the eye,
there are open sleeve articles on the www and arrl books,
 

Marconi

Usually if I can hear em' I can talk to em'.
Oct 23, 2005
7,048
2,061
343
Houston
bob85 said:
have a look at the 5 wire cage monopole,
http://www.antennex.com/w4rnl/col0807/amod114.html

Eddie said:
I'll check this out later and maybe I'll try and remember to respond, but I can imagine an explanation would be lengthy, and you already don't like long responses from me.

I'll try to keep the short Bob.

I've never seen this Cebik article before and it is interesting. It is 24 pages long, so I'll have to take some more time and read it again. I see some terms I'm familiar with at least. I've already made a preliminary conclusion. I'm a little surprised that Cebik is comparing modeling with results that are so close they show miniscule differences.

We are discussing CB antennas aren't we?
 

Marconi

Usually if I can hear em' I can talk to em'.
Oct 23, 2005
7,048
2,061
343
Houston
eddie,
im not dragging you anywhere, i want the truth of why i see what i see,

common mode radiation does not require coaxial cable, the currents exist in many places we don't want them, on poorly designed circuit boards, on 2 wire lines that are not balanced or have asymetry in the source placement ect,

i think i found what i was looking for with regards my question about method of moments and how it handles the two currents but i can't copy/paste it,

http://tinyurl.com/k55auvl [/QUOTE]

Bob, I think you intended to direct us to part 1.5.2, and if I'm right...I sure thank you for putting us right at the meat of your reference.

You are right, there is a lot of good feed line theory in between all the math. I also found a couple of pertinent links that I think say about the same...possibly in more understandable language, at least for me.

http://en.wikipedia.org/wiki/Coaxial_cable
http://www.w8ji.com/transmission_line_theory.htm


In part what I take away from Paul's 1.5.2 part of the article, is to me very important to understanding the basics of feed line theory. I figure you might agree. IMO, this also explains why I tend to refer to some objects as being coaxial rather than just talking about transmission line mode currents flowing somewhere on an antenna structure.

When Heaviside developed his theory for coax, I think he was intending to develop a feed line idea that did not respond like the 2 wire lines you described above. I think he did that, with one distinction in minf...the load and the location of the feed point must be near perfect, in balance, and resistive...and then and only then will the coax do what his design suggested. Otherwise the coax acts very similar to the 2 wire feed line that you noted. To me this describes what coaxial means.

Am I even close?
 

Marconi

Usually if I can hear em' I can talk to em'.
Oct 23, 2005
7,048
2,061
343
Houston
eddie,
im not dragging you anywhere, i want the truth of why i see what i see,

common mode radiation does not require coaxial cable, the currents exist in many places we don't want them, on poorly designed circuit boards, on 2 wire lines that are not balanced or have asymetry in the source placement ect,

i think i found what i was looking for with regards my question about method of moments and how it handles the two currents but i can't copy/paste it,

http://tinyurl.com/k55auvl

Bob, I think you intended to direct us to part 1.5.2, and if I'm right...I sure thank you for putting us right at the meat of your reference.

You are right, there is a lot of good feed line theory in between all the math. I also found a couple of pertinent links that I think say about the same...possibly in more understandable language, at least for me.

http://en.wikipedia.org/wiki/Coaxial_cable

http://www.w8ji.com/transmission_line_theory.htm

In part what I take away from Paul's 1.5.2 part of the article, is to me very important to understanding the basics of feed line theory. I figure you might agree. IMO, this also explains why I tend to refer to some objects as being coaxial rather than just talking about transmission line mode currents flowing somewhere on an antenna structure.

When Heaviside developed his theory for coax, I think he was intending to develop a feed line idea that did not respond like the 2 wire lines you described above. I think he did that, with one distinction in mind...the load and the location of the feed point must be near perfect, in balance, and resistive, and then and only then…will the coax do what his theory suggested. Otherwise the coax acts very similar to the 2 wire feed line that you noted. To me this describes what coaxial means.

Am I even close?
 

Needle Bender

...he thinks it's funny that I stepped in it
May 15, 2010
1,403
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Glad to see you back Needle Bender. I think your needle is bent.
ok, ok, an OFF-CENTER-FED fullwave dipole. Prolly phased around .625 and complimented by the bottom 3/8. As the ring is brought closer to the monopole, two opposing phased voltage nodes are getting closer together.
Y'all sure seem to want to complicate this thing.
And any CMC on the mast/coax would be out of phase from the radiator(s) and non-constructive.
Happy trails
 

Marconi

Usually if I can hear em' I can talk to em'.
Oct 23, 2005
7,048
2,061
343
Houston
ok, ok, an OFF-CENTER-FED fullwave dipole. Prolly phased around .625 and complimented by the bottom 3/8. As the ring is brought closer to the monopole, two opposing phased voltage nodes are getting closer together.
Y'all sure seem to want to complicate this thing.
And any CMC on the mast/coax would be out of phase from the radiator(s) and non-constructive.
Happy trails

NB, I'm still waiting for DB to show us his 4Nec2 Vector model that shows the nice gain that he and Donald claim, as well as Sirio's posting their specs for their New Vector 4K.

NB, your opinion is as good as any.

I may be changing my thinking on this design if DB can prove the increased gain he describe earlier.
 
Last edited:

Marconi

Usually if I can hear em' I can talk to em'.
Oct 23, 2005
7,048
2,061
343
Houston
DB, When asked about the cone, the specific questions you bring up were not mentioned in detail. The part of the email regarding the function of the cone is posted below.

"The presence of the cone (four elements around the whip), are the difference between a standard J-pole. The out of phase radiation is confined inside the cone and outside the cone the radiation is in phase. To understand the better performance of the antenna in comparison of the standard 5/8 Lambda, it is necessary to also consider that the radiation pattern has been maximized to irradiate on the horizon line and does not elevate like a standard 5/8 Lambda. Considering also the installation, the small current that descends on the first part (the most important) of the mast, near the antenna, is in phase (another small increase in gain) That is not true for a standard 5/8 Lambda."

Donald while I was waiting for DB to post the modeling details for his Vector model, where he claims the nice gain that you have suggested for a long time, and that is supported by the reports in Siro's specifications for the NV4K...I was reading over this thread to maybe see if I missed anything.

For those of you that really care about this issue and will speak out...I suggest you read Donald's email quote from Sirio's engineer noted in bold above...very carefully. You might have to click on the quote to show it all.

I have never seen or heard this information before,
and for me it describes what I've been saying for some time now...the bottom cone area does radiate a little...but it is not much. I've also suggests that their NV4K design may show signs of CMC on the attached mast.

In my real world testing that I did some years ago on my S4, in collaboration with Bob, we discussed the CMC's on the feed line that I was experiencing, and Bob described this as a transforming effect that allowed the feed point impedance change some. Right Bob?

I was changing feed line lengths, and saw this happening, just like many others have reported over the years, but they had no explanation...and were likely wondering if they were tuning the antenna,,,as many talk about.

It is also a fact that I have described the 5/8 wave radiator as an alternative example of what I see going on in the S4 design. In those cases, however, I said the bottom portion of the antenna does nothing to cancellation the bad effect from the bottom 1/8 wavelength out of phase area of the radiator, and thus all it effectively does is just raise up the maximum current point up a bit...compared to a 1/2 wave radiator.
 

bob85

Supporting Member
Mar 30, 2005
3,479
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173
england
if you see only impedance & reactance/resonance point change with small changes of coax length that's the coax transforming the conditions presented at the far end of the coax eddie,
if you see vswr change too that indicates you have common mode on the coax outer braid.
 

Marconi

Usually if I can hear em' I can talk to em'.
Oct 23, 2005
7,048
2,061
343
Houston
if you see only impedance & reactance/resonance point change with small changes of coax length that's the coax transforming the conditions presented at the far end of the coax eddie,
if you see vswr change too that indicates you have common mode on the coax outer braid.

Bob, you might not remember those contact experience, but I just mentioned it as an example.
If that is all you took away from my comments...then you missed the point about what is stated in Donald's email quote.

I understand...again it is just convenient.
 

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