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.
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 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.
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.
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?
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 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.
Same here.
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.
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.
