Base Open Sleeve EFD

[Marconi]

Personally, I was ready to let things cool off, too. However, the cooling off came a little late to save some well informed folks from abandoning a very good topic. Friendships and trusts seemed to have gone from warm, to cool, to cold...

Homer, over time I can't tell you for sure that I have never discussed the period since Henry published his report. After that and early-on, there were questions asked and few answers forthcoming...just like Steve recently noted here in this thread. I know I pissed of some folks asking questions back then. Some just don't like to be asked questions.

Folks, come and go on these forums all the time Homer. Among others, I regret seeing the guys that produce modeling they've done...they just seem to disappear. I don't think our talking about the report had anything to do with folks leaving. Other than maybe Donald and Henry...they may be the exceptions.

I never changed my point of view. I said all along that my experience with the Nv4k gave me better results than other monopole antennas. I said I did not believe it was "just a j pole" meaning it was only a baseline 1/2^ with a really large matching section. To that end perhaps Eddie's sense of the j pole's "sleeper" status needs exploration, however, that the j pole is just an unremarkable okay antenna is how it is generally presented to be as if the S4/V4k are nothing special because they are 'just jpoles".

Homer, I don't recall ever suggesting my models show anything that renders your Vector or any other Real World antenna more or less than they really are. I never said the S4/NV4K are just simple J-Poles either. I have noted that Sirio refers to their NV4K as a coaxial J-Pole. I also suggest Sirio might have similar results to mine on the NV4K and that might help explain why Sirio describes their antenna that way. That is not a fact, just my opinion.

I have said numerous times that it is a shame that more folks don't come on the forum and tell us about their experiences with their S4/NV4.

Below are two models.

1. is a J-Pole that has a mast directly connected to the antenna. The pattern is an ugly site.
2. is the same antenna that is (ISO) from the mast, and it suggests a better installation.
3. is 2 models for the NV4k with similar setups to #1 & #2.

If Marconi wishes to call it a j pole, then when his own models show it is better than either the j pole or the skeleton sleeved monopole decide to explore whether the j pole is under appreciated, I'm okay with that, too. If it's, back under examination from any angle I enjoy the conversation.

Why did you select a 2-meter J-Pole, instead of just building a cheap 2-meter Vector?

Saying it performs as it does only because it is sticking up higher in the air does not explain what is going on in Marconi's models.

I have a lot of models out there Homer. In some cases, if an antenna is just a few feet higher or lower than another...it could do something different in one direction and not in another. There might be a 1000 reasons why. Why would one expect to solve every situation with an antenna install or a model. We usually take whatever we get. If we can improve the setup, great. I will bet some of your neighbors like mine...wonder why we put up an antenna at all.

There are potential reasons for why one antenna can do noticeably better for one person than another - topography, soil conductivity, interaction with structures, feed line losses, etc.

I tend to agree!

BUT, none of those exist in the models of the three antennas compared by Marconi.
To bring them up now whether directly or by inference is only a subterfuge and distraction.

Homer, that's a pretty strong accusation. I did not infer anything. You gave us your opinion of a J-Pole and I gave my opinion. I was kind of thing that is what these forums are all about.
Do I also have to ask you, "May I," like I suggested to DB earlier?

I would be interested in more knowledgeable people than me discussing other aspects of Henry's thesis. Git ur dun.

I would like to see such discussed too. Maybe over on eHam would get some action...similar to Booty Monster showing them guys over there his homemade Vector.

You have your ticket, what is wrong with you going on eHam or on the WWDX ham section and pose your questions and Get ur dun...discussing Henry's report?

 

[HomerBB]

Okay, Marconi, here is your model overlay of the three antennas where the Nv4k is better than the SS and J-pole :
https://www.worldwidedx.com/threads/open-sleeve-efd.227590/

Bob, I do know that the higher placement of the current maxima can make a significant difference. My reference was to the over lay of three antennas in the above link that are the same length, same tip height, and of theoretically the same current maxima placement being compared to each other. One of them is still out performing the others. In this case, there is no current maxima height advantage, therefore no current maxima argument.

DB, here in this thread are those dimensions for my last iteration of the Nv4k - as close to specs as I could homebrew it:

https://www.worldwidedx.com/threads/vector-4000-remake.144592/

I apologize for seeming harsh. I can let frustration bleed through sometimes. I still hear the echoes of inconclusive debate at times and then when there is an opportunity to revisit a point of debate with more material it is passed over quite glibly. Perhaps I'm just stuck...
I'll be clearer.
It is said, Nv4k is just a J-pole, but the models that started this thread show that in terms of performance where all things are equal it is more than a J-pole, and more than a Skeleton Sleeve monopole.
It seemed to me that Eddie cited the simular shape of the radiation patterns of the j-pole and the Nv4k as a proof of the Nv4k as being a J-pole while ignoring the clear superiority of the additional gain the Nv4k has over both the other antennas, and the better overall radiation pattern the Nv4k has. Personally, it is of little to no relevance whether the Nv4k is or is not essentially a J-pole. What matters to me is that comparatively, both in the initial models presented in this thread, and in the experience of some who flew these the Nv4k is better. Why? has been asked, but the only answer put forth (that it is taller) has once again been challenged, not by its champions, but by someone who is essentially neutral to the what and why of it, Monsiuer Marconi, by way of his models. Perhaps he made a mistake? And certainly it hasn't been his intent.
I do appreciate Eddie's desire to understand the J-pole. It can perhaps shed more light on the entire panoply of extended (3/4^) monopoles that utilize cages of some sort in the lowest 1/4^ section.
And, finally, Marconi, in the models last posted, were the second of each antenna the ones where the mast was included? I ask because I almost always isolate from the mast. It may be that I should not do so with my J-pole
. . .
Reread your previous post. The isolated models are best.. thanks.

 

[bob85]

Homer,

a j-pole is said to get its name from its shape so clearly the vector is not a j-pole in the spirit of the name,

but they work in a similar way with regards to them been about 1/2wave radiator with a 1/4wave stub that has some but not a lot of radiation due to unbalanced impedance at the top of the stub,

they are in my experience the most effective single element cb antenna when mounted on the same mast as other antennas,

the advantage is most notable when the antennas are mounted low so that extra height not only places current maxima higher above ground but also allows the antenna to see over obstructions better,

under those conditions a vector longer than 3/4 but shorter than sirio's original 7/8 something like Donald's .82wave worked best in my yard and other friends yards.

i have built j-poles years ago that did not work as well, i did not build very good j-poles imho,

i have no idea why Eddies models show the skeleton antenna to act different to the other two, the vector is closer to been a skeleton than a j-pole.

 

[HomerBB]

Yes, Bob.
I have limited experience with Jpole antennas, and only just now experimenting with them as a ham.
One distinction between the SS is the radials and mount plate are insulated from the center vertical, unlike the J pole and V4k..

 

[Marconi]

Homer, I can't get the link to open. Adobe Acrobat gives me a pop-up saying the PDF file code was linked incorrectly.

 

[HomerBB]

Trying again. Maybe it attached this time.

 

[Marconi]

That works.