New thread to debate V-4000

[The DB]

if anyone is interested...the model is can be received send me a pm.
The model is has about 2000 wires so cant put it on the forum.
(roughly its 9 meters long....2.7meters for the cone and 60cm diameter.)

If you want I'm happy to post up the file for web download. Let me know and I'll send you a pm with my email address.

Was thinking in the line of...what if the cone was made so dense it became the "cage of faraday".
(leaving the top open though)

...

Now, the thing that "strikes" me...
The antenna is resonant lower in freq (roughly 1..2 Mhz)
the impedance is around 30 J0.
But at the higher frequency (29,5 in this case). The antenna provides gain with a good AGT.

That allone gives me hope we migth find the solution

Anyway...just thougth drop it on the forum for those who are interested.

I just had the idea of the radials acting like a faraday cage last night as well. After some research, some thinking, and some ah-ha moments, I now see it as being effectively both right and wrong at the same time. Right in concept and wrong in what is actually happening with the antenna... I must be crazy right??? No I haven't become a politician all of a sudden...

One of those ah-ha moments I mentioned completely changed how I look at antenna data. Before it was all simply data points, but now I'm actually visualizing the fields the antenna is creating, and their interactions with each other. In my head I'm seeing the vector math (same name as the antenna this thread is discussing... Nice coincidence) I studied on my own to learn more about antennas, and Maxwell's equations as well, in action. Its beautifully simple to me now. It all makes perfect sense. The hard part is finding the words to explain it all...

While I see the faraday cage effect is valid, I don't see the radials, in and of themselves, as being the only source of this effect, and that is assuming they are contributing to it at all. Perhaps using a lot of radials does simulate the effect as far as NEC is concerned, but that also changes other aspects of the antenna does it not? However, the idea is worthy of study.

The source of the faraday cage effect is the RF fields the radials generate and how those RF fields interact with each other...

Think of it like whirlpools in water. You have a set of four whirlpools arranged around a circle and the same distance apart on that circle. These whirlpools are all spinning the same direction (in phase) and are the same size (same magnitude).

Think of a fifth whirlpool right in the middle of the other four whirlpools, it is spinning the other way (or out of phase with the other four whirlpools).

Now the four outer whirlpools are spinning water in the same direction. Being close enough to interact with each other these individual spins are, in essence, creating two additional whirlpool effects, one on the inside of the four whirlpools and one on the outside.

The outside whirlpool effect is in phase with the four whirlpools that created it, and is free to radiate outwards, and does.

The inner whirlpool effect acts completely different. It is spinning the opposite direction of the whirlpools that created it, and is thus out of phase with those whirlpools. Because of this it is in phase with the fifth whirlpool in the middle, the inner whirlpool effect combines with the inner whirlpool. Because this new combined whirlpool has sources on the outside of the whirlpool itself, those sources function to contain the inner whirlpool as a whole. Therefore it cannot expand freely like the other whirlpool effect as described above.

These two whirlpool effects do interact with each other, but only on a limited basis in a limited area of space, namely the circle the four original whirlpools are on.

Long story short the inner whirlpool effect (combined with the inner whirlpool itself) is never able to expand beyond the four original whirlpools that helped create it as it is dependent on those whirlpools to continue to exist. The outer whirlpool, however, has no such outer barrier holding it in, and thus is free to expand unimpeded.

Now, look at the whirlpools described above as the fields being generated by the Vectors radial system and central vertical element. Look at the two whirlpool effects as the generated fields interacting with each other. Also, there is no coincidence that I used waves and whirlpools in water to try and explain electromagnetic waves and electromagnetic fields as the two act in exactly the same way as they travel through space...

Anyway, that is part of what I'm seeing now. Hope the visualized description helps explain it.


The DB

 

[Marconi]

Ya'll might not be surprised, but I don't understand any of this.

 

[Shockwave]

Henry, Your model looks like it demonstrates something no other NEC based model has so far. I see two separate current nodes on your model. Nothing like the free space pattern all the others have produced with a single lobe. To make that pattern indicates your model may be understanding the antenna functions as a collinear.

I've also noticed to please EZNEC, I always had to make the antenna shorter than the real thing or its resonance would always be lower. I'm very interested if your new model can pass the collinear phase test adding the 4 wires to the top as I've been discussing. If you're interested and need more details, please contact me.

The Avanti patent references 1939 artwork showing the basic design built with the cone as a Faraday cadge too.

 

[nosepc]

Think I see what you are saying, DB. Since the cone is inverting the current, the 4nec2 software can't model it and therefore render it correctly. While the CST software did catch it. OK. The mystery of the Sphinx is solved.

YES !!

 

[Marconi]

Donald is this the patent reference that you had in mind.



Don't you guys see here this idea is a complex scheme for a simple application of nothing more than an extension of a, more or less, non-radiating coaxial feed line, a continuation of a feed line that transitions up smoothly to feed the bottom current node of a 1/2 wave radiator...just like Ole' Freecell use to tell us along with telling us all radiators are nothing more than a basic 1/2 wave radiator.

The only difference in the S4 design is it can have but might not have two in phase current maximas...thus the whole antenna can radiate in the far field.

However with that said, the bottom cone area's contribution is at best...very small. This design works very much like a "coaxial j-pole," except the bottom area is better balanced and symmetrical thus improving the omni directional qualities, and the increase in height shows a bit better performance due to improved current distribution over a larger area, an it added length can produce a possible lower maximum radiation angle toward the horizon...due to some added height. This is very similar to the advantages that are noted for 5/8 waves over 1/2 waves, but none of these advantages can or will approach anywhere near a 3 db improvement in gain.

I recently talked about FC's old ideas, but not a single soul jumped on what I said back then, and I said some outlandish things trying to get somebody to look at this issue without being blinded by "Pie in the Sky" ideas...being paramont on their minds.

You guys are going overboard on what this design does...like it is totally unique...and I don't think that is the case at all. The design really works, and works well, but the only advantage I see is relatively small in contribution, and for me that is enough.

I'm not even sure the tenant's for this idea can effectively go much beyond the idea of a 3:1 ratio in the design and remain true to theory or design...just about like the idea that a .64 wave is a better design than a .625 wave antenna is.

 

[Lil'Yeshua]

Well,I for one would like to see how it operates and this thread is bringing more light on the subject at hand.
Skyfall - Quartermaster Clip (HD) - YouTube

 

[Marconi]

Henry, Your model looks like it demonstrates something no other NEC based model has so far. I see two separate current nodes on your model. Nothing like the free space pattern all the others have produced with a single lobe. To make that pattern indicates your model may be understanding the antenna functions as a collinear.

I've also noticed to please EZNEC, I always had to make the antenna shorter than the real thing or its resonance would always be lower. I'm very interested if your new model can pass the collinear phase test adding the 4 wires to the top as I've been discussing. If you're interested and need more details, please contact me.

The Avanti patent references 1939 artwork showing the basic design built with the cone as a Faraday cadge too.

Donald, I'm going to take a chance here and make some wild guesses that free space model that Henry posted is not what you think.

How can you possibly tell what kind of model produced that pattern? It looks more like a pattern for a 3/4 wave with horizontal ground planes, and not a good pattern for a Vector 4000 design like you descrived the other days saying the FS pattern angle was something like +*1 to -2* degrees from the horizon.

View attachment .75w with horizontal radials..pdf

I see Henry's models as a montage of models done using different programs and/or different settings in the same programs.

Based on the dimensions given the model(s) are very large for 29.5 mhz and CB. Henry says it is resonant 1-2 mhz lower than 11 meters...and that makes little sense to me as to why that is if we are talking about an 11 meter antenna.

The only issue is, Henry saw resonance at a very low frequency relative to 11 meters, and he found his feed point was set well for being very close to 30 mhz according to his AG report, or so he says.

If I did my math correctly...the radiator is about 35' feet long and the radials are about 10' feet long, and that makes for resonance well below CB...just like he told us.

IMO that pattern shows us a pattern that is, more or less what nosepc was likely seeing and reporting, that got you so upset, it is no-way-no model in any body's book.

 

[Marconi]

A major problem with your argument here is it is only true if the radials are on the same plane, (or are perfectly horizontal) and spaced evenly apart. Once any of this changes your tug of war analogy is no longer accurate.


I, personally, don't like that method of showing phases. It is highly misleading to those who don't know what they are looking at. Phase is *NOT* a line that is coming off of the antenna in a certain direction. The direction of the line is simply an indicator of the motion of the field that exists around the specific point of the antenna. If you have two radials that go in opposite directions that are fed by the same source, say one (but not both) of the wires that feed the antenna, the rotation, and thus phase, of the fields generated by said radials would be exactly opposite each other. This condition can *ONLY* exist as long as the radials are pointed in exact opposite directions.


Once you begin to angle the radials, and it doesn't matter if you angle them up or down, so long as they are no longer perfectly horizontal, the fields they generate are no longer exactly out of phase with each other. As a matter of fact, as the angle between the radials decreases the fields they generate begin to add up and act more and more like a single field. Actually, this is technically incorrect, their fields combine to create two separate fields. One of those fields exists only on the outside of the angled radials and is thus transmitted outwards, much like the set of radials were a single element. The other field exists on the inside of the radials and is trapped by the radials themselves and not allowed to radiate. These two fields are exactly out of phase with each other.

This same principle is why a quarter wavelength vertical antenna with radials that are angled down at a 45 degree angle acts like something in between a quarter wavelength vertical with horizontal radials and a half wavelength vertical dipole.


I have yet to see any NEC2 based models that can accurately show any of this. Not being familiar with the math behind the Method of Moments algorithms that make the software work (at least not yet...) I am not sure if it is possible. Remember, the Method of Moments that is used was originally designed to be used on machines with punch cards and limited processing capability. Even today most NEC based software uses text files that simply simulate this punch card data for both an input and output, then interpret said virtual punch cards to generate the pretty graphs and plots we see posted. Essentially NEC based software is still using decades old technology with decades old limitations. Even NEC4, which you have to pay for ($300 currently), has the same underlying technology. Honestly, over 20 years ago I used to directly manipulate data files that were generations beyond this technology.


I'm not saying the technology isn't useful, but in todays world why do we limit ourselves to such an old technology, aside from the fact that CST costs so much...


And for the record, you clearly have not debunked the CST data shown, and a good part of the reason you haven't is actually explained above in this post. You still haven't met the challenge I made back in that discussion... I'm still waiting...

One more thing, how many reasons have you listed to explain why the radials cannot effectively radiate anything into the far field? Many of these reasons are contradictory, which means they cannot all be right at the same time. So which explanation is it?

Actually, the correct answer to that question is non of them. I only asked to point it out. So who is just words?


The DB

DB, I'm impressed with the extent of you awareness. Can you post something, a reliable link maybe, that supports such ideas regarding the Nec engine being so antiquated?

BTW, can you give me a link to Maxwell's formulas you were checking out. I am always interested in learning something new.

Did you find something yet...I'm sitting here with nothing to do.

 

[Robb]

YES !!

You haven't proved your argument by one iota.
Clearly, the CST software displays properly what your 4nec2 just cannot do.

But you have been the real 'Sphinxter' all along . . .

 

[nosepc]

You haven't proved your argument by one iota.
Clearly, the CST software displays properly what your 4nec2 just cannot do.

But you have been the real 'Sphinxter' all along . . .

Yes!! and CST software is so good that you can tell which side melts faster ice cream. I assure you!

 

[The DB]

Can you post something, a reliable link maybe, that supports such ideas regarding the Nec engine being so antiquated?

I may be in the process of eating those words... I can say this, there is a version written by someone and available for free that does the exact same thing but is optimized for newer computes, and thus runs much faster... With 4nec2 it is simply a matter of overwriting a few files that came with the program. This version can run a frequency sweep in a significantly shorter amount of time on my computer than the stock nec2 files. The fact a faster version of said program exists does not make what I said earlier true. I was blaming the nec2 data when I maybe should have been blaming the programs that are interpreting it instead...

I have actually written and deleted in my next post after the one you quoted here that the needed data to simulate the fields I've been talking about is in the NEC2 .out file, and that a nec2 based software would simply have to use that data to generate the fields in question and simulate how they interact with each other. I have yet to see a nec2 based software do this.

BTW, can you give me a link to Maxwell's formulas you were checking out. I am always interested in learning something new.

They have to with more than just electromagnetics... They are also on wikipedia...

Maxwell's equations - Wikipedia, the free encyclopedia

If your not familiar with vector math I highly recommend doing some research on how vector math works first... Trust me, you won't regret gaining that knowledge first...


The DB

 

[Shockwave]

but none of these advantages can or will approach anywhere near a 3 db improvement in gain.

If nowhere near 3dbd to you means "within a db of ratings", than I agree. Otherwise you have to argue with CST and every field test conducted by every station for many years.

 

[Shockwave]

Donald, I'm going to take a chance here and make some wild guesses that free space model that Henry posted is not what you think.

How can you possibly tell what kind of model produced that pattern? It looks more like a pattern for a 3/4 wave with horizontal ground planes, and not a good pattern for a Vector 4000 design like you descrived the other days saying the FS pattern angle was something like +*1 to -2* degrees from the horizon.

View attachment 11747

I see Henry's models as a montage of models done using different programs and/or different settings in the same programs.

Based on the dimensions given the model(s) are very large for 29.5 mhz and CB. Henry says it is resonant 1-2 mhz lower than 11 meters...and that makes little sense to me as to why that is if we are talking about an 11 meter antenna.

The only issue is, Henry saw resonance at a very low frequency relative to 11 meters, and he found his feed point was set well for being very close to 30 mhz according to his AG report, or so he says.

If I did my math correctly...the radiator is about 35' feet long and the radials are about 10' feet long, and that makes for resonance well below CB...just like he told us.

IMO that pattern shows us a pattern that is, more or less what nosepc was likely seeing and reporting, that got you so upset, it is no-way-no model in any body's book.

All you got to do Marconi is build that collinear prototype that you already made in EZNEC. The one that shows good gain as a 1/2 wave over a 1/2 wave with a 180 degree phase shift in between. When you can make this antenna that EZNEC says will work so good, work with even the slightest improvement in the field, I'll eat my words. When your lazy ass that admits it has nothing to do but sit there, actually finds out it only takes a 90 degree phase shift, get the salt out. Then you can shut up about your not so humble opinions and actually have some facts to base them off of.

You and NoSee are more of a disappointment than a source of anger or upset. To upset me you would have to make an awful lot of antennas installed on towers worldwide, change their operating characteristics for the worse overnight. Since you and NoSee seem to be on the same page with this....perhaps you can borrow the magic wand he lent Mickey Mouse and make it finally happen.

 

[Marconi]

I may be in the process of eating those words... I can say this, there is a version written by someone and available for free that does the exact same thing but is optimized for newer computes, and thus runs much faster... With 4nec2 it is simply a matter of overwriting a few files that came with the program. This version can run a frequency sweep in a significantly shorter amount of time on my computer than the stock nec2 files. The fact a faster version of said program exists does not make what I said earlier true. I was blaming the nec2 data when I maybe should have been blaming the programs that are interpreting it instead...

I have actually written and deleted in my next post after the one you quoted here that the needed data to simulate the fields I've been talking about is in the NEC2 .out file, and that a nec2 based software would simply have to use that data to generate the fields in question and simulate how they interact with each other. I have yet to see a nec2 based software do this.

They have to with more than just electromagnetics... They are also on wikipedia...

Maxwell's equations - Wikipedia, the free encyclopedia

If your not familiar with vector math I highly recommend doing some research on how vector math works first... Trust me, you won't regret gaining that knowledge first...

The DB

CB, in my first year at the University of Texas in 1957, I took an advanced 1/2 credit elective course on Maxwell's World in Science. I had a youthful notion for science in my life in those days. I took that course at no cost for taking some advanced student testing. After that course...I changed to the school of business in economics, management, and accounting right fast.

I did learn some things about Maxwell's life and contributions however. I was lucky to have a down to Earth professor that was very hands-on and well skilled in his lab work. He taught his own class, and he could write and draw images that looked like art on the blackboards of those days. He also talk with a straight tongue, and that gave me confidence.

After that class however, I never had any more ideas that I would ever have any interest in the field of electromagnetic physics, science, or math however.

I asked the question, simply to see if you were thinking of the Maxwell I studied at UT, or the other Maxwell of modern day times that wrote on transmission lines and such.

 

[Shockwave]

Yes!! and CST software is so good that you can tell which side melts faster ice cream. I assure you!

Generally speaking, when you have options purchasing a product and one cost ten times more than the others..... you get a little more for your money buying the top of the line product. You may not use every option the expensive product offers on a daily basis. However, when demanding situations present themselves, one would be foolish to think the person who selected the top of the line product would not have the advantage as a result. Just because you can't understand how CST displays current phase doesn't mean everyone else is as confused. How hard do you think the engineers who built CST would be laughing at your ice cream cone if they could see your level of confusion now?