ASTROPLANE best vertical antenna ever?

[Marconi]

Nope, still puts it on the ground. The tool is called ground screen and I think it is meant to simulate radials on or under the ground on a ground mounted antenna.


The DB

Maybe that screen on the ground is what we saw below nospec's model posted above.

I would continue to look for such a feature that makes radials however, else how will you make odd numbers of radials (3,5,etc) and top hats that are outside of the default X & y coordinates?

 

[The DB]

Something like this?

That is a quarter wavelength vertical for 11 meters with five horizontal quarter wavelength radials spread equally from a common point on a plane... I had one with 255 radials just for kicks a few minutes ago...

4nec2 comes with a program called build that makes various shapes for you, and it can move them around in a three dimensional plane, as well as rotate the shapes. You simply use the file it generates to finish off your antenna... This will definitely be useful for future reference...


The DB

 

[Marconi]

Something like this?

That is a quarter wavelength vertical for 11 meters with five horizontal quarter wavelength radials spread equally from a common point on a plane... I had one with 255 radials just for kicks a few minutes ago...

4nec2 comes with a program called build that makes various shapes for you, and it can move them around in a three dimensional plane, as well as rotate the shapes. You simply use the file it generates to finish off your antenna... This will definitely be useful for future reference...


The DB

So 4nec2 can create radials for you, right? Do you also have a feature that will automatically create a loop, and a helix too...to the dimensions you wish?

I suspect we will find more similarities than not between these two programs...it just makes good sense to be that way.

 

[The DB]

When using the build program I used the plane screen to create the example above. It can also create rings in the radial system if so desired, and I suppose top hats as well.

Using that tool I can make other shapes as well... Patch, box, cylinder, parabola helix, and sphere are other shapes you can create and manipulate with the program. I can use the cylinder tool for example to create a downward angles radial set as found on the astroplane or the upward facing radial set found on a vector.


The DB

 

[nosepc]

I can and have built to specs the physical matching device (trombone) for my I-10K, and I can get the match to work for the model to effectively change the match, but I'm not sure of such results, because with these serial type inductors added...the model produces a pattern that seems to always show the antenna producing both horizontal and vertical polarity patterns.

At any rate I don't see there being much difference in the gain and angles noted for the antenna with a 1.20 SWR or a 15.5 SWR, so maybe that is the point as to our not needing to be overly concerned. Plus I generally see my models showing "less than" rather than "more than" good results as the model improves, but I could be wrong on that too.

hello Marconi ,

device drivers and adaptation of systems trombones, gamma-match etc , introduce losses irradiation and reception.

These are proportional to the diameter and length of them .

A larger diameter , the greater loss.

Who can assume that a driver does not radiate trombone ?
It does! and is no antenna is adapter.

Many years ago I designed and built VHF collinear antenna systems in phase, similar radar screens , yaguis , quad Swiss and I was able to appreciate this.

Many use 2000 watts in antennas, but in this case , are other problems , such as radiate that power without destroying the antenna, and these issues are irrelevant .

If they say that the I- 10K is good for it , beyond them, but that does not mean it's good antenna , antenna only says that supports a lot of power .

An antenna capable of radiating 5KW self-destruct , which means you benefit who uses 100 watts? ?

We must not confuse ability to radiate power with performance.

They are dissimilar things .

A 100KW dummy load antenna would be better if we think that way.

Greetings .

nosepc from Argentina .

 

[ghz24]

wire ends

Originally Posted by Marconi
In your description process using an editor, can you attach two wires together as follows: wire #1 end 1 to wire #2 end 1 without getting an error alert?

You don't get an error message and it does matter.
I was trying to recreate someones results with this model but it demonstrates what can happen if you reverse wires.
I think this is the right way.

CM 11 meter endfed halfwave (right ends) by ghz24
CE
GW	1	9	0	0	0	0	0	210	0.0404
GW	2	9	0	0	0	0	210	0	0.0404
GS	0	0	0.0254		' All in in.
GE	0
EK
EX	0	1	1	0	1	0
EX	0	2	1	0	1	0
GN	-1
FR	0	1	0	0	27.18	0

This one is in error.

CM 11 meter endfed halfwave (wrong ends) by ghz24
CE
GW	1	9	0	0	0	0	0	210	0.0404
GW	2	9	0	210	0	0	0	0	0.0404
GS	0	0	0.0254		' All in in.
GE	0
EK
EX	0	1	1	0	1	0
EX	0	2	9	0	1	0
GN	-1
FR	0	1	0	0	27.18	0

Compare them for yourself.

 

[Marconi]

I see the difference in data entry and I might agree in does make a difference, but what are the consequences for the model? This doesn't demonstrate anything from what I see here.

Can you be more specific in your suggestion?

 

[ghz24]

What I meant by compare for yourself was:

"Copy" the text in the highlighted Code box . "paste" the text into a new text file (like notepad) and save as "righttest.nec" (or wrongtest.nec ) save/move them to the "4nec2\models" folder.
Open 4nec2, click on the folder icon near the top left.
Select the file you want (righttest.nec or wrongtest.nec)and click open.
Find the calculator icon (or F-7 ) and select far field pattern and generate.

The most obvious difference is 2.79 dBi max gain at the horizon vs 1.49 dBi at 10 degrees.(on a free space model).

Wires should be constructed where "end one" is closest to the feed point.
That's my understanding of it. Though I can't seem to find this rule in the users manual.

I think it was a 3 wire dipole model I used originally to prove it to myself.

 

[Marconi]

What I meant by compare for yourself was:

"Copy" the text in the highlighted Code box . "paste" the text into a new text file (like notepad) and save as "righttest.nec" (or wrongtest.nec ) save/move them to the "4nec2\models" folder.
Open 4nec2, click on the folder icon near the top left.
Select the file you want (righttest.nec or wrongtest.nec)and click open.
Find the calculator icon (or F-7 ) and select far field pattern and generate.

The most obvious difference is 2.79 dBi max gain at the horizon vs 1.49 dBi at 10 degrees.(on a free space model).

Wires should be constructed where "end one" is closest to the feed point.
That's my understanding of it. Though I can't seem to find this rule in the users manual.

I think it was a 3 wire dipole model I used originally to prove it to myself.

24, I don't get the same gain and angle numbers when I model your L antenna using Eznec and I can't explain that. Does 4nec2 produce model integrity like Eznec does with its Average Gain test? Our gain numbers and angle are not even close, and my results for both models are the same regardless if I connect the wires...one way or another.

Said another way, when using Eznec the only different results I see when I fix the end connections for the two wires differently is the currents and phase distribution as noted in the output for the Tabular Currents Log, and the red line indicator for the phase noted for the models in the Antenna View.

Except for the phase and currents differences I see, I was surprised to see your models showing different results in gain and angle when you switched the end connections for your models. Can you also compare the currents between models. I just compare the first segments for the two wires in this case.

I also added a dipole model to my attachment below by making your L model straight like a dipole. That changed the match a bit, but I did not correct the dimensions in order to return the model to resonance like my L model shows. So, the model shows some reactance by moving the element into the vertical plane. However, the model is still pretty close to what theory predicts, and this is why I did this...just to show that my Eznec model is pretty close to what theory predicts for gain and angle in free space for a 1/2 wave dipole. You will also note that I too used a split feed point in order to get closer to the center of the radiator.

I have a feeling that in modeling we should always connect wire ends as follows. This also considers that the actural wire number used here or for example only...and is not significate to this issue. We can connect any wire to any other wire as long as the ends follow what I suggest below. I can be wrong on this however, if someone can explain this better or tell us why this doesn't matter. I tried to talk to Roy about this, but did not get to first base.

wire 1 end 1 connected to wire 2 end 2

and we should not connect as follows:

wire 1 end 1 connected to wire 2 end 1

I will add, that when I create radials or a top hat using the create radials feature in Eznec...all the elements look to connect in error to me as noted below:

wire 1 end 1 connects to wire 2 end 1 and so on with the other wire in the radial set

As a result the models with even number of radials always shows all radials are in phase including opposing radials, and as I understand this aspect of antenna theory, the two opposing radials with currents flowing out toward the open tips should be out of phase with each other...and thus cancel each other out into the far field.

Beyond this I cannot explain further why Eznec does what it does when the wires are connected the opposite way. I also can't explain why we are seeing different results in the gain and angle. By chance did your match also change when you changed the connections?

View attachment GHZ24's wire connection idea.pdf

 

[nosepc]

I do not know for what reason they can think of to use two points in a single antenna feed.

It makes no sense.

Should be taken into account when modeling, that the feeding point are the two that correspond to a radio frequency feed line, be it coaxial, parallel, etc..

In this place, the two poles apply therefore no longer needs the antenna, since the alternating current is applied to it.

If you use two feed points, with two parallel lines, they can be in phase or out of it, which is why 4nec2 gives different results, according to the phase.

nosepc

 

[Robb]

Astroplane is a decent antenna; but I certainly would call it the best vertical ever.

Now, a Vector 4000 or a GainMaster are still top of the list IMO.

 

[nosepc]

Astroplane is a decent antenna; but I certainly would call it the best vertical ever.

Now, a Vector 4000 or a GainMaster are still top of the list IMO.

What is the reason to say 4000 or Gainmaster vector are better antenna??

Models??*

True models including masts and coax do not say that.

All they say is, " it's better because it's bigger, has more signal" etc.

But the more the signal, noise is absent, or are also more noisy?

Because if the Vector 4000 is better, advertising does not show a pattern other than a hand drawing?

Why?

 

[Robb]

Because of locals that have bought them and put them up and what I hear as results. In fact, several of the locals have gone from other popular antennas like the Imax to the Vector in particular. While my evidence is anecdotal, it is based upon the difference that I can detect from their transmissions.

Those who have either antenna claim a cleaner, more sensitive receive. The GainMaster is a better antenna for those who are hams, because it provides better TX than the Imax as well as allowing other Ham bands to be used on it.

So it is a toss-up.
If you are a CBer or a Ham, the GainMaster is tops.
If you are a CB only guy, then the Vector is best.
JMHO.

 

[bob85]

lets make up our own laws of physics about hat loading, radiation resistance etc , misuse software to make an astroplane look way better than it is and post that crap all over a forum,

ampower has competition no doubt.

 

[Marconi]

I do not know for what reason they can think of to use two points in a single antenna feed.

It makes no sense.

Should be taken into account when modeling, that the feeding point are the two that correspond to a radio frequency feed line, be it coaxial, parallel, etc..

In this place, the two poles apply therefore no longer needs the antenna, since the alternating current is applied to it.

If you use two feed points, with two parallel lines, they can be in phase or out of it, which is why 4nec2 gives different results, according to the phase.

nosepc

nospec, I probably would have thought it doesn't make sense either until I learned to understand the idea, and why the "Split feed point" feature is provided.

When using the split feed point we are not using two feed lines nor do we have two feed points. The feature is just like it says, "Split." The feature is a virtual consideration and is not a physical reality. Check your manual for virtual features and/or split feed points.

Eznec will not allow us to place a feed point at the junction of two wires and I believe 4nec2 does the same.

So, in the case with a two wire dipole we can either locate the feed point on either wire at the end that is close to the connection, near the center of the dipole, or we can use a Split feature that allows us to split the feed point between the two wires at the virtual center of the connection of the two wires. This then places the feed point closer to the wire ends, splitting between the two wires at the connection and gets the feed point closer to the center of the dipole.

This is a virtual type feature that allows one to produce a dipole model that duplicates theory correctly and it minimizes the current differences in the two wires of the dipole and that provides for better symmetry and balance at the feed point. Only the Antenna View physically shows the split, all calculations include only one feed point, so I guess we should consider this a math function only.

You are using 4nec2, right?

If you look back at GHZ24's model of the L shaped dipole he posted earlier in this thread on the AstroPlane you will see the same two "0" "0" at the feed point he uses in his 4nec2 program, so you too can use the feature.

Note: this Split feature can only be used with two wire connections. So a two wire dipole with a mast attached in the center will have to use the standard feed point assignment feature (non-split), and that will place the feed point, at a minimum, several degrees away from the physical center of the model. Therefore there will remain a small amount of asymmetrical imbalance due to reactance in the model.