ASTROPLANE best vertical antenna ever?

[The DB]

Iron is a poor conductor. Conductivity is the ability of a material to propagate (force vectors of dielectric discharge) an electric current. Steel, including the range of grades known as stainless vary between 3% - 15% conductivity when referenced to copper at 100%. Aluminum comes in at 45 - 61%. See the chart posted further down the page.

Iron has extremely poor conductivity.
Ranking Metal % Conductivity*
1 Silver (Pure) 105%
2 Copper 100%
3 Gold (Pure) 70%
4 Aluminum 61%
5 Brass 28%
6 Zinc 27%
7 Nickel 22%
8 Iron (Pure) 17%
9 Tin 15%
10 Phosphor Bronze 15%
11 Steel (Stainless included) 3-15%
12 Lead (Pure) 7%
13 Nickel Aluminum Bronze 7%

First things first, nosepc was a troll. I doubt he actually put up an antenna made out of iron, or had the know how to actually make such an antenna.

And when it comes to metals used to make antennas, this really is irrelevant. You said you can use EZ-Nec? Why don't you try modeling the same antenna with different metals in it and see for yourself.

Some comparison models of an antenna made out of various metals and tuned to resonance with each... This was done in 4nec2.

[photo=medium]6462[/photo]

As we can see, the different metals don't make all that much difference when it comes to gain and angle. Seriously, stainless steel, about as bad of a metal commonly used to make antennas, has a loss of 0.07 dB compared to a perfect conductor. Good luck noticing that difference.

And here are the structure losses from the different metals.

• Perfect conductor, 0%
• Copper, 0.27%
• Aluminum, 0.33%
• Stainless Steel, 0.71%

Seriously, Stainless Steel, the worst metal commonly used to make antennas has a structure loss in this case of less than 1%? Again, gook luck noticing that difference...

There is a very good reason there is such a small difference in performance between these antennas. Most of the RF doesn't actually travel through the metal itself, but the space around said metal. If all of the RF traveled inside of the metal, we wouldn't have to worry about things like velocity factor, or said velocity factor would be specifically determined by the metal used, and not the dielectric material used in said coax.


The DB

 

[freecell]

I was just checking this out in the photo gallery before i saw your post here.

 

[The DB]

I was just checking this out in the photo gallery before i saw your post here.

I just made that image for that post. If your timing was good (bad?) you might have seen one with a mistake on it that I have since deleted and replaced...


The DB

 

[Marconi]

Modelled using eznec4, with the av101 at a feedpoint height of 36 feet we see the following:

Slice Max Gain: 4.38 dBi @ an Elevation Angle of 31.0 degrees.

freecell, how about showing us this model? Avanti has advertised their A/P making 4.46 dbi gain for ever, but I find that the gain for that model is overstated. According to my A/P model the gain is 2.5 - 2.9 dbi and the Average Gain report indicates the mold is reliable as to the gain. The A/P is a center fed 1/2 wave and not a Vector 4K antenna.

Try running the Eznec AG results in Free Space for your model. I think you might find your gain is overstated by about <>2.00 db gain...and this is due to some error noted by Eznec.

Here is my model of my Old Top One antenna in Free Space and over real Earth

 

[Shadetree Mechanic]

There is a very good reason there is such a small difference in performance between these antennas. Most of the RF doesn't actually travel through the metal itself, but the space around said metal. If all of the RF traveled inside of the metal, we wouldn't have to worry about things like velocity factor, or said velocity factor would be specifically determined by the metal used, and not the dielectric material used in said coax.

Wow, I never thought about it that way.

 

[freecell]

Show me the two quarter wave elements of this center-fed half wave dipole that you are seeing. Show me how the combination of elements 14, 46, 48 and 50 constitute the electrical equivalent of a half wave dipole. I'll wait.

 

[freecell]

Wow, I never thought about it that way.

Obviously some have never heard of the K factor. The velocity factor of a conducting element at any given frequency would be "specifically determined" by the λ / diameter or the length to diameter ratio of the conductor material in use.

 

[Marconi]

FC, I don't want to try and wage words with you.

Since you asked what I see, this is what I see and it is not complicated by a lot of technical back and forth.

Here are two models, so that maybe some folks can see what I see that gives me the opinion the A/P is a center fed 1/2 wave antenna.

1. is a gamma fed vertical 1/2 wave
2. is a model of my Old Top One - a knock-off of the Astroplane.

The patterns are a little different, because the A/P is asymmetrical by design, and the pattern is skewed a bit. These two patterns are surely not the patterns of a 5/8 wave or a 3/4 wave.

How do you describe the A/P?

 

[freecell]

You posted: "The A/P is a center fed 1/2 wave." Can you point out the two quarter wave elements of this center-fed half wave dipole that you are seeing? Can you point out how the combination of elements 14, 46, 48 and 50 constitute the electrical equivalent of a half wave dipole. I rephrased it since i know how much you like questions. BTW, have you ever read the A/P patent? I'll wait.

 

[Marconi]

I have read the patent.

Wires #7, #5. #1.

 

[freecell]

there are no conducting elements in the astroplane patent that are numbered using single digits. here's a copy of the original patent. AstroPlane AV101 https://www.freepatentsonline.com/3587109.pdf

The conducting elements listed according to the patent are: 14, 16, 18 ,20, 24, and 47 which is composed of elements 46, 48 and 50.

Can you show us the center-fed half wave dipole?

 

[loosecannon]

freecell,

you are the only one involved in this discussion that hasn't been here for the whole thing.
Why don't you go back and read the two+ years worth of posts that you have missed instead of trying to re-start an old argument.

I am not taking a position on what type of antenna the astroplane is, im only taking a position on the fact that you are coming off like a jerk.

Maybe you don't mean it that way, and maybe you have some great insights to offer, but do you really expect anyone to take you seriously when you try to jump back into something that has continued on without you for so long without even acknowledging that there has been many many pages written while you were gone?

If you want to challenge the contention that has been made on this forum regarding the type of antenna the AV-101 is, then go back and do the reading, and quote some past posts that you disagree with.

Trying to pick up where you left off and attempting to make others prove their positions to you, when you were the one who missed all the past posts is not the way to go about joining back in the discussion.
LC

 

[Marconi]

I just got out of the Hospital with Covid19.

That is the reason I didn't explain to FC that I was quoting my wire #'s based on the models that I've posted above and for a long time since. I just didn't feel like making a cross reference to the patent numbers too.

I got to feeling pretty bad with that bug Nov 4th, and I went straight to the Emergency Room on loosing all of my energy suddenly. I never felt sick just very weak for 83 years old, and I could not think, remember, or reason.

Now I'm back, but I going to try and take it slow for a while.

 

[murdog]

I just got out of the Hospital with Covid19.

That is the reason I didn't explain to FC that I was quoting my wire #'s based on the models that I've posted above and for a long time since. I just didn't feel like making a cross reference to the patent no's too.

I got to feeling pretty bad with that bug Nov 4th, and I when straight to the Emergency Room on loosing all of my energy suddenly. I never felt sick just very weak for 83 years old, and I could not think, remember, or reason.

Now I'm back, but I going to try and take it slow for a while.

 

[murdog]

Welcome back ....get well !