ASTROPLANE best vertical antenna ever?

[The DB]

There is no need to do such a thing. Just explain how in a resonant half wave dipole antenna where the current and voltage are in relation to their respective phase angle's, the relationship of those phase's to the distributed inductance and capacitance, explain where the current maxima is, where current minima is compared to voltage maxima and minima. Just explain why the antenna bottlenecks voltage and current in inductive and capacitive regions of the antenna. The whole thing can be written in less than 100 words.

Fine, I'll do it here then even though it is a bad idea. Sorry to everyone else for helping drive this thread off-topic. If it gets to be to much I'll trust the mods to move this stuff to a new thread, which is where this should be to begin with.

I'll even do it your way, but should we start talking past each other, that is on you. For the record, I still say we need to sort out terminology before talking how antennas work.

Lets see, 100 words or less...

I tries and got 25 words before I came to a part where it is like you are speaking a foreign language. You used two words differently than I have ever heard them used before by anyone. I also have never seen them written in books or articles with that usage, so before I butcher the explanation you want by limiting it to 100 words, I need clarification on some of your terminology.

the relationship of those phase's to the distributed inductance and capacitance. Just explain why the antenna bottlenecks voltage and current in inductive and capacitive regions of the antenna.

What are you referring to on distributed inductance and capacitance? Also, what part of the antennas would be inductive and capacitive? Inductance and capacitance aren't, as you are saying, distributed across the antenna. The only things that are distributed across the the antenna are voltage and current, and from these we can derive things like impedance and reactance, which are based on the relationship between voltage and current. Are you trying to equate current and voltage to inductance and capacitance or am I misunderstanding what your are thinking?


The DB

 

[nav2010]

The answer lies in the loop itself. What is the very first thing a loop antenna does when current and voltage appear at resonance? The very first thing before it produces radiation?

 

[The DB]

The answer lies in the loop itself. What is the very first thing a loop antenna does when current and voltage appear at resonance? The very first thing before it produces radiation?

Is this meant for me or Marconi?


The DB

 

[nav2010]

Fine, I'll do it here then even though it is a bad idea. Sorry to everyone else for helping drive this thread off-topic. If it gets to be to much I'll trust the mods to move this stuff to a new thread, which is where this should be to begin with.

I'll even do it your way, but should we start talking past each other, that is on you. For the record, I still say we need to sort out terminology before talking how antennas work.

Lets see, 100 words or less...

I tries and got 25 words before I came to a part where it is like you are speaking a foreign language. You used two words differently than I have ever heard them used before by anyone. I also have never seen them written in books or articles with that usage, so before I butcher the explanation you want by limiting it to 100 words, I need clarification on some of your terminology.



What are you referring to on distributed inductance and capacitance? Also, what part of the antennas would be inductive and capacitive? Inductance and capacitance aren't, as you are saying, distributed across the antenna. The only things that are distributed across the the antenna are voltage and current, and from these we can derive things like impedance and reactance, which are based on voltage and current. Are you trying to equate current and voltage to inductance and capacitance or am I misunderstanding what your are thinking?


The DB

I'll put it in easy terms:
A half wave dipole has current maxima, voltage minima, low impedance and has inductive properties at the feed, inductive means that it behaves like a coil on an LC circuit. The tips of the antenna are high voltage, current minima, capacitive in nature and high impedance at the resonant frequency. Capacitance is like when voltage is stored on a capacitor in a LC circuit, it has an electric field which stores electricity, on the dipole, one tip has the positive voltage and the other tip has the negative side of the voltage field. But unlike a normal capacitor, the tips of the antenna are not close enough for the electric fields to effect each other by proximity but they still do. How do they do it?
It is said that the reactances of the half wave dipole antenna cancel each other out so that the inductance and capacitance are cancelling and the oscillator see's a purely resistive load, explain this in the loop antenna such as the AP when there is a electrically conducting loop just like a conventional loop antenna, how does resonance divide electrical lengths or separate radiators that are in the same electrical loop?

 

[Marconi]

DB, I said above that I did not understand nav2010 words, but his image looks like I imagine the A/P to work.

I'll leave the question to you both. If you do take this debate to another thread, which I don't care one way or another, then I will proceed to post my new models with and without the Blue line. Then I will pose my question in good order.

nav2010 I will follow you guys to another thread, I think such a discussion might shed some light on the terms you use that I don't use in my own thinking.

Thanks,

 

[The DB]

I'll put it in easy terms:
I half wave dipole has current maxima, voltage minima, low impedance and has inductive properties at the feed, inductive means that it behaves like a coil on an LC circuit.

OK, here is part of the disconnect between us. I would have never guessed that that is how you are using that word "inductive" when referring to antennas. I have never read or heard anyone use that terminology in that way, and I have read some pretty advanced books on antenna theory and talked to people who have decades of professional experience in the field along with advanced training. Do you have any reputable sources for this way of describing this being accurate?

The tips of the antenna are high voltage, current minima, capacitive in nature and high impedance at the resonant frequency.

Here it is again. By what you said here, I would take it by extension that you mean that the low impedance part of the circuit is inductive? Again, not heard anyone anywhere explain this aspect of antennas in this way, and would love to see a source that .

Actually, based on what you are saying, I think the reason people don't refer to the impedance of antennas in this way is by definition resonance, in this context, is the perfect balance between capacitance and inductance. To call a part of the antenna that is "resonant" also "capacitive" or "inductive" only leads to further confusion when we have better, more descriptive words that are in far wider use already, namely "low impedance" and "high impedance". I guess I just don't get why you would use the words you are using instead of these, which are far easier for pretty much everyone to understand...

Capacitance is like when voltage is stored on a capacitor in a LC circuit, it has an electric field which stores electricity, on the dipole, one tip has the positive voltage and the other tip has the negative side of the voltage field. But unlike a normal capacitor, the tips of the antenna are not close enough for the electric fields to effect each other by proximity but they still do. How do they do it? It is said that the reactances of the half wave dipole antenna cancel each other out so that the inductance and capacitance are cancelling and the oscillator see's a purely resistive load,

You are answering a question with "it is said"? With all due respect, a lot of people say a lot of things about antennas that are not true.

However, whoever it is you are referring to ais correct, at least to a point. A center fed self resonant dipole is cut to have a balance of inductance and capacitance, thus being resonant with itself, or self resonant. Many people mistakenly think that self resonance is all their is to resonance, and at lest to this point, you appear to be among them. That is not the only way to achieve resonance, but it is perfectly adequate for a single band antenna that doesn't require a matching network.

explain this in the loop antenna such as the AP when there is a electrically conducting loop just like a conventional loop antenna, how does resonance divide electrical lengths or separate radiators that are in the same electrical loop?

I think that their is a bit more that needs to be covered before we transition to loops, but...

You have yet to prove that the AP is a loop antenna. That is your belief and I am not a "listen and believe" kind of guy, I need more than that. I, personally, see your description as an over simplification of what is happening with this antenna, and the modeling I have done also does not agree with your assessment.

You seem to want to get into loop antennas, so please, go ahead and explain how they work in your words.


The DB

 

[nav2010]

You asked me what inductance means, I described a coil as an example because there is no better way of putting it, a coil is indeed inductive in an ac circuit but a dead short in a dc circuit. You asked me what I meant by capacitance, capacitance is best described by the electric fields of a capacitor.
That does not mean the antenna when described as inductive behaves like a coil, it just means it has similar properties in it's make up. For example some antenna's are more inductive by nature and some are more capacitive by nature, in the case of a half wave dipole the two are cancelled out because it's a balanced antenna ....but that is not what truly happens.
You've failed to answer any question I asked you. I'll ask you another:
In a series tuned circuit which involves an ac source, a capacitor and an inductor, lets say for example a bog standard tank circuit, the current and voltage pass from component to component @ resonance freely until the system runs out of energy.
In a series tuned radio station, the voltage and current run along the 50ohm feed to the antenna and back. If the antenna is dc grounded we can see the physical means by which it does this, in a loop antenna we can see the physical loop in which the series circuit manifests. When the tips of a dipole appear open circuit, by what means is the series tuned circuit completed? How does the antenna complete the circuit and don't say because the feed point is 73ohms or something stupid.

 

[The DB]

I don't see the point in continuing in this. The point, from my side, was to understand your strange terminology, which as far as I can tell no one else in radio uses anywhere. I specifically wanted to get the terminology sorted so we didn't talk past each other, however, you seem to be intent on doing just that.

Your not dazzling me with brilliance, and your attempt at baffling me with bullshit... Well, for those who have a far lesser understanding of antennas and don't realize that it is bullshit would have fallen for it. You just picked the wrong target (even if I did play along for a bit).

That being said, you did start your last post with something funny, I didn't ask you what inductance means, like I would ask someone like you a question like that...


The DB

 

[nav2010]

I don't see the point in continuing in this. The point, from my side, was to understand your strange terminology, which as far as I can tell no one else in radio uses anywhere. I specifically wanted to get the terminology sorted so we didn't talk past each other, however, you seem to be intent on doing just that.

Your not dazzling me with brilliance, and your attempt at baffling me with bullshit... Well, for those who have a far lesser understanding of antennas and don't realize that it is bullshit would have fallen for it. You just picked the wrong target.

That being said, you did start your last post with something funny, I didn't ask you what inductance means, like I would ask someone like you a question like that...


The DB

I'm not dazzling anyone with BS lol. I'm using straight forward questions that anyone can understand. I asked you in a series tuned radio circuit how the system completes the electrical circuit back to the radio in an open ended dipole system. It's a straight forward question but it seems you can't give me a straight forward answer so i'll assume you don't know.
No need to get twitchy about not knowing something dude.

 

[nav2010]

I'll give you a clue, 'the hair stands up on the back of your neck while stood under power lines because...........?
or...
'The guy who invented the device for stealing juice from HT power lines was tuned into......?

 

[nav2010]

20 minutes and no answer.
Another clue:
A magnet is a dipole, we can create electromagnets with a very similar set up to a dipole antenna.
When we sprinkle iron filings at each end of the dipole or magnet on a piece of paper, the iron filings produce a pattern and show a field relationship between the positive side of the magnet and the negative side of the magnet.
This is known specifically as something....pmsl.

 

[The DB]

Haha, wow. You are a troll. Evidence, you asked another one of your questions that are irrelevant when I said there was no point. I was trying to give you the benefit of the doubt, but no more...

Its not like you can tell me anything about antennas and how they work that I don't already know anyway.

And because I didn't answer a question within 20 minutes you assume I don't know the answer? Their isn't any other possible explanation? I couldn't have, say, left my house and went to go out to eat dinner with a friend?


The DB

 

[Captain Kilowatt]

For example some antenna's are more inductive by nature and some are more capacitive by nature, in the case of a half wave dipole the two are cancelled out because it's a balanced antenna ....but that is not what truly happens.

I dropped out of this thread quite some time ago but just read something I have to bring up. In the case of a half wave dipole the inductance and capacitance are not cancelled out because it is a balanced antenna. Being balanced has NOTHING to do with it and the ONLY time the inductance and capacitance of ANY antenna is truly cancelled out is when the antenna is tuned to resonance. If the transmitter feeding that antenna is operated above the resonant frequency the feedpoint will exhibit inductive reactance but if it is operated below the resonant frequency the feedpoint will show capacitive reactance even in the case of a half wave dipole which is a balanced antenna. Being balanced has NOTHING to do with reactances cancelling out or not.

 

[Marconi]

DB, my model of the A/P with no blue line requires a mast 240" inches long to in order to show a good match of 45.46 - J 0.008199 ohms at resonance and it could be even better. So, you are right about the mast needing to be made longer in the absence of the blue line in order to see a good match.

Is this 240" inches antenna mast length inside and below the radials even close to what you get with your model?

That said, this model shows a gain of 5.11 dbi @ 11* degrees. I think you might have mentioned that your model showed better results (I could be wrong), but this 5.11 dbi gain my model shows is, IMO not possible with this CF1/2 wave.

So, I ran the model in FS and the Average Gain was 1.600 and that too is way out of a suitable range.

I don't believe we can remove this blue line wire from the model and just extended the antenna mast, and still expect any good results. I would hope you might shed some light of any error I made. This is why I keep asking if we are doing this model right using this trick...or should I say procedure for tuning a model.

The link to patent 3587109 below discusses this area in the abstract at column #4 lines 17-29, and is illustrated in Fig 5 on sheet 2 of 2. Both Fig 5 & 6 suggest and open loop idea, but in that case the feed point needs to be on wire #18 per the patent, the radial under the feed point on the real antenna.

I believe I have workable model that has a feed point on this wire #18 noted in the patent. I will see if it works when removing one of the small wires in the mounting bracket. also as noted in the patent as shown in Fig #5, in particular.

The patent also talks about the bottom area of the antenna being a closed loop with possible construction as an open loop. Again see column #4 lines 26-29 for alternative details. I'm not saying that I have the understanding of this issue, but these words seem pertinent and clear to me and the images helps too. They do call this area a loop. However, I would not swear to this base on anything I've read in nav2010 post on this subject...just to be clear I said it earlier.

Again, Nav's image did it for me, and I can only assume that his words somehow describe what he as saying. My words here are not meant to be critical.

https://www.google.com/patents/US3587109

 

[Marconi]

I believe I have workable model that has a feed point on this wire #18 noted in the patent. I will see if it works when removing one of the small wires in the mounting bracket. also as noted in the patent as shown in Fig #5, in particular.

DB, below is my model that follows the idea noted in Fig #5 in the patent. I used this model with the full 1/4 wave because I had fed it at the top of the radial under the A/P feed point.

I checked it out and set this model to a good match. Then I checked it in FS to get the Average Gain results and it produced 1.021 average gain. Then I removed the wire noted in Fig #5 per the patent.

Below is that model including the Average Gain Results done in a Free Space model to start this project on a good footing. I did not try and re-tune the model after removing wire noted in Fig #5 of the patent and I think it can be improved a little.

This model looks to not be ill-effected on removing this small 3" wire from the mounting hub as noted.