Response to Alabama Buckeye from another thread

[The DB]

I submit the following fodder:
View attachment 60035

I wonder what would happen if I modeled this, it looks similar to a 4nec2 model with information added...


Well, it appeared to have been a 4nec2 model but its not. Under closer inspection it appears to have been drawn in some photo editing program.

Anyway, I matched the colors up for ease of reference. The pic shows the 1/4 wavelength antenna at 5.2 dBi, while my models shows it at 5.15 dBi, not bad, so far pretty close. Their half wavelength is shown to be 6 dBi gain, while mine is 6.72 dBi? What are they short changing the half wavelength antenna? And the 5/8 wavelength model isn't much better, their is 6.6 dBi gain while mine is 8.01 dBi gain, again not even close.

Now I have to ask, did they just get lucky with the 1/4 wavelength gain?

So which of these is correct? The correct answer is neither. The problem with this model, and the diagram above, is they both assume a perfect ground, and if your not a boat floating on the ocean, you don't have anything even like perfect ground under your antenna. These are optimal readings that only exist in an optimal if not "perfect" scenario, lab conditions if you will, and most people will never see in their life. As these numbers simply do not translate to the real world, thus they are not relevant.

So lets see about making these numbers more relevant. Here I am taking the same antennas and putting them over average ground. Essentially changing one (ok, technically two) variable. The only difference from my model above and and my model below is the quality of the earth.


Wow, what a difference. The half wavelength here completely destroys everything else, and is in this case the only antenna with a positive gain. I wouldn't call this a simulation of reality, but it is one step closer than the models I made above. One simple change to make the results closer to reality and boom, drastic changes in some of the results. The hard question comes now, if I were to take this further, which reality should I try and simulate? My house? Your house? The antenna setup I see down the street? From experience I can tell you that in some cases, the 5/8 will outperform the 1/2, and in others the 1/2 will outperform the 5/8. It all depends on the variables, many of which most people who work with antennas don't even realize exists. Just one, for example, poor ground, good ground, are you near a lake? an ocean? And that isn't even considering other more well known things like height, which has the effect of bringing the outputs of the various antennas closer and closer together.

I can go on here, but I think I have demonstrated that a set of models, if they are even proper models, that exist with one specific set of variables, or even just made up on the spot as the image above appears to be, cannot be used as a general fact that applies to every antenna installation everywhere.

In essence, when it comes to antennas, the simpler something is to understand, the less likely it is to be true.

Based on 100 watt radio transmitted power.
I. At .5 wavelength (17.5481 feet) gain should be 13.15 dBi = 1259.378 watts ERP. with a radiation angle of 24 degrees.
II. At 1 wavelength (35.0962 feet) gain should be 14.62 dBi = 1766.673 watts ERP and a radiation angle of 15 degrees.
III. At 1.5 wavelength (52.6443 feet) gain should be 15.12 dBi = 1982.240 watts ERP and a radiation angle of 9 degrees.
IV. At 2 wavelengths (70.1924 feet) gain should be 15.09 dBi = 1968.594 watts ERP and a radiation angle of 6 degrees.

Note of importance is the diminished gain and ERP as antenna height moves higher than 1.5λ.

500W 10.64dBi ERP 3532
EIRP 5793

Pure ERP And EIRP Calculator

Pure ERP And EIRP Calculator

www.csgnetwork.com

Footnote 07.30.22 The calculations above were based on, if I recall correctly, a Imax 2000 DBi of 12.5; your results may vary based on wishful thinking or real world fact. Advertised DBi is all I can go on; that and reeducation. Thanks DB for your attendance.

I don't think we actually disagree over the general idea you are trying to put forth but...

So this is the actual advertised gain claims for the Imax? Wow, who the hell needs a 7 or 8 element yagi with the Imax around...

I know you are trying, but... A real world Imax isn't going to get anything like those gain figures. Could it be made to happen in a lab environment? Possibly, but even if it can, is that even relevant?

I know what you are saying here, and I never once disagreed with the idea that you are presenting, but these numbers...

To my amazement I read of the huge increases related to the values of Db gain.
Simply said a 10DBi gain is a 10-fold gain and jumps amazingly to 20-fold a mere 3DBi higher (13DBi). Nawh, I sez to myself, Shirley that is a lie.

Nope, not a lie. 3 dB gain is very close to doubling the reference figure. 10 dB gain is very close to a 10 fold gain in power. So 13 dB, you do the 10 dB first, which is a 10 fold increase, then you do the 3 dB which doubles the previous result for a 20 fold increase in power. Or you can do it the other way, the 3 dB first and the 10 dB second, same result.

Decibels are not linear, and should not be treated as such. They are actually logarithmic in nature, which is another way of saying an exponential scale. Where you add the dB's directly, you multiply the underlying values. Its a way of representing sometimes very large ratios with much smaller numbers. It is a system that definitely has its quirks, but if you take the time to learn those quirks, it is a very intuitive system.


The DB

 

[AudioShockwav]

I wonder what would happen if I modeled this, it looks similar to a 4nec2 model with information added...

View attachment 60041
Well, it appeared to have been a 4nec2 model but its not. Under closer inspection it appears to have been drawn in some photo editing program.

Anyway, I matched the colors up for ease of reference. The pic shows the 1/4 wavelength antenna at 5.2 dBi, while my models shows it at 5.15 dBi, not bad, so far pretty close. Their half wavelength is shown to be 6 dBi gain, while mine is 6.72 dBi? What are they short changing the half wavelength antenna? And the 5/8 wavelength model isn't much better, their is 6.6 dBi gain while mine is 8.01 dBi gain, again not even close.

Now I have to ask, did they just get lucky with the 1/4 wavelength gain?

So which of these is correct? The correct answer is neither. The problem with this model, and the diagram above, is they both assume a perfect ground, and if your not a boat floating on the ocean, you don't have anything even like perfect ground under your antenna. These are optimal readings that only exist in an optimal if not "perfect" scenario, lab conditions if you will, and most people will never see in their life. As these numbers simply do not translate to the real world, thus they are not relevant.

So lets see about making these numbers more relevant. Here I am taking the same antennas and putting them over average ground. Essentially changing one (ok, technically two) variable. The only difference from my model above and and my model below is the quality of the earth.

View attachment 60042
Wow, what a difference. The half wavelength here completely destroys everything else, and is in this case the only antenna with a positive gain. I wouldn't call this a simulation of reality, but it is one step closer than the models I made above. One simple change to make the results closer to reality and boom, drastic changes in some of the results. The hard question comes now, if I were to take this further, which reality should I try and simulate? My house? Your house? The antenna setup I see down the street? From experience I can tell you that in some cases, the 5/8 will outperform the 1/2, and in others the 1/2 will outperform the 5/8. It all depends on the variables, many of which most people who work with antennas don't even realize exists. Just one, for example, poor ground, good ground, are you near a lake? an ocean? And that isn't even considering other more well known things like height, which has the effect of bringing the outputs of the various antennas closer and closer together.

I can go on here, but I think I have demonstrated that a set of models, if they are even proper models, that exist with one specific set of variables, or even just made up on the spot as the image above appears to be, cannot be used as a general fact that applies to every antenna installation everywhere.

In essence, when it comes to antennas, the simpler something is to understand, the less likely it is to be true.



I don't think we actually disagree over the general idea you are trying to put forth but...

So this is the actual advertised gain claims for the Imax? Wow, who the hell needs a 7 or 8 element yagi with the Imax around...

I know you are trying, but... A real world Imax isn't going to get anything like those gain figures. Could it be made to happen in a lab environment? Possibly, but even if it can, is that even relevant?

I know what you are saying here, and I never once disagreed with the idea that you are presenting, but these numbers...



Nope, not a lie. 3 dB gain is very close to doubling the reference figure. 10 dB gain is very close to a 10 fold gain in power. So 13 dB, you do the 10 dB first, which is a 10 fold increase, then you do the 3 dB which doubles the previous result for a 20 fold increase in power. Or you can do it the other way, the 3 dB first and the 10 dB second, same result.

Decibels are not linear, and should not be treated as such. They are actually logarithmic in nature, which is another way of saying an exponential scale. Where you add the dB's directly, you multiply the underlying values. Its a way of representing sometimes very large ratios with much smaller numbers. It is a system that definitely has its quirks, but if you take the time to learn those quirks, it is a very intuitive system.


The DB

Thanks for the effort DB.

73
Jeff

 

[338_MtRushmore]

While I don't doubt that he knows something, he has a history of presenting false statements as fact on other forums.

I hope that being questioned about his statements doesn't detour him from sticking around and learning more.

 

[AudioShockwav]

While I don't doubt that he knows something, he has a history of presenting false statements as fact on other forums.

I hope that being questioned about his statements doesn't detour him from sticking around and learning more.

There is a lot of bad info floating around CB groups nowadays, I appreciate guys like DB that make efforts to point out correct answers.
Never to old to learn.

73
Jeff

 

[The DB]

Thanks for the effort DB.

73
Jeff

There is a lot of bad info floating around CB groups nowadays, I appreciate guys like DB that make efforts to point out correct answers.
Never to old to learn.

73
Jeff

Thank you.

While I don't doubt that he knows something, he has a history of presenting false statements as fact on other forums.

I hope that being questioned about his statements doesn't detour him from sticking around and learning more.

Yes, he is trying to help others, or at least that is how it appears to me, which is mostly why I am spending so much time trying to explain things to him. I don't think he understands how wrong some of the things he is putting out actually are, and I don't blame him. As sad as it is, if you do general searches, that is the stuff that you find. Get some knowledge behind him and he can be the asset to the community as a whole that he seems to want to be.

Ultimately, he has the potential, but weather he wants to reach that potential or not is entirely up to him. I can only give him the opportunity.


The DB

 

[AudioShockwav]

Thank you.



Yes, he is trying to help others, or at least that is how it appears to me, which is mostly why I am spending so much time trying to explain things to him. I don't think he understands how wrong some of the things he is putting out actually are, and I don't blame him. As sad as it is, if you do general searches, that is the stuff that you find. Get some knowledge behind him and he can be the asset to the community as a whole that he seems to want to be.

Ultimately, he has the potential, but weather he wants to reach that potential or not is entirely up to him. I can only give him the opportunity.


The DB

A example of a old dog learning....
When the Gainmaster first came out I quickly dismissed it as another end feed 1/2 wave, and even started to argue about it.
People here convinced me I was wrong, and they are absolutely correct.
There is always something to learn.
Antennas can be some of the most hotly debated subjects when it comes to radio because of myths that abound.

73
Jeff

 

[Alabama Buckeye]

I wonder what would happen if I modeled this, it looks similar to a 4nec2 model with information added...

View attachment 60041
Well, it appeared to have been a 4nec2 model but its not. Under closer inspection it appears to have been drawn in some photo editing program.

Anyway, I matched the colors up for ease of reference. The pic shows the 1/4 wavelength antenna at 5.2 dBi, while my models shows it at 5.15 dBi, not bad, so far pretty close. Their half wavelength is shown to be 6 dBi gain, while mine is 6.72 dBi? What are they short changing the half wavelength antenna? And the 5/8 wavelength model isn't much better, their is 6.6 dBi gain while mine is 8.01 dBi gain, again not even close.

Now I have to ask, did they just get lucky with the 1/4 wavelength gain?

So which of these is correct? The correct answer is neither. The problem with this model, and the diagram above, is they both assume a perfect ground, and if your not a boat floating on the ocean, you don't have anything even like perfect ground under your antenna. These are optimal readings that only exist in an optimal if not "perfect" scenario, lab conditions if you will, and most people will never see in their life. As these numbers simply do not translate to the real world, thus they are not relevant.

So lets see about making these numbers more relevant. Here I am taking the same antennas and putting them over average ground. Essentially changing one (ok, technically two) variable. The only difference from my model above and and my model below is the quality of the earth.

View attachment 60042
Wow, what a difference. The half wavelength here completely destroys everything else, and is in this case the only antenna with a positive gain. I wouldn't call this a simulation of reality, but it is one step closer than the models I made above. One simple change to make the results closer to reality and boom, drastic changes in some of the results. The hard question comes now, if I were to take this further, which reality should I try and simulate? My house? Your house? The antenna setup I see down the street? From experience I can tell you that in some cases, the 5/8 will outperform the 1/2, and in others the 1/2 will outperform the 5/8. It all depends on the variables, many of which most people who work with antennas don't even realize exists. Just one, for example, poor ground, good ground, are you near a lake? an ocean? And that isn't even considering other more well known things like height, which has the effect of bringing the outputs of the various antennas closer and closer together.

I can go on here, but I think I have demonstrated that a set of models, if they are even proper models, that exist with one specific set of variables, or even just made up on the spot as the image above appears to be, cannot be used as a general fact that applies to every antenna installation everywhere.

In essence, when it comes to antennas, the simpler something is to understand, the less likely it is to be true.



I don't think we actually disagree over the general idea you are trying to put forth but...

So this is the actual advertised gain claims for the Imax? Wow, who the hell needs a 7 or 8 element yagi with the Imax around...

I know you are trying, but... A real world Imax isn't going to get anything like those gain figures. Could it be made to happen in a lab environment? Possibly, but even if it can, is that even relevant?

I know what you are saying here, and I never once disagreed with the idea that you are presenting, but these numbers...



Nope, not a lie. 3 dB gain is very close to doubling the reference figure. 10 dB gain is very close to a 10 fold gain in power. So 13 dB, you do the 10 dB first, which is a 10 fold increase, then you do the 3 dB which doubles the previous result for a 20 fold increase in power. Or you can do it the other way, the 3 dB first and the 10 dB second, same result.

Decibels are not linear, and should not be treated as such. They are actually logarithmic in nature, which is another way of saying an exponential scale. Where you add the dB's directly, you multiply the underlying values. Its a way of representing sometimes very large ratios with much smaller numbers. It is a system that definitely has its quirks, but if you take the time to learn those quirks, it is a very intuitive system.


The DB

Well that horse is dead and my back is all cut to hell. Shirley and I knew it wasn't a lie. Just another target.

As to Advertising, it's surely a policy in the field of shysters, repeat a lie often enough, without challenge at the first utterance, it is deemed truth. The Supreme Court so much as declared it so.

Spotlight Newspaper v William F Buckley/ and that rag Pres. Reagan deemed worthy of daily reading. Why do we need the Senate. The Supreme are the law makers, these daze, based of outhouse courts setting unchallenged precedence. Like Corporations gaining personhood; through contorted and unchallenged precedence set through reinterpretation of the 14th Amendment.

No doubt the 11.9Dbi is a wild exaggeration as is 9.9 for the A-99. Really a monopole with such gain while an Italian made Sirio 5/8 wave monopole (Blizzard) is but 3.6Dbi. Perhaps Italians value truth in advertising.

 

[The DB]

As to Advertising, it's surely a policy in the field of shysters, repeat a lie often enough, without challenge at the first utterance, it is deemed truth. The Supreme Court so much as declared it so.

Yep, thats the world we live in, unfortunately. You could also say that a lie spreads half way around the world before the truth straps on its boots. The problem with this is, people also tend to believe whatever they hear first and disregard the rest.

Really a monopole with such gain while an Italian made Sirio 5/8 wave monopole (Blizzard) is but 3.6Dbi. Perhaps Italians value truth in advertising.

I don't think its necessarily an Italian thing, but Sirio does tend to offer more realistic gain figures than most others out there. They are a good company, I have worked with several of their products and have no complaints.


The DB

 

[338_MtRushmore]

I don't think its necessarily an Italian thing, but Sirio does tend to offer more realistic gain figures than most others out there. They are a good company, I have worked with several of their products and have no complaints.


The DB

Since it was brought up, what do you think Sirio's best vertical is?

 

[Marconi]

338, I had a lot of very good performance from my Gain Master, but I also had an M400 and a Top One both of which performed a little better at times...when I set them close to a similar tip height.

They all had very low noise levels compared to some other verticals I've used.

Sirio gets a with me.

Watch the signals on the video below and check out the noise level for the Top One compared to the Gain Master. At about 4:00+ minutes check Tim's signals, he is about 60 miles due North of me in Plantersville, Texas.

 

[Crawdad]

Even a minimal understanding, which is all I could claim, will tell you that most of the advertised gain figures are a bit too good to believe. Especially the ones that don't bother telling us dBi or dBd.
When the advertised gain of a omni-directional vertical approaches those of directional antennas, flashing lights and bells should be be going off.

 

[Alabama Buckeye]

Thanks for the effort DB.

73
Jeff

Yes, Thank you DB for your efforts.
I derived the inflated Imax 2000 Gain from the only published data I was aware of. Namely, +2 dB over the A99 which was itself, I now realize, highly inflated.
The Imax 2000 Gain should be more correctly, I defer "accurately" to the more informed, the gain is 5.3dBd.

please Pardon the long deserved thank you.

 

[The DB]

Since it was brought up, what do you think Sirio's best vertical is?

I must have missed this back in time. I'm going to answer this with a little different twist, I am going to mention the antennas I think are the most interesting instead of best performing. That being said, two of them are the best performing in specific circumstances, so I guess that is something.

First the Vector 4k/Sigma 4. What can I say, a big chunk of my figuring things out was when there was a great debate over these antennas, how they work, ect. If you look back literally thousands of pages have been posted on this antenna on this forum alone. When it comes to performance, if you can get this antenna some height, and you take the time to dial it in, in my opinion it is the best performing antenna for local contacts out here, period, end of story. The reason comes down to this antenna's ability to steer its output by changing its dimensions. Its one of only two single antennas I am aware of that can do this. Unfortunately, very few people will ever have the knowledge/time to dial said antenna in. Of all the people across all the forums I have read posts to, I can count the people who have done such experiments on one hand, and have fingers left over, but the potential in the antenna design is there.

As a side note, perhaps an honorable mention that is based on the Vector antenna, there is one model I made when I was trying to force the modeling software into what I'm going to call the Shockwave/bob85 view at the time. Its the most interesting model I have ever seen, and there are things happening with that model I have yet to explain, and have never seen in any other antenna model I have ever made.

The next antenna on my list is the Astroplane. When it comes to performance at low heights, if you can mount this antenna at the same tip height as any other antenna, this antenna will perform as well if not better than said other antenna. What draws me to it, however, is not its performance but the fact that the models are interesting. Notice a pattern here? Of the models I have made of this antenna, more interesting things happen than any other actual antenna out there. What I call the "blue wire" which is a wire on the model that should have significant currents flowing on it yet almost none appear to be present, and how this wire affects the rest of the antenna. Another example is 1/4 wavelength current distribution on the 1/2 wavelength mast that sticks out below the antenna. I can go on here, and I don't think all of the quirks with this antenna have yet been explained, or even discovered.

The third antenna is the Gainmaster, although this antenna isn't as interesting to me as it used to be. The reason is I have not only modeled this antenna successfully, but I am able to explain any and all aspects of it, including why it has the bandwidth it has, any why it is different from other wide bandwidth antennas, such as the a99/imax. If you get this antenna high enough off the ground, I think it will work at lest as well as any other other antenna out there in the all around category.

As you can see, I don't like antennas because of how well they perform, but the antennas I do like tend to perform well in certain circumstances, so I guess there is that. And its not something that is limited to Sirio, Sirio (and by extension Avanti that they purchased) simply has the most interesting antennas when it comes down to how they actually work, and that is including every other manufacturer and their antennas that I am aware of out there. This is where the creativity is, and if there is an advancement, this is where I think it will come from.

As an honorable mention, I'm going to throw an unexpected pair of non-Sirio antennas in here. The A99 and Imax 2000 antennas. There are various aspects of both of these antennas that I have not seen anywhere else, especially with the Imax and its capacitor that is up on the element. This also includes their ground plane kit, and how it works with said antennas and more. There are things with these antennas that if I hadn't gotten into modeling and modeled my self I would have never considered as important parts of their design. Even if you want to call them crap antennas, there are brilliant points in the designs of these antennas, things that it would take a well rounded if not downright brilliant engineer to come up with.


The DB