sigma4 article is online

[Robb]

R&D DEPT

Our equipments:

• Shielded anechoic chamber for 1- 50 GHz measurement.
• 3D Electromagnetic computer simulation CST Microwave Studio. It is a special 3D simulation software for product developement.
• Network analyzer: Agilent ENA E5071B, Agilent ENA E5062A, Rohde & Schwarz ZVL-6.
• Climatic chamber Votsch VC4018 for test on materials. Range: from -40°C to + 80°C & 0% to 100% Humidity.

http://www.sirioantenne.it/company_all.php

Seems that Sirio has enough software and analysis equipment to backup their claims.
They aren't into this game for the short run - IMO . . .

 

[Marconi]

Thanks DB, I agree, and IMO you said it very well and I do understand what you are telling us. My interest was for confirmation of what I think I see too, and you did that.

I asked another question though. With this information does this difference account for why and how Homer reports his long distance difference he reports...or is it even close?

Thanks

@Homer and others,
The reason I have more to add here is my attempt to possibly help Homer answer his own questions about his long distance contacts. The only exception for me is I have no story to tell about comparing antennas in my experiences on this issue. You guys know me, and in the past I hardly ever had the same antenna up and working very long...so I could have been working just about anything back in those days. There are old post here on WWDX that might shed light on what I was doing at some point in time, and even conversations with Lee talking about our experiences on the radio. So this might be checked out to confirm.

I've had similar long distance contacts before, and at different times some were repeated over and over again. Back in 2006, I was posting in a thread here on WWDX, and a new member came on, Mr_DX, WDX-861.

His name is Lee Whiting, and he lives in Boerne, Tex, some miles NE of San Antonio, Tex. At some point we talked on this forum about trying to make contact. I was encouraged we could connect, because I've talk to guys in the San Antonio area often of a morning for years, and mostly when I was working a Starduster. To be clear, this was not unique for me only, buddies all around me were talking down there early in the morning for years. I was trilled to make such contacts, but to me it was neither remarkable nor the contact of all contacts I've made in my 47 years + on the air.

On the map Boerne is 222 miles from me. This is just one of numerous such contacts that I've made repeatedly over many years, but I never felt this happened due to any one antenna I could have had up over time. Lee has talked into this area for years and some of his buddies in that area do it too, of a morning when conditions are good and DX is not prevailing. I have even made contacts with Lee where I and others locals were verifying a new antenna install that Lee put up and was testing. I can also claim to have had regular contacts (repeat) with 10> local area guys over 100 miles from me for years.

I can say they were regulars in sort of a way, but I can also sense a difference...that I cannot explain. IMO however, this had nothing to do with any particular antenna I can lay claim too or you would have heard me talk about such. I consider these as success in communications, but I have to also consider them as anomalies of sorts.

Lee if your out there, come tell us your story.

Homer you use to live in this area, if you worked SSB on 38-39, did you ever hear any of the local guys talking out there including me...early of a morning or latter near evening?

 

[HomerBB]

The reason why the surface wave etc its not applied as a" general rule"
is various;

1- different groundconductivity will have influence -

http://upload.wikimedia.org/wikiped..._States_Effective_Ground_Conductivity_Map.png ground conductivity at my house = 8

2- different polarisation will have influence

vertical

3- the "type" of modeling will have influence

Whatever you are using

4- things like the "transmitter" height above ground....will have influence etc.

my radio is 2.5' above the earth, the tip of my V4k was 61'

5- are all "other waves" included as well ?

I don't know if Standing waves or reflected ground waves, etc, were used in the models

6-what distance ?

100 km and out from there

7-what freq

27. 350 - 27. 555

 

[Marconi]

R&D DEPT

Our equipments:

• Shielded anechoic chamber for 1- 50 GHz measurement.
• 3D Electromagnetic computer simulation CST Microwave Studio. It is a special 3D simulation software for product developement.
• Network analyzer: Agilent ENA E5071B, Agilent ENA E5062A, Rohde & Schwarz ZVL-6.
• Climatic chamber Votsch VC4018 for test on materials. Range: from -40°C to + 80°C & 0% to 100% Humidity.

http://www.sirioantenne.it/company_all.php

Seems that Sirio has enough software and analysis equipment to backup their claims.
They aren't into this game for the short run - IMO . . .

I also remember seeing the Sirio antenna testing range in some of their links, and it was on top of their building, and they might have been reporting gain over a distance pretty small compared to 18 miles or more that Henry did.

The thing that I might question is I realize that most performance results are probably done in Free Space, and then I question the results that Sirio post for their New Vector 4000 at 4.15 dbi. and the best my Eznec Fee Space model will predict is 2.49 @ 3* degrees for my New Vector 4000 model just doesn't jive with me. Some would say, "...I smell a rat."

So, I just don't understand the difference, but Henry did report this value as a range of 2.20 -2.50 dbi without noting the maximum angle. The gain put me close to Henry's model, but I'm not even close to Sirio's report of 4.15dbi for there NV4K nor do they publish a gain in their gain report.

So, are we just seeing some puffing here or is the maximum angle of radiation in a Free Space model...just not that important?

 

[Robb]

I also remember seeing the Sirio antenna testing range in some of their links, and it was on top of their building, and they might have been reporting gain over a distance pretty small compared to 18 miles or more that Henry did.

The thing that I might question is I realize that most performance results are probably done in Free Space, and then I question the results that Sirio post for their New Vector 4000 at 4.15 dbi. and the best my Eznec Fee Space model will predict is 2.49 @ 3* degrees.

Somehow I just don't understand the difference, but Henry did report this value as a range of 2.20 -2.50 dbi and that put me close to Henry's model, but I'm not even close to Sirio's report of 4.15dbi for there NV4K. Are we just seeing some puffing here?

No; just some real high-end test gear with RF engineers posting their results is all. Since there is so much conjecture going on, just thought it was refreshing to realize that this company is not a small time operation. They build all manner of antennas and use a no-nonsense approach to compete and hold a very large market share. I am confident with their test results.

I do see a lot of huffing and puffing in some of the previous dialog - tho . . . /

 

[The DB]

@ dB...

I all ready provided such a plot in the article ....showing indeed that 2 dB distant"gain" difference..Using enzec pro/4 (see article)
Where all others were "optimal"
We had in the beginning in this thread some talk about it ?

I must have missed it, and I'm not seeing it now when I scan through. I'm seeing all kinds of stuff, just not anything that resembles a chart like that in any form.

I provided to you:
The indication of the surface wave on 4nec2 with "pre-caution".
With the "pre-caution" as i wasnt sure if it was "wise" to do so, as i was worried about possible errors within 4nec2.
If I may ask...have you done some verifications ?
Did you came across some "issues" ?were they inline with the results I provided ?

I have not verified it, what must be done to verify such a feature? I can give you the models used in the chart above if that would help.

In aspect tot hte negative lob...
Yes you can measure a negative elevation lob.
With that said, he (donald) did his testing at relative low height.

The reason why the surface wave etc its not applied as a" general rule"
is various;

1- different groundconductivity will have influence
2- different polarisation will have influence
3- the "type" of modeling will have influence
4- things like the "transmitter" height above ground....will have influence etc.
5- are all "other waves" included as well ?
6-what distance ?
7-what freq
etc etc etc..

So in order to make it a "general" thing we all....need to "agree" on several aspects.
That wont happen hihi.

I would expect various things to be of more importance for a surface wave than the standard far field gain, such as the ground quality that you mentioned. After all, the signal in the immediate vicinity of the earth as you move out is the signal that should be affected by it the most is it not? That being said, much of what is being referred to are the same things that one already has to be wary about with the standard models we see.

Speaking of earth quality, this would be a potential issue when attempting to directly match someone's results. I bet I could count on one hand the number of people who have actual experience measuring ground quality on this forum, and have fingers left over. I could also likely count on one hand the number of people on this forum that could build an add on for their VNA, and based on the results from that determine the quality of the earth in the immediate area measured (I put myself in this group as I have done research on doing exactly this in the past, although I've not actually done it I have the information needed should I decide I need or want to...).

Further, I don't think there is necessarily a need for a general set of rules that we all need to "agree" on, although we should be able to explain what we did, how we did it, and why we did what we did. I already see those as critical elements when I make a model that I intend to release publicly, as I feel others here do as well (perhaps I have to much faith in my fellow modelers?).

Though similair "data" is often used for MW broadcasting stations
Often inserted in geographical maps.(sure a couple will be online somewhere)

This is something I want to do at some point, if only just to see the differing effects a single antenna can have at various places in the world...

Good to see you get the hang of it...important to realise

Kind regards,

H>

I guess the next step is verification. I don't want to waste my time with incorrect data... That being said, on some level, wouldn't the EZNEC PRO feature been based on the NEC2 code?[/QUOTE]


The DB

 

[The DB]

I asked another question though. With this information does this difference account for why and how Homer reports his long distance difference he reports...or is it even close?

Thanks

I'm admittedly still learning about this feature and playing with various aspects of the surface waves to try and learn how they function. I would prefer to hold off on answering this type of question until I have more experience working with them and seeing what they do and what changes affect them and how and why...

There is also that Henry is not sure of the accuracy of the results from 4NEC2, so I'll add that to this list of why I prefer to wait first.

That being said, I can already tell you these types of waves do act differently than the far field waves we like to look at. I have seen a situation where an antenna had a higher max far field gain than another, but the other had a stronger surface wave at a given distance form the antennas. Unfortunately I didn't save the models in question as they were intended to be modified quickly and often while checking the varying results the modifications create.


The DB

 

[Henry HPSD]

@Robb
Seems that Sirio has enough software and analysis equipment to backup their claims.
They aren't into this game for the short run

Indeed, they are not, they have been doing it for a long time allready.
And If you would ask me personal...I actually like them.

But as with a lot of manufacturers their advertised claims could be point of discussion.
And although we have seen a large improvment of those claims over the last couple of years. They still have "issues" as the 3el SY-3 will never provide 10,65 dBI the 4el wont do 13 etc dBI
The difference between the GPS1/2 wave and GPE 5/8 wave is a couple of radials where the total height remains more or less equal....but still one is a 1/2 wave and the other a 5/8 wave ?
I dont get it. etc.

But as mentioned: they have shown a road to be more "trustworthy"...so I hope they will continu doing so....I hope they will provide a "honest" anwer when is possible.

And i actually can imagine "claims" from manufacturers, as you want to compete with "others"...but where is the stop ?
Im hoping: we are at a turning point where it was normal 20 years ago to tell "idiot" things in aspect to gain figures...
Im hoping in 20 years time from now we can all say : hm...do you remember ? when there once was a time... where there were hose who "got away" with high gain figures hihi...(im hoping)


Kind regards,

H>

 

[Henry HPSD]

@ Homer,

Yes, for me and dB it is not difficult to understand.
The questions I gave ...was not a question I had.
They were an answer to why it is not used as "primairy" antenna figure ....like "freesapce gain....a kind of:"general" rule....

As for each situation all will be different, which isnt the case with "freespace".

Kind regards,

H.

 

[HomerBB]

@ Homer,

Yes, for me and dB it is not difficult to understand.
The questions I gave ...was not a question I had.
They were an answer to why it is not used as "primairy" antenna figure ....like "freesapce gain....a kind of:"general" rule....

As for each situation all will be different, which isnt the case with "freespace".

Kind regards,

H.

I understand. I was giving as much of the information about my location as I could just in case someone wanted to use it.

 

[Henry HPSD]

@DB

The graph at 30 Km is done with Pro/4.
Perhaps that is confusing ?

The "real" gain measurments were done at 30 wave lengths.
(2 meters = 60 meter distance)

Ill try to answer the rest of u tonigth...all ready 07.37 running late....

Kind regards,

H>

 

[Henry HPSD]

Oke,

Dont think im around the weekend...
...seem im in Germany
Be back on Monday or so..

@ DB:
Well, I really do not know if 4nec2 is oke with providing the "total thing"
That is why I asked you to find out before putting things on line.
I can imagine it pretty much to be so, but Im not confident.
And one needs to be in order to provide information.

So, in the mean time i set out the question to several different people.
To see if 4nec2 is "oke" with it, or that you will need to apply pre-cautions etc.
As I mentioned previously i noticed "differences"...but didnt investigate so far.
Did you include things like a "mast" ?

Anyway :

This is what it Eznec Pro4 says:
And I see the confusion, i could have been more clear ...tnx for tip. always difficult when you write yourself. Think I will write that along with it and "update" the version.

Bare in mind....this is with ideal antennas. where the bottom of the antenna was kept equal.
In my mind i can imagine other antennas to perform worse, there for enhancing the signal of the vector.




And yes, there are several aspects that will have influence.
Ehm ..we must include a mast for example.
Evan though it is not "dc" connected to the antenna etc.

Kind regards,

H>

 

[HomerBB]

Interesting, but it does not represent either my antenna or my set up.
I used a modified Nv4k and the current maximums were at equal height. Also, this is not reporting the findings at 100 km.
There is ground conductivity, too. On the scale of 2 to 30 for the USA, 30 being the best, it is an 8 where I live. That isn't quite medium soil.

http://conductivity.parksdigital.com

We speak of variables, so they have to be accurate for the setup in question. For me, the variable are too generalized to represent my setup.

And, this chart Henry put up appears to be about gain, unlike DB's.

 

[Henry HPSD]

But Homer,

With all due respect...
Why would you think "we" are trying to duplicate your situation?

Im afraid we or atleast I cant do that...we can only provide an "average" situation.
It would be quite some work to really duplicate yours.
There are too many variables....for your situation alone it would be an almost impossible task to duplicate them.

That can never be done, well never....but ehm...You know i like to be accurate.
That can not be done like this ....

Though there are some "indications"...
You just told me the relative dielectric constant (i think you talk about)
seems to be around 8.
Which is rather "poor" ground, a good reason why you could have seen enhanced performance of the vector.

But not only the ground "at" your location will have influence.
So will the ground between your "receiving" location.
What do we have in between ? houses ? wetland ? forrest ? see ?
All maters....
How were your antennas positioned ? Could they interacting with each other ?
Or were they both in the far field ? Did you measure the Choke imp ?
Were the antennas both made from the same material ? If so ? what type ?
were they both "polished" ? Was the antenna isolated from the mast ? and if so... was the mast made from metal (besides it was isolated) ?
Were there any other objects within the first 10 wavelengths etc etc etc. Homer,"doubling" your situation isnt something easily done.

PS1 : there also is another graph with tip height equal.....
PS2: I also explained allready why or why not the difference of 100 Km versus 30 Km is of use.

And what would be the difference between the "unit dB" figure and the uV/m if I may ask ?

The best you can do is "play"with the link i provided in:
(see post : 114 ) (dont know how to insert link to post hihi)

Where i also said.,.... Quote:

The PRO version of Eznec CAN include all the diferent waves (except the reflected one obvious)....hence the diagrams i have provided which are so valuable.
End of Quote !


Hope it is of use !

H>

 

[HomerBB]

Henry, I know you're not trying to duplicate ANYONE'S situation. It does not serve your purposes. Therefore . . .

here we are again.

The article gives me no usable insight into why my antenna, and Bob's, and Donald's, and perhaps other antennas out there have experienced the consistent unexpected performance advantages they have.

I happen to agree with DB, in order to examine all the possibilities one must duplicate the situation about which we are inquiring.

I find it a curious thing that you can not see the problem with using generalizations about this antenna. As you say all that can be done is to find a general, or mean, set of variables for this discussion, I see that as itself a limited amount of data that proves to support your theory, but excludes any other possible answers. Meaning your conclusions are based on a limited set of data, which is, IMO, a limited criteria useful only for the article as it is.

You are looking at antennas in general.

From the beginning, although some have strayed, this discussion across a few years has centered on the remarkable experiences of a few, and why. Although it has inflamed the thread to say so, which is not what I'm trying to do, I believe Bob has strayed from that original driving catalyst for the discussions. Donald wearied with trying to stay on this point because the discussion has side tracked on other tangents and left the discussion, and you, Henry, did not write the article in such a way as to try to discover why some of the primary participants experienced what they did.
As you've said, the article is written to determine the relationship between the cone and the center radial, and if that relationship provides more gain to a certain measurable degree.

Without attempting to provide models with the variables we have in our locations your models do not show what we may be experiencing.

Ironically, if the variables are needed for accuracy for a certain location, as you say, then they are necessary for any accurate model. I stand with my unshakable conclusion that your models do not reflect my, and others, experiences. The playing field is leveled, and in fact, represents no ones actual experiences in the real world.

Perhaps another reading of what DB posted relative to the way we are examining this issue needs to be done as you are still focused on a different discussion than that I've been trying to have. I don't know if what DB wrote will help, but it is certainly not an exhausted topic, yet.

This may never be resolved for me. Perhaps in a few years when I am retired I will learn modeling should I be still interested. Right now, from what the experienced modelers are saying, modeling has a very limited, incomplete, utility.