New antenna from Sirio Gain-Master

[Shockwave]

Homber,

yeah, lol.. if noticed that too..but am afraid the others or inaccurate.

I didnt say by the way that it isnt true..it is misleading... for the reason mentioned.
The "freespace" pattern of a end fed 5/8 wave has a disadvantege at 0 degree angle. They are taking advantege of that.
Thats not fair. You cant say :a Landrover drives faster than a ferrari simply cause you test it in a swamp. Nobody drives a car in a swamp... (at least not here..you get the point).


There is other misleading information from sirio, information wich certainly is not true.
Take for instance the 4el yagi:

SY 27-4: 11 dBd, 13.15 dBi

That wont happen...on a approx 12 feet boom.
Around 8dBI or 9dBi would be more accurate so thats atleast 4 dBI of lies.
So yes, they do mislead...

However, i also have to mention there are quite some antennas from sirio who have a honest gain figure.


Take care!

Henry

Henry, you always bring out the most interesting points. For a while I had a hard time understanding why all of the big broadcast antenna manufacturers from ERI to Shively have been providing Cartesian free space plots for all of their antennas. This free space plot is what the FCC accepts to calculate the ERP and RF exposure levels even though it never lines up with a real world installation.

The only reason this seems logical to me is that there is no simpler way to produce ratings or fairly compare two antennas without knowing the specific mounting height in each application. By using free space it removes all of the ground reflections and only considers the performance of the antenna and not the location it's mounted in. I don't think it's the most accurate result but it is a compromise that is commonly accepted in the commercial market.

With respect to the four element beam, I can't defend that 11 dbd claim either, regardless of how much I like the companies products. You know that is determined mostly by boom length sometimes more so then number of elements. They have updated most of their gain figures to be highly accurate compared other manufacturers but that one is out in left field. Perhaps this model got overlooked but that's just my opinion.

 

[Henry HPSD]

Hi Shockwave,

Actually, i had such a line written down in the earlier post..about that they migth have forgotten to change the dB figure of the 4el..
But i changed my mind and deleted it...funny though.

Honestly...i tend to value the gain figures given.
Im also quite sure they will change that figure in the future.
Perhaps, when (if at all) you mail with them you can notify them as it looks like they have learned from the past.
If i could just mention a company in wich im dissapointed giving wrong gain figures it would be those of array solutions.
As one would expect a straigth answer of them instead of adding "ground gain".
Im expecting wrong figures from jogunn maco wolf etc so that doesnt worry me lol.


Yes, you are rigth about the freespace gain figure beeing a "standard".

But where it goes wrong:
That freespace gain figure is given at a maximum peak gain. NOT at 0 degrees.
But what sirio does is they take the maximum peak gain of the gain master at 0 degrees, and compare that to a 5/8 wave at a a 0 degree angle. But the 5/8 wave isnt at its peak...thats where it goes wrong.
I do not want to know what the gain is at 0 degrees in a freespace model..
We need to know what maximum gain is in a freespace model..no mather at what angle..
Then elements like "ground" will take care of that angle.

Kind regards,

Henry
11 meter Dx antenna systemx

 

[Marconi]

Henry, it's just a language difference. I don't think we disagree on that much, but you must feel different. I just get tired of hearing these guys bitterly complain that everything other guys do on this forum is always wrong, without any consideration and never asking real questions in a effort to better understand a different point of view. It's not even argument, its just petty bitching.

What I say about Eznec is my personal disclaimer, hoping to avoid all the claims from some that I might question their understanding of Eznec.

I also might be wrong about the "average gain" function use of a - vs +. I think I got that info from you, but again it must be a language problem or else I'm just wrong. If there were questions concerning modeling that might be answered then that is one thing, but what I mostly get is just some categorical comment suggesting that I'm always wrong. Like your comment that I suggest there is a difference in the AG when the result is a - as apposed to a +. Are you suggesting this distinction has no meaning or significance?

I think it best that I continue to discuss other things as I please, but not modeling. It is just not fruitful.

I didn't call Simon a bad name or curse him. He did however publish that I stole from him, and IMO that is a petty comment and is not true. I don't even think it falls under the purview of the Forum Rules he suggested. Under the circumstance this is only thing I meant to imply and I didn't think he would comment further, because of his showing discontent with me previously. If you can read his mind, then please confirm the claim he made. I don't expect him to answer or you either for that mater.

 

[Shockwave]

But where it goes wrong:
That freespace gain figure is given at a maximum peak gain. NOT at 0 degrees.
But what sirio does is they take the maximum peak gain of the gain master at 0 degrees, and compare that to a 5/8 wave at a a 0 degree angle. But the 5/8 wave isnt at its peak...thats where it goes wrong.
I do not want to know what the gain is at 0 degrees in a freespace model..
We need to know what maximum gain is in a freespace model..no mather at what angle..
Then elements like "ground" will take care of that angle.

Kind regards,

Henry
11 meter Dx antenna systemx

I'm trying to be as unbiased as possible with my responses and still disagree based on what I've seen on the Sirio site for the Gain-Master and my actual results with the antenna. I see your point that the free space CST plot for the GM is showing the antenna at 0 degree TOA. They also give the same plot information for the typical 5/8 wave ground plane in free space simply to show the current distribution between the two. They did not take the free space 0 degree gain of the GM and compare that to what the 5/8 wave ground plane would have over real earth at 0 degrees.

Knowing that the majority of the competition the GM would be facing was the 5/8 wave ground plane, their advertising point is focused on the 1 to 2 db increase in gain on the horizon over that antenna. This comparison is over real earth and is within the range the typical user will see if replacing the ground plane with the GM at the same height. It lines up with the results I saw by equaling a stock Vector that beat my 5/8 wave ground plane.

 

[Henry HPSD]

I'm trying to be as unbiased as possible with my responses and still disagree based on what I've seen on the Sirio site for the Gain-Master and my actual results with the antenna. I see your point that the free space CST plot for the GM is showing the antenna at 0 degree TOA. They also give the same plot information for the typical 5/8 wave ground plane in free space simply to show the current distribution between the two. They did not take the free space 0 degree gain of the GM and compare that to what the 5/8 wave ground plane would have over real earth at 0 degrees.

Knowing that the majority of the competition the GM would be facing was the 5/8 wave ground plane, their advertising point is focused on the 1 to 2 db increase in gain on the horizon over that antenna. This comparison is over real earth and is within the range the typical user will see if replacing the ground plane with the GM at the same height. It lines up with the results I saw by equaling a stock Vector that beat my 5/8 wave ground plane.

Shockwave,
I highly appriciate your input as it means that either you or me can learn.
And i always keep in mind i could be very wrong.

The pattern i am speaking about is the one "typical radiation pattern" in wich they say maximum radiation of a 5/8 wave at 24 degrees...that one..

Oke,
A freespace plot is "meaningless" in reference to elevation.
Simply cause it is in freespace, there is no "real"angle to wich it is compared with.
A freespace model is significant for the fact it shows the maximum gain number.
wheter it is a what angle ..that is of less intrest.

You have eznec, test a mobile antenna it will have maximum gain at 0 degrees...
though we both know that is not the case in real life.
You can test a 5/8 wave in freespace and you will notice it is not at 0 degrees.
You can test a center fed 1/2 wave dipole and will notice it is at 0 degrees
So in either case you can make the "standard" 5/8 wave "look bad" refering to this.

Oke..so they say in freespace the GM has 1..2 dB gain at a low angle..
But to have a low angle the angle must be reference to something.
Not just because the radiation pattern "fits" in that way on that plot.
Im not saying they compare real life against freespace.

Im saying they compare freespace against freespace..
In that comparisment they have taken the maximum gain of the gm wich is in this case at 0 degree. The 5/8 wave has the max gain at 24 degrees acoording sirio.
But they dont compare 0 to 24 degrees they compare 0 to 0 degrees..so automaticly one of the antennas will be worse.

That yellow part they have highlighted could also be in favour for the 5/8 wave if they did it between 15 and 90 degrees...
But no, they did it between 15 and - 40 degrees...

They focus on 0 degrees and tell us..at that point there is 1..2 dB, well yes that can be.
But that doesnt meanthere truly is 1..2 dB difference in real life at a low angle! It just means there is 1..2 dB differnce at a freespace plot at 0 degree.
Well the 5/8 wave has about 3dB gain over a SGM at say 45 degrees...this is true, reading the plot but meaningless as it is of no use...

A reference to freespace is done towards the maximum amount of gain somewhere in that plot.
The angle is under wich this is is of less importans as there isnt anything in freespace to compare that angle with.

The 5/8 wave is doomed too loose.. infact it will loose from a halve wave vertical just as easy...Try it with your eznec..
(and we both know a dipole is 2,14dI and a 5/8 about 3,5 dBI)

If we would place both antennas in real live and ground influence are accounted for Both antennas will have a low angle TOA ..but neither will that be 24 or 0 degree.
(it can be 24 degrees but that is just lucky lol).
Most of the time somewhere between 5-15 degrees.
Now we do have both antennas in a fair battle...that fair battle is not happening in my opinion when one reference to certain angles in a freespace plot.

The comparisment cant be over real earth as you think.
No antenna will have a 0 degree toa besides, how can you explain the radiation below 0 degree?
That plot cant be true for real earth situations we are living.

Hoping your getting and hoping you are agreeing with what im saying, im off to bed now, already late...ill do a re-read tomorrow and see if i can explain it better.
Perhaps you do understand me and im wrong...well in that case...happy to learn

Enjoy,

Henry
11 meter Dx antenna systemx

 

[Marconi]

I'm trying to be as unbiased as possible with my responses and still disagree based on what I've seen on the Sirio site for the Gain-Master and my actual results with the antenna. I see your point that the free space CST plot for the GM is showing the antenna at 0 degree TOA. They also give the same plot information for the typical 5/8 wave ground plane in free space simply to show the current distribution between the two. They did not take the free space 0 degree gain of the GM and compare that to what the 5/8 wave ground plane would have over real earth at 0 degrees.

Knowing that the majority of the competition the GM would be facing was the 5/8 wave ground plane, their advertising point is focused on the 1 to 2 db increase in gain on the horizon over that antenna. This comparison is over real earth and is within the range the typical user will see if replacing the ground plane with the GM at the same height. It lines up with the results I saw by equaling a stock Vector that beat my 5/8 wave ground plane.

Shockwave I said the other day that something had to be making the difference we have seen repeatedly in the last couple of months. Even if the two antennas show the same gain and angle over real Earth, I see a difference, that might make the difference, in the GM's superior use of the full physical length of the radiator. It is all in phase and the end fed 5/8 wave is not, to say nothing about being well designed and symmetrical, which I think is often overlooked in performance.

 

[HomerBB]

Not to mention some think it's prettier. I remember something about pretty antennas . . .

 

[MrSuburban]

Shockwave I said the other day that something had to be making the difference we have seen repeatedly in the last couple of months. Even if the two antennas show the same gain and angle over real Earth, I see a difference, that might make the difference, in the GM's superior use of the full physical length of the radiator. It is all in phase and the end fed 5/8 wave is not, to say nothing about being well designed and symmetrical, which I think is often overlooked in performance.

Ok after 70 pages what is the physical advantage the Gainmaster has over any other 5/8 wave that gives it magical powers. I dont want to hear TOA, if your gonna say that then what is this antenna doing that others arent to achieve low TOA.

 

[Marconi]

Hello Henry, Normally I would agree it's impossible for the smaller, lighter antenna to rival the performance of a bigger one. You have to remember I've had 4 antennas on the same mount and coax in the last 2 years. First was a metal 5/8 wave with ground radials. Stock and modified Vector 4000. Now the Gain-Master. All of the prior antennas were larger and heavier yet none produced more detectable signal 50 miles away. That's how I judged the gain on the horizon.

SW, I think some new results I might provide soon may put a different light on your categorical claim above...at least in reference to the word "impossible". I can't argue that most will not get better performance from the larger antennas, in many if not most cases, but I have read reports from some important antenna guru's...that indicate other factor not generally considered can and do balance the traditional gain chart to about even.

BTW, and again for the umpteenth time, the gain chart typically used to show the difference between the 1/4, 1/2, and 5/8 wave radiators indicates these gain figures are over a conductive and infinite ground plane, and that is only a theoretical designed condition, like free space, which other's will argue is also not a real world factor of much importance.

Prior to the GM I could never keep my PC speakers turned on in the radio room while I was talking. I can no longer get RF into my PC speakers with the GM. That choke doesn't just isolate the coax from radiating, it does the same thing to the mast and it's a very significant improvement. Granted it's not an infinite impedance at 28 MHz but it removed any trace of RFI in my installation.

THIS ONE NEEDS TO BE SAID EMPHATICALLY. IT IS TRUE!!!! I HAVE NEVER SEEN ANOTHER ANTENNA THAT APPEARS TO ABSOLUTELY HANDLE THE COMMON MODE CURRENTS LIKE THE SIRIO GAIN MASTER.​

I can't prove it, but I do have a video which I never posted, and I think it shows how little current I see at my location when transmitting from my Gain Master. Henry obviously has and opinion, but is missing the vital experience to say different even though I allow him the fact that few things in human nature happen at 100%. SW, you are not the only one to talk about this fine characteristic, one that is often overlooked, and that may be a big part of what helps make this vertical CB antenna so effective IMO.​

With respect to the one tube EL-509 in a KLV200, I can't replicate anything remotely similar to that circumstance with the GM. Being that I had an interest in learning everything about this antenna, I know exactly what it took to burn mine up. The FL-2100B (two 572B's) arced the cap in my first cable testing on 28.390 right around 700 watts PEP. I now keep my ALC set to clamp the output just under 500 watts PEP with no issues in any weather.

Did you fry you GM? News to me if you did.

I haven't tried high power with mine on purpose, but several times I caught myself putting 100+ watts into my Swan Mark II. I don't use a inlne meter except when testing, tuning, or a new antenna, so I don't know the watts. Generally that is about 1000+ and mine GM still works. I don't think that is a good idea however. I hardly ever use and amp, but when I do I keep it under 500 also, just like you.

 

[Marconi]

Ok after 70 pages what is the physical advantage the Gainmaster has over any other 5/8 wave that gives it magical powers. I dont want to hear TOA, if your gonna say that then what is this antenna doing that others arent to achieve low TOA.

I think I've given my ideas before, and TOA is not a subject that I talk about much. It is somewhat ambiguous in a real world setting is my opinion. I think the center fed balance, and symmetry, that results in using the full radiator length to radiate and receive is probably a plus. Of course the antenna would be nothing without the choke design at the bottom. I also think maybe Sirio was very smart to utilize controlled common mode currents in the design in order to get the feed line up to the center of the radiator.

If I understand the workings of the typical end fed 5/8 wave the bottom 1/8 wavelength current flow is effectively canceled as a portion of the radiator, allowing only, the higher up top 1/2 wave portion to radiate effectively, and it does at a very low angles in a lobe near the horizon. My models above will suggest that the GM shows a bit more gain at 8* degrees than the 5/8 wave at 8*, so the TOA would likely be considered the same. The GM model also shows the pattern to be pressed down at the top forcing more RF into the lobes near the horizon, maybe there is the added gain.

This information bears repeating with my Signal Reports comparing my antennas. Since I lost several regular contacts at some point the actual numbers for my subsequent reports will be skewed with the averages only. The individual reports for contacts that remain should remain about the same excepting for conditions or operator changes. Don't look to compare and old report with a more current report and say why does the Sigma4 not compare as well. The three missing contacts average signal was about 7.1 to 7.3, and this weighted average weighs heavy on a maximum average of 7.3 for the GM, A99, and the I-10K over the period from 12/3/10.

Statistically, the old base line established by the old reports is gone.

 

[Shockwave]

I think Marconi is on track. Having all of the currents in phase on the GM radiator reduces the energy in the higher angle secondary lobe and is where the extra db or two on the horizon comes from. Much the same way as folding the radials upwards on the Sigma IV does. I notice if I model the Sigma directly over ground, the more out of phase radiation I let radiate from the base, the more the 45 degree lobe increases it's intensity.

Let it all escape by folding the radials down and the primary lobe now becomes the 45 degree lobe. That could be why most antennas longer then a 1/2 wave always show a secondary lobe even when modeled directly over ground. Those that are 1/2 wave or less with all currents in phase never do.

I now see what you're saying about the "typical radiation pattern" Henry. It is free space. I suppose I don't find it as misleading because I've seen it's gain over the 5/8 wave ground plane on my roof. I don't care what it does in free space either but what I see is every bit of 1 db on the distant horizon. I was skeptical about the claims of the GM too and that's why I ordered one.

Marconi, not so long ago I did damage the cap in my GM with the FL-2100B. I was experimenting to see what it could handle and as soon as I got in the area of 700 watts there was an enormous increase in reflected power. I think I was lucky because I was watching the meter at the time, ready to cut the transmitter right off. The arc did not produce a bad carbon trail because it was not allowed to continue any length of time.

This made it possible to continue using it at reduced power with no ill effects until the new cable arrived. It just couldn't handle as much power as it did before. I like it enough to keep it on the roof in spite of the power limitation because it has gain that I notice in the receiver. My amp does less then your Swan so I have to say you are pushing your luck with that. Do it when it's raining, damp, or dew has formed and the cap could turn into a nice low ohm carbon resistor.

 

[hotrod]

Ok after 70 pages what is the physical advantage the Gainmaster has over any other 5/8 wave that gives it magical powers. I dont want to hear TOA, if your gonna say that then what is this antenna doing that others arent to achieve low TOA.

i agree this doesnt seem to be about a antenna anymore

 

[okiebob]

I made a 40 mile contact last night with the old Gain Master.
Not bad for a barefoot base. I was hitting him with 3-4S.

 

[dxswe]

I have been tested 700watts on fm band.But then the antenna broke.
I have replaced the koax inside with an new.
So my recommendation is max rfpower on fm band 200 watt
ssb 350-400watt.
This antenna can not handle high power for long qso.
So be careful.So this is the negative with the GM the power.
But it works great and no more problem with the RFI

 

[hotrod]

I made a 40 mile contact last night with the old Gain Master.
Not bad for a barefoot base. I was hitting him with 3-4S.

sounds good how hiogh is your gm. and what mode was ya using?