Maco VQUAD vs Siro 27-4

[lonestarbandit]

Ok antenna gurus.

As my VQUAD was made a mess by the tornado (have to pull it down again and put some more screws in I think the Gama matcher is losing intermittent connection to antenna probably in the slider area as it took a beating) and since insurance paid for a new one its only right and proper to not defraud and indeed buy a new beam aka siro 27-4 as it has much lighter weight than maco m103 or m104s for my puny rotor and I think I can get the VQUAD back in reasonable shape.

My question is how is the VQUAD modeled as 12.xx dbi gain and 27-4 as 8.xx dbi gain. Surely that can't be possible? What am I missing here as surely a 4 element yagi should outperform a 2 element VQUAD?
I know the VQUAD can beat the Maco m103 3 element yagi (spec included here for reference) but a 4 element?

 

[Captain Kilowatt]

The simple answer is the same answer most people do not want to hear. Gain figures in MOST cases are pure bullshit and designed for sales, not truthfulness. CB antenna have the worst reputation for that. Not to say SOME ham antennas are not exaggerated, but for the most part they are much more realistic. Also it is very possible for an antenna of fewer elements to outperform an antenna of more elements if the boom is longer. Antenna gain has more to do with boom length than number of elements on it.......to an extent.

 

[lonestarbandit]

I certainly agree much of the advertised specs are just that, advertising. I guess what I'm saying is will the 4 element Siro outperform the VQUAD (which we know isn't a true quad but a delta loop).
All I have are the specs SOMEONE modeled to compare, with no experience or evidence either way to go on as to if its worth money to buy the Siro. If my patched up clunker is a better antenna then there's really no point of wasting money on the Siro? Perhaps I'm better off getting another new VQUAD?

 

[The DB]

Looking at these models closely, I'm curious where you got these models?

The first and third models, that is the Sirio SY 27-4 which is said to be from the Sirio web site, and the Maco M103C which is said to be from the Maco web site. The curious thing about these two models is they screem that they are made by the same person with the intention of comparing these antennas with each other.

The middle model, the VQ-2, however, is made by a completely different person, or at the very least was not made in such a way that it appears to be comparable to the other two. The style and how this antenna was made and modeled is nothing like the other two in any way. Its at a different height, using a different lenght measurement (inches instead of millimeters), the result layout is compeltely different, ect, ect, ect.

I suggest using caution when comparing this to the other two models present.

The first question that pops to mind is why does the antenna that is lower than the other two have so much more gain. This the opposite of what it should be. At the very least, the environment around the antennas is not the same. There is one thing I can see making this much of a difference, AGT.

AGT stands for Average Gain Test. It is a measurement of the model's accuracy. AGT measurements should be at or very close to 1. Any AGT value over 1 will over-report gain, and any gain value below 1 will under-report gain. I have shown in the past on this forum a singel antenna, with nothing but a minor change having drastic changes in reported gain, literally hundreds of DB gain difference, and this was models with exactly the same layout. With this technique, a skilled modeler can literally make virtually any model show pretty much anything they want, within certain limits, so you also need to make sure they don't have a bone in the fight...

Its possible that their are other diffrences that can cause this as well. I would have to see modeling data that goes beyond what is shown to tell more.

The lesson is you can't just find random models made by different people and compare them together. There are just to many differences. Hell, the same applies to modeles made by the same person made at two different times for different purposes. To often people fall into this trap of comparing apples to oranges and they don't even know it.

Sorry for the long post, but I figured the point of view of someone who has a lot of experience in modeling may be helpful.


The DB

 

[lonestarbandit]

To be honest I don't know where I got them. They were saved to my phone years ago when I was first hunting for an antenna before I chose my VQ3 and VQUADs. I certainly appreciate the explanation and the great information. I did notice however you didn't state an opinion on, all things being equal, would a longer boom 4 element yagi outperform the shorter Delta loop aka VQUAD? I did attempt to compare apples to apples but thats why I had to ask the questions here as this is not (clearly) my area of expertise. If anyone has better more accurate data to compare please tell / show me so I know what to buy! I've been very pleased with the VQ series but if the Siro would get me further then I'm not married to the VQ. (Not a brand snob). I cannot use the Maco Yagis as they are too heavy for my little TV rotor and pole arrangement.

 

[lonestarbandit]

Loop or Yagi?

www.antennas27.com

If this is accurate (though this information is not on the 10/11m band maybe I am better off sticking with the Delta loops aka VQUAD?

Also has anyone here used both and have any observations to aid my choice?

 

[Captain Kilowatt]

I could never understand why they called it a V-quad. A quad has 4 sides. A V-quad has three sides and in fact is a delta loop. Call it what you will but a V-quad is really a delta loop, nothing more and nothing less.

 

[BC Coyote]

I run a homemade delta loop here for skip. It's fabricated from 36 feet of wire, a 4:1 balun and a peice of random length RG-8. I hung it between two trees at about 25 feet above ground. Took about an hour to make and an hour to hang it. Cost nothing to build as I had all the bits laying around.
And the best part ? It way outperforms my A-99 on DX, at least 70 or 80% of the time, likely because of its horizontal polarization.
Obviously it's bidirectional and non-rotatable, but it does a stellar job and works much better than a dipole.

 

[lonestarbandit]

I could never understand why they called it a V-quad. A quad has 4 sides. A V-quad has three sides and in fact is a delta loop. Call it what you will but a V-quad is really a delta loop, nothing more and nothing less.

Yeah IDK... marketing probably...

 

[lonestarbandit]

Pulled the battered beast down and drilled and screwed her and yes I know I wont be able to move Gama sliders but lo the phantom SWR glitching with wind vanished. Have a decent antenna tuner so not too worried. Seems to be working well now SWR rock solid no more fluctuations.