sirio 827 5/8 vs gainmaster

[hotrod]

well guys i believe ya saw what ya saw. i guess i dont understand this G.M.
so heres my understanding the GM is a center fed dipole
a dipole has NO gain
gp antennas with gain listed as db is over a dipole
the 827 is listed at 1.5 db more than a dipole
knoow i admit im no antenna gru by any means this
is some of my antenna understanding if its wrong
then tell me im always wanting to learn more. like
i said this is just MY understanding of things sorta

 

[gamegetter]

except that it is a 5/8 wave dipole and not the "standard" 1/2 wave dipole you are thinking about.

 

[BOOTY MONSTER]

im with you hot rod , i dont understand it either ..... but i'll add it to the list of a gazillion other things i dont understand either

i also dont understand why some coax in a fiberglass sleeve cost so dang much ...... that's a gazillion and 2

 

[gamegetter]

Sirio solved the considerable mismatch that occurs between the antenna and the high impedence feed line which results in severe radiation in the wrong direction depending on ground conditions for a dipole antenna when it is in the vertical position. It also solved the counterpoise issue by the resulting balanced antenna.

 

[hotrod]

except that it is a 5/8 wave dipole and not the "standard" 1/2 wave dipole you are thinking about.

ok, wow that does change everything.ive looked around a bit for info
on a 5/8 dipole but no luck. i,ll have to keep looking , booty im glad
im not the only one who dont understand.......lol

 

[Marconi]

ok, wow that does change everything.ive looked around a bit for info
on a 5/8 dipole but no luck. i,ll have to keep looking , booty im glad
im not the only one who dont understand.......lol

Hotrod there are lots of high-brow ham sites and theoretical sites for the 5/8 wave dipole, but here is a pretty straight forward and simple site that discusses the math for how to build such an antenna as the EDZ extended double zep, a 5/8 wave dipole that will provide some gain (reported to be 3 db gain) over a 1/2 wave dipole.

I don't fully understand all the particulars for the GM, but gamegetter makes some very good points. I bought one just to check out what I was hearing an seeing with this new antenna design. It is even more refined than the very old EDZ idea, because it will mount and self support in a vertical position, using 50 ohm coax, and still maintain what is reported to be a well balanced dipole pattern. To me, and among other things, this is the magic of the design.

Here is a site for a 6 meter version of a standard EDZ: 6 METER EDZ EXTENDED DOUBLE ZEPP SIGNAL SQUIRTER

 

[gamegetter]

I would say that one of the top reasons for figuring out and building a sophisticated antenna is to control the radiation pattern. Which is done by focusing the radiated energy. Geometry of antenna and proximity of nearby objects being controlling factors.

I remember shockwave discussing this in one of the original GM threads many months ago- When this energy is focused, the energy radiated in one or more directions will be increased, and the energy radiated in other directions will decrease. This is what gives an antenna "gain".

The GM has done what has troubled antenna builders in taking a horizontal dipole and running it in the vertical position and end feeding it. The problems being already mentioned in the above threads.

So you have a matched, wideband, no tuning, no counterpoise light weight vertical dipole antenna with gain!

 

[Oggy]

One Year On!!!

Well a year has passed since I conducted my first tests of The Sirio Gainmaster.
It is waiting to go back up in the place of the Bigstick in spring.
It's superb that nearly everyone has come to the same conclusion I did back in November 2010.
Indeed this antenna is not Snake Oil and I didn't dream it all up

73 Dave M0OGY

 

[IMD262]

Indeed this antenna is not Snake Oil and I didn't dream it all up

73 Dave M0OGY

I think your buddy was dreaming or high when he said this about the gainmaster :

"..i would say it will whoop the snot out of a 3 element all day long i don't care what the propagation is but it will give a 4 element a run for its money".

 

[Oggy]

What??

I don't know who your refering too.....but I do understand how Yagi beams work.
I use various Yagis for all other bands, I never compared this antenna to a beam, but it outguns every other vertical Omi I have ever owed in 30+ years.

 

[HomerBB]

Easily, the most believable statement made in this entire thread.

the 827 is nothing special, it can't equal my i10k

Comparisons to a real GP 5/8 wave antenna like the I-10k, or SP500 would be more interesting, or even a tuned 5/8 version of a V4k.
I'm not the one to put a GM up and compare it. I can't spend that kind of money for the antenna.

The 827 type homebrew version 5/8 wave I made was such a disappointment compared to other 5/8 GP I'd made it had the shortest run time in the air of anything I've ever seriously put together. In fact, the AP kicks its behind every day of the week.


Additionally, comparing the antennas within 20/30 miles does not actually speak to the proclaimed advantage of a low TOA max-gain antenna. Higher radiation lobes are in play there. So, when any advantages are claimed in terms of DXing ability, where low TOA, max-gain designs are in their element everyone starts screaming "FOUL" because "you can work DX with a wet noodle if conditions are right." Real world testing is so contradictory to antenna design intent that these discussions become circular to the point it's like a reality show based around a dysfunctional family.
I have read with interest many pages of threads on the Low TOA antennas such as this one. In each case someone is arguing the contradictions of high angle performance vs the antennas design - low angle performance. Regardless of whether it is accepted as proof of the pudding, this is the very most interesting statement made in this entire thread:

i need to either finish my sigma4i or change antenna, im not happy with how the i10k works in dx to the usa at the height its at,
its embarrasing getting your ass whipped into the states by locals on imax 2000's using less than half the power, that never happened when i was using the vector hybrid

This statement begs the question of WHY?, and, in my opinion, comes closer to speaking to the issue of a low TOA max-gain antenna design than closer-range-could-do-this-with-a-1/4ƛ-GP-antenna-everyday kind of test. Additionally, before I am beaten up and laughed to scorn for expressing my frustration with testing that doesn't test the design of these antennas, in every case that I read recommendations for an antenna setup on Amateur sites and literature the given antenna is recommended because of its DX abilities, and great pains are taken to clarify height, orientation, polarity, gain, etc and how all these play into maximizing these antennas for DX with the proof of the antenna some success contacting distant difficult DX stations.

Hopefully you understand my rant.

Respectfully,
Homer

 

[bob85]

homer we each have our opinions hopefully based on our experience of tests we did rather than anything written on a forum such as a 5/8wave is a 5/8wave is a 5/8wave,
that may be the case @some locations but it is not what we see here in any tests we do,
at any location in this area there are differences in the signal strength different antennas produce when mounted on the same mast,

the imax that is whipping me on a regular basis in usa dx was my imax, the same imax i tested against the i-10k, his loction is better than mine for local or dx but his antenna is not as good, the imax is not his best antenna either,

as soon as i removed the vector hybrid and put the i-10k up in its place my dxing changed to short hop skip that i hardly ever heared on the vector, at the same time my longer distance contacts and local out to 70+ miles went down the pan, that situation has remained for the 7 or so years i have been using the i-10k,
the i-10k is great if i want to talk to iceland or this side of france but its not the antenna of choice for what i want to do.

 

[HomerBB]

Thank you, Bob.

I know anecdotal reports are disfavored in favor of theoretical discussions and modeling, but the proof is always in the tasting for an empiricist like me.
So I wonder, how does the GM do against the V4k-hybrid, or the I-10k, or a P500, or Maco V5/8, etc on DX. DX, and out-lying distant local communications are what the low angle TOA antennas are meant for.
That's why I found your statement about the comparison between the I-10k and the V4k, with the Imax2k more interesting than closer in comparisons.

I had rather talk DX than local rag chews. Local rag chews are why God made tin cans on the end of strings, or cell phones; take your pick.

It matters little to me that DXing is not popular as a test of antenna performance because the truth is that certain antennas were made with that in mind, and comparisons of their performance ought to be made by utilizing their designs.

What you said, and I quoted, came the closest to that IMO, and I was glad to read it. Nothing wrong with reporting consistent DX results for a comparison, and 7 years of consistent difference between certain antennas certainly takes into account many propagation variables although much lesser time periods would be useful, too.

Thanks again,
Homer

 

[Needle Bender]

well i can tell you both that my gainmaster is blowing me away with its ability to break pileups and hammer into europe. its much better then my imax or penetrater ever was and i keep getting reports of s9+10 to s9+20 only running 100w. the penetrater seemed best talking 15 or 50-70 miles and the imax liked more like 5-10 miles but the gainmaster feels more like a beam the way it both hears and transmits european dx mounted at 54 feet above ground as well as local rags chew from 5 to 75 miles. its quiet on static and i think it has better ears then the penetrater and much better then the imax

 

[bob85]

another local swapped his 5/8wave sirio 827 for a gainmaster today, same 20ft pole / coax, the antenna is just above gutter height near the roof,
i saw just over 1/4 s-unit improvement @15 miles with the gainmaster, the least increase i have seen so far,
he saw a healthy increase on his icom s-meter.