best 11meter vertical ever, period.

[228]

exactly. i knew there was some reason i kept you around.

"I can take one of my I-10Ks and interconnect the end of the radials. Of course this effectivley loads the ends and I would have to shorten the actual radials. But why would we want to do that?"

to cancel the added inductance introduced into the system by connecting the radial elements together. shortening the elements increases capacitance to offset the inductance.

if you were to record the resonant frequency, 2:1 VSWR bandwidth and values of reactance present at the feedpoint before you added the wire and then connected the far ends of the radials together you would be able to answer your own questions.

"We all know there is nothing better than full size elements. In this case, those elements ARE a ground plane; in the Sigma IV, they are not."

very few of us realize that when an element is physically shorter or longer than is necessary for resonance (according to formula) that more times than not the differences in length can be accounted for by minor adjustments made to cancel either capacitive or inductive reactances in the antenna system at or near the intended frequency or range of frequencies to be operated.

radial elements require shortening and active elements usually end up slightly longer to compensate for capacitive coupling effects. one of the benefits of shortening the radials after interconnection, like i said before, is to cancel the inductance introduced by the change. look at the 2:1 VSWR bandwidth before you connect them, after you connect them and again after you shorten the radials to cancel the inductive reactance you'll see that resonant frequency, bandwidth and reactance present at the feedpoint all are changing all along the way.

it's no wonder people had trouble trying to match them. a head full of preconceived notions is all that is required to turn this antenna tuning project into an all day sucker.

 

[Master Chief]

no, YOU can't get any further until i'm as wrong as you are.

That is not what i said. I said "we" can't until "we" agree. That means, either you agree with me, I agree with you, or we both meet someplace in between.

the three, upwardly swept 1/4 wave conductors in the Sigma 4 comprise a ground plane and when you can think and analyze in at least three dimensions you'll come to realize it.

First, show me where in the patent it says that. Be specific! Next, try to explain this to me.

Those 3 elements are are in close proximity to the main element. They function as matching section with the bottom 1/4 wave of the antenna.....just like a J-Pole. I've heard the term, TRANSFORMER, but a little hesitant to use it here just yet.

if you have actually read anything in the patent you would already realize that you're in a no-win situation.

I have read it, and youhave yet to prove your point other than saying I'm wrong. Please tell me where I'm wrong. And if this is such an insanely stupid thread, why are you so passionate about it. Just don't read it.

 

[Master Chief]

when we see the same 3 or 4 1/4 wave elements swept upwards, all of a sudden that's not a ground plane anymore.

When the elements were brought UP, they now interact directly with the main element constituting part of the matching network; just like the j-pole. Do you understand where I'm coming from? I didn't ask you if you agree (I had to throw this comment in for 228), I just asked if you understand where I'm coming from.

I didn't make this up and I didn't design this antenna. All I ask is that you show me where I'm wrong. Get me to agree with you and I will sing your praises from the top of the hills.

 

[228]

"When the elements were brought UP, they now interact directly with the main element constituting part of the matching network;"

so you're saying that if the radials aren't swept up that there's no interaction and now they don't constitute part of the matching network? you yank the radials off of any ground plane based antenna system and let me know if you still have a "match." i believe a VSWR between 2.5:1 - 3:1 is typical for a ground plane design in the absence of its radial system. if you do then the radials aren't part of the matching network. the arguments get more and more ridiculous.

my points will be more than evident as soon as you give the documentation more than a cursory reading. we're looking at the same copies but you don't see the answers. they're all there.
there's no point in between. that only applies in government controlled schools when we can't tell little Johnny that "He's Wrong" after he incorrectly answers the question, what is 2 + 2? we're going to have to be a little more definitive here than that.

and i have found 3 places now where the inventor speaks of the entire length of the element as radiating.

 

[crusader]

hope you guys resolve the burning issue,1/2 wave or 3/4 wave i dont know,would be good to hear direct comparison test results
on a99 i10k etc.
I may be galactically stupid, a youngling even! but that antenna worked well for me, and its no good wasting time working out the formula for calculating the amount of pickled eggs in a jar if you cant get the dam lid off !

 

[freecell]

"When the elements were brought UP, they now interact directly with the main element constituting part of the matching network;"

what you're not understanding is that the radial elements interact directly with the main element AND constitute part of the matching network in ANY like design antenna, regardless of the angle of the radials from the vertical element. in your mind though it's apparent that when the radials are SO CLOSE to the main element that now either they're no longer radials or now they're doing something that they weren't doing before. this is incorrect. the one important parameter that is greatly altered by the close proximity of the radials with the main element as in the case of the Sigma 4 is additional or increased capacitive reactance. this is generally cancelled by slightly lengthening the main element, can be compensated for in the adjustment of the gamma match or a combination of the two.

 

[Captain Kilowatt]

Of course the entire length radiates.Just like the bottom 1/4 wave section of a J-pole radiates.It just radiates two equal fields of opposite phase that cancel out.Not radiating is one thing but radiating two fields that cancel out is differant.

 

[bob85]

how many times have we been through this?, i dont pretend to understand how it works, i have got to the point that i dont care how it works i dont care who says what about the design, even the so called designer contradicts what the patent says. whoever thinks the sigma4 wont outperform a sigma2 is wrong including the guy you claim designed it, i had one and a wilson v1 vertical and an electronica special i replaced them with the sigma4 because it performed better, if thats not what your tests confirm then you just like a few others i know over here could not set a sigma4 style antenna up correctly if your life depended on it, theres other people near me that have had 5/8 groundplanes and sigmas that believe the sigma4 beats the sigma2 and they would argue with ya all day long if they were on this forum, get ya heads out of the books and do some real world tests, the patent states that it gives higher gain than the 5/8 and that is true from my tests which i believe more than what anybody else says just as you would, the documentation in the box and printed on the box said whole antenna radiates, another fact is that my 32 foot hybrid does beat the avanti and this is confirmed by a friend that did the same as me to see for himself if i was right or wrong, my other friend 15 miles away took down his battered 7/8 and put up a 5/8 and to be fair his 5/8 is not as good as my i10k but his 7/8 was never set up right either and it was battered in the wind, his signal dropped by 1 s unit which is a half in power on my radio, i could retell more similar tales but why bother you think what you want and i will believe what i have seen time and time again, calling people stupid because they think one antenna beats another at their location is not the way to get your point across, my response to such a taunting comment is if you really want to see stupid then go buy a full length mirror and take a good look into it! but lets not start all that nonsense again and cause mole to have to flex his muscles, as to the big avanti style vs i10k argument i cast my vote neither way right now, i will tell you the i10k is infinately stronger than the sirio 7/8 version, unlike most people commenting about it i will not get my answer from a book i will do my own tests at my own location within 10 minutes of each other with reliable stations at night so agc's are not getting pumped by locals skewing meter readings and decide for myelf, comparing them in skipland is near meaningless, i can work 12000 miles easy on 100w into aus @signal 9+ and get my name called on the superbowl using just 10w am with my 7/8 mounted at 12 feet or so, does that make it many times better than a guys antenna in the states that cant get on the bowl with way more power than 10w? i dont think so its all in the conditions at the very moment you key your mic, i will always champion the i10k as the best 5/8 i ever owned and one of the strongest antennas for 11mtrs you can buy today or in the past, what i wont do is laydown and just accept that a regular 5/8 will beat my 7/8 hybrid because i know that is not true at my location and nobody else on here has ever had one to compare it to anything, now where are all the guys that think an imax or a starduster beats everything out there? :roll: .

 

[freecell]

"It just radiates two equal fields of opposite phase that cancel out."

if this were true then the net result would be 0 radiation. now we're just getting stupid.

 

[Master Chief]

Of course the entire length radiates.Just like the bottom 1/4 wave section of a J-pole radiates.It just radiates two equal fields of opposite phase that cancel out.Not radiating is one thing but radiating two fields that cancel out is differant.

Yep, but I guess we should use the term "essentially" though or FC will post exactly what he did above. Some guys get it while others do not.

BTW, the Bird dummy load I have also radiates. Its not supposed to, but it does. Hey, my coax radiates too. As a matter of fact, my radio radiates too! I checked it with a Field Strength Meter. Are you beginning to see the futality in that argument?

I guess this is why they call it antenna therory. Thanks QRN, I'm glad to see I'm not the only one who gets it.

 

[Captain Kilowatt]

"It just radiates two equal fields of opposite phase that cancel out."

if this were true then the net result would be 0 radiation. now we're just getting stupid.

Zero radiation is what you want from a matching stub.

As for your comment ..... FU freecell. :x You are just a pompous a$$ looking for a place to crap.I am sick and tired of you thinking everyone is stupid because they don't conform to your way of thinking.

My apologies to everyone else on the forum and I fully expect my post to be either edited or deleted and so be it.No need to worry in the future as I will not be commenting in threads that freecell is in as I would not want to make myself or anyone else look STUPID in his eyes. :x

 

[Master Chief]

Its OK QRN! Let it go..let it go. I'm a little slow and just realized that FreeCell and 228 work together. I've had problems with FreeCell in the past. A lot of people have! I just reviewed 228's posts and other than calling 38LSB the superbowl of SSB, his posts are antagonistic.

I'm with you. As long as FreeCell and 228 are allowed their attack tactics out here, I too will choose not to participate. I really wish the moderators would get a handle on them. Its one thing to add to a conversation and something else to tear it apart.

FreeCell is the KING of plagerism. While I don't believe he is an idiot, he does need to get out and learn to interact with people appropriately. Next time I'm heading out I-40, maybe I'll stop in the Hopi and see if he really is a troll.

I just hope the others out here will see them for who they are.

 

[228]

this was the last post in the thread that had any real content and was addressed directly to MC.

"When the elements were brought UP, they now interact directly with the main element constituting part of the matching network;"

so you're saying that if the radials aren't swept up that there's no interaction and now they don't constitute part of the matching network? you yank the radials off of any ground plane based antenna system and let me know if you still have a "match." i believe a VSWR between 2.5:1 - 3:1 is typical for a ground plane design in the absence of its radial system. if you do then the radials aren't part of the matching network. the arguments get more and more ridiculous.

my points will be more than evident as soon as you give the documentation more than a cursory reading. we're looking at the same copies but you don't see the answers. they're all there.
there's no point in between. that only applies in government controlled schools when we can't tell little Johnny that "He's Wrong" after he incorrectly answers the question, what is 2 + 2? we're going to have to be a little more definitive here than that.

and i have found 3 places now where the inventor speaks of the entire length of the element as radiating.

QRN's response was totally unrelated and uncalled for. it's clear that when the post can't be addressed directly that you would rather engage in obfuscation and change the subject rather than take anything point by point and refute what Freecell posted because you simply can't. i also don't need to be led by the hand thru the patent notes to discover the references that Freecell referred to.

so when his points can't be refuted with anything intelligent than it's time to resort to what some of you do best here. now all we're waiting for is peddler to come in behind bullwinkle and rocky to clean up the mess. it was good there for a while.

 

[bob85]

chief/freecell/228 i enjoy reading and trying to understand all your posts, you got me thinking antennas again just when i need to be sleeping, hope we can come to some agreement on this heated debate,its not going away so here goes.

things i would like answers to?
it states in the patent that the hoop interconnecting the flaired rods is merely to broadband the antenna while at the same time reducing the physical length of the rods so lets imagine the antenna uses just straight rods with no hoop for a moment, at what point as we increase the angle between radiator and rods do the said rods become groundplanes? at 90 degrees they are groundplanes we can agree, as we raise them chief says they become something other than groundplanes freecell and 228 say they are still groundplanes?

it states clearly in the patent that at the 10 degrees angle the antenna has a gain of 2.2db over a dipole wheras the 5/8 has 1.2db approx, it also states that with an increased angle ( rod tips about 9 feet appart ) gain is increased by another 1/2 db or so with even higher gain possible at angles greater than this but no specific angle is mentioned, now why would the designer tell chief that the 5/8 was the better antenna because of takeoff angle, if the gain is higher on the 3/4 then the radiation angle would i think have to be higher too for the 5/8 to beat it, then why do all my and my friends tests show the sigma4 style to be stronger locally and at distance than our regular 5/8 antennas?,

why does using 4 rods rather than 3 increase useable bandwidth on both the 3/4 and 7/8 length radiator?

why does increasing the radiator length to 32 feet approx increase signal strength over all distances out to around 90 miles which is my max talking distance from my present location and at least 110 miles from my parents house?

why does moving the gamma tapping point and retuning by altering gamma and radiator length for a low vswr while monitoring distant reliable stations ( houres of work ) allow an increase in signal strength on tx and rx by as much as almost 1.5 s units ( measured on yaesu ft990's ) over the factory tapping point and tuning instructions, the gains are permanent and more than the difference between our 5/8 and the 7/8 locally by almost 1s unit,
i did not tell my buddy what to expect just that he should try this and report back with what he found, i pointed him in the right direction he saw a tiny increase and found himself out every night tuning untill he got it optimal, is it coincidental that we both found a similar increase using ft990's or is there some other explanation to it??, unbeknown to us a local ham using an avanti 3/4 on 10mtrs was listening to us and decided to lengthen his antenna to 7/8 and repeat what he had heared us talking about, weeks later he broke in on our groupe and reported almost 1 s unit gain, he thanked us saying he would never have believed the day would come when a couple of cbers taught him something usefull about antennas.

 

[freecell]

....so lets imagine the antenna uses just straight rods with no hoop for a moment, at what point as we increase the angle between radiator and rods do the said rods become groundplanes? at 90 degrees they are groundplanes we can agree, as we raise them chief says they become something other than groundplanes freecell and 228 say they are still groundplanes?

they're behaving as ground plane radial elements regardless of the angle from the radiator and as long as they are an integral component of the three parameters mentioned elsewhere in this thread. (bandwidth, matching and system reactance)

in the case of the Sigma 4 the inventor added the loop at the upper end of the radial elements to increase the operating bandwidth of the antenna. in doing so however, the additional inductive loading of the radial elements created by the addition of the loop required that the radial elements be shortened up to cancel the inductive reactance with a more or less equal amount of capacitive reactance. that's why they measure somewhat less than a full size 1/4 wave element.

if you read back through the posts made by 228 and myself you'll see that we pointed out that the upwardly swept rods under 90" are in fact the 1/4 wave radial elements. they are somewhat shorter than the usual 1/4 wavelength radials because of the close proximity to the main element and because of the addition of the loop mentioned above. they have all of the same properties as the radials in any other antenna that you can think of and they're connected in exactly the same fashion. the ground plane and its associated elements always have a potential directly opposite that of the main element and play integral roles in establishing bandwidth, facilitating the feedpoint matching and controlling reactances in the system.

there is absolutely no difference in the function of the radial elements in the Sigma 4 when compared to any other ground plane antenna utilizing 1/4 wave elements as a radial system.

like we said before, if you want to prove it for yourself, remove them and see what happens. what you will see is the same thing that happens when you install any ground plane antenna without the radials or when you install a mobile antenna for base operation without the addition of an elevated radial system. the behavior is identical. VSWR measurements in the vicinity of 2.5:1 - 3:1 will be seen at the feedpoint.

just remember this:

MC stated:

"When the elements were brought UP, they now interact directly with the main element constituting part of the matching network;"

so you're saying that if the radials aren't swept up that there's no interaction and now they don't constitute part of the matching network? you yank the radials off of any ground plane based antenna system and let me know if you still have a "match." i believe a VSWR between 2.5:1 - 3:1 is typical for a ground plane design in the absence of its radial system. if you do then the radials aren't part of the matching network.

P.S. if you still see a good match (with the radials removed) then not only are the radials not part of the matching network, they're not behaving as radial elements.

what you're not understanding is that the radial elements interact directly with the main element AND constitute part of the matching network in ANY like design antenna, regardless of the angle of the radials from the vertical element. in your mind though it's apparent that when the radials are SO CLOSE to the main element that now either they're no longer radials or now they're doing something that they weren't doing before. this is incorrect. the one important parameter that is greatly altered by the close proximity of the radials with the main element as in the case of the Sigma 4 is additional or increased capacitive reactance. this is generally cancelled by slightly lengthening the main element, can be compensated for in the adjustment of the gamma match or a combination of the two.

they are still acting, performing and adhering to the properties of an elevated ground plane radial system. the author explains very clearly why he chose to sweep them upward and deal with the increased capacitive -jX reactance to achieve his design objectives.

the 3 upwardly flaring, base mounted 1/4 wave conductors form the ground plane / counterpoise for the bottom 1/4 wave portion of the vertical element. the reason for sweeping the radial elements in the upward direction was to reduce the amount of lateral or horizontal space required for mounting and to minimize the deleterious effects in the surrounding environment such as "buildings, guy wires and other interfering masses."

MC posted:

"Maybe you can explain how 3 "diverging elements" shorted at the end constitutes a ground plane."

the same way the ground plane in the body of a vehicle or a solid cone shape would replace the 3 diverging elements in the Sigma 4. i already understand what constitutes a ground plane or counterpoise "mass." whether it's formed by skeleton elements or continuous sheet metal it's still a ground plane.

the author even mentions the idea that the upswept radial elements could be replaced with a cone of the same geometry to achieve his design objective. i fully understand why he went with the skeleton element design instead.