Modified Vector 4000

[Marconi]

5 year anniversary Bob. Do we have the answer? I was reading this old thread from 2009, and was reminded of your comments. Those were the good old days.

Happy New Year,

Eddie

For those that were wondering what my measurements on this antenna are......Here you go. The vertical whip is 29 feet 7 and 1/4 inches long from the bottom of the connector bracket to the tip of the whip. The four radial arms are 81 and 1/2 inches long from end to end. The loop is 129 inches in circumference. The gamma is simply adjusted for lowest VSWR. Sorry I did not measure the gamma and I did use a home made Teflon gamma match with a weatherproof HN connector.

You may notice this last version of the antenna is more sturdy. I used the parts from two Vector 4000 antennas so that I could double up the lower sections and cut the flimsy top sections off. The four black plastic arms that hold the radials in place are also taken from two antennas. The ends were cut and then two pieces were screwed together with 4-40 hardware to make them longer.

The antenna was tuned on 11 meters and still provides under 2:1 VSWR on 10 meter SSB. The gain and bandwidth with the larger loop seems better to me and certainly exceeds what is possible with a 5/8 wave. The main advantage of the gamma match versus a coil with a tap is that a gamma allows you to tune out both capacitive reactance and inductive reactance. The coil only allows you to adjust the inductive component.

heres a post i made on cbjunk when MC jumped ship explaining how i came down this road of thinking.

Re: avanti sigma4 an alternative view

by bob85 » Wed Feb 18, 2009 4:53 am
thanks for the comments guys, the sigma4 is not an antenna you can look up in a book like other commonly used antennas, consequently as cebik said it is very much misunderstood,

you may wonder how i came to my conclusions,
well it all started when i first posted about the sigma on wwrf, discussion/arguments ensued,
MC put forward a compelling argument backed by what an avanti engineer told him, it all sounded very plausible apart from one problem,
i had built jpoles for 27mhz and the sigma did not perform like a jpole at all for me, i had a gut feeling that there must be another explanation some addition from the basket that overcame the traditional problems of pattern breakup with radiators longer than .64wave but the only facts i had was the fact i knew what i and others had observed,
comming to terms with that been an illusion was not on the agenda just yet, not until i had done some research,
since then me and mc have taken almost every opportunity to have a poke at each other whenever the sigma4 gets a mention

,

we had something that a few people were intersted in but we did not agree on how it worked or how well it worked in practice,
i knew what i had been seeing for years but i wanted to know why some folk did not, i was pretty sure avanti had not invented something that nobody else had ever seen before, it must work on known principles,
i looked at the other things lou and herb had designed for clues and found none, lou was a kind of inventor, his field of invention was not restricted to antennas,

after the usual trawling the net / antenna books and finding nothing that seemed applicable other than an idea that if it did outperform other antennas it could not be any single element antenna i could find so in my mind the whole antenna must radiate just like it said on the box,
as unusual as it may seem for cb antennas i actually believed what it claimed and what the patent claimed but had no real idea how that could be, what they claimed fit what i observed but why?,
the patent seemed long winded for a tall story and it was herbs name on the patent not ampowers,
the sigma was not the only antenna avanti made that had people baffled, the astroplane does the same thing but more on that one later,
avanti thought out of the box, not following convention,

back then only one person agreed with me that i knew of, he claimed the lower portion radiated but getting anything else from jack ( freecell ) is hard work or should i say he likes to make you work for your information,
he did say one thing, that i should not give up and throw years of experience in the bin,

after corresponding with cebik and him not falling out of his chair laughing but on the contrary said it was possible and you can make a none apparent colinear array i wanted to know more,
i could not find anything about none apparent colinears,
what did he mean "its not apparent to most people" and usually generates lots of arguments,
hell yeah, he was right about the arguments that bit was easy to understand, what about the rest,

i started searching different ideas like "radials radiate in phase with vertical radiator" etc and eventually came across the open sleeve antenna or skeleton sleeve fed monopole,

holycow batman, this antenna has all the ingredients im looking for,

it can be 3/4wave or slightly longer,
it has radials folded up beside the radiator like cebik said,
the radials radiate in phase with the upper portion of the radiator in a colinear effect improving gain like cebic said,
it could operate in two modes ( antenna mode and transmissionline mode ) i figured if id never heared of two mode antennas then it was probably not apparent to most other people like cebik said,
some referances to the skeleton sleeve antenna call it a form of jpole like mc's avanti engineer said,
a form of jpole with a twist as mc said it may be ( after some poking ) lol,

i punted the idea around a few people with no negative comebacks and one positve then pondered on it while still looking for alternatives, so far i have found none that seem to fit as closely as a modified form of open sleeve antenna,
it ticks all the boxes imho,

cebik told me that the sigma would not be easy to model and get accurate results, i tried and got kind of lost in eznec4,
sadly by the time i had gained enough confidence in the idea to contact cebik and ask him "am i right in thinking the sigma style antennas operate on the principles of open sleeve antennas" hed gone silent key

,

thanks to all who have been involved in the sigma debate over the last 5 years or so

both on the forums and in pm/email,
i suggest you do your own tests and decide for yourself the validity of my conclusion, let us hope we have it figured out within the next 5 years

heres a post i made on cbjunk when MC jumped ship explaining how i came down this road of thinking.

Re: avanti sigma4 an alternative view

by bob85 » Wed Feb 18, 2009 4:53 am
thanks for the comments guys, the sigma4 is not an antenna you can look up in a book like other commonly used antennas, consequently as cebik said it is very much misunderstood,

you may wonder how i came to my conclusions,
well it all started when i first posted about the sigma on wwrf, discussion/arguments ensued,
MC put forward a compelling argument backed by what an avanti engineer told him, it all sounded very plausible apart from one problem,
i had built jpoles for 27mhz and the sigma did not perform like a jpole at all for me, i had a gut feeling that there must be another explanation some addition from the basket that overcame the traditional problems of pattern breakup with radiators longer than .64wave but the only facts i had was the fact i knew what i and others had observed,
comming to terms with that been an illusion was not on the agenda just yet, not until i had done some research,
since then me and mc have taken almost every opportunity to have a poke at each other whenever the sigma4 gets a mention

,

we had something that a few people were intersted in but we did not agree on how it worked or how well it worked in practice,
i knew what i had been seeing for years but i wanted to know why some folk did not, i was pretty sure avanti had not invented something that nobody else had ever seen before, it must work on known principles,
i looked at the other things lou and herb had designed for clues and found none, lou was a kind of inventor, his field of invention was not restricted to antennas,

after the usual trawling the net / antenna books and finding nothing that seemed applicable other than an idea that if it did outperform other antennas it could not be any single element antenna i could find so in my mind the whole antenna must radiate just like it said on the box,
as unusual as it may seem for cb antennas i actually believed what it claimed and what the patent claimed but had no real idea how that could be, what they claimed fit what i observed but why?,
the patent seemed long winded for a tall story and it was herbs name on the patent not ampowers,
the sigma was not the only antenna avanti made that had people baffled, the astroplane does the same thing but more on that one later,
avanti thought out of the box, not following convention,

back then only one person agreed with me that i knew of, he claimed the lower portion radiated but getting anything else from jack ( freecell ) is hard work or should i say he likes to make you work for your information,
he did say one thing, that i should not give up and throw years of experience in the bin,

after corresponding with cebik and him not falling out of his chair laughing but on the contrary said it was possible and you can make a none apparent colinear array i wanted to know more,
i could not find anything about none apparent colinears,
what did he mean "its not apparent to most people" and usually generates lots of arguments,
hell yeah, he was right about the arguments that bit was easy to understand, what about the rest,

i started searching different ideas like "radials radiate in phase with vertical radiator" etc and eventually came across the open sleeve antenna or skeleton sleeve fed monopole,

holycow batman, this antenna has all the ingredients im looking for,

it can be 3/4wave or slightly longer,
it has radials folded up beside the radiator like cebik said,
the radials radiate in phase with the upper portion of the radiator in a colinear effect improving gain like cebic said,
it could operate in two modes ( antenna mode and transmissionline mode ) i figured if id never heared of two mode antennas then it was probably not apparent to most other people like cebik said,
some referances to the skeleton sleeve antenna call it a form of jpole like mc's avanti engineer said,
a form of jpole with a twist as mc said it may be ( after some poking ) lol,

i punted the idea around a few people with no negative comebacks and one positve then pondered on it while still looking for alternatives, so far i have found none that seem to fit as closely as a modified form of open sleeve antenna,
it ticks all the boxes imho,

cebik told me that the sigma would not be easy to model and get accurate results, i tried and got kind of lost in eznec4,
sadly by the time i had gained enough confidence in the idea to contact cebik and ask him "am i right in thinking the sigma style antennas operate on the principles of open sleeve antennas" hed gone silent key

,

thanks to all who have been involved in the sigma debate over the last 5 years or so

both on the forums and in pm/email,
i suggest you do your own tests and decide for yourself the validity of my conclusion, let us hope we have it figured out within the next 5 years

 

[bob85]

answer to what question Eddie ?

 

[Marconi]

It wasn't really a question Bob, at least it didn't have a ? at the end of your words above.

It was more like a hopeful conclusion from you, that maybe within possibly another 5 years or so, someone would come forward with a new and convincing response to your "Avanti S4, an alternative view" idea.

As you noted in your remarks, what may be another 5 years, and I just noticed the date was December of 2009, and I thought it curious. Right now it has been exactly another 5 years, and the issue is still with us...even though we seem to have, more or less, stopped the discussion. I never said it, but I've heard it said...such discussions are meaningless. I have a question however, is that all this has been about?

I was just taking my time, and re-reading the whole thread to see what part I might have played in this epoch. I really don't even know how I got to this old thread of yours...but I think somebody posted a link, and I followed it.

I wasn't up to no good Bob. Still just curious with my own point of view.

 

[bob85]

its not over Eddie,
we just don't talk about the vector on here as much as in the past,

im still 100% sure they beat a 5/8wave on the same mast,

i know the current maxima been higher plays a major part in the vector putting more signal at low angles than a 5/8wave ground-plane,

we figured out what was happening with Donald's co-linear & 4 wire test,

still not sure about the magnitude of the cones contribution,
or the exact cause of been able to manipulate signals but i think we are getting there.

 

[Lil'Yeshua]

Let's go for it!

 

[Marconi]

its not over Eddie,
we just don't talk about the vector on here as much as in the past,

I agree.

im still 100% sure they beat a 5/8wave on the same mast,

In part I might agree.

Attached below is an overlay of my latest update on my S4, where I just today fixed a very minor error in dimensions that I had previously over-looked.

Then did an overlay of................
my Sigma4 to specs, except of the tapper of course - the black trace
my Vector to specs that you posted, except for the tapper,
my I-10K with the physical trombone matcher, except for the tapper.
my I-10k without the matcher, except of the tapper.

i know the current maxima been higher plays a major part in the vector putting more signal at low angles than a 5/8wave ground-plane,

I think the attached models confirm your thinking Bob, but maybe there is something else going on...in particular with the I-10K. I've posted about this before, but I didn't get much response, and no discussion as I recall. Maybe this time I can get my observations across.

In each of my 5/8 wave models without a matcher added I see a 5/8 wave is a 5/8 wave. However, I see a notable difference when I add the matcher and the trombone matcher to the I-10K reacts the best.

I see something similar, but very much less of this effect with my SP500, Maco V58. So, IMO the 5/8 wave I-10K, based on my models...shows a noticeable difference that I have never seen before in any other CB vertical model...except in these three 5/8 wave models with their physical matcher included in the model.

This effect appears to me to contribute horizontal radiation in the antennas pattern. Again some 5/8 waves look to be more than others, but I see horizontal RF noted in the Eznec patterns, that I do not see with other CB verticals.

With that said, my S4 produces the best gain of these models and at the lowest angle, just like you claim here. So I do not differ with your thinking about this. The only difference I have ever claimed is...I don't think the difference is as much as others claim.

Regarding my Eznec model of the New Vector 4000 to specs, that you posted for the group a while back...I have never been able to get it to show as much gain, but it does show a much better pattern than all in this list...I have to admit.

we figured out what was happening with Donald's co-linear & 4 wire test,

still not sure about the magnitude of the cones contribution, or the exact cause of been able to manipulate signals but i think we are getting there.

No comment if I have to ask.

I also added an attachment for the I-10K with matcher, and the overlay of it vs. the Sigma 4, just to try and show proof of what I see in modeling.

 

[bob85]

i don't notice anything different going on with how my i-10k responds to horizontal signals from locals using yagi's Eddie,

i don't doubt that the trombone has some radiation, you are not the first person to claim the 10k will have some horizontal radiation,
i remember your model looked to have more horizontal radiation than i can imagine coming from the trombone or the asymmetric radial setup but i would not argue over it,

id say this about the i-10k,

they are sturdy in our weather, put it up on a pole no weaker than scaffold pole and forget about it, we don't get ice like 1-800 toll free,

they don't go open circuit and blow your amplifier, don't snap in wind up to 100mph, won't burn out well below rated power handling,

in my yard it has the edge over other 5/8 its been up against including the gain-master,

that may not be the case if the antennas were well above ground in my dads field like the good old days but that's how it pans out here in the yard,


your sigma model looks the best in that group but the vector does better when its adjusted for best signals,

i can't give you dimensions, i don't think you want the same dimensions at every location/ mast height,
the only way i know is adjusting for maximum signal on the mast/feed-line you will be using,

i still think its likely we are altering takeoff angle, i don't think we are increasing gain much if at all,
nor do i believe gain is as important as which antenna puts the bigger signal at low angles,

thanks for the models.

 

[Marconi]

i don't notice anything different going on with how my i-10k responds to horizontal signals from locals using yagi's Eddie,

Bob, I had my I-10K up April 4, 2002, when I first got it, and I saw it work nicely with DX and local, but I hadn't yet really started comparing CB antennas either. Back then guys on the Internet complained too, that there was no way that my SD'r could match the I-10K, even they saw the signals on their own radios, and that was local and skip over that year. If I recall correctly...DX was just fading away and that would have to be considered in any comparison work.

I had the I-10K up about 68' feet to the tip in the back yard with my SD'r at about 50' feet to the hub in the top of an Oak Tree in my front yard. They were 60' feet or more apart, and I could not tell any difference, even though the I-10K was higher at 68' feet to the tip on a 50' crank up mast I had.

At that time I don't recall ever considering the idea of the I-10K having some horizontal radiation. All I remember was the talk was about the trombone tuner being more efficient.

I still am not sure why this horizontal pattern shows up on these 5/8 wave Eznec models. That is why I posted this stuff.

My point here was that Eznec surprisingly showed this in the model...and I sure didn't plan on that ever happening. I use to say that the AstroPlane, with its big top hat and horizontal hoop at the bottom showed strong tendencies to work horizontal signals however. That was because Signal Engineering claimed that their G45 mobile responded well to horizontal signals. I still believe there may be something to that idea...but it could be that these antennas as just real quiet on receive too.

In the recent WDX contest I used my Sirio New Top One, and I was not able to notice a difference on most receive signals, but the bottom hoop was only 20' feet above the Earth, 32' feet to the tip. The GM is over 61' feet to the tip, and on many receive signals I could not see a difference. I did get some TX comparison reports switching antennas and several showed my GM TX signals 1-2 Sunits better signal on the other end however, but that is DX and few depend on such signals.

To me these models show to be just about what I might expect in the real world as far as the gain and angle goes...even though I have no way to measure either except by modeling maybe. I've claimed the same thing I've seen here for many years.

My only point in posting this I-10K model, was to show the guys this horizontal effect that I can easily see...when adding the big old trombone matcher to the I-10K model.

I also said these models are all just too close for me to tell, and I don't think we could likely see a difference just using our radios. So, that is also why I've reported the same thing about my real world experiences with these antennas, and here we see about the same thing IMO...if all these antennas are equally mounted to the current maximum...then they don't show much difference here at my location.

As I already said however, these models do look to me to support your claims, with the S4 design out in front...and if the series matcher is not included in these 5/8 wave models, then for sure a 5/8 wave is just a 5/8 wave for me.

This is what I take away from what I posted here. Your mileage may vary.

 

[HomerBB]

Just a thought.
Signals coming in the same for a 5/8 wave and a 1/4 wave antenna is as likely a matter of where he signals are coming from as gain, ie TOA.

My half wave vertical dipole is receiving at certain times of the day as well as my Moxon, but despite arguments to the contrary, although the meter on the radio says the signals are the same, the Moxon is clearer and louder with less fluctuation on receive.

Signals can be the same, but quality of receive can differ. TOA can do this if the locations of TX and RX stations dictate. Other times of the day the vertical is no where in the game for receive. I hear some things on the Moxon I do not hear at all on the vertical.

What does the time of day have to do with it? Where the DX is coming from.

 

[Marconi]

Just a thought.
Signals coming in the same for a 5/8 wave and a 1/4 wave antenna is as likely a matter of where he signals are coming from as gain, ie TOA.

My half wave vertical dipole is receiving at certain times of the day as well as my Moxon, but despite arguments to the contrary, although the meter on the radio says the signals are the same, the Moxon is clearer and louder with less fluctuation on receive.

Signals can be the same, but quality of receive can differ. TOA can do this if the locations of TX and RX stations dictate. Other times of the day the vertical is no where in the game for receive. I hear some things on the Moxon I do not hear at all on the vertical.

What does the time of day have to do with it? Where the DX is coming from.

Homer I think we all have seen the conditions you describe. If you look close at the pattern for the I-10K with the matcher it is noted that the pattern is very flat in its maximum gain range. This area is also right in the best low angle range to the horizon, and it shows no apparent nulls over this entire range. I don't see that as being similar to what I've seen in other antenna patterns for any other CB vertical antenna, and for me that should be an advantage.

So, I'm not sure this setup works this way in the real world, but this is what I see in this model, and IMO this makes it different from the others in this group.

If we could measure the currents in the trombone like this Eznec model does...we might see what I see as the maximum amperage in the radiator of 1.25 (amp) and in the tuner it is 1.77 (amp), so there looks to be a lot of current in the tuner.

This is the point, but only if it is true, and if it is not true...then a 5/8 wave is just a 5/8 wave, and I still see them all working about the same.

 

[HomerBB]

I see what you mean in the model, Marconi.
As you say, if the real world performance of the I-10k follows the model it can be a real difference.
The lack of significant nulls in the prominent well placed lobes are interesting.
As we know, it is the nulls that are most significant in DX situations.

 

[Marconi]

i don't doubt that the trombone has some radiation, you are not the first person to claim the 10k will have some horizontal radiation,
i remember your model looked to have more horizontal radiation than i can imagine coming from the trombone or the asymmetric radial setup but i would not argue over it,

Bob, I just checked on my I-10K's asymmetry in the radial area and it is worse than I remembered. The top radial is 1" inch offset from the middle of the radiator and the bottom radial is not only lower, it is 1.5" inches offset due to being on the outside of the mounting bracket.

My I-10K model is setup symmetrical. I made it offset at first, but the model just never looked right in any category. I thought it was because I added the matcher, but over time fiddling with the dimensions...I decided to fix the offset and then the model's matcher started responding nicely.

I don't know how that effects the match, but it is bound to have some ill-effect that needs to be compromised in setting the match.

Maybe that is why we use to complain to Jay about the resonance and the best SWR seeming to be at the opposite ends of the CB band.

Have you seen any promotion of the new "Shockwave" version of the I-10K with the trombone at a 45* degree angle to the radials? That guy fixed the asymmetry in the radials setup nicely.

 

[bob85]

i have seen 4-400's shockwave, looks nice for a 5/8wave, i prefer the symmetrical look.

 

[Shockwave]

Several years ago I made three 5/8 wave antennas for some of my locals. Nothing fancy, just a good low loss matching network that would not heat with RF. One used it with four 4-400A tubes on channel 6 regularly professing he was talking on his "Shockwave 5/8 wave groundplane". He got quite a bit of attention for that because few people believed he could be using a groundplane. They typically assumed the antenna must have been special without considering the only thing special was it could handle more power and it was being used. I find it less than coincidental that BM Technologies copied Jay's antenna and copied the name describing a 5/8 wave antenna he's probably heard on the air in DX more than a thousand times over the last few years.

 

[Needle Bender]

i don't notice anything different going on with how my i-10k responds to horizontal signals from locals using yagi's Eddie,

i don't doubt that the trombone has some radiation, you are not the first person to claim the 10k will have some horizontal radiation,
i remember your model looked to have more horizontal radiation than i can imagine coming from the trombone or the asymmetric radial setup but i would not argue over it,

id say this about the i-10k,

they are sturdy in our weather, put it up on a pole no weaker than scaffold pole and forget about it, we don't get ice like 1-800 toll free,

they don't go open circuit and blow your amplifier, don't snap in wind up to 100mph, won't burn out well below rated power handling,

in my yard it has the edge over other 5/8 its been up against including the gain-master,

that may not be the case if the antennas were well above ground in my dads field like the good old days but that's how it pans out here in the yard,


your sigma model looks the best in that group but the vector does better when its adjusted for best signals,

i can't give you dimensions, i don't think you want the same dimensions at every location/ mast height,
the only way i know is adjusting for maximum signal on the mast/feed-line you will be using,

i still think its likely we are altering takeoff angle, i don't think we are increasing gain much if at all,
nor do i believe gain is as important as which antenna puts the bigger signal at low angles,

thanks for the models.

My GainMaster was junk, crap, trash, poop - until I elevated it well up & away from any other antennas, trees, wires, yellow jacket nests, etc, then it woke the F#c% up!
Now it bests the metal 5/8 by the exact 2dB claimed.