Avanti AV-190 Saturn construction and operation

[Marconi]

Bob, I have been studying this antenna manual: View attachment avanti_av190_om.pdf. It is amazingly well constructed for a CB antenna. Probably no one in CB would go to the trouble to produce anything like it today.

I am interested in how you think the horizontal side works?

I was trying to figure how long the radials might be and I noticed that the three two piece baluns look to be about 110" inches each, while the three single element separators look to be about 106.5". This is all close to a 1/4 wave for CB, but I thought when we add a peripheral wire we had to shorten the radials to maintain the resonance.

Can you see the connections inside the insulator? What is inside?

How long is tube G? Does this tube and the insulator base come assembled?

Where is the bottom of this antenna, at the horizontal feed point?

Have you ever talked to anybody that has used one of these antennas?

What do you think about Avanti's suggestion to use 1/2 wavelength or multiples for the feed line in order for the polarity to work right?

 

[bob85]

im not sure how it works eddie, they are complex for a cb antenna,

tube g is 36" and comes assembled with the insulator aluminum plugs and so239 connector,

avanti av-190 saturn :: basetube & hub picture by ukmudduck - Photobucket

the balun arms are in parallel screwed into a plug inside the fiberglass, its the same setup as the sigma2 pic on the right, the arms tap part way down the balun wire,
because the horizontal uses the center connector the vertical uses an external connection and two more plugs above the horizontal feed plug,

there are three 1 wavelength loops with the first and last 1/4wave of each forming part of the baluns or transmissionlines, the middle 1/2wave been perimeter wires between them supported at their center by the single 1/4wave radials, radials look to be equal length,
i don't know how it works but i will wager both transmissionline and antenna mode currents are at play,

not sure about the 1/2wave multiples eddie, it could be to keep the phase separation at the switchbox,

the bottom of the vertical is at the top of the hoop, coax shield on both feedlines are at the hub level,

who knows whats going on with the radials in the vertical mode, a rf current probe would probably answer that,

a couple of guys on forums have used them and love them but i have not gone into any details,


the design deserves some study but like other avanti antennas there is little info out there, they don't work like your run of the mill cb antenna, nearest thing i found was the cloverleaf.

 

[Marconi]

Bob, I agree one of the images you posted is similar to the vertical side of the Saturn, being very much like the Sigma2.

I agree there would probably be another small circular slug inside the insulator that is connected to the small wire inside, and if that small wire has a coil, then the slug would likely be positioned between that coil and the SO239---acting as a feeder connection point for the horizontal feeder rods, which I believe are likely fed directly by the coax with no matching device. The matching coil would be above this connection point and would feed the vertical side of the antenna. I think we more or less agree on how the construction might look inside the insulator on the Saturn.

I also think this antenna uses three independent diamond shaped quad elements with the 1/2 wave peripheral wires (sides 2 & 3) serving as the horizontal polarity radiators. I also see the 1/2 wave wires supported in the middle by the grounded separator arms which for me creates a setup similar to the configuration of a radiating grounded yagi element. As I note above, I see this horizontal quad element being direct fed with two possibilities for the feeding mechanism for this bugger.

Originally, I thought in my minds eye this was a form of a folded 1/2 wave dipole positioned as the leading edge (1st side) of each quad element, feeding the 1/2 wave perimeter wire (sides 2 & 3) as noted above. I don't know for sure, but I think a true folded dipole will exhibit about 300 ohms of resistance at the feed point. For me, this one looked like half of a folded dipole, so I was thinking it may show a feed point impedance of about 150 ohms. With three such systems connected in parallel, I would expect the net impedance at such a feed point connection to likely be 50 ohms---and therefore need no matching device. I was reminded of the folded GP image below when I first saw the Saturn manual:

The second idea I had was maybe this antenna is similar to the matching at the bottom of the AstroPlane. But, instead of end feeding the 1/4 wave top element at a current node on the grounded hub of the AP, this one is instead end feeding a 1/2 wave radiating element from a voltage node at both the ends of the balun wire making up part of the 1/2 folded dipole. Again, with these three quads connected in parallel---the net feed point impedance should be about 50 ohms. I also think theory suggest that folded dipoles provide very nice bandwidth, and this would be a plus. I'm not too sure that the AstroPlane does not use some of this idea in its feeding scheme. In the patent Avanti does describe the bottom as some form of a open or closed ended cubical circuit I think.

Bob, I'm just piddlin' with my imagination, and not real sure about any of this however.

You and I just recently had a discussion regarding the use of 1/2 wl, 1/4 wl, or random length feed lines, and here again we have Avanti talking about such things in the Saturn manual. I also recently read, what looks like a new article on vertical monopoles by W8JI, where he again talks about the affects on performance etc., with different length feed lines and heights above ground that result in worst case scenarios. So, I'm still not sure what all this business is about with feed line length. Your claim that it is all CB BS may be the case, but these words I keep reading by such dignitaries leaves me to wonder. Avanti recommends again the use of 1/2 wavelength or multiples for the feed line on the Satrun. Avanti claims that it helps improve the polarity separation for the antenna, or as you note "...it keeps the phase separation at the switch box." For years I had heard not to use a resonant feed line like a 1/2 wavelength or multiples, because it encouraged CMC to flow into a low impedance condition more easily. I'm sure the Avanti engineers tested their ideas, both in theory, and in the real world, so I'm still wondering.

I don't know anything really about the cloverleaf designed antenna, but that it has a low angle of radiation horizontally, and is broad banded enough for some multiband use. I have seen them with stub matching and using folded dipoles to feed a modified quad element, as I note above.

What I think Avanti is good at, with these antennas, is using the mysteries of the circuit to build antennas that follow the principals of the circuit to produce the same results in many different configurations, as in the case of the Saturn horizontal side and the AstroPlane. I think in their Sigma IV design Avanti used such skills to make that really long radiator work as you have experienced, in a rather non-apparent collinear manner---even while other's say "...such a long radiator is nothing more than a cloud warmer."

This antenna must be a monster, but I would love to build and test that thing.

 

[bob85]

eddie the only coil in a saturn is the external dc ground shunt for the vertical, it does the same job as the coil in the mk2 sigma2 pictured on the left,
the hortizontal feed looks just like the sigma 2 vertical feed with 3 balun arms screwed into the upper plug,
avanti extended the fiberglass, added 2 extra plugs for the vertical feed and fed it externally through the loop,

i would agree each horizontal antenna would be 150ohm, they seem to get there with a tapped transmissionline setup at each end of the fullwave loops that i have never seen in any other antenna, there is a 3/4wave path up one balun and down the spreader,
it may work something like your second idea,

the astroplane is i believe a form of transmissionline antenna,

the electrical length of the outside of the feedline between feedpoint and ground will effect common mode impedance, thats not the electrical length of the feedline,
the electrical length of the mast will also effect common mode impedance, some lengths/multiples are worse than others,
i would like to see w8ji's new info on the subject,

there are situations where line length is critical and situations where line length makes no difference at all other than the change in losses
i cut my coax to electrical halfwaves becasue its not always practical to take a reading at the feedpoint, i would not chop coax to transform a poor match to something the radio or amp is happy with unless i had no alternative at the time, id make my amps work right not prop them up with different jumper lengths,
the only other time i would be troubled with line length is when phasing or splitting/combining signals,
i doubt avanti would advise 1/2wave lines without reason,

avanti were and still are in a league of their own as far as cb antenna design goes, they made antennas that work great from the best quality tube that people still to this day don't understand,
i think but not sure that their "coinductive" claim could be a combination of regular antenna mode currents and transmissionline mode currents,

yes the saturn is a bit of a monster, its not apple tree friendly.

 

[mackmobile43]

eddie the only coil in a saturn is the external dc ground shunt for the vertical, it does the same job as the coil in the mk2 sigma2 pictured on the left,
the hortizontal feed looks just like the sigma 2 vertical feed with 3 balun arms screwed into the upper plug,
avanti extended the fiberglass, added 2 extra plugs for the vertical feed and fed it externally through the loop,

i would agree each horizontal antenna would be 150ohm, they seem to get there with a tapped transmissionline setup at each end of the fullwave loops that i have never seen in any other antenna, there is a 3/4wave path up one balun and down the spreader,
it may work something like your second idea,

the astroplane is i believe a form of transmissionline antenna,

the electrical length of the outside of the feedline between feedpoint and ground will effect common mode impedance, thats not the electrical length of the feedline,
the electrical length of the mast will also effect common mode impedance, some lengths/multiples are worse than others,
i would like to see w8ji's new info on the subject,

there are situations where line length is critical and situations where line length makes no difference at all other than the change in losses
i cut my coax to electrical halfwaves becasue its not always practical to take a reading at the feedpoint, i would not chop coax to transform a poor match to something the radio or amp is happy with unless i had no alternative at the time, id make my amps work right not prop them up with different jumper lengths,
the only other time i would be troubled with line length is when phasing or splitting/combining signals,
i doubt avanti would advise 1/2wave lines without reason,

avanti were and still are in a league of their own as far as cb antenna design goes, they made antennas that work great from the best quality tube that people still to this day don't understand,
i think but not sure that their "coinductive" claim could be a combination of regular antenna mode currents and transmissionline mode currents,

yes the saturn is a bit of a monster, its not apple tree friendly.

No trees in the way here bob, do the right thing and give the av-190 a good home.

 

[bob85]

tell you what mackduck,
you study antennas, figure out how it works, convey that information to me, and i may send you a photograph of the saturn on my little crank up pole

 

[Marconi]

Bob, about a new article by W8JI. I think I misspoke saying the article was new. I went to his website and noticed it looked different than I recalled. I read some of his stuff on verticals and ground planes with common mode problems. I printed out one articles and it all looked different (I said to myself it must be new) and that is what I was thinking when I posted here.

I didn't go to my paper record and compare his stuff from my past record, but I did suspect at least that his webpage had been updated. For one thing he started using word wrap with some images and groups. The category list on his front page looked much bigger, more articles. I think if there were any new revelations, they were likely in my imagination, but since he doesn't date his articles, he could change stuff without our really knowing.

I recall one article I printed it out, entitled "Ground Plane Verticals" at Ground Plane Verticals. In another thread some of us had been talking about radials, and his reference in the first paragraph to word "radials" caught my eye. I don't think there is anything new in the website that suggest W8JI has changed his mind, so this is not a mind changer.

What was it you said in a post the other day regarding radials and decoupling. I think you mentioned somebody by name, I don't recall who though. I think you also intimated that the big GP on the Saturn with all of its radial elements and peripheral wires would probably be a strong contender. If that is true, and I believe it could be, then why did you suggest to Booty Monster he is probably wasting time adding radials to his 5/8 wave, or did I misunderstand your words.

 

[bob85]

eddie, his site has changed but i have not looked for any new articles,

i don't think the 9 1/4wave radials on a saturn will make it significantly better than 4 1/4wave radials if the antenna is well clear of the ground,
i said if the more radial deal were true then the saturn would take some beating, i cant think of another 5/8wave with so many fat radials,

having played with radial angle years ago with my A/S mighty magnum and more recently talking to cebik about it, i don't see radial angle making a significant difference over average ground if the antenna is mounted high but thats no reason not to experiment,
what you see @ 10 feet off the ground may not be what you see when you raise the antenna well above ground so imho you really want to do the testing with the antenna at the height you will use it,

over poor ground/desert cebik hinted that 90 degree radials could have an advantage when the antenna is not mounted very high,

if im folding radials im folding them up

 

[Marconi]

eddie, his site has changed but i have not looked for any new articles,

Neither have I and I don't intend to try and check it out right now.

i don't think the 9 1/4wave radials on a saturn will make it significantly better than 4 1/4wave radials if the antenna is well clear of the ground, i said if the more radial deal were true then the saturn would take some beating, i cant think of another 5/8wave with so many fat radials,

Here I could give a short response too, but I would like to try and explain why I believe what I believe.

Bob and I were basically the only ones in this discussion, but I don’t really need to be explaining stuff to him. He and others will understand what I say here. They may or may not agree, but I think they will understand. Besides I have been thinking for a while that quite often all we get are remarks about radials, but hardly ever do we read the “why” of the story told.

I hate it, but I’m not physically up to it this year. If I was, I would check out using 4 & 8 radials on my I-10K or my .64 Wolf. It shouldn't be a hard thing to do since the hardware is similar and the radials s/b easy to add. The following ideas are the genesis of the inquiry I did in 2006. I tried again in 2009, but got frustrated with a new model of my Marconi and quit trying to duplicate that previous work. I don't know of another soul that is willing to do this comparison work or that cares enough to test the idea of adding radials and reporting if it makes a difference in performance. I guess we'll have to wait until Booty Monster does his work.

BM, how say you?

Personally I don't think BM will see much difference either, and for sure like Bob says, being close to the Earth may not prove good results. Bob and I might disagree whether adding radials can improve performance or not, but for me this is because I don't believe there is much current flowing in the radials on end fed verticals that are longer than a 1/4 wavelength. I still believe adding radials to my 1/4 wave Marconi 6 will show a measurable increase in performance based on my 2006 field strength readings. If and when I am able to re-do that work and duplicate the results, I will post the error of my ways if I'm wrong---that adding more radials to a 1/4 wave radiator is not worth the time and trouble.

The current distributions for 1/4, 1/2, 5/8 waves are all different, and in order for radials to be effective they need to be located very close to where the maximum current flows. The maximum current that flows in an end fed 1/2 wave element is 1/4 wavelength away from the feed point. The maximum current that flows in a 5/8 wave is about 3/8 of a wavelength away. These characteristics are why the longer antennas are said to perform better---when compared with the feed points at the same heights. It is said their raised current distributions give them an edge. I could stop here and Bob and some others will understand what I’m thinking.

I believe antennas with 1/4 wave radiators really need radials, and this is due to the need for all antennas to have two poles like the dipole. The 1/4 wave is surely missing that other half, they say, if radials are not used. In the 1/4 wave antenna these radials are located at the base of the radiator where the maximum current flows. I say again, IMO this is not the case for the longer wavelength radiators with radials, where the maximum currents are a 1/4 to 3/8 wavelength away.

There is a consideration to be made with the 5/8 wave, where the base is noted to be only 1/8 wavelength away from the bottom current minimum. This provides that radials may be more of a necessity in such cases, because there is some current flowing in this area. I think most of you will understand this to be true, but did you know or think about why 5/8 wave antennas are said to need radials or use them better than end fed 1/2 waves?

You can see this all here in Bob's ezbob modeling software:

Just take a guess as to where the maximum current is flowing in an end fed 1/2 wavelength radiator. Isn't the maximum current near the middle of the 18' radiator, at the current node, while the maximum voltage flowing is near both the ends---at the voltage nodes? And this is true for both the end fed 1/2 wave and the center fed dipole. With this said, where do folks install their GPK’s on end fed 1/2 waves? Could this be why so many people say they see no difference when they add the radial GPK to their A99.

I say, “…maybe it’s because there is very little to no current flowing down there in your end fed 1/2 wave antenna.”

having played with radial angle years ago with my A/S mighty magnum and more recently talking to cebik about it, i don't see radial angle making a significant difference over average ground if the antenna is mounted high but thats no reason not to experiment, what you see @ 10 feet off the ground may not be what you see when you raise the antenna well above ground so imho you really want to do the testing with the antenna at the height you will use it,

Bob, could it be that the Mighty Magnum is a 1/2 wave ground plane and you didn’t see any differences because there wasn’t much if any current flowing down there like I try to explain above?

over poor ground/desert cebik hinted that 90 degree radials could have an advantage when the antenna is not mounted very high,

if im folding radials im folding them up

Hey Bob, tell us why, please tell us why.

I tested my Marconi in 2006 with a FS meter using a remote antenna that was at 23’ high to the base just like the Marconi. I don’t know if that is high enough, but I also found that horizontal radials made more signal than slanted down. However when I added both slanted and horizontal together is where I got the best signals of all.

Come on BM, we're depending on your report even if the antenna is too low.

 

[W5LZ]

Something to think about with those three horizontal 'loops'. If you parallel three 150 ohm resistors, what's the final resistance? Works the same way with impedances too, right?
- 'Doc


Tried to do a 'model' of three loops as shown, but at this time of day, I'm just too lazy to do the plotting. From their placement, the pattern ought to be symmetrical anyway.

 

[bob85]

eddie, even though the mechanical design of the a99 does not allow you to connect radials right at the feedpoint we still saw a large reduction in rfi in the shack and some improvement in signal strength when we isolated and added two 1/4wave radials to the a99 and an improvement in signal with the spiderplane so i can't claim they don't work in at least some situations, how much of that improvement was due to the 1/2waves not been resonant across the frequency spread we use i don't know,

i can't say much about the 6ft radial kits other than they are short floppy in the wind and people get variable results from no claimed improvement to a notable improvement,
another factor is mast and coax outer shield to ground common mode impedance, some folk pick a lucky length and some don't,

i don't know how much difference the radials make on a magnum but they work well for a halfwave endfed and it screws up the tuning if you remove them, likewise on the 5/8waves, as you or the wind removes radials from a sirio 827 the vswr goes up, you would have to retune the antenna between tests and maybe move the transformer tapping point too,


regarding the marconi, adding extra radials may be reducing cm currents on the feedline/mast,
does the stronger field strength equate to stronger signals from distantant stations?,
would you see the same results if the marconi was isolated and choked as indicated by w8ji, im not sure you would but what matters is what works best for your situation,


i understand your interest in the marconi/starduster style antennas, its simple ( nothing to burn out ) light/easy to work on and mount higher on lightweight poles plus it seems to perform well compared to larger antennas at your location and mounting height,
i was happy years ago with my stardusters mounted high, id choose one over a no radial endfed mounted at the same tip height,
we naturally lean towards what we experience as working best for us which draws me to the sigma style and big-mac antennas,
i am also interested in the astroplane, i have a few ideas i will run by you,


end fed 1/2 wave matching system end feed


why would i fold radials up?
because thats the first step in building a sigma style antenna

 

[Marconi]

Maybe I was lumping apples and oranges together when I talked generically about 1/2 wave end fed (EFHW) antennas. The fact that the A99 works without radials and shows a good match, suggests to me that it's not similar to the Mighty Magnum, because you note that it works poorly showing a bad match without the full set of radials as designed. I started to add some words to my previous post, talking about these differences, but I didn't feel like trying to explain the nuances as I see em'.

Just as an aside on the GPK being in the wrong place, and the location of the actual feed point in the A99. I see it differently Bob. I think the A99 is best described like AA5TB does it in his work on "The End Fed Half Wavelength Antenna." W8JI refers to his work somewhere, maybe in the link you just provided. I don't recall what W8JI said in that regard, but his words could cause me to reconsider. When I read AA5TB's work, I recall feeling enlightened by his approach to a big argument on EFHW's. This work is the bases of my opinions of the A99, the location of the feed point, and the need-or-not for radials.

If you look at this image, I suggest the feed point is at the top end of the approximate 12" RG8x pigtail jumper, (the bottom end in the image). For me the SO239 is nothing more than a barrel connector, extending your feed line up to the real feed point. As a result, I see the GPK being installed right on top of the feed point and not at the bottom of the matching/mount section of the antenna where the SO239 is located. If I'm right then I also don't understand the location for the typical Imax GPK install at the bottom as you suggest. Why is there this difference between these two similar type of antennas?

In AA5TB's work, as I read his theory, he attempts to prove that the only counterpoise necessary for this particular antenna is no more than the RG8x pigtail and a GPK is not necessary. He notes that he measures the necessary counterpoise at .05wl using modeling and experimentation. In my post above, I think I made a brief reference to such a situation when I spoke of a possible mitigating solution, and Bob that would be your ideas on GPK radials, chokes, and isolating the mast. I would have been referring to the A99/Imax for sure because they can operate without radials and still show a good match.

I believe your experience with the A99 and the other antenna that Multimode modified, but when I insulated my A99 for the mast, albeit it was not raised like you guys did it, I saw a difference with radials attached. However, my signal reports didn't seem to change when I removed the radials from that setup. So I can't really say what is going on either. This is just going to take more experimentation.

'Doc you could be right, but I thought about three 150 ohm resistors in parallel and dividing by 3 seemed to make sense for my argument. Since I was brain storming I just went with the 50 ohm result. Maybe I was wrong, but I did try to use the formula Rx=1/(1/R1 + 1/R2 + 1/R3) and I still got 50 ohms. I'm not good at electricity and circuits, just dangerous.

I'm pretty sure that the horizontal side of the Saturn will show close to 50 ohms at the feed point and I believe the feed point is fed directly without a matching device and for me that proves it's close.

 

[bob85]

i agree the feedpoint on the a99 is at the top of the pigtail, thats why you can't easilly access it, the top of the tube is not connected to the top of the pigtail so the closest you can get is about 1ft down from the feedpoint if you mount the radials at the bottom of the mounting tube on the a99,
a local has a broken imax for me to strip and look at, im pretty sure they are the same setup,
i have no idea how much that effects how well radials work, it could also be that we had a poor choice of feedline or mast length and with other lengths we may not see the same results,

any of the endfeds like 1/2wave gp's or the 827 can be tuned with or without radials, sometimes you have to move the tap on the coil as well as adjust radiator length, adding radials to the a99 seems to do little to the match,

i gave the matching circuit of an a99 just like the one in the pic ( no rings ) to a friend to use as a temorary antenna that his landlord would not see, after adjusting the radiator wire he could throw it out of the 3rd floor window and talk to his locals with a low vswr and the antenna effectively upside down,

 

[Marconi]

i agree the feedpoint on the a99 is at the top of the pigtail, thats why you can't easilly access it, the top of the tube is not connected to the top of the pigtail so the closest you can get is about 1ft down from the feedpoint if you mount the radials at the bottom of the mounting tube on the a99,

You're right Bob, I never thought about the actual electrical connection in the base tube on the A99, relative to where the radials are attached. I agree that the radials have to be close to something, but now I'm not sure about how this all works in the A99. I don't see how the shield attaches to the tube except at the SO239 like you say, and that could be a foot or two away. Me thinks you have said this before, but I didn't get your point. This may explain why it doesn't appear to work for so many.

I recall trying to add radials to my Wolf 50_11m, a Ringo style 1/2 wave with a coil like the V58, but I could not get close enough (8">) to the feed point I thought. This addition did not make a bit of difference as best I could tell. Now it makes more sense to me, the GP was too far away. Thanks for clearing that up some.

I never asked, but how are you guys mounting the A99, GPK, with the hub at the bottom of the tube? You would have to mount the hub far enough away from the supporting mast for the hub to clear. Do y'all mount the GPK at the bottom of your A99's like folks do with the Imax?

Another thing, I suspect the matching device is placed inside the tube for several good reasons, but one was to help reduce radiation from that point. Reason is, when I took apart the one in the picture I posted above, this is when I found the shield un-tinned and wires flaring out ever where with many loose ends just sticking out. I figured this may be why the antenna was so nasty with TVI. I repaired it as best I could. I hooked it up with some additional wire on top to make the antenna the right length and hung it from a tree without being inside the tube. I worked it like you friend. The repair did cut down on the TVI considerably, but I suspected it still radiated too much where it shouldn't. Back in those days I probably didn't consider CMC, but maybe exposing that matcher really unleashes such currents.

a local has a broken imax for me to strip and look at, im pretty sure they are the same setup,

I think the Imax has fewer windings, but the designs are the same. I hear a lot of complaints about the A99, and some is justified for sure, but in my book the design is remarkable and pretty effective for all that it is, very simple.

i have no idea how much that effects how well radials work, it could also be that we had a poor choice of feed line or mast length and with other lengths we may not see the same results,

I agree. With no radials, no choke, and not being insulated could make such problems even worse. Maybe this is what better decoupling does for us.

any of the endfeds like 1/2wave gp's or the 827 can be tuned with or without radials, sometimes you have to move the tap on the coil as well as adjust radiator length, adding radials to the a99 seems to do little to the match,

I threw all my tuning records away for my A99 last summer, so I'm not sure what that could have shown regarding the effects on tune.

i gave the matching circuit of an a99 just like the one in the pic ( no rings ) to a friend to use as a temporary antenna that his landlord would not see, after adjusting the radiator wire he could throw it out of the 3rd floor window and talk to his locals with a low vswr and the antenna effectively upside down,

I didn't do my A99 matcher upside down, but it worked too. I'm not surprised it worked upside down either. The bottom of mine was only about 15', but I remember it still made TVI, not as bad as it was before I took the thing apart, but still bad.

 

[bob85]

eddie,
i have seen a99 radials mounted in both locations, even saw one with two sets of radials one up one down, they must use some standoff blocks or similar to clear the hub,
the 1/4wave wire radials im sure were connected at the bottom of the tube with a99 isolated and feedline choked just below the antenna,

its years since i cut open an a99 but as far as i can remember the bottom of the coil/top of coaxial tail sits up inside the fiberglass part way up the black threaded section above the mounting tube with the brass cap up inside the white fiberglass,
the mounting tube with coax connector at the bottom reminds me of a poorly made vhf none radaiting sleeve balun,

i can't say i dont like the a99 eddie, i had an a99 on a racal pnumatic mast here for a few years and it worked ok, i would not use one today but i wish i had designed and marketed it,
its a clever antenna that meets many peoples needs,
you get a reasonable performer thats easy on the eye, fairly strong, lighweight, broadbanded and very easy to tune at a reasonable price that meets the cb antenna safety standards.