still has a hoop at ther bottom .
i wonder how it would do with a coil under the tophat ?
still just a hair under 12 feet tall .
still has a hoop at ther bottom .
i wonder how it would do with a coil under the tophat ?
still just a hair under 12 feet tall .
Booty, I don't understand why it is so difficult for you to understand what the top hat actually does with the signal. I have a dual coil Predator 10K that has both vertical and horizontal holes at the top section where a stinger can place either way. Regardless whether the stinger is placed vertically or horizontally, the antenna on a mobile polarizes in a vertical pattern. However, when the stinger is placed horizontally, it changes the angle of radiation enough to perform differently under different situations. Please take the input and think about it.
I bought one of those new astro planes and it was a piece of junk! What a waste of hard earned money.
so why not eliminate the verticle all together ? like a pair of X's laid down one on top of the other , one being ground and the other being radiator ?
MG did you have a clone/copy of the astroplane or one of these new ones like in the pic ? sirio has a rep for poor quality/durability of their antennas .
Booty, there are antennas designed like that. Special needs and special conditions call for different types of radiation angles and patterns as well as practicality of location and your logistics.
Super Laser, Moonraker and some homemade cubical quad antennas are some "X" style antennas that come to mind for base applications.
but those are standing up not laying down like 2 sets of ground planes off a maco 5/8 without the radials , one set being ground and one set being radiator . know what i mean . if a lil is good is more better ?
Same with beams Booty. On a dual-polarity beam, your un-used polarity serves as your ground plane to the used polarity. For example, on my Gizmo I have (1) 1/4 wave vertical and (1) 1/4 wave horizontal, both have matches on them. The third element serves as the ground radial. For quick reply, I may have the third element and other matched element confused, but the principle is the same.
I also have a little different idea regarding the ground radials in the Gizmotchy, but that would require another thread.
I agree with you that your P10K remains vertically polarized either way it is setup---with either a vertical or horizontal stinger. IMO this situations also applies to base antennas as well.
You also make a claim that this top hat configuration changes the angle of radiation somewhat. I have not found much technical reporting that specifically supports that a top hat will do that, but I also can't really argue either way. On-the-other-hand I have personal experiences that suggest that something is going on when the top hat is physically large enough. Generally speaking, I consider most top hats, that are of a smaller profile, as just being there or included on the antenna to help discourage lightening---and for sure to help in tuning of a shortened radiator when such use is necessary. For a confirmation of my point on this issue, check the AstroPlane patent #3587109 for an idea of when to use a top hat and check what is said about angle of radiation.
So, even though I sometimes find that a top hat style antenna makes a difference, on receiving certain signals, when Iím comparing one to a purely vertical styled antenna---and sometimes I don't. When I do see the top hat respond dramaticaly vs the signal from my full length vertical, I tend to think maybe the top hat in fact responds better to horizontal signals than does the other verticals. A good example of an antenna with a top hat is the AstroPlane. I think we have all hear how well it work DX. When we do we may even hear it said that, even so it does not perform as well locally. I would call that a trade off or compromose. If top hats always acted with such a response as intimated here, I would think we would see and hear about a lot more use of the idea. Signal Engineering talks about this distinction in the promotional material as well, but we have to consider what marketing has done with CB products, so a little caution with information may be a good idea.
Conversely, we can read a lot of reports that technically indicates---nothing beats a full-length element over a shortened element, except maybe when youíre trying to go thru a 14' drive thru with a 102" whip on top of a pickup. Could this be the difference you are seeing 557? I'm not sure really what the deal is. Either way I think we might expect to see some differences, but this is my point of view.
557, I just canít be as categorical as you are about what a top hat may or may not do that really helps, but like I said we hear a lot of radio talk and forum comments about TOA, angle of radiation and such, but the topic seems to be very complex and depends on lots of vague factors which I personally know to be very difficult to understand---and for sure almost impossible for us CB minded folks to measure or calculate. But, when I see a big difference that is a polarity difference it seems to be to be an easier thing to understand. Good thread and I enjoy the banter.
So, maybe you could provide us a link or two that lead you to your conclusions.
I forgot where I ordered the thing. Let's see, the two rods that form the X at the top is supposed to be secrured by a set allen screw. On mine, the set screw only secured on of the rods leaving the other one to fall out if you tipped it to the side. The piece of tubing that screws into where the coax screws into was a mess. The plastic insulator was machined too small for the radiator tube to be inserted enough to catch the treads. I had to ream it out to get it in far enough to hit the treads. Very poor design!
MG is right, the points he talks about can be a problem. First off the set screw he mentions needs to be replaced with a SS set screw if you can find one or a small SS bolt that will fit. After a while in the weather the set screw will set with rust and never be removed. That is probably not very good if you ever want to tighten or loosen to remove the wire elements. The idea in this important connection is the two small holes drilled for the two wires are set with a very small overlap. This is so the two wires will touch as they are entered into the small hub assembly in the top of the top vertical element. When you tighten the set screw against the top wire it is supposed to press against the bottom wire and this process secures both wires inside the small top hub assembly. These two wire must be tight and stay tight in the hub in order to maintain continuity thoughout the entire antenna. This antenna will not work, even when fully assembled, unless all elements are electrically connected very well including the mast support pipe you supply. A good ohm's check with a direct short result between every element is always a good check when you have this antenna going up. If you have a problem then when it comes down, ohm check it first thing.
The stud in the bottom of the radial that screws into the hub assembly under the feed point can be and needs to be a tight fit inside the plastic receiver insulator. Apply some good lube like WD40 to both parts that go together and it should make the job easier.
If you have a knock off, then the other side of the large hub bracket where the top element goes, is designed with what looks like an insulator. The purpose of the insulator was probably done just to allow for the hub bracket to be made as one piece rather than a two piece bracket---as it was in the original. In the original Avanti, the element that goes up, opposite the feed point, and the top element do not screw into the hub or an insulator, it is a metal to metal compression fit on this side. The smaller bottom element goes up inside the larger top element. As I said they are clamped together in the two piece hub bracket. When the insulator was added to the kit, they had to install threaded studs in the ends of the elements. These studs screw into a long nut like an all-thread joiner nut. These elements are not actually insulated from the hub assembly, like it looks. There is a allen head bolt that attaches the insulator housing to the hub bracket and this bolt provides the electrical connection to the nut inside the insulator to the ground side of the antenna. So, we have a grounded antenna with an electrical connection all the way from the feed point to the tip of the wires in the top hat. I'm not totally sure, but I think the direct feeding of the AP is accomplished thru phase shifting somehow of the RF currents in this antenna.
Note: all the small hub assemblies, for the wires, and the three stud ends of elements in this knockoff antenna are crimped to fit tight. They should be very tight iside the elements and should not spin when tunred. If you can't tell by hand twisting, a sure sign is when the elements will turn and cannot tighten up in the insulators. If this happens you may still get a workable connection most of the time, but it will be questionable. If you have a reasonable connection where you do not see a bad SWR readings, then you should be good to operate. Just watch the SWR though. If the SWR ever goes up unexpectedly, then take the antenna down and try to fix it if you can. If you cannot fix it, maybe you could send it to me, I need the parts. I will pay for shipping and if I can fix the part you need, then I will ship it back to you and you pay the shipping. If I have parts and the part goes to another that has not provided parts, then you will pay for parts, labor, and shipping. Right now I just have a full top section with wires that needs fixing.
BTW, I know now why no-one has the Top One for sale anymore, the new Top One is probably on its way to market now. Maybe it will be here soon and maybe it will be better too.
From looking at the pictures however, it looks more like an new shortened Starduster with a gamma matcher. Finally a tunable 1/4 wave type ground plane antenna. Problem will be how do you get up there to tune it or is it really tunable?
you know ....... it would actually make a good dunce hat .
hey coolio ..... put that thing on and go sit in the corner . :lol::lol::lol::lol:
That's a horse of a different color and pretty much a direct statement that relates some understanding that goes well beyond just the senses. Your "real world" comment may not apply. When 557 implies that Booth Monster needs to, "...understand what the top hat actually does with the signal." for me that pretty much implies that 557 knows exactly what the the top actually does. Would you argue that?Originally Posted by Mr. 557
I would be satisfied if 557 came on and said his comment were base on his real world expeniences. I still might agree, and I might even try to convice him of a different point of vies. So, I would naturally ask him to elaborate a little. That is what conversation is all about, a little give and a little take---not just one liner comments.
As I suggested before, this idea of angle of radiation is very complicated, yet it is banded about quite often trying to explain all kinds of effects with radio antennas. One rather commonly know fact about this angle is that increased antenna height actualy lowers this angle. I buy that comment when used and never question the source. It is pretty much good science and common knowledge. But, I would like for somebody to give me a convincing document, study, or vertical antenna modeling that shows that adding a top hat to a vertical antenna will effectively lower the angle of radiation.
I gave a link to a resource that talks about such issues. Please look and see if you can find where Avanti added the top hat to the AstroPlane in order to lower the radiation angle. What Avanti did was design an antenna that physically placed the current node above the voltage node thus producing an improved radiated pattern that shows a lower angle of radiation than previous vertical ground plane antenna designs. The top hat was added to antenna help tune and resonate a shorter radiating element in order to allow the feed point and maximum current node to be raised higher, well above the same for other vertical ground plan antennas, and still remain within FCC guidelines for the maximum tip height of 60' feet for CB operations.
557 and 870 have just repeated what they have heard and it is arguably misinformation.
Some of this information is my opinion and some is from the Avanti Patent #3587109. Show me some report, or modeling, or a technically oriented website, and if it shows I'm wrong, I will agree with your opinion 870 and tell everyone that I was wrong and that you are right. Maybe you would like to argue the merits of my statements?
Just a few things here:
Adding a capacity hat just above an inductor is bad. This is a bad idea.
You can't take the ground radials off of a V58. You need the other half of the antenna for it to work correctly. Please stop saying that.
The Gizmotchy beam does not have a ground radial. It has the other half of the antenna and it too is needed. Actually, they all three work together.
This new abortion from Sirio is just another example of the piece of crap coming out of italy.
People on here are truly lacking the basics of how an antenna works, but are quick to throw out their opinions. :mad2: This doesn't apply to everyone however.
Other than that, this thread is a waste of space.
I suspect that those down radials are likely shorter than 1/4 wavelength considering the connecting hoop is there, but I believe they will respond just like the radials on a Starduster---to help tune and resonate the shortened antenna to a full 1/2 wavelength.