| Author |
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Galileo
| | Posted on Wednesday, March 06, 2002 - 8:45 pm: | 
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I have an new Imax 2000, and a Maco 5/8th's..I am thinking of using the radial setup off the Maco on the Imax...I used it on my A-99, and it seemed to help...Any ideas on which of these 3 antennas will offer the best performance, parts may be mixed and matched so to speak....The height at base of the antenna will be around 46 feet...Thanks for any help..... |
Bullseye
| | Posted on Wednesday, March 06, 2002 - 10:01 pm: |
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MACO-MACO-MACO-MACO-MACO. Sorry had to get that off my chest. I don't care for the 99 but the other 2 are ok. Personally I like the GUESS |
Taz
| | Posted on Thursday, March 07, 2002 - 7:52 pm: |
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THE IMAX IS THE WAY TO GO! TRUST ME!
I MIGHT ONLY BE 14 BUT I KNOW FROM EXPERIENCE!
THEY EVEN CAME OUT WITH A GROUND PLANE KIT FOR THE IMAX! |
Mikefromms
| | Posted on Monday, June 16, 2003 - 9:08 pm: |
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I thought the astro-plane is better than the I-Max 2000? Oh, that's just at under 30' heights.
mikefromms |
Kc0gxz
| | Posted on Sunday, June 22, 2003 - 7:51 pm: |
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Galileo
The Ground Plane Kit WILL help a little bit on the receive-end only. It will also help to eliminate some TVI. However, it WILL NOT do anything for your transmitted signal.
Or, look at it this way. If a ground plane was REALLY NEEDED on the A-99 or the I-max, then why wasn't it packaged with the antenna?
Read all about it in the "Product Review" that Tech-833 did on the A-99, I-Max 2K, and the GPK for them.
VERY INFORMATIVE AND REVEALING INFORMATION.
73s
Jeff, kc0gxz |
Tech833
| | Posted on Monday, June 23, 2003 - 11:10 am: |
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The reason it was not packaged with the antenna is that would bring the price of the A99 near $100 and the Imax 2000 up to well over $100, and that would knock it out of the price range of many budgets. |
Kc0gxz
| | Posted on Tuesday, June 24, 2003 - 1:32 am: |
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Tech833. Good point.
OK. Lets talk about that. Fiberglass is a much cheaper material to use in the manufacturing of antennas AND, lets not forget the A-99 was on the market BEFORE a GPK was offerd.
In other words, if the A-99 actually had needed a ground plane to operate, of course it would have been in the box along with the antenna. Otherwise, the antenna would have been useless. And I believe it would have still been competitivly priced against its competitors because of the few dollars it actually cost to build the antenna. Or, possibly even a few bucks more ONLY because it doesn't cost the company but a few bucks (if even that) more to make the stupid ground plane radials to begin with.
Back when Antron first put the 99 on the market, they were proud to claim that they had developed a 1/2 wave over a 1/4 (or vice-versa) wave fiberglass antenna that worked without the need of a ground plane. And if I have my facts correct, the GPK wasn't developed until AFTER Antron sold the rights to Solarcon. I could be wrong there. If someone knows, please correct me.
Since the GPK is not needed, to the best of my knowledge, neither Antron or Solarcon have ever made claims that the A-99 WILL TRANSMIT BETTER with a GPK. It will however, help a bit in receive. I only recomend the GPK to my customers that are experiencing a little TVI. The GPK does appear to be of some help there for obvious reasons.
And your point is Jeff?
Well, IF a ground plane WAS needed, then how could Antron ever make the claim that they had a antenna that "DOES NOT REQUIRE A GROUND PLANE". Put it up anywhere. "NO GROUND PLANE NEEDED".
If anyone buys a GPK for any reason other than a TVI problem, the money they are wasting could be put towards a better antenna.
OK, I'm done now.
If anyone knows the above statements about Antron or Solarcon to be incorrect, please don't hesitate to correct me. I can handle it.
PS: Has anyone ever seen or remember a black fiberglass 99?
73s
Jeff, kc0gxz. |
Tech833
| | Posted on Tuesday, June 24, 2003 - 10:36 am: |
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Jeff,
As we have found, the A99 is a simple 1/2 wave antenna, regardless of the advertising claims. It is well known that an end fed 1/2 wave antenna does not 'require' a ground plane to work. HOWEVER, we do know that a ground plane, or counterpoise, will increase the feedline decoupling and therefore, slightly change the radiation pattern and thus, the takeoff angle. Particularly at low altitudes.
I agree that the ground plane will do almost nothing for the on-air performance of an A99, and I have said that many times. However, a ground plane on an Imax 2000 makes quite a lot of difference. It increases the bandwidth, lowers the takeoff angle and makes the feedpoint slightly less lossy. Not to mention better RF decoupling from the feedline. The decoupling is the only effect on the A99, that I can find.
I have had an A99 and an Imax 2000 on the antenna test range both with and without ground planes, so I am not strictly speaking in terms of theory and known operation factors by design. I am speaking from having repeatable test data I gathered myself.
In case you are not aware of my background, I am 'in the business' you might say. I sorta know the pointy end from the connector end of an antenna. |
Kc0gxz
| | Posted on Tuesday, June 24, 2003 - 5:28 pm: |
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Tech833
Yes, I am VERY aware of your background and I love reading your reviews. That's why I take them as gospel and also try to remind others here on the forum to read them.
I have now come to the conclusion that some people think I come across as a know-it-all when they read some of my posts. If that is the case, then I am very sorry. I don't mean to come across that way. And I will be the first to admit that I DO NOT KNOW IT ALL!! I would have no need to come to this forum if that was the case. This forum is like a free school for crying out loud. It's great.
I'd like to explain why I am here.
I have been playing with CB radios since the late 60s and have been in the CB business since the late 70s. I DO NOT have the education and theory that you (Tech833) have. Most of what I know has been passed on to me from other shops that I have worked in and also much of it is self-taught from experience and experiment.
I have (in the past) been to many forums. And they are now, as far as i'm concerned, history. And why? Because no one takes the time to discuss theory.
To my knowledge, the Copper Forum is the ONLY forum that has brought in REAL Techs for us that come from a "professional electronics background". That's why I have dropped all of the other forums. The theory and knowledge you are sharing with us is priceless.
So when I question you, I AM NOT trying to insult or question your intelligents. I question you because, I DON'T KNOW, and I know that you do. So please do not take my questions/answers as a challenge. There was a another post in another section of this forum that I touched on about this in answer to your post about grounding a lowpass filter.
Just about anyone can "hop up" a radio. But not everyone understands what is actually happening with the circuitry when they do. I consider myself fortunate to understand most of it. But like I said before, I don't know it all and I know I NEVER will.
I'm going on 56 years old and I do know a little something about this stuff myself from my 30 some years of experience, but, as long as I can still read and write, I won't hesitate to seek knowledge and will continue to question the masters like you.
If I am being too aggressive or abrasive, or come off as being "challenging" with my questions or answers in my posts, then I WILL do my best to correct it.
Jeff, kc0gxz
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Tech833
| | Posted on Tuesday, June 24, 2003 - 10:48 pm: |
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Jeff,
You are just fine the way you are. I am very glad you are here! You bring up questions that need to be discussed, and I am so very happy to discuss them.
I guess that now would be a good time to admit to the board that I do not know everything either. I may know a lot about a few specific areas, but little outside my area of expertise. I do much more reading here than posting, and I am learning a lot about CB.
Confession: Coming from a broadcasting background, the CB crowd is a culture shock. However, I have never felt so welcome. MY kind of people!! |
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