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End Fed 1/2 wave antenna

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  #57  
Old 05-20-2012, 02:12 PM
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Quote:
Originally Posted by HomerBB View Post
I was just reporting everything on the MFJ screen.
I understand Homer. My meter probably does all of the stuff you reported, but each result is under a different function key on my meter, and each is produced by itself, so your meter is more versatile than the Autek VA1 in that regard.
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  #58  
Old 05-21-2012, 08:59 AM
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Well Homer, it looks like nobody is interested in this subject...excepting maybe you and me. Even NB or BM haven't popped up appearing curious. I guess you're right this subject is best left in silence, because since you posted your results it's just me and you that have an interest in the truth we both have reported in our real world testing, right or wrong.

I do have another question about your test however.

I note that you didn't record the SWR. You may have don't it however, and the lowest and highest numbers for <2.00:1 SWR is the data points you noted, or so I assume.

I did the math and it indicates the bandwidth for the models with radials is a bit more narrow, than the models without radials. If I'm right in my assumptions here, do you realize this is also another thing that I've reported in regards to my work with my end fed 1/2 wave A99, with and without radials, for some time back?

It was my experience that was the only real thing I noticed when using radials vs. no radials on my A99. The bandwidth curve for the antenna with radials seemed a bit more narrow with more of a bowl shaped curve. The same antenna without the radials showed to be wider and flatter. For me, this alone might suggest that there was some improvement with the efficiency using radials, but that difference was was just too small of a change to really see...just working my radio.

I guess nobody believed me when I reported that either, because it might have shatter a few untested ideas that were claimed for the A99, with and without the GPK. So, I doubt anybody here has ever really checked it out either, excepting maybe you, when you did your testing and report.

So, I might even go so far as to now challenge others to do some testing, and report their findings as well. I know there are a few out there that can do the work, if their not too afraid it will force then to consider something else regarding a GPK, attached or not, to their A99.

My first clue to all this possible BS, that an A99 actually needs x feet of coax to work right, was revealed to me when I tested the match right at the feed point, and I saw no significant difference in the match compared to my using a 14' foot length jumper.
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  #59  
Old 05-21-2012, 01:22 PM
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Originally Posted by Marconi View Post
Well Homer, it looks like nobody is interested in this subject...excepting maybe you and me. Even NB or BM haven't popped up appearing curious. I guess you're right this subject is best left in silence, because since you posted your results it's just me and you that have an interest in the truth we both have reported in our real world testing, right or wrong.
I don't know much about how others feel, but I have noticed that some threads last longer than others. When I started this thread it was merely to share my effort to make and load effectively an end fed 1/2 wave no-radial antenna. Helping you test the effects of a GP on the antenna has been fun and interesting. I speculate that not many are as interested in the likes of the A99 more because they've decided it unworthy of mention in the same breath with more exotic antennas that have odd shapes. But in any case, it's okay with me because I get tired of a given antenna pretty quickly, too.
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Originally Posted by Marconi View Post
I do have another question about your test however.

I note that you didn't record the SWR. You may have don't it however, and the lowest and highest numbers for <2.00:1 SWR is the data points you noted, or so I assume.
Yes, the first column on the left is the SWR. I know some like to see the :1 behind the numbers, but my analyzer seems to think leaving it off is okay so I didn't write it down that way either. Anyone familiar with SWR will do as you've done and assume it is a report of the Standing Wave Ratio.
Quote:
Originally Posted by Marconi View Post
I did the math and it indicates the bandwidth for the models with radials is a bit more narrow, than the models without radials. If I'm right in my assumptions here, do you realize this is also another thing that I've reported in regards to my work with my end fed 1/2 wave A99, with and without radials, for some time back?
Me. too. I didn't do models, but I noticed that trend with the real world testing.
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Originally Posted by Marconi View Post

It was my experience that was the only real thing I noticed when using radials vs. no radials on my A99. The bandwidth curve for the antenna with radials seemed a bit more narrow with more of a bowl shaped curve. The same antenna without the radials showed to be wider and flatter. For me, this alone might suggest that there was some improvement with the efficiency using radials, but that difference was was just too small of a change to really see...just working my radio.

I guess nobody believed me when I reported that either, because it might have shatter a few untested ideas that were claimed for the A99, with and without the GPK. So, I doubt anybody here has ever really checked it out either, excepting maybe you, when you did your testing and report.

So, I might even go so far as to now challenge others to do some testing, and report their findings as well. I know there are a few out there that can do the work, if their not too afraid it will force then to consider something else regarding a GPK, attached or not, to their A99.

My first clue to all this possible BS, that an A99 actually needs x feet of coax to work right, was revealed to me when I tested the match right at the feed point, and I saw no significant difference in the match compared to my using a 14' foot length jumper.
I am not sure about what they are thinking, but I do notice many are enamored of the A99 Exposed thing and that seems to have settled the discussion for them. That's okay with me, too. I don't care about it. Personally, I've read that article a good half dozen times and gotten much of nothing from it except that someone cut the antenna open and took some less than totally revealing photos of it. I suppose that antenna expose's require a modicum of modesty to tantalize the taste buds of imagination.
Anyway, I'm glad to have helped you with whatever I could.
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  #60  
Old 05-21-2012, 03:29 PM
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Quote:
Originally Posted by HomerBB View Post
I don't know much about how others feel, but I have noticed that some threads last longer than others. When I started this thread it was merely to share my effort to make and load effectively an end fed 1/2 wave no-radial antenna. Helping you test the effects of a GP on the antenna has been fun and interesting. I speculate that not many are as interested in the likes of the A99 more because they've decided it unworthy of mention in the same breath with more exotic antennas that have odd shapes. But in any case, it's okay with me because I get tired of a given antenna pretty quickly, too.

Yes, the first column on the left is the SWR. I know some like to see the :1 behind the numbers, but my analyzer seems to think leaving it off is okay so I didn't write it down that way either. Anyone familiar with SWR will do as you've done and assume it is a report of the Standing Wave Ratio.

Me. too. I didn't do models, but I noticed that trend with the real world testing.

I am not sure about what they are thinking, but I do notice many are enamored of the A99 Exposed thing and that seems to have settled the discussion for them. That's okay with me, too. I don't care about it. Personally, I've read that article a good half dozen times and gotten much of nothing from it except that someone cut the antenna open and took some less than totally revealing photos of it. I suppose that antenna expose's require a modicum of modesty to tantalize the taste buds of imagination.
Anyway, I'm glad to have helped you with whatever I could.
Yep, you told us what your goal was in make this 1/2 wave end fed, and I appreciate your help. At the very least this will make a record that can argue some to the ideas that guys get from checking out what's on the local Truck Stop restroom walls.

I saved your report to my disk and it was very small type, so I printed it out and it chopped-off every thing before the Frequency column, and that is why I didn't see the SWR. You may see that where I reposted your report from my hard disk. It had nothing to do with your leaving off the :1 at the end of your SWR information.

If I said I got my bandwidth info from modeling, that was not what I meant to say. My idea for the bandwidth curve differences I've reported for a long time, testing between the A99 with and without radials, goes way back to my first real world testing of the antenna. I can model the A99, but not the matching device, so what I get is a terrible match. Thus I can't get anything constructive even running an SWR scan, so no SWR bandwidth curves in my models for this one. This is probably the big issue from my critics, as to why my models are worthless, because some show a bad match.

I say to them to just check out the models from their favorite guru's, and they won't likely find their antennas to be matched either. So make a real point.

I understand your last remarks too, and I also think that a lot of misunderstanding and miscommunications were leveled about that report. I have found it to be true with some A99's that I've had, and not true at all in most of the other cases.

So I knew the difference, and I posted my ideas on that subject, but no one listened. Again as I've tried to say before, I've found a few times that an A99's acted bad, and many times I could not tell, so IMO those problems are just bad workmanship, and has little to nothing to do with the design, whether the A99 uses the coax as a counterpoise or not.

I take it, you didn't notice such problems with your matching design, right?

Thanks for your help Homer. And you didn't even have a clue what you would find, but nobody else would have even bother.
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  #61  
Old 05-21-2012, 08:53 PM
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I have the antenna in the air using it right now, When conditions are in I do just fine with it DX wise, and local seems to work although there isn't much local going on.
Like you, I have a set of PC speakers in the shack that love to report RF issues. I am currently getting no such squawk from them whether running a little power or not.
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  #62  
Old 05-21-2012, 09:45 PM
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Quote:
Originally Posted by HomerBB View Post
I have the antenna in the air using it right now, When conditions are in I do just fine with it DX wise, and local seems to work although there isn't much local going on.
Like you, I have a set of PC speakers in the shack that love to report RF issues. I am currently getting no such squawk from them whether running a little power or not.
Can't beat that.
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  #63  
Old 05-22-2012, 12:23 PM
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Eddie, you seem to have an idealogy that because GP kits do not and havn't worked for you then they cannot possibly work for anyone or in any other case scenario. I've had results with GP kits on half wave end feds, .64 homebrew and an Antron 99 which I am currently using. I have the mast isolated from the antenna, I do this so that the electrical length of the ground planes cannot be affected by the mast and detune them, I also have a choke on the feed point so as to force CMC's into those very radials and operate at what ever electrical length I want them to, it this case they are 3 quarter wave radials.
Fact - My A99 is no longer a static monster, I no longer or very seldom get static build up which interferes with RX/TX.
Fact - There are 20 breakers in this region ranging from 1 mile to 25 miles and my antenna is on a par with most of them as far as performance is concerned.
Fact - My A99 is equal to a Sirio 827 for breakers 25 miles or more away and I've had an 827
Fact - I DX'd into the United States from the UK on my A99 on 5 watts PEP and 10 watts on a whistle when some local breakers couldn't even break the skin using 100 watts PEP on their antenna's.
Fact - unless you isolate it from the mast and choke your antenna you will NOT force current into those radials and be able to utilize their electrical length to their full potential.
Fact - Strapping a 20 foot mast onto the electrical length of any tuned circuit is an act of madness, ....you wouldn't do it with your driven element so don't do it with your radials.
Crack on old lad.
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Old 05-22-2012, 01:48 PM
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I would also like to add this:- All unbalanced antenna's no matter what they are will try to form a balancing act with what ever they can get their hands on to do the job. Sometimes they will use the ground, sometimes they will use the mast, sometimes they will use the feedline and sometimes they will use a combination of the three. If we allow an unbalanced antenna to makes its own choice of what it needs to perform this balancing act it may not always benefit us as the operator to allow it to do so. This is why we cut coax into electrical half waves etc. In the case of the end fed vertical antenna we balance the antenna with a tuning coil in as far as the impedance is concerned but that isn't always a perfect way of determining the current and voltage maxima of such an arrangement. Very lossy, leaky and undetermined to a certain degree and the antenna will naturally try to find voltage and current balances in other conductive materials i.e the feedline. The trouble with that is that the antenna can actually detune itself in doing so aswell as causing trouble at the operating end with unwanted currents. All we are doing by Isolating the mast and choking it is to try and force those currents into a beneficial determined electrical property of the antenna as much as we can rather than allowing the antenna to detune itself on undetermined mast and feedline lengths etc. Maxwell tells us that all antenna's try to become a dipole and therefore become balanced, end feds do not have a proportional balance for this to happen and they will find anything they can to correct the balance, its up to you as the operator to intercept that search the antenna is performing and try to persuade it to take the alternative route you have provided.
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