|
Art Unwin KB9MZ wrote:
However he has rejected this aproach. Art, just because I don't buy a Big Mac today doesn't mean that I reject Big Macs. I was just in the mood for an egg sandwich on cinnamon-raisin toast. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Cecil
I understand what you are saying but it is still a rejection That seems to follow a general pattern of late where a stance is taken and all else is rejected sometimes without cause. In this particular case Bart also brought the same subject ( at least I think he did) as something to ponder about and on this very same thread. where you supplied drawings of collinear dipoles. I admit not being able to follow a lot of the to and fro auguements about contraflow movements e.t.c. which to me is the study of individual movements by tracking footprints after the Mall has closed which provides little benefit , but surely Bart's posting gives you something to ponder upon as your present stance has not won over any converts and which could possibly be presented in a different manner to make your case more digestable. Anyway, I bow to your more intimate knowledge of the subject of inductance and that the inclusion suggested adds no value. Best regards Art "Cecil Moore" wrote in message ... Art Unwin KB9MZ wrote: However he has rejected this aproach. Art, just because I don't buy a Big Mac today doesn't mean that I reject Big Macs. I was just in the mood for an egg sandwich on cinnamon-raisin toast. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
On Sat, 31 Jan 2004 19:20:18 GMT, Gene Fuller
wrote: |Yuri, | |You are absolutely correct; this thread has drifted beyond recognition. Actually, as threads go this one isn't all the bad. As the originator of the thread I believe I know what the topic is. Yuri can claim that this is away from the "original problem", however, the original problem, as he calls it, wasn't the topic of the paper to which my original posting pointed. | |Please note that I have never questioned your experiment or your data. I am |merely commenting on the highly unscientific handwaving approach taken RRAA's |most prolific "scientist". | |73, |Gene |W4SZ | |Yuri Blanarovich wrote: |This has become unusually entertaining. |....... snipydyduda |However, I do not believe I have ever encountered a "scientist" who rejected |both experimental and mathematical approaches at the same time. | |73, |Gene |W4SZ | | | | | | Hey, | this is getting off on the tangent, away from the original "problem". | I and Barry W9UCW found, measured differences in the typical loading coil | currents in order of 40 - 60%. See article and pictures on my web www.K3BU.us. | W8JI and flat earth society proclaimed it can't be so. They argued and | "calculated" that current at both ends of a loading coil in quarter wave loaded | radiator has to be the same. W5DXP explained why the current is different, | other sources and past publications affirm that. | | As I mentioned, time permitting, I will put together article explaining what is | happening, describe experiments that can be replicated by non-believers and | elaborate on the significance of the effect on the design of shortened (loaded) | antennas. | | Nobody has argued the seven points I raised earlier, and those who measured, | including W8JI found that current IS different (but still says it is NOT). | | The reality is that current is different, Eznec can't model it, you can | speculate and theorize all you want, it will not revert the Earth to be flat. | Big men will admit they were wrong, thank the enlighteners and RF life goes on. | | Yuri, K3BU.us |
On Sat, 31 Jan 2004 19:52:23 GMT, Richard Clark
wrote: |On 31 Jan 2004 17:24:18 GMT, oUsama (Yuri Blanarovich) |wrote: | |The reality is that current is different, Eznec can't model it | |Hi Yuri, | |I would suggest that you visit a very informative site that says quite |the opposite with: |Roy Lewallen, W7EL, author of EZNEC and Richard Clark, KB7QHC |recommend workarounds to replace the coil with cylinder of similar |size or breaking the coil to number of physical segments with appropriate inductances. | |This may be found at: |http://www.k3bu.us/loadingcoils.htm That's it, point him to an "expert." [g] |
On Sat, 31 Jan 2004 08:04:47 -0600, Cecil Moore
wrote: |Wes Stewart wrote: | | wrote: | |Don't know how. But assuming I can learn how to do that in HTML, I'll | |try to post those files tomorrow. | | As you can see from my home page I'm not, nor do I want to be, a web | page designer. But even I know that you can just ftp your files to | your web page. You don't need to create a link on a page, just tell | us the file name. I do it all the time. | |Thanks for the tips, Wes, and it does work. The names of the .EZ files |are on the .gif graphic that I prepared which illustrates the current |magnitudes and phases for 3/2WL phased arrays. | |http://www.qsl.net/w5dxp/phasesbw.gif I downloaded a couple of them, but I have a question. I opened them using MultiNEC, which reads all of the popular modeling program file formats. The loads did not import, but when I opened the same files in EZNEC 3 I saw them as R+jX loads with only an 'X' value. I learned from Dan, AC6LA, the author of MultiNEC, that some early EZNEC versions save all loads as Laplace and he doesn't read those into MultiNEC. Opening the files in EZNEC 3 and then just resaving them makes the import into MultiNEC work okay, but this makes me suspect that using your earlier files in my later version might be a problem. The documentaion says otherwise though, but to be sure, what are the actual load parameters. I don't want to comment further until I know exactly what you are using. |
Bart Rowlett wrote:
Thanks, Bart. [Lots of good stuff trimmed.] In reality, the common mode impedance to ground of an isolated LC circuit is not infinite. Both the inductor and capacitor have capacitance to space which will provide some 'grounding' effect. At MF through VHF, the components would generally need to be physically very large to have a usefully low common mode impedance to ground however. Seems that answers the phase-reversing coil question. It has to be physically very large. As Kraus suggested, a 1/2WL element coiled up would necessarily be physically very large. It would actually be the physical size of a 1/2WL helical antenna. A pancake coil might work well in that situation. My 75m Texas Bugcatcher coil is also physically very large. -- 73, Cecil http://www.qsl.net/w5dxp "One thing I have learned in a long life: that all our science, measured against reality, is primitive and childlike ..." Albert Einstein -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
I think that there is more to Bart's posting than that!
First the idea given by certain people to model by breaking up the inductance into small parts is nothing but crap and suedo scientific hoodwinking. Since inductance in a coil per unit length is not uniform ( Reg alluded to this also ) any breaking up into parts involves an increase in inductance to maintain resonance. Thus the aproach does nothing more than break up a large part as a means for scientific hood winking for the unsuspecting to assist digestion. It does nothing to bring a dimension less lumped load to an item of the real world which requires a fully dimensioned item.or it's equivalent. If the inductance were to be resonant then it can certainly be replaced by a parallel loop circuit of size of the original real world inductance and where current in versus current out can be ascertained together with any phase when ground is placed in the required position.. The same aproach also covers the actual placement of the coil on any vertical radiator since resonance must be maintained To consider this discussion in any other way is totally pointless and thru time obscures the original intent of the post.and where certain obduration rather than education prevails Best regards Art Unwin KB9MZ....XG "Cecil Moore" wrote in message ... Bart Rowlett wrote: Thanks, Bart. [Lots of good stuff trimmed.] In reality, the common mode impedance to ground of an isolated LC circuit is not infinite. Both the inductor and capacitor have capacitance to space which will provide some 'grounding' effect. At MF through VHF, the components would generally need to be physically very large to have a usefully low common mode impedance to ground however. Seems that answers the phase-reversing coil question. It has to be physically very large. As Kraus suggested, a 1/2WL element coiled up would necessarily be physically very large. It would actually be the physical size of a 1/2WL helical antenna. A pancake coil might work well in that situation. My 75m Texas Bugcatcher coil is also physically very large. -- 73, Cecil http://www.qsl.net/w5dxp "One thing I have learned in a long life: that all our science, measured against reality, is primitive and childlike ..." Albert Einstein -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Art Unwin KB9MZ wrote:
I think that there is more to Bart's posting than that! Of course there is, Art. I just chose to reply to one topic. I respect Bart not only because he is brilliant and knowledgeable, but because he doesn't engage in ad hominem attacks like some other people I know. That being said, I don't think a ground is necessary to cause a phase reversal. A 2WL centerfed dipole has phase reversals even when positioned in free space. I don't see any reason to suspect that a 2WL centerfed helical dipole doesn't exhibit the same phase reversals. If you replace the helical on each side of the phase reversals by straight wires, I don't think the phase reversal will magically disappear in the part of the helical antenna coil that remains. I could be wrong, but common sense seems to work pretty well in the area of antennas (if not for QED. :-) -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
On Sun, 01 Feb 2004 16:49:39 GMT, " Art Unwin KB9MZ"
wrote: First the idea given by certain people to model by breaking up the inductance into small parts is nothing but crap and suedo scientific hoodwinking. Art, As usual you are long on condemnation, and short on facts. 73's Richard Clark, KB7QHC |
"Cecil Moore" wrote in message ... Art Unwin KB9MZ wrote: I think that there is more to Bart's posting than that! Of course there is, Art. I just chose to reply to one topic. I respect Bart not only because he is brilliant and knowledgeable, but because he doesn't engage in ad hominem attacks like some other people I know. Now that Cecil I heartedly agree with, kudo's to Bart since the trend is to attack the man to cover ones inadequacies with respect to the subject at hand. That being said, I don't think a ground is necessary to cause a phase reversal. A 2WL centerfed dipole has phase reversals even when positioned in free space. I don't see any reason to suspect that a 2WL centerfed helical dipole doesn't exhibit the same phase reversals. ** Cecil you are trying to jump the Grand Canyon it two jumps by looking at phase angle alone for picture purposes rather than have the total picture for overall analysis. ** If you replace the helical on each side of the phase reversals by straight wires, I don't think the phase reversal will magically disappear in the part of the helical antenna coil that remains. I could be wrong, but common sense seems to work pretty well in the area of antennas (if not for QED. :-) ** Well common sense can also be intuitive sense which can be in error by 180 degrees. to common people that does not have the backing of MENSA The point I am trying to make is to stay on track with the subject that was raised in the first place as many have now forgotten what the initial point is thus the reactions that are not pertinent. The statement presented by your own hand stated that eznec cannot model it thus leading to conjecture. That you will object to since you are confident by virtue of some aquired knoweledge but has no value unless that analysis is shared by all, and that is clearly not so which has led to wierd suggestions and semantics to overcome that obstacle. My point is that understanding and agreement will only come when clarity is applied as to why Eznec cannot solve the problem. and replace it. It is evident that Eznec cannot deal the way we want with lumped loads, but it is also incapable of working backwards in a complex circuitry mode to formulate an equivalent circuit. This is because the program is reactive rather than proactive with respect to radiation. To be proactive one must be able to transform radiation resistance to many other forms of resistance i.e. skin resistance, coupling and the like .. Fortunately there are other programs out there that can work backwards from lumped loads complex circuit style that can do this ensuring that radiation efficiency is emulated in its entirety. Thus I and I suspect Bart also and not forgetting Reggies comment regarding what every body is ignoring, that for clarity sake to ensure that all are paddling in the same boat is to basically put the inductance as an equivalent circuit in a ' black box" where entry and exit parameters can be compared in a logical manner instead of falling back on 'common sensen So I am calling for collective analysis instead of raising ones voice when talking to someone who does not know your language. Nothing personal and I am not pointing fingers,but I fear that most are in different boats and paddling in multiple direction that if attitudes doesn't change this thread is all for nought. Best regards Art -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
On Sun, 01 Feb 2004 20:36:18 GMT, " Art Unwin KB9MZ"
wrote: Eznec cannot deal the way we want with lumped loads Art, This is baloney. 73's Richard Clark, KB7QHC |
Richard you are so quick to show an example of what Cecil was talking
about.but then it is to be expected. Talk but no walk If you had studied engineering instead of getting a degree in shakespear and shakesperian literature you would have realised that exposing yourself on center stage not only makes you apear effeminate but devoid of factual information to cover your own inadequacy,.which clearly shows now that Roy is not around to hang onto his coattails. Eznec cannot in anyway create a circuit that can emulate a lumped load. If one took a look at the underpinnings of complex circuitry you will immediatly understand that all variables are interconnected with each other for legitamate equivalency. The Eznec program only has a following because of its longevity because of its inability to be proactive in dealing with variables.. For true equivalency everything must be treated as variable for legitamcy until the number crunching is finished.and most modern programs have that ability which does not in anyway demean old antenna programs which are now eclipsed by the new. Frankly Richard you should have stayed in the navy where your particular atributes aparently attracted many that were starved of companionship than being uniterested in physical facts. Art KB9MZ XG "Richard Clark" wrote in message ... On Sun, 01 Feb 2004 20:36:18 GMT, " Art Unwin KB9MZ" wrote: Eznec cannot deal the way we want with lumped loads Art, This is baloney. 73's Richard Clark, KB7QHC |
On Sun, 01 Feb 2004 21:17:20 GMT, " Art Unwin KB9MZ"
wrote: Eznec cannot in anyway create a circuit that can emulate a lumped load. Art, This is baloney. 73's Richard Clark, KB7QHC |
Nothing on that post
"Richard Clark" wrote in message ... On Tue, 27 Jan 2004 05:43:07 -0700, Wes Stewart wrote: On Tue, 27 Jan 2004 00:27:15 -0600, 'Doc wrote: | | |Wes, | Do you really think that it makes ~that~ much |difference? | 'Doc Yes... or no... or maybe, depending on what "it" is and how much difference "it" does or does not make. Regards, Wes Hi Wes, The difference in your examination satisfyingly amounts to: 1.) the absence of ego towering over the problem; 1a.) the corresponding lack of sneer review that reduces the argument to "you won't change my mind"; 2.) the presence of clear unequivocal study of the problem; 3.) less than 1dB. 73's Richard Clark, KB7QHC |
Nothing on that post
"Richard Clark" wrote in message ... On 28 Jan 2004 00:45:14 GMT, (Tdonaly) wrote: Steve wrote, It's more of a math term than an antenna term. I believe this refers to the 'method of moments' used to calculate the far field. Take the currents in all the little sections of the antenna and sum the contributions of each for the total field...like what happens in real life. Steve N. Thanks Steve. The way the fellow used it it sounded like a single quantity the square of which was proportional to the radiation resistance. People who write articles for journals sometimes get a bit fanciful in their terminology. 73, Tom Donaly, KA6RUH Hi Fellows, I dunno. When I read it, it looked like a reference to graphical analysis or the projection of a point that represents a mean within a surface area (which, again, harkens back to the "sinusoidal" current distribution curve). 73's Richard Clark, KB7QHC |
Gee no facts or anything on that one either
"Richard Clark" wrote in message ... On 31 Jan 2004 19:32:18 GMT, (Tdonaly) wrote: I have to eschew Gesundheit |
Nothing again just talk no walk
"Richard Clark" wrote in message ... On Sun, 01 Feb 2004 20:36:18 GMT, " Art Unwin KB9MZ" wrote: Eznec cannot deal the way we want with lumped loads Art, This is baloney. 73's Richard Clark, KB7QHC |
Hmm again no input or facts
"Richard Clark" wrote in message ... On Sun, 01 Feb 2004 21:17:20 GMT, " Art Unwin KB9MZ" wrote: Eznec cannot in anyway create a circuit that can emulate a lumped load. Art, This is baloney. 73's Richard Clark, KB7QHC |
Hmm no facts except calling the kettle black again
Surely there is a post from him with something! "Richard Clark" wrote in message ... On Sun, 01 Feb 2004 16:49:39 GMT, " Art Unwin KB9MZ" wrote: First the idea given by certain people to model by breaking up the inductance into small parts is nothing but crap and suedo scientific hoodwinking. Art, As usual you are long on condemnation, and short on facts. 73's Richard Clark, KB7QHC |
Jimimny this guy is elusive suggests he has something to offer but he has
hidden it well. "Richard Clark" wrote in message ... On 31 Jan 2004 02:18:33 GMT, (Tdonaly) wrote: This is vintage Moore. You were expecting chopped liver? Tom, you and Wes and.... know better. 73's Richard Clark, KB7QHC |
Obscure posting. Is he hitting at the poster again ?
"Richard Clark" wrote in message ... On 31 Jan 2004 17:24:18 GMT, oUsama (Yuri Blanarovich) wrote: The reality is that current is different, Eznec can't model it Hi Yuri, I would suggest that you visit a very informative site that says quite the opposite with: Roy Lewallen, W7EL, author of EZNEC and Richard Clark, KB7QHC recommend workarounds to replace the coil with cylinder of similar size or breaking the coil to number of physical segments with appropriate inductances. This may be found at: http://www.k3bu.us/loadingcoils.htm 73's Richard Clark, KB7QHC |
On Sun, 01 Feb 2004 23:17:56 GMT, " Art Unwin KB9MZ"
wrote: Hmm again no input or facts Hi Art, Exactly. 73's Richard Clark, KB7QHC |
On Sun, 01 Feb 2004 23:16:52 GMT, " Art Unwin KB9MZ"
wrote: Nothing again just talk no walk Art, You think you could add anything instead of agreeing? 73's Richard Clark, KB7QHC |
On Sun, 01 Feb 2004 23:19:38 GMT, " Art Unwin KB9MZ"
wrote: Hmm no facts except calling the kettle black again Surely there is a post from him with something! Art, I've looked, but all you have to offer are your problems of sexuality. 73's Richard Clark, KB7QHC |
Hmmm
He is knocking Roy now but again he is contributing nothing what gives with this guy, does he think he is at an opers ? "Richard Clark" wrote in message ... On Thu, 29 Jan 2004 15:26:44 -0600, Cecil Moore wrote: Einstein once said that all our models are flawed. -- 73, Cecil, W5DXP Maybe because his browser couldn't open pages, and pdf wouldn't work for him. Or was that Galileo? Hi Wes, I am glad you aren't spinning this out like Roy used to. I got tired of those "I'm outta here" responses linked down the page like dominoes. 73's Richard Clark, KB7QHC |
Same stuff
"Richard Clark" wrote in message ... On Fri, 30 Jan 2004 13:54:46 -0800, Jim Kelley wrote: It's a peculiar kind of bird. Like the asian chicken-flu. |
I give up this person has no clothes
"Richard Clark" wrote in message ... On Fri, 30 Jan 2004 19:22:03 -0700, Wes Stewart wrote: But even I know that you can just ftp your files to your web page. You don't need to create a link on a page, just tell us the file name. I do it all the time. This is the up and coming thing of pre-schoolers now. 45% are making their own web sites. They also know EM theory better. 73's Richard Clark, KB7QHC |
On Sun, 01 Feb 2004 23:14:22 GMT, " Art Unwin KB9MZ"
wrote: Nothing on that post I dunno. When I read it, it looked like a reference to graphical analysis or the projection of a point that represents a mean within a surface area (which, again, harkens back to the "sinusoidal" current distribution curve). Art, Write again when you do have something then. 73's Richard Clark, KB7QHC |
On Sun, 01 Feb 2004 23:15:41 GMT, " Art Unwin KB9MZ"
wrote: Gee no facts or anything on that one either Gesundheit |
On Sun, 01 Feb 2004 23:13:26 GMT, " Art Unwin KB9MZ"
wrote: Nothing on that post Hi Wes, The difference in your examination satisfyingly amounts to: 1.) the absence of ego towering over the problem; 1a.) the corresponding lack of sneer review that reduces the argument to "you won't change my mind"; 2.) the presence of clear unequivocal study of the problem; 3.) less than 1dB. 73's Richard Clark, KB7QHC Still less than 1 dB |
|You are absolutely correct; this thread has drifted beyond recognition.
Actually, as threads go this one isn't all the bad. As the originator of the thread I believe I know what the topic is. Yuri can claim that this is away from the "original problem", however, the original problem, as he calls it, wasn't the topic of the paper to which my original posting pointed. Wes, N7WS Sorry again, must be the remnants of Bahama Mammas in me. I didn't realize the precise name of the (new) thread, kinda assuming we are talking "old" stuff. Looks like I have to be more sharper and precise. That Caribbean stuff sure relaxes and blurs things :-) Yuri, C6AYB |
Richard, then please,please provide us all with
the facts that you are holding back and enlighten Cecil and others how Eznec can be manipulated into tackling the problem of replacing a non dimensional inductance to one that has physical dimensions so that all pertinent questions can be answered If Roy has published a later version of Eznec that can handle variables which is now the norm for modern programs more power to him but I am sure he would let us know So Richard you have posted many times on this thread with your normal aloofnes but now is the time surely that you supply the facts. I and many others say Eznec cannot handle it,you say baloney yet your last stab at it proved fruitless This time give us the real skinny on how Eznec can handle it. Since you knocked Roy's socalled poor attitude on one of your latest posts he obviously is not going to return purely to save you. So to prove that it is baloney step forward with the facts which up to now you have not divulged. Yup it is crunch time, we are all waiting for this gottcha that you are poised to declare. We are listening ,show us and especialy Cecil what you are made of, that with one single posting you can put us all to shame Art Unwin KB9MZ.....XG Richard Clark wrote in message . .. On Sun, 01 Feb 2004 23:14:22 GMT, " Art Unwin KB9MZ" wrote: Nothing on that post I dunno. When I read it, it looked like a reference to graphical analysis or the projection of a point that represents a mean within a surface area (which, again, harkens back to the "sinusoidal" current distribution curve). Art, Write again when you do have something then. 73's Richard Clark, KB7QHC |
"Art Unwin KB9MZ" wrote in message m... Richard, then please,please provide us all with the facts that you are holding back and enlighten Richard speak up.... You are on center stage what you have always wanted. We can all see you standing their with your tights on and the ochestra has given you more than one cue but still nothing. We don't mind if you stutter or if your voice is high pitched we are all interested in the facts that you are about to share with respect to Eznec and lumped circuitry. Cum on now, don't be shy, it is your moment on center stage... sieze the opportunity. Let me get you started Eznec can do it by....by... cum on say it Sargent Friday surely told you what your audience is waiting for. No we are not looking at that evr growing pool at your feet we just want what Joe Friday wants the facts,nothing but the facts. I am not going to ignore you anymore, I have succumbed to your need to show everybody your special skills so have at it I am listening to the one who not only threw the first stone but also the second and third stone so now you have my full attention. This thread has obviously come to an end and you have the last word, the facts and only the facts No don't say not enough facts have been given to you like you said on the lightening thread, we will wait while you refresh your memory or put on a clean pair of tights.n fact put on a cumber band at the same time incase you go belly up when you come back. We will wait for you, remember now Eznec can be used to solve the problem to say otherwise is baloney because I...I ....I am now going to share with all the true facts that I have been holding back which is, which is....er...er which is...is....I know , you are trying to expose me for what I am !!!! Art Unwin KB9MZ....XG |
Art Unwin KB9MZ wrote:
My point is that understanding and agreement will only come when clarity is applied as to why Eznec cannot solve the problem. and replace it. The basic problem is that there is a phase shift through every real-world coil. The lumped inductive reactance model that EZNEC uses doesn't account for any phase shift. If one takes a look at the page of Diamond vhf/uhf antennas in QST, one will observe phasing coils in every one of them. The radiation patterns of these antennas cannot be modeled with EZNEC using the simple lumped inductive reactances. I and others have demonstrated a work-around for horizontal phased arrays by simply using multiple sources or phase-reversing stubs. There exists a 1/2WL of wire with an undesirable current phase. Folding it into a 1/4WL stub works to minimize radiation. Mashing it into a coil works to a certain extent. Even fractal folding would probably work to perform that radiation minimizing function while bringing the radiating array elements into physical alignment. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Cecil Moore wrote: Art Unwin KB9MZ wrote: Did you find something wrong with my suggestion above? Nope, nothing "wrong". I just avoid making assertions when I'm not 95% certain that I am correct. Thus, most of the time, I am unresponsive. I am 95% certain that the average humongous mobile loading coil is not "physically small" and is more like a certain percentage of a helical antenna which indeed does obviously demonstrate a net current gradient. It's certainly true that such a coil is not 'electrically' small. 73, Jim AC6XG |
Jim Kelley wrote:
Cecil Moore wrote: Nope, nothing "wrong". I just avoid making assertions when I'm not 95% certain that I am correct. Thus, most of the time, I am unresponsive. I am 95% certain that the average humongous mobile loading coil is not "physically small" and is more like a certain percentage of a helical antenna which indeed does obviously demonstrate a net current gradient. It's certainly true that such a coil is not 'electrically' small. And it seems to me that most of the coil models assume "physically small" coils which leads me to my next question. Are there no models for "physically large" coils? The arguments involving "physically small" coils are only valid for physically small coils. What about all the other coils in the world that are not "physically small"? Seems to me that a helical antenna functions approximately the same above ground or in free space. Where is the virtual ground in free space? -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Richard Clark wrote:
What is more to the issue, is that it doesn't amount to 1dB difference, a fact that is clearly upheld by work outside of EZNEC by Wes. www.qsl.net/n7ws Ahhhh, but the argument was *never* over the dB's of difference. The argument was over whether a current taper exists in a mobile 75m Bugcatcher coil. Wes's modeled distributed coils even possess a current taper as does all but one of the coils measured by W7EL and W8JI. Introducing dB's of difference is just a diversion. "What difference does it make how many angels can dance on the head of a pin?" is one more question that doesn't even come close to answering the original question. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Jim What is electrically smal and compared to what ?.
If one can make a small loop containing a small variable inductance as one would make a variable capacitive form which is what, 1/10 of a wave length and is inserted in Cecils drawing which is more than a wavelength long I would consider that relatively small. Since the circuit generated is purely from the constituents of the original inductance then the relatively small loop can be inserted. Knowing that the radiating surface is the inductance before it was reduced what is to stop inserting the small loop in a black box that has dimensions such that ports can be directly compared.? Cecil has stated that he is is confident that he is correctin his assertions ( and he may well be) he is not interested in counter proposals. Sort of reminds me that Bush also comes from Texas ! We therefore must accept what Cecil says as unreservidly correct.and there is nothing more to be said regarding the technical underpinnings. Either that or attack the man himself which cannot provide resolution. Regards Art "Jim Kelley" wrote in message ... Cecil Moore wrote: Art Unwin KB9MZ wrote: Did you find something wrong with my suggestion above? Nope, nothing "wrong". I just avoid making assertions when I'm not 95% certain that I am correct. Thus, most of the time, I am unresponsive. I am 95% certain that the average humongous mobile loading coil is not "physically small" and is more like a certain percentage of a helical antenna which indeed does obviously demonstrate a net current gradient. It's certainly true that such a coil is not 'electrically' small. 73, Jim AC6XG |
Cecil Moore wrote: Jim Kelley wrote: Cecil Moore wrote: Nope, nothing "wrong". I just avoid making assertions when I'm not 95% certain that I am correct. Thus, most of the time, I am unresponsive. I am 95% certain that the average humongous mobile loading coil is not "physically small" and is more like a certain percentage of a helical antenna which indeed does obviously demonstrate a net current gradient. It's certainly true that such a coil is not 'electrically' small. And it seems to me that most of the coil models assume "physically small" coils which leads me to my next question. Are there no models for "physically large" coils? The arguments involving "physically small" coils are only valid for physically small coils. What about all the other coils in the world that are not "physically small"? Do you mean physically small coils that are, naturally, also electrically small. Or do you mean physically small coils that are somehow electrically large? 73, Jim AC6XG |
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