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I wonder why everybody isn`t using this antenna? .......
Because a rotatable yagi is usually better in most cases. But people do run those...Probably more set them up to be switchable, or even steerable, instead of just one direction. I ran phased dipoles on 40m, and they worked quite well. I switched direction by changing feedline lengths. Some use the "l/c" phaser boxes...But I can throw up my A4 real quick, and do about 7 dbd?? or so, in any direction. Kinda makes the phased dipoles a mute point, except for maybe the lower bands. If you connect with a harness, which I didn't do, you need to transpose the feed for the 2nd antenna. IE: reverse the feedline...That ladder line will have a single twist if I remember correctly. MK |
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O.K..O..K Seems like everybody has forgotton the basics of the polygon of
forces and other uses of vector so I will go over the basics. At the age of 14 yearsI entered the School of Engineering and Navigation where they hashed things from first principles, Since I had little schooling during those war years it gave me an accelerated course on what I had missed during those schoolless years which meant a lot of homework and I had to work like hell. From the name of the school it was evident that I would get a quick introduction on vectors for forces and navigation .. This went as follows: When you swim across a swimming pool then you can swim point to point. If you swim across a river and tried to swim point to point you finish up on the other side but down, stream thus to get to the original point of the endeavor you must swim upstream. If you are a ship or a plane it is obvious that you must have enought fuel to get from point to point so this becomes very important. Thus going back to the river swim you can draw a vector or line that follows the path you took first to cross the river. Since you have units such as time and distance you can draw that line in scalar form. Then you add on to the tail end of the line the journey upstream again in scalar form which will be something less than a 90 degree angle. If you then look back at the point that you started from it becomes obvious that when you swim across stream the angle you must follow is the angle which is shown from the beginning of the triangle to the point that you finished up. Next time you are on a plane look downwards and pick up the flight pattern of small private planes and you will see that their flight path is different from the angle projected by the fuselage All this is in accordance with Newton's law that 'every action has an equal and opposite reaction.' Now look below at my original post to what I said and you will see that I applied a scalar drawing that consisted of many scalae directions in the same way a sailing ship would do if it had to keep changing direction to get to shore. The first vector drawn for an element with known phase and current was drawn which happened to be a vertical line of known length. The next line was then added at the end to reflect the current and phase of the next element chosen and then onto the next element chosen. But this element presented a phase and current that was equal and opposite to the one previously drawn which meant that I was back to the tail end of my first vector chosen ! Thes two elements are termed destructive In fact this happened several times where vectors cancelled each other so we are just left with a singe vector in our scalar drawing .This meant to get back to the point of origin and remembering Newton's law previously alluded to the scalar drawing it represents a vector that is equal to the starting vector drawn, THE SAME PHASE and same CURRENT. Thus the polygon reflects an array where the phase is constant but the currents are ADDITIVE This represents the radiation pattern of a figure eight EXCEPT all the radiation is now to one side of the feed point and comprising of a single and larger circle. All of this reflects exactly what I stated below except I assumed that the pologon phase drawing was already known to all, for which I apologise. With NEC I constructed a model that closely followed this format though the real world did not make elements exactly equal but when I rehashed in my mind the basic priciples the polygon aproach verified that this aproach does give extraordinary front to back/rear figures that gave rise to mistrust of the softwear being used where you may remember that I commented on a model that I made and where the response was that the f/b was to high a point that had troubled me for many a month. Sorry for the long winded response which reflects what I have gone thru with my postings which apparently projected me as a total fool that gave rise to dirisive comments. Now I ask again, is there any written work that pertains to max gain and f to b/rear being on the same frequency? Best regards to all, no hard feelings Art KB9MZ................XG " wrote in message news:dySVd.30807$r55.174@attbi_s52... I have just come to realise that if one drew a polygon of element phases in a array and all elements were 180 degrees to its companion element and excluding the driven element, the max gain and max front to back will occur at the SAME frequency! Until now I was of the understanding that these two max figures could not occur at the same frequency. Is there anything written about this possibility? Regards Art |
Art If your question is "is there any written work that pertains to how gain and sidelobes are related", the answer is Yes. I dont know where back issues of the IRE Proceedings can be found. But, the Proceedings of the Professional Group on Antennas will have so much information on current distribution on a planer array that you may not have enough time left to read it all. The current distribution across an antenna aperature has been studdied very seriously. I am not qualified to discuss phased arrays. I am convinced that max gain will not be acheived with the same current distribution as for minimum side lobes. I realize that you write only "back lobes". But, thats a side lobe at that special angle I am rather simple minded when it comes to phased arrays. I use Referance Data For Radio Engineers as a referance book. It has alot of information on phased arrays. I suspect all the information I have has already been concidered by you. Jerry " wrote in message news:2w_Xd.52445$Ze3.8223@attbi_s51... O.K..O..K Seems like everybody has forgotton the basics of the polygon of forces and other uses of vector so I will go over the basics. At the age of 14 yearsI entered the School of Engineering and Navigation where they hashed things from first principles, Since I had little schooling during those war years it gave me an accelerated course on what I had missed during those schoolless years which meant a lot of homework and I had to work like hell. From the name of the school it was evident that I would get a quick introduction on vectors for forces and navigation . This went as follows: When you swim across a swimming pool then you can swim point to point. If you swim across a river and tried to swim point to point you finish up on the other side but down, stream thus to get to the original point of the endeavor you must swim upstream. If you are a ship or a plane it is obvious that you must have enought fuel to get from point to point so this becomes very important. Thus going back to the river swim you can draw a vector or line that follows the path you took first to cross the river. Since you have units such as time and distance you can draw that line in scalar form. Then you add on to the tail end of the line the journey upstream again in scalar form which will be something less than a 90 degree angle. If you then look back at the point that you started from it becomes obvious that when you swim across stream the angle you must follow is the angle which is shown from the beginning of the triangle to the point that you finished up. Next time you are on a plane look downwards and pick up the flight pattern of small private planes and you will see that their flight path is different from the angle projected by the fuselage All this is in accordance with Newton's law that 'every action has an equal and opposite reaction.' Now look below at my original post to what I said and you will see that I applied a scalar drawing that consisted of many scalae directions in the same way a sailing ship would do if it had to keep changing direction to get to shore. The first vector drawn for an element with known phase and current was drawn which happened to be a vertical line of known length. The next line was then added at the end to reflect the current and phase of the next element chosen and then onto the next element chosen. But this element presented a phase and current that was equal and opposite to the one previously drawn which meant that I was back to the tail end of my first vector chosen ! Thes two elements are termed destructive In fact this happened several times where vectors cancelled each other so we are just left with a singe vector in our scalar drawing .This meant to get back to the point of origin and remembering Newton's law previously alluded to the scalar drawing it represents a vector that is equal to the starting vector drawn, THE SAME PHASE and same CURRENT. Thus the polygon reflects an array where the phase is constant but the currents are ADDITIVE This represents the radiation pattern of a figure eight EXCEPT all the radiation is now to one side of the feed point and comprising of a single and larger circle. All of this reflects exactly what I stated below except I assumed that the pologon phase drawing was already known to all, for which I apologise. With NEC I constructed a model that closely followed this format though the real world did not make elements exactly equal but when I rehashed in my mind the basic priciples the polygon aproach verified that this aproach does give extraordinary front to back/rear figures that gave rise to mistrust of the softwear being used where you may remember that I commented on a model that I made and where the response was that the f/b was to high a point that had troubled me for many a month. Sorry for the long winded response which reflects what I have gone thru with my postings which apparently projected me as a total fool that gave rise to dirisive comments. Now I ask again, is there any written work that pertains to max gain and f to b/rear being on the same frequency? Best regards to all, no hard feelings Art KB9MZ................XG " wrote in message news:dySVd.30807$r55.174@attbi_s52... I have just come to realise that if one drew a polygon of element phases in a array and all elements were 180 degrees to its companion element and excluding the driven element, the max gain and max front to back will occur at the SAME frequency! Until now I was of the understanding that these two max figures could not occur at the same frequency. Is there anything written about this possibility? Regards Art |
Thank you for your polite response. Hopefully the written description of my
thought processes will satisfy a few tho not probably all Regards Art " wrote in message news:dySVd.30807$r55.174@attbi_s52... I have just come to realise that if one drew a polygon of element phases in a array and all elements were 180 degrees to its companion element and excluding the driven element, the max gain and max front to back will occur at the SAME frequency! Until now I was of the understanding that these two max figures could not occur at the same frequency. Is there anything written about this possibility? Regards Art |
Sorry, Art, but the reason I don't appreciate your ideas isn't because I
don't understand vectors or analysis from first principles or because I have some sort of prejudice against something in your background. It's simply that you're unable to communicate your ideas in a way I can understand them and, for all your many postings, I've yet to see any data that show you've done something extraordinary. I can only speak for myself, but suspect that some others might be in the same boat. Roy Lewallen, W7EL wrote: O.K..O..K Seems like everybody has forgotton the basics of the polygon of forces and other uses of vector so I will go over the basics. At the age of 14 yearsI entered the School of Engineering and Navigation where they hashed things from first principles, Since I had little schooling . . . |
Well we shall see Roy, but I find it hard to believe that you
with your antenna knoweledge plus being an engineer do not understand vectors. I can only believe that American education skirts this issue but then all of my engineering books including those by known antenna engineering gurus dwell upon it as well as authors in subjects such as classical electromechanical fields. Frankly, I see you as an expert in the field with long experience and as such feel that all is known about antennas and you cannot contemplate the idea that this is not so and you of all people missed the importance of what I stated. This is very much like the editing of a movie when it is found that the most interesting parts finished up on the cutting room floor as it was deemed insignificant. If what I state is confirmed then I will present it to the Radcom people since QST is now firmly in the hands of experts that believe all is known and has lost touch with the experimentor to which many of the ham fraternity still belong. I am aware that to some I am a poor communicator, but I went out of my way to clearly inform people on the subject of vectors and carefully tied the subject back to my original post such that those with a non science background can follow step by step the trend of thought of my original posting. Regards Art "Roy Lewallen" wrote in message ... Sorry, Art, but the reason I don't appreciate your ideas isn't because I don't understand vectors or analysis from first principles or because I have some sort of prejudice against something in your background. It's simply that you're unable to communicate your ideas in a way I can understand them and, for all your many postings, I've yet to see any data that show you've done something extraordinary. I can only speak for myself, but suspect that some others might be in the same boat. Roy Lewallen, W7EL wrote: O.K..O..K Seems like everybody has forgotton the basics of the polygon of forces and other uses of vector so I will go over the basics. At the age of 14 yearsI entered the School of Engineering and Navigation where they hashed things from first principles, Since I had little schooling . . . |
On Thu, 10 Mar 2005 20:30:15 GMT, "
wrote: Well we shall see Roy, but I find it hard to believe that you with your antenna knoweledge plus being an engineer do not understand vectors. This in response to Roy's post that states in part: "...but the reason I don't appreciate your ideas isn't because I don't understand vectors." [snip] I am aware that to some I am a poor communicator, Here is the problem, simply stated. but I went out of my way to clearly inform people on the subject of vectors and carefully tied the subject back to my original post such that those with a non science background can follow step by step the trend of thought of my original posting. We don't need a long convoluted pseudo treatise on vectors, give us some raw meat that simply states what it is that you're trying to/are doing. And, I have to ask since it is the subject, why is necessary or important to have max gain and F/B at the same frequency? |
Oh come on Wes look at your last posting where you poked fun at the idea of
a polygon phasor array. And look at the other postings where it was obvious that many were not familiar with the same and needed more direction. Look at Roy, he admitted he knows nothing about the subject which when he next argues with the like of Cecil and others I will now have to think twice instead of accepting his typical riposte that he supplies. But I give Roy credit for being honest in the face of personal embarassment regarding his lack of knoweledge You say it was not necesary to provide a long convoluted pseudo treatise on vectors but many asked for it and you made a joke of the idea, Regarding front to rear occuring at the same frequency. An operator wants as much gain as possible when communicating so he does not need to resort to more power than needed. For best communication it is nice to block of interference to the rear and thus he needs best front to rear at the frequency of communication even tho it is of interest that he had better rejection at a lower frequency. The fact of the matter is that it is not the frequency being used, he has to live with a lesser value of rejection, your opinion may well be different. Now you also remarked that you do not want explanations, just the meat. I gave what you call a "treatise" that explained the theoretical underpinnings of what I have stated. It would be unwise at this point to declare success without not only having a NEC model to confirm it but also a 20 meter antenna and not say a 144 meg equivalent. Today we had snow, wind and rain so I could not complete the job.If by chance the antenna gives a third aproval i.e.Nec model then polygon discussion plus the antenna then I will forward it to RADCOM for peer review. It is at that time you can vent your displeasure that you rejected my offer to share the actual mathematical and physical findings. If you were looking for a way to undermine what I had stated then my " treatise" now arms you with the knoweledge to disprove what I have stated as it is one factor that convinces me of my origonal findings. If you need more information regarding vectors I will be happy to aid you in your quest Regards Art...KB9MZ....XG "Wes Stewart" wrote in message ... On Thu, 10 Mar 2005 20:30:15 GMT, " wrote: Well we shall see Roy, but I find it hard to believe that you with your antenna knoweledge plus being an engineer do not understand vectors. This in response to Roy's post that states in part: "...but the reason I don't appreciate your ideas isn't because I don't understand vectors." [snip] I am aware that to some I am a poor communicator, Here is the problem, simply stated. but I went out of my way to clearly inform people on the subject of vectors and carefully tied the subject back to my original post such that those with a non science background can follow step by step the trend of thought of my original posting. We don't need a long convoluted pseudo treatise on vectors, give us some raw meat that simply states what it is that you're trying to/are doing. And, I have to ask since it is the subject, why is necessary or important to have max gain and F/B at the same frequency? |
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