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Antenna physical size
Art Unwin wrote:
If Kraus said "The radiation is perpendicular to the accelleration" then the book is worthless. Balanis says, speaking of an infinitesimal dipole: "Integrating the complex Poynting vector over a closed sphere, ... results in the power (real and imaginary) directed in the radial direction. Any transverse components of power density, ... will not be captured by the integration even though they are part of the overall power." Apparently, Kraus' assertion is a result of the integration math and does not necessarily correspond to reality. -- 73, Cecil http://www.w5dxp.com |
Antenna physical size
John KD5YI wrote:
It is laughable to think anybody would consider you an authority on the subject, much less a greater authority than Kraus or any other contributor to this group. You really should get some psychiatric help to quell those delusions of grandeur you have. John, to be fair, in another posting, I quoted Balanis as saying: "Any transverse components of power density will not be captured by the [Poynting] integration even though they are part of the overall power." Balanis seems to imply that it is possible for transverse radiation components to exist but get lost inside the math model. -- 73, Cecil http://www.w5dxp.com |
Antenna physical size
Art Unwin wrote:
By the way John, read the book and determine why he points to a pitch angle for best results Thus pitch angle is not at right angles so perhaps you can explain that. Art, don't know if you have Balanis or not, but on page 134 of "Antenna Theory", 2nd edition, his example of a radiation vector from an infinitesimal dipole is not perpendicular to the dipole direction. -- 73, Cecil http://www.w5dxp.com |
Antenna physical size
On Mar 11, 10:50 am, Cecil Moore wrote:
Art Unwin wrote: By the way John, read the book and determine why he points to a pitch angle for best results Thus pitch angle is not at right angles so perhaps you can explain that. Art, don't know if you have Balanis or not, but on page 134 of "Antenna Theory", 2nd edition, his example of a radiation vector from an infinitesimal dipole is not perpendicular to the dipole direction. -- 73, Cecil http://www.w5dxp.com I haven't got that book but it doesn,t matter. The group will chose to believe the books that put it at parallel to the radiator axis. It is easier to belittle the truth rather than put a radiator at say 12 degrees to the earth surface and compute for max horizontal radiation. Repeat but make the radiator parallel. If the program agrees with you then buy it for future proof. I said this before Cecil but this group were frightened to explore for themselves and chose to belittle instead. Many were educated by remembering,few checked things out for themselves. Same goes for small antennas, they confuse small antennas with electrically small antennas big difference. Academia referrs to small electrical antennas when discussing the subject, My antenna is NOT electrically small. Period. Regards Art |
Antenna physical size
I listen to the "little guy against the establishment, and I would be
willing to grant that some "establishment types" can be a little stodgy, and sometimes "illiberal". Bot only if those on the other side will quit pulling out the "noble and plucky inventor", who works to advance science against establishment ridicule. A wiser man than myself who was himself ridiculed by some in the "establishment" once said..... But the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers. But they also laughed at Bozo the Clown. - Carl Sagan - - 73 de Mike N3LI - Delaying any judgment on the antenna at hand, but starting to think that it is looking like a tuned circuit on the end of some coax....... In the absence of any real info, we are left guessing. |
Antenna physical size
"Cecil Moore" wrote in message
... John KD5YI wrote: It is laughable to think anybody would consider you an authority on the subject, much less a greater authority than Kraus or any other contributor to this group. You really should get some psychiatric help to quell those delusions of grandeur you have. John, to be fair, in another posting, I quoted Balanis as saying: "Any transverse components of power density will not be captured by the [Poynting] integration even though they are part of the overall power." Balanis seems to imply that it is possible for transverse radiation components to exist but get lost inside the math model. -- 73, Cecil http://www.w5dxp.com Cecil, I did nothing more than supply a quotation from a respected authority on the subject. I did not support the authority. Art dismissed the quotation without so much as a single reference to any other authority. He did not provide any supporting math or technical papers. Isn't this like saying "It is so (or not so) because I said so. Take my word for it." And he did not answer a single question I asked. Hmmmmmm. At least you supplied another viewpoint from an authority, although you go on to reduce my confidence in the quote with "seems to imply" and "it is possible" (but not certain). 73, John |
Antenna physical size
On Mar 11, 12:37 pm, Michael Coslo wrote:
I listen to the "little guy against the establishment, and I would be willing to grant that some "establishment types" can be a little stodgy, and sometimes "illiberal". Bot only if those on the other side will quit pulling out the "noble and plucky inventor", who works to advance science against establishment ridicule. A wiser man than myself who was himself ridiculed by some in the "establishment" once said..... But the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers. But they also laughed at Bozo the Clown. - Carl Sagan - - 73 de Mike N3LI - Delaying any judgment on the antenna at hand, but starting to think that it is looking like a tuned circuit on the end of some coax....... In the absence of any real info, we are left guessing. 15 years ago I stated that radiation is in the form of pulses,all laughed Since then I have itemised the steps to make the small antenna, all laughed. The info is in the archives many many times but to my knoweledge nobody has tried it for themselves preferring to memorise what the books say. Yes it does look like a tuned circuit on the end of a coax but what if it is? Can you comment on the tilt angle of a radiator to ground to achieve max horizontal polarisation? Are you equipped to ascertain the answer for yourself? If so then do it and explain it to all, real proof you say. Hams can't handle theb truth When the results come out it will prove nothing to this group as they then will revert to attack the method of testing or the tester himself. I already have read one comment that has attacked the volunteer tester and that is with just about zero knoweledge about antennas. How many have come forward to explain to others what Gauss meant by equilibrium? How many have asked what equilibrium means? If anybody read the instructions on how to make it in the archives and followed them then you wouldn't be left guessing Art |
Antenna physical size
John KD5YI wrote:
At least you supplied another viewpoint from an authority, although you go on to reduce my confidence in the quote with "seems to imply" and "it is possible" (but not certain). Those are my guarded words, not Balanis'. :-) -- 73, Cecil http://www.w5dxp.com |
Antenna physical size
On Mar 11, 1:06 pm, "John KD5YI" wrote:
"Cecil Moore" wrote in message ... John KD5YI wrote: It is laughable to think anybody would consider you an authority on the subject, much less a greater authority than Kraus or any other contributor to this group. You really should get some psychiatric help to quell those delusions of grandeur you have. John, to be fair, in another posting, I quoted Balanis as saying: "Any transverse components of power density will not be captured by the [Poynting] integration even though they are part of the overall power." Balanis seems to imply that it is possible for transverse radiation components to exist but get lost inside the math model. -- 73, Cecil http://www.w5dxp.com Cecil, I did nothing more than supply a quotation from a respected authority on the subject. I did not support the authority. Art dismissed the quotation without so much as a single reference to any other authority. He did not provide any supporting math or technical papers. Isn't this like saying "It is so (or not so) because I said so. Take my word for it." And he did not answer a single question I asked. Hmmmmmm. At least you supplied another viewpoint from an authority, although you go on to reduce my confidence in the quote with "seems to imply" and "it is possible" (but not certain). 73, John John, Roy's program is very old and basic, but it is free to use. This radiation question is also very basic. So for once do something for yourself review your results and tell all what is correct or what not is correct and that includes Roy's program i.e. is it reliable if it does not concurr with the books.? This question can be resolved very easily and very quickly tho Roy has never talked about it. People on this group consistently avoid testing this out for themselves possibly because they also distrust NEC programs. If that is the case view the following: You have two vec tors that represent electrical field and magnetic fields each at 90 degrees to each other which provides a resultant vector at 45 degrees. Now we must consider the remainig vector that is named "curl". Now something you can guess at. At what angle must the "curl" vector with reference to the axis of the radiator be placed to verify the statement of 90 degree radiation as stated in books? Do the books confirm that resultant angle via mathematics? Note this also inplies that the magnitude of the resultant vector for the fields is equal to the magn itude of the "curl " vector. Do the books point this out also? Do the work yourself and learn by it Art |
Antenna physical size
Art wrote:
"Can you comment on the tilt angle of the radiator to the ground to achieve max horizontal polarization?" Vertical radiators over the earth are optimally exactly vertical. Were it not so, broadcasters would use tillted towers. An excercise I`ve performed countless times is microwave path establishment and optimization. I`ve bolted the tiny dipole feed into the dish selecting horizontal polarization over vertical polarization in most cases. To establish a path, I set the azimuth using a transit and Coast and Geodetic Survey maps to aim the dish on path. To aim for the horizon as needed for a long path, I simply use a bubble level on the feed horn. As soon as the signal appears, optimizarion begins by refining azimuth, elevation, and polarization for maximum limiter current in the receiver. Never have I seen any adjustment other than azimuth make any change in the signal received. Parallel antennas at both ends of the path are optimum. The same is true with vertical polarization for what is essentially free-space propagation except for the grazing near the middle of the path. Tilt as Art implies it is a myth. Best regards, Richard Harrison, KB5WZI |
Antenna physical size
On Mar 11, 5:10 pm, (Richard Harrison)
wrote: Art wrote: "Can you comment on the tilt angle of the radiator to the ground to achieve max horizontal polarization?" Vertical radiators over the earth are optimally exactly vertical. Were it not so, broadcasters would use tillted towers. An excercise I`ve performed countless times is microwave path establishment and optimization. I`ve bolted the tiny dipole feed into the dish selecting horizontal polarization over vertical polarization in most cases. To establish a path, I set the azimuth using a transit and Coast and Geodetic Survey maps to aim the dish on path. To aim for the horizon as needed for a long path, I simply use a bubble level on the feed horn. As soon as the signal appears, optimizarion begins by refining azimuth, elevation, and polarization for maximum limiter current in the receiver. Never have I seen any adjustment other than azimuth make any change in the signal received. Parallel antennas at both ends of the path are optimum. The same is true with vertical polarization for what is essentially free-space propagation except for the grazing near the middle of the path. Tilt as Art implies it is a myth. Best regards, Richard Harrison, KB5WZI Richard, You are living in the past. Learn how to use a computor then use it to learn for yourself so that you can be a worthwhile contributor instead of a book parrot. First proove it for your self then share findings that you obtain for yourself.Ofcourse that isn't going to happen since you don't want to learn how to use a computor because you hate change. If Roy is a friend of yours ask him to check it out on his computor program or ask anybody who has a computor to check it for you before mounting your podium. with silly statements. Why can't you do that vector trial have you forgotten that ol;d electrical stuff? Does old age give you enough license to live a continual senior moment for days at a time? |
Antenna physical size
"Cecil Moore" wrote in message . net... John KD5YI wrote: At least you supplied another viewpoint from an authority, although you go on to reduce my confidence in the quote with "seems to imply" and "it is possible" (but not certain). Those are my guarded words, not Balanis'. :-) -- 73, Cecil http://www.w5dxp.com Oh, crap, Cecil! I know they were not Balanis' words. The point was that you did not need to supply your own interpretation of Balanis' quote ("seems to imply" and "it is possible"). You could have simply supplied the quote and left it at that just as I did in my original post in this thread. The apparent intention of your "guarded words" was to support your own viewpoint with Balanis' quote. Cheers, John |
Antenna physical size
On Tue, 11 Mar 2008 11:18:08 -0700, Art Unwin wrote:
15 years ago I stated that radiation is in the form of pulses,all laughed Since then I have itemised the steps to make the small antenna, all laughed. In refutation, the proof. The info is in the archives many many times but to my knoweledge nobody has tried it for themselves preferring to memorise what the books say. Yes it does look like a tuned circuit on the end of a coax but what if it is? Actually, if that is what it is, then fine! antennas such as that are perfectly legit. It will almost certainly use the feedline as a large part of the radiator. This antenna bears some resemblance to the Isotron line of antennas. Not for everyone, for sure, but I'm not going to get into a definition war on what comprises a "good" antenna, at least in this case.. But unless there is something new going on - and I don't buy claims of newfangled physics without proofs - especially physics that need to include apparent ability of comprehension on my part, it is another radiating feed line antenna, and not much more. -73 de Mike N3LI - |
Antenna physical size
John KD5YI wrote:
The apparent intention of your "guarded words" was to support your own viewpoint with Balanis' quote. Nope, I don't have a dog in this fight. -- 73, Cecil http://www.w5dxp.com |
Antenna physical size
Art wrote:
"Why can`t you do that vector trial have you forgotten that old electrical stuff? Not completely but it serves little purpose in this arena. I admit that being retired for decades requires me at times to search my memory for awhile to retrieve something stored there but that is where the books come in as reminders. Richard Clark noted that "size counts" appears on page 3 of Ed Laport`s "Radio Antenna Engineering". Richard was right: "---concerns the field around a very short doublet in free space composed of a straight conductor of length l in which a sinusoidal alternating current of frequency f is flowing. The current is assumed to be uniform throughout the length of this doublet." The above exerpt is sufficient to show the field around a very short (elementary) doublet in free space is a function of length l as previously reported from page 864 of Terman`s 1955 opus. The old masters agree. So call me a parrot already. I don`t care. I gave you examples of my experience with microwaves. These showed antennas with the same polarizatiions have the least path loss. Polarization diversity in addition to space and frequency diversity has been used to improve reception and reliability on mivrowave paths. When one polarization, position, or frequency falters, a switch is automatically made to the other alternative. Reliability is greatly improved. Surely other readers have had similar experiences with antenna alignment to receive the best signal. It requires that the antennas be parallel. Crossed antenna polarization on line-of-sight paths causes huge (30 dB?) loss. FM broadcasting began with horizontally polarized antennas. Automobiles using vertically polarized antennas required FM broadcasters to add vertical polarization to serve a mobile audience. Best regards, Richard Harrison, KB5WZI |
Antenna physical size
I'm a little concerned about the authoritative quotes I've seen lately
which state that the field from a conductor is directly proportional to the current in the conductor. While true, it's seemingly being used to support the conclusion that a longer conductor inherently produces a greater field, and by extension, that a larger antenna fundamentally radiates more than a smaller one. Those conclusions are false, and I'll explain why. It's useful to start with the law of conservation of energy. If an antenna is lossless, then all the power fed to it must be radiated. This has to be true regardless of the antenna's size. So how can this be, if the field is proportional to the conductor length? Are longer conductors less lossy than short ones? No, the principle of field being proportional to current and conductor length assumes zero loss, so it has to apply to small and large antennas alike. But so does the law of conservation of energy. The answer to this apparent dilemma is that if you put a fixed *power* into dipoles, say, of various lengths, the current will increase as the antenna gets shorter. This keeps the product of length X current essentially constant, resulting in a nearly constant radiated field for a fixed power input. Another way of expressing the same thing which might be more familiar is that the radiation resistance decreases as the antenna gets shorter. Consequently, the current increases for a given power input. To look at it yet another way, consider that if all the power is to be radiated by both a short and long antenna, the current must be much higher to get the same radiation from a short conductor as a long one. This increase in current becomes dramatic when the antenna gets very small (in terms of wavelength), and that's where one of the problems lies with short antennas. The I^2 * R conductor loss can become not only significant but large even with very good conductors, when the antenna is small. And that's why small antennas are often less efficient than larger ones. It turns out to be due to the fact that the field is proportional to the current and conductor length but not for the simplistic reasons being implied. But the poor efficiency of a small antenna is a practical matter which can be mitigated, often to a very great extent, by using large and good conductors for example. It's not due to any fundamental rule of radiation. Another reason that looking only at the current - length rule for field strength can be misleading is that the radiated field is the sum of many incremental fields from the various parts of the antenna. Some antennas, such as small loops or a W8JK beam, create fields which fully or partially cancel in all directions. So the fields generated by the individual parts of the antennas are greater than they'd otherwise need to be in order to generate the resulting total radiation field. This further reduces the efficiency of these antenna types, since higher currents are being required to generate the larger fields. Still, though, the law of conservation of energy applies -- except for power lost to heating, all the power applied ends up in the radiated field, even if it takes a much larger local (near) field in order to produce it. There are other consequences of making an antenna small. One is that if you do succeed in making it efficient by keeping loss very low, the bandwidth will be very narrow. Another is that the very small radiation resistance is accompanied by a very high feedpoint reactance. Any practical network used to match this to the common 50 + j0 ohms required by most transmitters and receivers will also be likely to be quite lossy due to very high currents and/or voltages within the network. And, like the antenna, most reasonably efficient matching networks will tend to be very narrowbanded when being required to effect such an extreme impedance transformation. The considerations above are why small antennas are invariably narrowbanded, inefficient, or both, and if the matching network loss is included in the efficiency calculation, virtually never very efficient. Claims to the contrary are heard all the time. But under scrutiny and controlled test conditions, they don't fare any better than water dowsing. Roy Lewallen, W7EL |
Antenna physical size
On Mar 12, 1:54 am, Roy Lewallen wrote:
I'm a little concerned about the authoritative quotes I've seen lately which state that the field from a conductor is directly proportional to the current in the conductor. While true, it's seemingly being used to support the conclusion that a longer conductor inherently produces a greater field, and by extension, that a larger antenna fundamentally radiates more than a smaller one. Those conclusions are false, and I'll explain why. It's useful to start with the law of conservation of energy. If an antenna is lossless, then all the power fed to it must be radiated. This has to be true regardless of the antenna's size. So how can this be, if the field is proportional to the conductor length? Are longer conductors less lossy than short ones? No, the principle of field being proportional to current and conductor length assumes zero loss, so it has to apply to small and large antennas alike. But so does the law of conservation of energy. The answer to this apparent dilemma is that if you put a fixed *power* into dipoles, say, of various lengths, the current will increase as the antenna gets shorter. This keeps the product of length X current essentially constant, resulting in a nearly constant radiated field for a fixed power input. Another way of expressing the same thing which might be more familiar is that the radiation resistance decreases as the antenna gets shorter. Consequently, the current increases for a given power input. To look at it yet another way, consider that if all the power is to be radiated by both a short and long antenna, the current must be much higher to get the same radiation from a short conductor as a long one. This increase in current becomes dramatic when the antenna gets very small (in terms of wavelength), and that's where one of the problems lies with short antennas. The I^2 * R conductor loss can become not only significant but large even with very good conductors, when the antenna is small. And that's why small antennas are often less efficient than larger ones. It turns out to be due to the fact that the field is proportional to the current and conductor length but not for the simplistic reasons being implied. But the poor efficiency of a small antenna is a practical matter which can be mitigated, often to a very great extent, by using large and good conductors for example. It's not due to any fundamental rule of radiation. Another reason that looking only at the current - length rule for field strength can be misleading is that the radiated field is the sum of many incremental fields from the various parts of the antenna. Some antennas, such as small loops or a W8JK beam, create fields which fully or partially cancel in all directions. So the fields generated by the individual parts of the antennas are greater than they'd otherwise need to be in order to generate the resulting total radiation field. This further reduces the efficiency of these antenna types, since higher currents are being required to generate the larger fields. Still, though, the law of conservation of energy applies -- except for power lost to heating, all the power applied ends up in the radiated field, even if it takes a much larger local (near) field in order to produce it. There are other consequences of making an antenna small. One is that if you do succeed in making it efficient by keeping loss very low, the bandwidth will be very narrow. Another is that the very small radiation resistance is accompanied by a very high feedpoint reactance. Any practical network used to match this to the common 50 + j0 ohms required by most transmitters and receivers will also be likely to be quite lossy due to very high currents and/or voltages within the network. And, like the antenna, most reasonably efficient matching networks will tend to be very narrowbanded when being required to effect such an extreme impedance transformation. The considerations above are why small antennas are invariably narrowbanded, inefficient, or both, and if the matching network loss is included in the efficiency calculation, virtually never very efficient. Claims to the contrary are heard all the time. But under scrutiny and controlled test conditions, they don't fare any better than water dowsing. Roy Lewallen, W7EL I go along with that but only if you meant electrically small antennas. Some of the group confuse electrically small with physically small. Richard for years has viewed them as being the same despite my corrections. Fractional wavelength is electrically small tho some would say it must be less than 0.1 WL Art |
Antenna physical size
On Mar 11, 9:54 pm, Mike Coslo wrote:
On Tue, 11 Mar 2008 11:18:08 -0700, Art Unwin wrote: 15 years ago I stated that radiation is in the form of pulses,all laughed Since then I have itemised the steps to make the small antenna, all laughed. In refutation, the proof. The info is in the archives many many times but to my knoweledge nobody has tried it for themselves preferring to memorise what the books say. Yes it does look like a tuned circuit on the end of a coax but what if it is? Actually, if that is what it is, then fine! antennas such as that are perfectly legit. It will almost certainly use the feedline as a large part of the radiator. This antenna bears some resemblance to the Isotron line of antennas. Not for everyone, for sure, but I'm not going to get into a definition war on what comprises a "good" antenna, at least in this case.. But unless there is something new going on - and I don't buy claims of newfangled physics without proofs - especially physics that need to include apparent ability of comprehension on my part, it is another radiating feed line antenna, and not much more. -73 de Mike N3LI - On a more serious note, you consistently refer to heating problems or feed line radiation. Will you be good enough to explain what creates these functions and why you can thus refer to them as my problems? To put things in order. My antenna does not require a ground system Electrical WL is alwaysa WL or more in length. Measurements at the antenna are devoid of reactance at the point of resonance Measurements at the transmitter is the same. Movement away from resonance supplies reactance. Conformance with Maxwells laws are adhered to. Now all these facts have been stated many times before, yet you repeat your views so the actions that create feedline radiation and antenna melting problems are totally different to what I understand. When moving away from the resonant point it provides reactance in addition to the resistance All frequencies have more than one resonant point |
Antenna physical size
On Wed, 12 Mar 2008 07:42:54 -0700, Art Unwin wrote:
But unless there is something new going on - and I don't buy claims of newfangled physics without proofs - especially physics that need to include apparent ability of comprehension on my part, it is another radiating feed line antenna, and not much more. -73 de Mike N3LI - On a more serious note, you consistently refer to heating problems or feed line radiation. Will you be good enough to explain what creates these functions and why you can thus refer to them as my problems? To put things in order. You might have me mixed up with someone else, Art. I have commented on feedline radiation in this context, but my only posts about heating problems was with that antenna produced by the U of Delaware in which the initial press release touted that the original antenna was so efficient that it burnt up when 100 watts was applied. Subsequently removed from later text. I don't think that many people would believe that an antenna that melts is radiating efficiently. Otherwise I only predict that your feedline likely will radiate, not that it will heat. My antenna does not require a ground system Electrical WL is alwaysa WL or more in length. Measurements at the antenna are devoid of reactance at the point of resonance Measurements at the transmitter is the same. Movement away from resonance supplies reactance. Conformance with Maxwells laws are adhered to. Now all these facts have been stated many times before, yet you repeat your views so the actions that create feedline radiation and antenna melting problems are totally different to what I understand. Sigh... would you like to point out the post(s) where I said all this? Aside from that, I expect the feedline to radiate. -- -73 de Mike N3LI - |
Antenna physical size
On Mar 12, 8:22 pm, Mike Coslo wrote:
On Wed, 12 Mar 2008 07:42:54 -0700, Art Unwin wrote: But unless there is something new going on - and I don't buy claims of newfangled physics without proofs - especially physics that need to include apparent ability of comprehension on my part, it is another radiating feed line antenna, and not much more. -73 de Mike N3LI - On a more serious note, you consistently refer to heating problems or feed line radiation. Will you be good enough to explain what creates these functions and why you can thus refer to them as my problems? To put things in order. You might have me mixed up with someone else, Art. I have commented on feedline radiation in this context, but my only posts about heating problems was with that antenna produced by the U of Delaware in which the initial press release touted that the original antenna was so efficient that it burnt up when 100 watts was applied. Subsequently removed from later text. I don't think that many people would believe that an antenna that melts is radiating efficiently. Otherwise I only predict that your feedline likely will radiate, not that it will heat. My antenna does not require a ground system Electrical WL is alwaysa WL or more in length. Measurements at the antenna are devoid of reactance at the point of resonance Measurements at the transmitter is the same. Movement away from resonance supplies reactance. Conformance with Maxwells laws are adhered to. Now all these facts have been stated many times before, yet you repeat your views so the actions that create feedline radiation and antenna melting problems are totally different to what I understand. Sigh... would you like to point out the post(s) where I said all this? Aside from that, I expect the feedline to radiate. -- -73 de Mike N3LI - Well I may have mixed people up. Sorry about that. What will cause the feedline to radiate given the facts I have provided? Art |
Antenna physical size
Art Unwin wrote:
On Mar 12, 8:22 pm, Mike Coslo wrote: On Wed, 12 Mar 2008 07:42:54 -0700, Art Unwin wrote: But unless there is something new going on - and I don't buy claims of newfangled physics without proofs - especially physics that need to include apparent ability of comprehension on my part, it is another radiating feed line antenna, and not much more. -73 de Mike N3LI - On a more serious note, you consistently refer to heating problems or feed line radiation. Will you be good enough to explain what creates these functions and why you can thus refer to them as my problems? To put things in order. You might have me mixed up with someone else, Art. I have commented on feedline radiation in this context, but my only posts about heating problems was with that antenna produced by the U of Delaware in which the initial press release touted that the original antenna was so efficient that it burnt up when 100 watts was applied. Subsequently removed from later text. I don't think that many people would believe that an antenna that melts is radiating efficiently. Otherwise I only predict that your feedline likely will radiate, not that it will heat. My antenna does not require a ground system Electrical WL is alwaysa WL or more in length. Measurements at the antenna are devoid of reactance at the point of resonance Measurements at the transmitter is the same. Movement away from resonance supplies reactance. Conformance with Maxwells laws are adhered to. Now all these facts have been stated many times before, yet you repeat your views so the actions that create feedline radiation and antenna melting problems are totally different to what I understand. Sigh... would you like to point out the post(s) where I said all this? Aside from that, I expect the feedline to radiate. -- -73 de Mike N3LI - Well I may have mixed people up. Sorry about that. What will cause the feedline to radiate given the facts I have provided? Remember that I do not have all the facts here. There are certainly assertions. One of the "problems" with scientific inquiry is that it helps to have an actual device to test. There appears to be one device (two maybe? and it is in the hands of a snowbound ham in the great north. I really want to see the test results. So I just don't know. I trust that you would expect no less from me. I have to go on the limited description, and that description sounds like the tuned circuit on the end of coax, giving rise to an unbalanced condition, from there, we can expect feedline radiation. I understand your frustration Art. I have some of my own. I've asked twice now for a test protocol, and gotten nothing. I'm hoping that a test protocol is not asking too much... - 73 de Mike N3LI - |
Antenna physical size
On Mar 13, 12:46 pm, Michael Coslo wrote:
Art Unwin wrote: On Mar 12, 8:22 pm, Mike Coslo wrote: On Wed, 12 Mar 2008 07:42:54 -0700, Art Unwin wrote: But unless there is something new going on - and I don't buy claims of newfangled physics without proofs - especially physics that need to include apparent ability of comprehension on my part, it is another radiating feed line antenna, and not much more. -73 de Mike N3LI - On a more serious note, you consistently refer to heating problems or feed line radiation. Will you be good enough to explain what creates these functions and why you can thus refer to them as my problems? To put things in order. You might have me mixed up with someone else, Art. I have commented on feedline radiation in this context, but my only posts about heating problems was with that antenna produced by the U of Delaware in which the initial press release touted that the original antenna was so efficient that it burnt up when 100 watts was applied. Subsequently removed from later text. I don't think that many people would believe that an antenna that melts is radiating efficiently. Otherwise I only predict that your feedline likely will radiate, not that it will heat. My antenna does not require a ground system Electrical WL is alwaysa WL or more in length. Measurements at the antenna are devoid of reactance at the point of resonance Measurements at the transmitter is the same. Movement away from resonance supplies reactance. Conformance with Maxwells laws are adhered to. Now all these facts have been stated many times before, yet you repeat your views so the actions that create feedline radiation and antenna melting problems are totally different to what I understand. Sigh... would you like to point out the post(s) where I said all this? Aside from that, I expect the feedline to radiate. -- -73 de Mike N3LI - Well I may have mixed people up. Sorry about that. What will cause the feedline to radiate given the facts I have provided? Remember that I do not have all the facts here. There are certainly assertions. One of the "problems" with scientific inquiry is that it helps to have an actual device to test. There appears to be one device (two maybe? and it is in the hands of a snowbound ham in the great north. I really want to see the test results. So I just don't know. I trust that you would expect no less from me. I have to go on the limited description, and that description sounds like the tuned circuit on the end of coax, giving rise to an unbalanced condition, from there, we can expect feedline radiation. I understand your frustration Art. I have some of my own. I've asked twice now for a test protocol, and gotten nothing. I'm hoping that a test protocol is not asking too much... - 73 de Mike N3LI - I don't think we have the right to ask him anything. He volunteered to do it and I accepted If he answered everything on this net it would start a lot of insults again. He has offered to do it for me not the group. He can make any furthur descisions after that So we must all be patient and let him do things how he wants after which you can ask him anything where he may chose to answer or not. He has been an observer for a long while and has tried to curtail the insults that have gone around these past few years and contrary to others is willing to pursue anything that may profit ham radio and not retard it because of dislike of change. We are fortunate that there are people around that do not have to add insults to their expertise to get the ears and attention of fellow hams He deserves our respect. Art Regard Art |
Antenna physical size
Art Unwin wrote:
I understand your frustration Art. I have some of my own. I've asked twice now for a test protocol, and gotten nothing. I'm hoping that a test protocol is not asking too much... - 73 de Mike N3LI - I don't think we have the right to ask him anything. Of course we have a "right". And I've gotten my answer. Asking for a test protocol for your antenna tests is too much to ask. Okay. So I'll sit back and patiently watch for any results proffered. But you might want to think about it. What if some parameter in the test process is such that will make the antenna test out as performing poorly when in fact it does not. He volunteered to do it and I accepted If he answered everything on this net it would start a lot of insults again. With all due respect, what is this with the insults? I've worked with engineers of all stripes, and the conversations can get pretty animated at times. I've been told my ideas are stupid on occasion, and have told others the same. Then we have a cup of coffee, and get back to work. Engineering of any sort should not the province of people with easily bruised egos. He has offered to do it for me not the group. Perhaps it would have been better to tell us about it after the tests were finished, then no one would be insulting anyone. The you could present the test results and the rest of us could eat crow. - 73 de Mike N3LI - |
Antenna physical size
On Mar 14, 8:02 am, Michael Coslo wrote:
Art Unwin wrote: I understand your frustration Art. I have some of my own. I've asked twice now for a test protocol, and gotten nothing. I'm hoping that a test protocol is not asking too much... - 73 de Mike N3LI - I don't think we have the right to ask him anything. Of course we have a "right". And I've gotten my answer. Asking for a test protocol for your antenna tests is too much to ask. Okay. So I'll sit back and patiently watch for any results proffered. But you might want to think about it. What if some parameter in the test process is such that will make the antenna test out as performing poorly when in fact it does not. He volunteered to do it and I accepted If he answered everything on this net it would start a lot of insults again. With all due respect, what is this with the insults? I've worked with engineers of all stripes, and the conversations can get pretty animated at times. I've been told my ideas are stupid on occasion, and have told others the same. Then we have a cup of coffee, and get back to work. Engineering of any sort should not the province of people with easily bruised egos. He has offered to do it for me not the group. Perhaps it would have been better to tell us about it after the tests were finished, then no one would be insulting anyone. The you could present the test results and the rest of us could eat crow. - 73 de Mike N3LI - I think you have now chosen the correct path because a lot of people are going to have to eat crow. I am not sure if you are computor savvy but it appears that those who do are holding back on sharing the tipped radiator thing. Can you do it for those who are not computor savvy because at the moment nobody has stepped forward and helped them determine if it is correct or not. At the moment Richard has stated it is a myth but he is not computor savvy so his remark is off the cuff. So again amateurs are being left in the dark by the computor savvy people of this newsgroup who refuse to help. What gives? regards Art |
Antenna physical size
Mike, N3LI wrote:
"There appears to be one device (two maybe?) and it is in the hands of a snowbound ham in the great north." Build a small scale model that can be tested indoors and report its characteristics. Antennas are scaleable. Best regards, Richard Harrison, KB5WZI |
Antenna physical size
On Fri, 14 Mar 2008 09:02:57 -0400, Michael Coslo
wrote: Perhaps it would have been better to tell us about it after the tests were finished, then no one would be insulting anyone. The you could present the test results and the rest of us could eat crow. Hi Mike, A case of "Life is short, eat desert first." 73's Richard Clark, KB7QHC |
Antenna physical size
Richard Harrison wrote:
Build a small scale model that can be tested indoors and report its characteristics. Antennas are scaleable. For an antenna like this, would the wire diameter also have to be scaled? -- 73, Cecil http://www.w5dxp.com |
Antenna physical size
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Antenna physical size
Richard Harrison wrote:
Build a small scale model that can be tested indoors and report its characteristics. Antennas are scaleable. That's more easily said than done. One of the critical characteristics of a small antenna is loss. And to correctly replicate loss in a scaled antenna requires scaling the conductivity of the conductors as the square root of the frequency. To scale to a higher frequency requires that the conductivity be better than the original. Unless the original is made from lead and the scale factor moderate, this wouldn't be possible. Roy Lewallen, W7EL |
Antenna physical size
Richard Clark, KB7QHC wrote:
"Something tells me NO ONE knows why." The technique works. Before erection we had a newly designed 6&7 MHz curtain antenna modeled in the lab at 450 MHz, about a freq. ratio of 70. The as-built antennas were measured and found to perform exactly as predicted by the scaled-down version. Cecil`s question about continuously loaded antennas is appropriate. I suspect the wire size needs to be modeled too, but Cecil knows much more about loading coils than I do. Best regards, Richard Harrison, KB5WZI |
Antenna physical size
Richard Harrison wrote:
Cecil`s question about continuously loaded antennas is appropriate. I suspect the wire size needs to be modeled too, but Cecil knows much more about loading coils than I do. I doubt that, Richard. When the length of a dipole is much, much greater than the diameter of the wire, the antenna will scale appropriately. But what happens when the length of the antenna is not a lot greater than the diameter of the wire? It is the same problem as trying to use water in scale models of boats. It just doesn't work. -- 73, Cecil http://www.w5dxp.com |
Antenna physical size
Cecil Moore wrote:
"When the length of a dipole is much, much greater than the diameter of the wire, the antenna will scale appropriately. Yes. An assumption made to ease calculations is that the diameter of the radiator is vanishingly thin. Art`s antenna configuration is something of a mystery to me but I infer that it may be a dipole in which the two lengths of wire have been wound into coils and not extended to their maximum length. Further, my guess is that the dipole is resonant so that it readily accepts energy. Such antenna elements, I believe usually emit energy in the radial mode and resemble the continuously loaded vertical antenna as shown on page 6-28 in the 20th edition of the ARRL Antenna Book. Description of the resonant element includes: "The relationship between length of wire needed for resonance and a full quarter wave at the desired frequency depends on several factors. Some of these are wire size, diameter of the turns, and dielectric properties of the form material to name a few. Experience has indicated that a section of wire approximately one half wavelength long, wound on an insulating form with a linear pitch (equal spacing between turns) will come close to yielding a resonant quarter wavelength. Bill Orr says about the same thing on page 78 of "Vertical Antennas". Continuing from the Antenna Book: "Therefore, an antenna for use on 160 meters would require approximately 260 feet of wire spirally wound on the support." If Art has made a dipole of two such 1/4-wave elements, it should have about a full wavelength of wire which I believe is consistent with his miserly description. Performance of a full wave of coiled wire will be much less than the performance of the same wire stretched out into a straight line at the same height above earth. Best regards, Richard Harrison, KB5WZI |
Antenna physical size
On Mar 8, 11:21 am, (Richard Harrison)
wrote: Art wrote: "---my antenna is a full wavelength which meets Maxwell`s requirements, it is just that the volume is small despite the wavelength." In 1949, I worked at the KPRC-KXYZ broadcast plant. Another operator there, J.L. Davis, W5LIT had a new 1949 Ford in which he installed a surplus ART-13 and a PE-103 dynamotor. For an antenna he wound wire turn by turn on a bamboo pole until it was resonant on a slice of the 75-meter band. When J.L. modulated, Q in the coil produced a tip corona on the first good peak and modulation became loud without a receiver. The 20th edition of the ARRL Antenna Book on page 16-13 says this about continuously loaded antennas: "The general approach has been to use a coil made from heavy wire (#14 or larger), with length-to-diameter ratios as high as 21. British experimeters have reported good results with 8-foot overall length on the 1.8- and 3.5 MHz bands. The idea of making the entire antenna out of one section of coil has been tried with some success." Art`s antenna containing a "full wavelength" of wire would likely feature a greater loss than J.L.`s 1/4-wave resonant coil from simply a greater length of wire while both have peactances balanced to zero. Art`s lower Q would probably kill the corona, increase the bandwidth, while losing the gain that a fullwave straight conductor enjoys. Cecil can probably report on results of continuously loaded mobile antennas versus a bug catcher loaded whip in the California shoot-outs. Best regards, Richard Harrison, KB5WZI Considering that it meets Maxwells requirements and is at least a wavelenght of a radiator my expectations are much higher than yours I suspect that the output will exceed that of a 160 M antenna which has a ground plane. I also suspect that if I diddn't concentrated so much on small physical size it could easily be uprated to compete with a yagi! I would anticipate that in a couple of years the top band will have twice as many users that it has now. I am hoping also that its small size will allow for receiving abililities in line with the angle of incoming radiation via its manouvarability. Of course if all is already known about radio this would seem impossible but in a few weeks I myself will have a few QSOs to see how it matches up to my expectations. The archives show all the building instruction but it appears that readers have concentrated on nonsensical retorts without reading the content. If an antenna is at least off one wavelength and is in equilibrium I see no reason why it should not beat existing antennas with ground plane losses regardless of its shape or size. Time will tell. Either way the experimental trail undertaken I have found to be very rewarding as many other amateurs have had when experimenting with antennas and who refuse to accept that all is known Art |
Antenna physical size
"Art Unwin" wrote in message ... On Mar 8, 11:21 am, (Richard Harrison) wrote: Art wrote: "---my antenna is a full wavelength which meets Maxwell`s requirements, it is just that the volume is small despite the wavelength." In 1949, I worked at the KPRC-KXYZ broadcast plant. Another operator there, J.L. Davis, W5LIT had a new 1949 Ford in which he installed a surplus ART-13 and a PE-103 dynamotor. For an antenna he wound wire turn by turn on a bamboo pole until it was resonant on a slice of the 75-meter band. When J.L. modulated, Q in the coil produced a tip corona on the first good peak and modulation became loud without a receiver. The 20th edition of the ARRL Antenna Book on page 16-13 says this about continuously loaded antennas: "The general approach has been to use a coil made from heavy wire (#14 or larger), with length-to-diameter ratios as high as 21. British experimeters have reported good results with 8-foot overall length on the 1.8- and 3.5 MHz bands. The idea of making the entire antenna out of one section of coil has been tried with some success." Art`s antenna containing a "full wavelength" of wire would likely feature a greater loss than J.L.`s 1/4-wave resonant coil from simply a greater length of wire while both have peactances balanced to zero. Art`s lower Q would probably kill the corona, increase the bandwidth, while losing the gain that a fullwave straight conductor enjoys. Cecil can probably report on results of continuously loaded mobile antennas versus a bug catcher loaded whip in the California shoot-outs. Best regards, Richard Harrison, KB5WZI Considering that it meets Maxwells requirements and is at least a wavelenght of a radiator my expectations are much higher than yours I suspect that the output will exceed that of a 160 M antenna which has a ground plane. I also suspect that if I diddn't concentrated so much on small physical size it could easily be uprated to compete with a yagi! I would anticipate that in a couple of years the top band will have twice as many users that it has now. I am hoping also that its small size will allow for receiving abililities in line with the angle of incoming radiation via its manouvarability. Of course if all is already known about radio this would seem impossible but in a few weeks I myself will have a few QSOs to see how it matches up to my expectations. The archives show all the building instruction but it appears that readers have concentrated on nonsensical retorts without reading the content. If an antenna is at least off one wavelength and is in equilibrium I see no reason why it should not beat existing antennas with ground plane losses regardless of its shape or size. Time will tell. Either way the experimental trail undertaken I have found to be very rewarding as many other amateurs have had when experimenting with antennas and who refuse to accept that all is known Art of course all is known, we have been trying to tell YOU that but you won't believe it and insist on trying things that are known NOT to work. you will learn, it will be a long and hard experience from what we have heard from you on here, but you will learn someday that there ain't no such thing as a free lunch when it comes to antennas. |
Antenna physical size
On Mar 15, 11:31 am, "Dave" wrote:
"Art Unwin" wrote in message ... On Mar 8, 11:21 am, (Richard Harrison) wrote: Art wrote: "---my antenna is a full wavelength which meets Maxwell`s requirements, it is just that the volume is small despite the wavelength." In 1949, I worked at the KPRC-KXYZ broadcast plant. Another operator there, J.L. Davis, W5LIT had a new 1949 Ford in which he installed a surplus ART-13 and a PE-103 dynamotor. For an antenna he wound wire turn by turn on a bamboo pole until it was resonant on a slice of the 75-meter band. When J.L. modulated, Q in the coil produced a tip corona on the first good peak and modulation became loud without a receiver. The 20th edition of the ARRL Antenna Book on page 16-13 says this about continuously loaded antennas: "The general approach has been to use a coil made from heavy wire (#14 or larger), with length-to-diameter ratios as high as 21. British experimeters have reported good results with 8-foot overall length on the 1.8- and 3.5 MHz bands. The idea of making the entire antenna out of one section of coil has been tried with some success." Art`s antenna containing a "full wavelength" of wire would likely feature a greater loss than J.L.`s 1/4-wave resonant coil from simply a greater length of wire while both have peactances balanced to zero. Art`s lower Q would probably kill the corona, increase the bandwidth, while losing the gain that a fullwave straight conductor enjoys. Cecil can probably report on results of continuously loaded mobile antennas versus a bug catcher loaded whip in the California shoot-outs. Best regards, Richard Harrison, KB5WZI Considering that it meets Maxwells requirements and is at least a wavelenght of a radiator my expectations are much higher than yours I suspect that the output will exceed that of a 160 M antenna which has a ground plane. I also suspect that if I diddn't concentrated so much on small physical size it could easily be uprated to compete with a yagi! I would anticipate that in a couple of years the top band will have twice as many users that it has now. I am hoping also that its small size will allow for receiving abililities in line with the angle of incoming radiation via its manouvarability. Of course if all is already known about radio this would seem impossible but in a few weeks I myself will have a few QSOs to see how it matches up to my expectations. The archives show all the building instruction but it appears that readers have concentrated on nonsensical retorts without reading the content. If an antenna is at least off one wavelength and is in equilibrium I see no reason why it should not beat existing antennas with ground plane losses regardless of its shape or size. Time will tell. Either way the experimental trail undertaken I have found to be very rewarding as many other amateurs have had when experimenting with antennas and who refuse to accept that all is known Art of course all is known, we have been trying to tell YOU that but you won't believe it and insist on trying things that are known NOT to work. you will learn, it will be a long and hard experience from what we have heard from you on here, but you will learn someday that there ain't no such thing as a free lunch when it comes to antennas. Nothing free....I have done a lot of work. Now I get the benefits of that work. I disagree that all experiments on antennas should stop based on the proweress of your particular brain. You have consistently over estimate your abilities |
Antenna physical size
On Sat, 15 Mar 2008 06:46:31 -0700 (PDT), Art Unwin
wrote: I suspect that the output will exceed that of a 160 M antenna which has a ground plane. Hi Ęther, Suspect away, but the best you could accomplish is in the digits to the right of the decimal place of percent efficiency. On the S-Meter scale of any listener, that would be an invisible shift of the needle. Of course, their only experience of this antenna will be at least a 10dB drop from a conventional antenna which would be easily seen on the S-Meter. I also suspect that if I diddn't concentrated so much on small physical size it could easily be uprated to compete with a yagi! Suspect some more, but that is not going to happen unless you have more elements, widely dispersed (and we've been there before, and the yagi is more efficient than any of your usual suspects). As you discard planarity, so do you discard directivity unless you drive every element directly. You don't do this, and you have yet to exhibit the knowledge of why you have to, to meet your claims. This lack of knowledge, in itself, clearly reveals that not all is known about antennas. However, others who can accomplish recovering this directionality do exhibit this knowledge. The readers can discern how the remainder of your post lacks in this regard. I would anticipate that in a couple of years the top band will have twice as many users that it has now. The Solar cycle will have more to say about that than any suspicion. I am hoping also that its small size will allow for receiving abililities in line with the angle of incoming radiation via its manouvarability. No need for hope, transistor pocket radios have been doing that for, what, 50 years? Even there, loop sticks have probably been around longer than that. Try transmitting through one and discover fire again. Of course if all is already known about radio this would seem impossible No, if everything written above has been forgotten (or never learned, same thing) THEN it would seem impossible. but in a few weeks I myself will have a few QSOs to see how it matches up to my expectations. Without comparisons, any contact is bound to raise the estimation of such expectations. The archives show all the building instruction but it appears that readers have concentrated on nonsensical retorts without reading the content. The same archives show a multiplicity of "instructions." However, as they all suffer in comparison to simple antennas, they are easily dismissed against the claims presented for them. It merely takes diligence to take them on one at a time, as they are announced, and line them up like dominoes to watch them tumble in line. The archive contains these results for all time. This design is no different in that respect than the last, or the several before the last. If an antenna is at least off one wavelength and is in equilibrium I see no reason why it should not beat existing antennas with ground plane losses regardless of its shape or size. And yet they don't, and so reason is not a principal component here so much as wish and hope braced with the courage of ignoring knowledge. Time will tell. Either way the experimental trail undertaken I have found to be very rewarding as many other amateurs have had when experimenting with antennas and who refuse to accept that all is known The sad truth is that only one, maybe two here have the professional contacts to antenna test sites, and you have refused their offers. I have dog-eared the post: On Thu, 13 Mar 2008 12:13:02 -0700 (PDT), Art Unwin wrote: He volunteered he answered He has offered He can make let him do how he wants ask him he may chose He has been He deserves our respect. It is notable you always fail to identify "Him." Throughout the entire post you use the impersonal "He" and never a name. So, I am going to turn you slowly on the spit over the fire of dignity, are you going to use "His" name? We have call signs that makes us brothers, can Cain acknowledge Abel? 73's Richard Clark, KB7QHC |
Antenna physical size
On Mar 15, 7:46 am, Art Unwin wrote:
On Mar 8, 11:21 am, (Richard Harrison) wrote: Art wrote: "---my antenna is a full wavelength which meets Maxwell`s requirements, it is just that the volume is small despite the wavelength." In 1949, I worked at the KPRC-KXYZ broadcast plant. Another operator there, J.L. Davis, W5LIT had a new 1949 Ford in which he installed a surplus ART-13 and a PE-103 dynamotor. For an antenna he wound wire turn by turn on a bamboo pole until it was resonant on a slice of the 75-meter band. When J.L. modulated, Q in the coil produced a tip corona on the first good peak and modulation became loud without a receiver. The 20th edition of the ARRL Antenna Book on page 16-13 says this about continuously loaded antennas: "The general approach has been to use a coil made from heavy wire (#14 or larger), with length-to-diameter ratios as high as 21. British experimeters have reported good results with 8-foot overall length on the 1.8- and 3.5 MHz bands. The idea of making the entire antenna out of one section of coil has been tried with some success." Art`s antenna containing a "full wavelength" of wire would likely feature a greater loss than J.L.`s 1/4-wave resonant coil from simply a greater length of wire while both have peactances balanced to zero. Art`s lower Q would probably kill the corona, increase the bandwidth, while losing the gain that a fullwave straight conductor enjoys. Cecil can probably report on results of continuously loaded mobile antennas versus a bug catcher loaded whip in the California shoot-outs. Best regards, Richard Harrison, KB5WZI Considering that it meets Maxwells requirements and is at least a wavelenght of a radiator my expectations are much higher than yours Typical of one with delusions of radiation grandeur... I suspect that the output will exceed that of a 160 M antenna which has a ground plane. How many people do you know that use elevated ground planes on 160m? This may or may not be a trick question. I also suspect that if I diddn't concentrated so much on small physical size it could easily be uprated to compete with a yagi! I suspect it would also be capable of browning the food, if said food was placed close to the device when high power was applied. But the last time I checked, food warmers are not known as very good radiators of RF. I would anticipate that in a couple of years the top band will have twice as many users that it has now. Because all of a sudden you show up using a sub par antenna? How would this effect the number of users of that band? Why would anyone modify their operating habits because you refuse to use an antenna that is halfway efficient? I am hoping also that its small size will allow for receiving abililities in line with the angle of incoming radiation via its manouvarability. Of course if all is already known about radio this would seem impossible Only to you I suspect... but in a few weeks I myself will have a few QSOs to see how it matches up to my expectations. Matches? This is the part of the system which is going to eat your lunch. Chortle... The archives show all the building instruction but it appears that readers have concentrated on nonsensical retorts without reading the content. I have no time to waste on sub par antenna designs. If an antenna is at least off one wavelength and is in equilibrium I see no reason why it should not beat existing antennas with ground plane losses How many people do you know that use elevated ground planes on 160m? This may or may not be a trick question. But even if one was to use an elevated ground plane, or even a ground mounted vertical, who are you to say if the system is lossy or not? I know of plenty of vertical systems on 160m which will whip your puny shoe box antenna like a long lost stepchild, regardless of the level of equilibrium noted. Whatever that means... regardless of its shape or size. Regardless of shape or size... yea right... Time will tell. Either way the experimental trail undertaken I have found to be very rewarding as many other amateurs have had when experimenting with antennas and who refuse to accept that all is known Art The only thing I "know" for sure is you have your head stuck so far up your whiny kazoo it has clouded all rational thought. As an example.. I disagree that all experiments on antennas should stop based on the proweress of your particular brain. You have consistently over estimate your abilities #1, define proweress... #2 define your abilities, and then we will all vote as to who has the greater level of proweress between the particular brains in question. Everyone is brain dead, except for prior Art. lol... BTW, I said I would wait for your grand test before I commented further, but seeing as you continue to spew your silly bafflegab, and also horses ass comments to anyone that dare question your silly crap, I retire my earlier stance. MK |
Antenna physical size
On Fri, 14 Mar 2008 11:57:41 -0700, Roy Lewallen wrote:
Richard Harrison wrote: Build a small scale model that can be tested indoors and report its characteristics. Antennas are scaleable. That's more easily said than done. One of the critical characteristics of a small antenna is loss. And to correctly replicate loss in a scaled antenna requires scaling the conductivity of the conductors as the square root of the frequency. To scale to a higher frequency requires that the conductivity be better than the original. Unless the original is made from lead and the scale factor moderate, this wouldn't be possible. If what I suspect is true, would not the coax also need to be scaled? - 73 de Mike N3LI - -- -73 de Mike N3LI - |
Antenna physical size
On Sat, 15 Mar 2008 06:46:31 -0700, Art Unwin wrote:
Considering that it meets Maxwells requirements and is at least a wavelenght of a radiator my expectations are much higher than yours I suspect that the output will exceed that of a 160 M antenna which has a ground plane. A full length vertical is what you are talking about? I also suspect that if I diddn't concentrated so much on small physical size it could easily be uprated to compete with a yagi! Now here do you mean a directional antenna of your kind, or which? Of course if all is already known about radio this would seem impossible but in a few weeks I myself will have a few QSOs to see how it matches up to my expectations. The archives show all the building instruction but it appears that readers have concentrated on nonsensical retorts without reading the content. Art, throw me a bone here. I've looked in the archives a bit, and you've been a prolific poster! I saw a 160 meter vertical you were posting about, but it had a radial system, and I don't think this one does. -73 de Mike N3LI - |
Antenna physical size
On Mar 15, 8:52 pm, Mike Coslo wrote:
On Sat, 15 Mar 2008 06:46:31 -0700, Art Unwin wrote: Considering that it meets Maxwells requirements and is at least a wavelenght of a radiator my expectations are much higher than yours I suspect that the output will exceed that of a 160 M antenna which has a ground plane. A full length vertical is what you are talking about? I also suspect that if I diddn't concentrated so much on small physical size it could easily be uprated to compete with a yagi! Now here do you mean a directional antenna of your kind, or which? Of course if all is already known about radio this would seem impossible but in a few weeks I myself will have a few QSOs to see how it matches up to my expectations. The archives show all the building instruction but it appears that readers have concentrated on nonsensical retorts without reading the content. Art, throw me a bone here. I've looked in the archives a bit, and you've been a prolific poster! I saw a 160 meter vertical you were posting about, but it had a radial system, and I don't think this one does. -73 de Mike N3LI - OK mike one last time. Make a former to wind apon. Set it up vertically and secure so that it doesn't fall over. Get two reels of insulated wire preferbly pre wound paired wire on each reel. Join the paired wires Put the joint at the rear of the former with one reel to the left and one reel to the right. Wnd one wire clockwise and then wind counterclockwise the wire from the other reel. Repeat these two functions making sure the overlapped wires stay parallel with each other. When you have completed the length of the spool then join one wire to another wire from the opposite reel. You now have two wires in your hands one from each of the reels. These two wires are what you connect to the transmission line.. Suggestions for the former. Make two cross arrangements using 1/2 inch plastic piping. At each of the 8 ends place a tee connection. Four pipes around a foot long can the join the two sections, Use tees instead of elbows so the antenna is easier to mount. If you want it to be all frequencie: Cut a 1/2 inch plastic pipe in half,' length wise. Make wire loops and fit them over the cut pipe and solder them tight. Place a quick start threaded rod inside the cut pipe with a motor at one end. Make a electrical wiper to place on the quick start thread to make electrical connection to the loops as the motor turns. Connect a meter to one of the start wires and disconnect it from the joint. Place a sowing needle on the other end of the instrument and pierce the wires in sequence until one gets to the coax connection points marking each wire that is connected to the meter. Connect the marked wires to the loop that were made sp electrical contact can be made to the threaded shaft Connect the shaft to one of the wires that consists of the feed points. Rejoin the wire connections at the start point so that now you have a complete electrical circuit starting at the feed points Place assembly anywhere and apply power and have a qso. Now will somebody that is savvy with computors do that excercise that I suggested with regard to tipped radiators and report on it before you make this antenna or start tilting towers around ten degrees sinc the change is not worth it when calculating total gain? Art Unwin KB9MZ...XG (uk) Art |
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