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On 5 Apr 2007 10:05:43 -0700, "art" wrote:
On 26 Mar, 21:49, (Richard Harrison) wrote: Art wrote: "Any thoughts as to why it sgould be so and the scientific facts to support it?" We have plumb lines and bubble levels which allow easy determination of vertical and horizontal directions. We often inhabit a nearly horizontal plane If we are as likely as not to communicate with any particular direction, an omidirectional vertical antenna makes sense. An inclined wire would favor some direction to the detriment of another. Sure a slopimg wire works but doesn`t reach maximum height or length as effectively as a vertical or horizontal wire would. Why a straight dipole and not a V-shaped element? The V-shape corrupts the nulls at the ends of the straight wire. Vertical and horizontal antennas are not solely accidents of history. Best regards, Richard Harrison, KB5WZI Richard, It is well known that near maximum "overall" polarity gain can be obtained by placing a vertical at right angles with respect to earth. Now -a -days maximum gain is required of a certain polarity which requires a specific accuracy of less than 1 degree . So yes, in your working years straight up is good enough but these days of WiFi and all that concentration is applied for purity of polarity which requires a resonance at around 3 degrees to the vertical. This can be determined arithematically according to known laws. Ofcourse as one moves higher this offset angle changes. This same phenomina or tilt angle applies for all polarities where maximum gain is required for purity of polarization.The days have gone where just putting up a wire satisfies all. Regards Art Educate me, Art, what is 'polarity' gain? Walt |
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#2
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On 5 Apr, 10:32, Walter Maxwell wrote:
On 5 Apr 2007 10:05:43 -0700, "art" wrote: On 26 Mar, 21:49, (Richard Harrison) wrote: Art wrote: "Any thoughts as to why it sgould be so and the scientific facts to support it?" We have plumb lines and bubble levels which allow easy determination of vertical and horizontal directions. We often inhabit a nearly horizontal plane If we are as likely as not to communicate with any particular direction, an omidirectional vertical antenna makes sense. An inclined wire would favor some direction to the detriment of another. Sure a slopimg wire works but doesn`t reach maximum height or length as effectively as a vertical or horizontal wire would. Why a straight dipole and not a V-shaped element? The V-shape corrupts the nulls at the ends of the straight wire. Vertical and horizontal antennas are not solely accidents of history. Best regards, Richard Harrison, KB5WZI Richard, It is well known that near maximum "overall" polarity gain can be obtained by placing a vertical at right angles with respect to earth. Now -a -days maximum gain is required of a certain polarity which requires a specific accuracy of less than 1 degree . So yes, in your working years straight up is good enough but these days of WiFi and all that concentration is applied for purity of polarity which requires a resonance at around 3 degrees to the vertical. This can be determined arithematically according to known laws. Ofcourse as one moves higher this offset angle changes. This same phenomina or tilt angle applies for all polarities where maximum gain is required for purity of polarization.The days have gone where just putting up a wire satisfies all. Regards Art Educate me, Art, what is 'polarity' gain? Walt- Hide quoted text - - Show quoted text - Walter Gain is the total radiation at a particular angle which can be the summation of all polarities such as in the case of vertical and horizontal antennas. If one want's maximum gain with a particular polarization in mind then resonance is to be found at an angle other than 90 degree multiples to the earths surface. This is why I have made the point for years that the yagi has put antennas back nearly 100 years. In amateur work it is not so important tho it does explain why the augument rages between a yagi and a quad with the latter providing a much larger arrival area that allow people to hear more. On top of that the yagi becomes less efficient as one adds elements which means progressive polarity inaccuracy for each added element not only for a particular polarity but also for the increase in reactance for the array as a whole. I have mentioned 3 degrees but that was only by the eye on print out for a single element. I never did associate the tip angle with respect to frequency and height tho I am sure this can be done via Matlab for both a single element or an arrangement of elements. One day they will put this in a book, hopefully the ARRL editions, so the derogatory statements from the older education type guys will cease but I am to old to see that day Regards Art |
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#3
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Art wrote:
"I have mentioned 3 degrees but that was only by eye on print out for a single element." I have set the vertical angle of many highly directional dish feed horns using a bubble level when the path was long. The best setting will be horizontal so that the signal skims the earth when there are no obstructions. Never did subsequent adjustment of elevation angle for best signal ever alter the bubble setting by one iota. Why vertical or horizontal? To get the antennas parallel to each other. That`s why. All electrical charges exert forces on one another. At great distances, the forces become vanishingly small. Even so, every effective antenna is coupled to other conducting matter in its rdiation path to do work in maintaining periodic motion of charges, however faint, throughout the universe. Energy transferred by an antenna to the universe is said to be radiated. Radiation reflected by the ionosphere surrounding the earth is found to be scrambled in its polarization (the direction of its E-field). Energy directly communicated between line-of-sight antennas is most effective when the transmitting and receiving antenna conductors are parallel. Conversely, when they are cross-polarized, loss may exceed 20 dB. Best regards, Richard Harrison, KB5WZI |
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#4
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On 5 Apr, 14:12, (Richard Harrison) wrote:
Art wrote: "I have mentioned 3 degrees but that was only by eye on print out for a single element." I have set the vertical angle of many highly directional dish feed horns using a bubble level when the path was long. The best setting will be horizontal so that the signal skims the earth when there are no obstructions. Never did subsequent adjustment of elevation angle for best signal ever alter the bubble setting by one iota. Why vertical or horizontal? To get the antennas parallel to each other. That`s why. All electrical charges exert forces on one another. At great distances, the forces become vanishingly small. Even so, every effective antenna is coupled to other conducting matter in its rdiation path to do work in maintaining periodic motion of charges, however faint, throughout the universe. Energy transferred by an antenna to the universe is said to be radiated. Radiation reflected by the ionosphere surrounding the earth is found to be scrambled in its polarization (the direction of its E-field). Energy directly communicated between line-of-sight antennas is most effective when the transmitting and receiving antenna conductors are parallel. Conversely, when they are cross-polarized, loss may exceed 20 dB. Best regards, Richard Harrison, KB5WZI No Richard, you are out of date.I'm sure that more about antennas is taught these days that has never showed up in Terman. On the tipping thing many towers have multiple beamms on them and when one is added then owners have to reset their antennas. Now ofcourse one can now move them remotely until max polarity is observed. As far as parallel is concerned, anytime you introduce reactance to the resonance to an individual element you lose out on efficiency if polarity is a concern qand in Termans time polarity was not that much of a concern. I truly believe that most auguments on this newsgroup is because teachings of yesteryear do not match up to present day teachings. With weather forcasters they now direct R.F at a front first with horizontal polarization and then with vertical polarization and then merge the reflected pictures, thus it is imperitivethat polarization is dead on for 3 D analysis of the weather front. Lots of things are done these days that wasn't even thought about as little as 20 years ago such that you must read iee antenna findings every month to keep up. Art |
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#5
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On 5 Apr 2007 15:04:13 -0700, "art" wrote:
On 5 Apr, 14:12, (Richard Harrison) wrote: Art wrote: "I have mentioned 3 degrees but that was only by eye on print out for a single element." I have set the vertical angle of many highly directional dish feed horns using a bubble level when the path was long. The best setting will be horizontal so that the signal skims the earth when there are no obstructions. Never did subsequent adjustment of elevation angle for best signal ever alter the bubble setting by one iota. Why vertical or horizontal? To get the antennas parallel to each other. That`s why. All electrical charges exert forces on one another. At great distances, the forces become vanishingly small. Even so, every effective antenna is coupled to other conducting matter in its rdiation path to do work in maintaining periodic motion of charges, however faint, throughout the universe. Energy transferred by an antenna to the universe is said to be radiated. Radiation reflected by the ionosphere surrounding the earth is found to be scrambled in its polarization (the direction of its E-field). Energy directly communicated between line-of-sight antennas is most effective when the transmitting and receiving antenna conductors are parallel. Conversely, when they are cross-polarized, loss may exceed 20 dB. Best regards, Richard Harrison, KB5WZI No Richard, you are out of date.I'm sure that more about antennas is taught these days that has never showed up in Terman. On the tipping thing many towers have multiple beamms on them and when one is added then owners have to reset their antennas. Now ofcourse one can now move them remotely until max polarity is observed. As far as parallel is concerned, anytime you introduce reactance to the resonance to an individual element you lose out on efficiency if polarity is a concern qand in Termans time polarity was not that much of a concern. I truly believe that most auguments on this newsgroup is because teachings of yesteryear do not match up to present day teachings. With weather forcasters they now direct R.F at a front first with horizontal polarization and then with vertical polarization and then merge the reflected pictures, thus it is imperitivethat polarization is dead on for 3 D analysis of the weather front. Lots of things are done these days that wasn't even thought about as little as 20 years ago such that you must read iee antenna findings every month to keep up. Art Art, you still haven't explained what 'polarity' gain is. And what is maximum polarity? I learned polarity as being plus or minus. Are there other 'polarities'? Walt, W2DU |
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#6
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On Thu, 05 Apr 2007 22:20:51 GMT, Walter Maxwell
wrote: Are there other 'polarities'? Art and AntiArt? Hi Walt, I hope your procedure went well. 73's Richard Clark, KB7QHC |
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#7
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On Thu, 05 Apr 2007 15:27:05 -0700, Richard Clark wrote:
On Thu, 05 Apr 2007 22:20:51 GMT, Walter Maxwell wrote: Are there other 'polarities'? Art and AntiArt? Hi Walt, I hope your procedure went well. 73's Richard Clark, KB7QHC Sorry Richard, my surgery had to be postponed a second time, first, to wait after my cataract surgery, and second, just before the procedure was to be performed, my dentist discovered an infected tooth. One of its roots was cracked, and I spent one heluva night last night after having the root removed. Consequently, my spinal surgery has been moved to April 18. This is gettin' ridiculous! But thanks for your concern. Walt |
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#8
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On 5 Apr, 15:20, Walter Maxwell wrote:
On 5 Apr 2007 15:04:13 -0700, "art" wrote: On 5 Apr, 14:12, (Richard Harrison) wrote: Art wrote: "I have mentioned 3 degrees but that was only by eye on print out for a single element." I have set the vertical angle of many highly directional dish feed horns using a bubble level when the path was long. The best setting will be horizontal so that the signal skims the earth when there are no obstructions. Never did subsequent adjustment of elevation angle for best signal ever alter the bubble setting by one iota. Why vertical or horizontal? To get the antennas parallel to each other. That`s why. All electrical charges exert forces on one another. At great distances, the forces become vanishingly small. Even so, every effective antenna is coupled to other conducting matter in its rdiation path to do work in maintaining periodic motion of charges, however faint, throughout the universe. Energy transferred by an antenna to the universe is said to be radiated. Radiation reflected by the ionosphere surrounding the earth is found to be scrambled in its polarization (the direction of its E-field). Energy directly communicated between line-of-sight antennas is most effective when the transmitting and receiving antenna conductors are parallel. Conversely, when they are cross-polarized, loss may exceed 20 dB. Best regards, Richard Harrison, KB5WZI No Richard, you are out of date.I'm sure that more about antennas is taught these days that has never showed up in Terman. On the tipping thing many towers have multiple beamms on them and when one is added then owners have to reset their antennas. Now ofcourse one can now move them remotely until max polarity is observed. As far as parallel is concerned, anytime you introduce reactance to the resonance to an individual element you lose out on efficiency if polarity is a concern qand in Termans time polarity was not that much of a concern. I truly believe that most auguments on this newsgroup is because teachings of yesteryear do not match up to present day teachings. With weather forcasters they now direct R.F at a front first with horizontal polarization and then with vertical polarization and then merge the reflected pictures, thus it is imperitivethat polarization is dead on for 3 D analysis of the weather front. Lots of things are done these days that wasn't even thought about as little as 20 years ago such that you must read iee antenna findings every month to keep up. Art Art, you still haven't explained what 'polarity' gain is. And what is maximum polarity? I learned polarity as being plus or minus. Are there other 'polarities'? Walt, W2DU- Hide quoted text - - Show quoted text - Walt, if you are looking for maximum horizontal or any other polarity it can only be obtained by removal of reception of other polarities, this maximum is obtained by having the radiator at 90 degree multiples with respect to earth. You can prove this to your self anytime by calculating max horizontal gain by progressively tipping a dipole while keeping it resonant until the maximum is reached. If your concern is for total gain without regard to polarity mix then the vertical position total gain will equal the total gain of the tipped dipole. The difference is that one arrangement has a mixture of polarities where-as the tipped antenna will only provide a single polarity. If another element or anything else is added near enough to add reactance then the prior antenna must be adjusted to remove it, thus the reason for remote adjustment which is much cheaper to maintain rather than regular trips up a tower by maintanance men. Hopefully Walter this will bring you up to date. I have no reason for a 300 posting thread as I do not intend to write rev 3 of Reflections or anything else. Regards Art |
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#9
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On 5 Apr 2007 16:13:12 -0700, "art" wrote:
On 5 Apr, 15:20, Walter Maxwell wrote: On 5 Apr 2007 15:04:13 -0700, "art" wrote: On 5 Apr, 14:12, (Richard Harrison) wrote: Art wrote: "I have mentioned 3 degrees but that was only by eye on print out for a single element." I have set the vertical angle of many highly directional dish feed horns using a bubble level when the path was long. The best setting will be horizontal so that the signal skims the earth when there are no obstructions. Never did subsequent adjustment of elevation angle for best signal ever alter the bubble setting by one iota. Why vertical or horizontal? To get the antennas parallel to each other. That`s why. All electrical charges exert forces on one another. At great distances, the forces become vanishingly small. Even so, every effective antenna is coupled to other conducting matter in its rdiation path to do work in maintaining periodic motion of charges, however faint, throughout the universe. Energy transferred by an antenna to the universe is said to be radiated. Radiation reflected by the ionosphere surrounding the earth is found to be scrambled in its polarization (the direction of its E-field). Energy directly communicated between line-of-sight antennas is most effective when the transmitting and receiving antenna conductors are parallel. Conversely, when they are cross-polarized, loss may exceed 20 dB. Best regards, Richard Harrison, KB5WZI No Richard, you are out of date.I'm sure that more about antennas is taught these days that has never showed up in Terman. On the tipping thing many towers have multiple beamms on them and when one is added then owners have to reset their antennas. Now ofcourse one can now move them remotely until max polarity is observed. As far as parallel is concerned, anytime you introduce reactance to the resonance to an individual element you lose out on efficiency if polarity is a concern qand in Termans time polarity was not that much of a concern. I truly believe that most auguments on this newsgroup is because teachings of yesteryear do not match up to present day teachings. With weather forcasters they now direct R.F at a front first with horizontal polarization and then with vertical polarization and then merge the reflected pictures, thus it is imperitivethat polarization is dead on for 3 D analysis of the weather front. Lots of things are done these days that wasn't even thought about as little as 20 years ago such that you must read iee antenna findings every month to keep up. Art Art, you still haven't explained what 'polarity' gain is. And what is maximum polarity? I learned polarity as being plus or minus. Are there other 'polarities'? Walt, W2DU- Hide quoted text - - Show quoted text - Walt, if you are looking for maximum horizontal or any other polarity it can only be obtained by removal of reception of other polarities, this maximum is obtained by having the radiator at 90 degree multiples with respect to earth. You can prove this to your self anytime by calculating max horizontal gain by progressively tipping a dipole while keeping it resonant until the maximum is reached. If your concern is for total gain without regard to polarity mix then the vertical position total gain will equal the total gain of the tipped dipole. The difference is that one arrangement has a mixture of polarities where-as the tipped antenna will only provide a single polarity. If another element or anything else is added near enough to add reactance then the prior antenna must be adjusted to remove it, thus the reason for remote adjustment which is much cheaper to maintain rather than regular trips up a tower by maintanance men. Hopefully Walter this will bring you up to date. I have no reason for a 300 posting thread as I do not intend to write rev 3 of Reflections or anything else. Regards Art Art, using correct terminology is essential in preventing misunderstandings, as you have done with 'polarity'. You have confused 'polarity' with 'polarization'--the two are not synonomous, but are distinctly different. Sorry, Art, your misuse of this term has been confusing, rather than enlightening. Are you blaming me for the more than 300 postings on this thread? Walt |
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#10
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Walter Maxwell wrote:
On 5 Apr 2007 10:05:43 -0700, "art" wrote: On 26 Mar, 21:49, (Richard Harrison) wrote: Art wrote: "Any thoughts as to why it sgould be so and the scientific facts to support it?" We have plumb lines and bubble levels which allow easy determination of vertical and horizontal directions. We often inhabit a nearly horizontal plane If we are as likely as not to communicate with any particular direction, an omidirectional vertical antenna makes sense. An inclined wire would favor some direction to the detriment of another. Sure a slopimg wire works but doesn`t reach maximum height or length as effectively as a vertical or horizontal wire would. Why a straight dipole and not a V-shaped element? The V-shape corrupts the nulls at the ends of the straight wire. Vertical and horizontal antennas are not solely accidents of history. Best regards, Richard Harrison, KB5WZI Richard, It is well known that near maximum "overall" polarity gain can be obtained by placing a vertical at right angles with respect to earth. Now -a -days maximum gain is required of a certain polarity which requires a specific accuracy of less than 1 degree . So yes, in your working years straight up is good enough but these days of WiFi and all that concentration is applied for purity of polarity which requires a resonance at around 3 degrees to the vertical. This can be determined arithematically according to known laws. Ofcourse as one moves higher this offset angle changes. This same phenomina or tilt angle applies for all polarities where maximum gain is required for purity of polarization.The days have gone where just putting up a wire satisfies all. Regards Art Educate me, Art, what is 'polarity' gain? That's when you go to a Polish wedding and put on weight from eating kielbasa. This is related to the "purity of polarization" which is a measure of the quality of the kielbasa served and the Polish music played at the wedding. -- Jim Pennino Remove .spam.sux to reply. |