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#11
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"William H. O'Hara, III" wrote in
. 97.142: I did quickly in the middle of the night. I will look it over and see I can find some problem with the wires. I used EZNEC demo 4.0. Thanks Bill Maybe you should check your connections and try again. For what it's worth, the pattern is like most large horizontal loops, except for two large lobes in the direction of the top corners of the tee. I did get it to model SWR with high reactances(to me anyways). Does this seem right? I dunno. Thanks Bill |
#12
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On Tue, 14 Dec 2004 18:46:22 -0600, "William H. O'Hara, III"
wrote: I did get it to model SWR with high reactances(to me anyways). Does this seem right? I dunno. Thanks Hi Bill, At this point, you need to provide more specifics. One, what frequencies? Two, did they match your experience with a physical model? To answer your question lacking this information, yes this seems right - at least somewhere in the panorama of all possible outcomes. It stands to reason that ANY antenna, when looked at across a wide enough spectrum, will reveal both resonances and high reactances, and many combinations in between. This is just par for the course. Now, if you find you are experiencing these high reactances in nature as well as in modeling; then try one thing: Break the wire at a point that is on the opposite side of the loop from the feedpoint and see what happens. 73's Richard Clark, KB7QHC |
#13
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![]() On 14-Dec-2004, "William H. O'Hara, III" wrote: "William H. O'Hara, III" wrote in . 97.142: I did quickly in the middle of the night. I will look it over and see I can find some problem with the wires. I used EZNEC demo 4.0. Thanks Bill Maybe you should check your connections and try again. For what it's worth, the pattern is like most large horizontal loops, except for two large lobes in the direction of the top corners of the tee. I did get it to model SWR with high reactances(to me anyways). Does this seem right? I dunno. Thanks Bill The reactive components are just an indication that the applied frequency is too high (+X), or too low (-X). Adjust the frequency or the size of the loop till X = 0. Or just don't worry about it and use high impedance parallel line with a tuner. Ken Fowler |
#14
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![]() Now, if you find you are experiencing these high reactances in nature as well as in modeling; then try one thing: Break the wire at a point that is on the opposite side of the loop from the feedpoint and see what happens. I haven't strung the actual one yet. My EZNEC model got everything high. There wasn't a frequency better than 8:1. Everything was much higher. I am going to try with the square loop. Bill Bill |
#15
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On Wed, 15 Dec 2004 19:04:36 -0600, "William H. O'Hara, III"
wrote: My EZNEC model got everything high. There wasn't a frequency better than 8:1. Everything was much higher. I am going to try with the square loop. Hi Bill, Still need some particulars: What frequencies? What length of wire? How high? 73's Richard Clark, KB7QHC |
#16
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Richard Clark wrote in
: On Wed, 15 Dec 2004 19:04:36 -0600, "William H. O'Hara, III" wrote: My EZNEC model got everything high. There wasn't a frequency better than 8:1. Everything was much higher. I am going to try with the square loop. Hi Bill, Still need some particulars: What frequencies? What length of wire? How high? 73's Richard Clark, KB7QHC 12# wire at 40 feet in the air with 90 feet to each side for the basic square. I wanted to see it would resonate on 80 down. bill |
#17
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On Thu, 16 Dec 2004 18:23:46 -0600, "William H. O'Hara, III"
wrote: 12# wire at 40 feet in the air with 90 feet to each side for the basic square. I wanted to see it would resonate on 80 down. Hi Bill, Even at a glance and simplistic conversion to metric would say you were expecting 120M of wire to resonate at 80M. Far too much wire. 73's Richard Clark, KB7QHC |
#18
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Richard Clark wrote in
: 12# wire at 40 feet in the air with 90 feet to each side for the basic square. I wanted to see it would resonate on 80 down. Hi Bill, Even at a glance and simplistic conversion to metric would say you were expecting 120M of wire to resonate at 80M. Far too much wire. I should actually double it. Tree configuration is very tough. I do the have the option of potentially doing a T shape or the box with 90 feet sides. Not up yet.. Getting side tracked Bill |
#19
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On Sat, 18 Dec 2004 20:01:25 -0600, "William H. O'Hara, III"
wrote: Far too much wire. I should actually double it. ???????????????? |
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