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#21
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Constant impedance response to infinity with point radiation
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#22
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Constant impedance response to infinity with point radiation
In article ,
Cecil Moore wrote: I suspect that the Isotron performs best when the feedline is radiating like crazy. That's consistent with the installation instructions that state that it must be mounted on a metal mast. So the question is: Has anyone ever tried to maximize feedline radiation? Seems that is what the Carolina Windom has done by accident. Can it be done on purpose? Use a simple wire or rod radiator tied to the center conductor of the coax, no radiator tied to the shield, and a length of feedline which is an even multiple of a halfwave (at the exterior shield's velocity-of-propagation) back to ground or the transmitter, serving as a counterpoise? -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
#23
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Constant impedance response to infinity with point radiation
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#24
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Constant impedance response to infinity with point radiation
Cecil Moore wrote in news:taSLj.2051$%V7.192
@newssvr14.news.prodigy.net: wrote: The word "cinderella" means one who unexpectedly achieves recognition or success after a period of obscurity and neglect. A very appropriate name for my dog obtained from the dog pound. Kudos Cecil! - 73 d eMike N3LI - |
#25
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Constant impedance response to infinity with point radiation
On Apr 13, 1:56 am, Richard Clark wrote:
.. I have modeled ALL of Art's contraptions. I doubt that, if you had modeled the antenna described in Art's posts of the 17 march onward you "may" have changed your opinion but then that would go against the grain would it not. Your problem is you have allowed your antagonism towards Art cloud your judgment, one has only to look at your post's to see that no matter what Art claim's are you will rubbish them as you have consistently for the last year or so that I have followed this group. Derek |
#26
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Constant impedance response to infinity with point radiation
On Apr 13, 10:21 am, Mike Coslo wrote:
Anxiously awaiting that test report..... You should have built one, you would not have been disappointed. I predict that Denny is feeling like the cat who got the cream right at this moment. Derek |
#27
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Constant impedance response to infinity with point radiation
Dave Platt wrote:
Use a simple wire or rod radiator tied to the center conductor of the coax, no radiator tied to the shield, and a length of feedline which is an even multiple of a halfwave (at the exterior shield's velocity-of-propagation) back to ground or the transmitter, serving as a counterpoise? Seems to me, the "ground" would cause reflections, turn that "even multiple of a halfwave" into a standing-wave antenna, and maybe be more efficient than an Isotron? -- 73, Cecil http://www.w5dxp.com |
#28
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Constant impedance response to infinity with point radiation
wrote in message ... On Apr 13, 10:21 am, Mike Coslo wrote: Anxiously awaiting that test report..... You should have built one, you would not have been disappointed. have YOU built one? and if so, have you compared it with a full size antenna?? and what were your results??? |
#29
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Constant impedance response to infinity with point radiation
In article ,
Cecil Moore wrote: Use a simple wire or rod radiator tied to the center conductor of the coax, no radiator tied to the shield, and a length of feedline which is an even multiple of a halfwave (at the exterior shield's velocity-of-propagation) back to ground or the transmitter, serving as a counterpoise? Seems to me, the "ground" would cause reflections, turn that "even multiple of a halfwave" into a standing-wave antenna, and maybe be more efficient than an Isotron? Better be careful about that dreaded word "efficient", especially in the context of small antennas - Art might take umbrage. On the basis of the usual "power radiated, divided by power input", the type I suggested *might* be more efficient than an Isotron... but only because its losses might be lower. Most of the Isotron designs I've seen pictured, have a tuned circuit of some sort at the feedpoint (e.g. a big air-wound coil and a metal-plate capacitor), and there will no doubt be some losses in this tuned circuit. I don't know which antenna would have more directional gain at its primary lobe, or which one would have a stronger signal in whatever specific angle its operator found most useful at any particular moment. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
#30
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Constant impedance response to infinity with point radiation
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