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#1
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Art,
I want to know about this concept. Can you tell me how to build one? By what means might it change the very simple calculation of efficiency given in the long and rambling thread which I am trying to avoid. Take an antenna, any antenna you can dream up, measure the power radiated in each direction. Add it all up. Compare that to the power fed to the antenna. A 100% efficient antenna radiates all the power it's fed. A 50% efficent antenna radiates half the power it's fed. A 150% efficent antenna radiates half again as much power as it's fed. Why is an inherently directional "dipole" different from a yagi in this respect? Dan |
#2
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#3
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John Smith wrote:
wrote: Art, ... JS Oh yeah. That ~98% figure, that took for granted the antenna conductors were chilled at or very near superconducting temps. or, the conductors were constructed of a "yet to be developed" superconducting material. But, certainly, you picked up that, that was implied from my previous text. In fact, the skin effect is a phenomenon which could consume a whole book to itself. I mean, why rf chooses to only travel the surface of metal conductors? (why would the surface of metal offer less resistance than the atoms of the metal inner most? Indeed, if you make the inner material of silver and the other covering of a conductor of iron, it still attempts to favor the iron!) Almost leading one to believe it (rf) is attempting to "leap to the superconducting ether", but then, I dream a lot ... Regards, JS |
#4
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John,
Obviously you can have neither a 100% efficent antenna nor a 150% efficient antenna. That doesn't change the definition of efficiency. That was my point. It doesn't matter if you're talking about possible or impossible antennas, efficiency is power out divided by power in. Also, yes, a dipole has directional characteristics, but it would seem that Art is talking about something more directional than a dipole that is not a multielement array, and he asks us to imagine a dipole with inherent directional capabilities This suggests that it doesn't have the familar dipole directionality, but something else. What is that something else? How does it bear upon efficiency? Dan |
#5
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#6
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If I had seen this thread I wouldn't have wasted the time I spent just
making a post on 'efficiency.'.. Look guys... Antennas are not magic wands... They are well understood EM entities, mathematically described by Maxwell and others in equations, and subject to the laws of physics... When you guys get tired of discussing the dark side of the force, check back in... denny / k8do |
#7
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