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Roy Lewallen wrote:
So now you're saying that any coil at the base of a short vertical antenna, regardless of its value, will have equal currents at the input and output? No, I didn't say that. I wish you would read what I say. If the coil is a low reactance (not many degrees) and the current maximum point is inside the coil, the two currents will tend to be equal. Ok, suppose I make the measurement at, say, 10 MHz, where the coil is no longer at the current maximum. Tell you what. I'll set up a 33 foot wire vertical, to eliminate the difficulty of the mounting arrangement. I'll furnish you the base impedance at 10 MHz, and even let you choose the inductor value. Be sure and choose a value that will clearly illustrate your point. Using the fine education you received from Balanis et al, calculate the current into and out of the inductor (phase and magnitude), and I'll set it up and measure it. Since it is a fair amount of work on my part, though, I'd like to do a dry run first, using, say, the base impedance predicted by EZNEC. Then, after you've shown us how you make the calculations, I'll build the antenna and do the measurement. I'd hate to go to the considerable trouble of setting it up and find that you somehow aren't able to do the calculation. I can't do the calculation because I don't know the attenuation factor. Do you think my inability to do the calculation proves anything about what's happening in reality at the antenna? You guys need to turn loose of the concept that what happens or doesn't happen on a piece of paper dictates reality. I can describe a base-loaded configuration that will demonstrate the principle. Take a 75m bugcatcher coil, one of the 6"x6" models, and choose a stinger that resonants the antenna in the 75m-80m band. Then measure the in and out currents at a frequency a little below resonance. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
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