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![]() wrote in message Let's focus on one thing at a time. You claim a bug cather coil has "an electrical length at 4MHz of ~60 degrees". That concept is easily proven false, just like the claim a short loaded antenna is "90-degree resonant". Both can be shown to be nonsense pictures of what is happening. Assume I have a 30 degree long antenna. If the loading inductor is 60 electrical degrees long, I could move it anyplace in that antenna and have a 90 degree long antenna. We all know that won't happen, so what is it you are really trying to say? 73 Tom OK lets get me some educating here. I understand that, say quarter wave resonant vertical (say 33 ft at 40m) has 90 electrical degrees. Is that right or wrong? The current distrubution on said (full size) vertical is one quarter of the wave of 360 deg. which would make it 90 degrees. Max current is at the base and then diminishes towards the tip in the cosine function down to zero. Voltage distribution is just opposite, min at the base, feed point and max at the tip. EZNEC modeling shows that to be the case too. Is that right or wrong? If we stick them end to end and turn horizontal, we get dipole, which then would be 180 deg. "long" or "180 degrees resonant". If not, what is the right way? If I insert the coil, say about 2/3 up (at 5 ft. from the bottom) the shortened vertical, I make the coil size, (inductance, phys. dimensions) such that my vertical will shrink in size to 8 ft tall and will resonate at 7.87 MHz. I learned from the good antenna books that this is still 90 electrical "resonant" degrees. Maximum of current is at the feed point, minimum or zero at the tip. If you stick those verticals (resonant) end to end and horizontal, you get shortened dipole, with current distribution equal to 180 degrees or half wave. Max current at the feed point, minima or zero at the tips. (RESONANT radiator) How many electrical degrees would that make? How do you arrive at that? Why is this a nonsense? Can we describe "pieces" or segments of the radiator as having proportional amount of degrees corresponding to their physical length, when excited with particular frequency? If I can be enlightened about this, we can go then to the next step. Answers, corrections please. Yuri, K3BU |
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