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Dave wrote:
Cecil --- you are begging the question!! Of course I am, nobody knows *why* things are the way they are. There is no 'why' built into quantum mechanics. There is only probability. Why does one photon wind up in an inner interference ring and one wind up in an outer interference ring? Nobody knows. I reported that the addition of 3 or 4 inches above the coil produces a much larger shift in frequency than adding the exact same length below the coil [by almost a factor of 100:1]. That is empirical data. It is real and measurable. My question is one of Physics. I think everyone who reads this list knows it happens. The real question is: Why?? Why the difference in antenna resonant frequency? I thought my stub examples would answer that question. Anything done below the coil affects the number of degrees subtracted from the antenna by the bottom element to coil interface. Anything done to the stinger affects the number of degrees added to the antenna by the coil to stinger interface. For a given element delta length, the number-of-degrees-added effect is greater than the number- of-degrees-subtracted effect. Let's take a lossless resonant electrical 1/4WL stub where Z01 = 600 ohms and Z02 = 4000 ohms. Source-----Z01A-----+-----Z02-----+-----Z01B-----open Let's assume that Z01A is 45 degrees and Z02 is 45 degrees. How many degrees does Z01B have to be to make the stub an electrical 90 degrees long? Hint: 36.5 degrees is lost at the Z01A to Z02 junction. -- 73, Cecil http://www.qsl.net/w5dxp |
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