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#1
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Pseudo experts of fractional wavelength antennas.
Where does the current flow when it reaches the END of a fractional length? verticle antenna and why? How does this relate to the term "end effect"? If you have already written a book then tell us what the auther said. Art KB9MZ.....XG |
#2
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On Thu, 18 Oct 2007 17:04:26 -0700, art wrote:
Where does the current flow when it reaches the END of a fractional length? Does this question anticipate your introduction of a PaleoGaussic theory of any single electron flowing from end-to-end (of any antenna) in the time it takes to resonate? Hint: Even an English Major knows Electrons at 160M would barely wiggle an µM away from the feedpoint before they turned around and went back on the next half of the first cycle - etc. 73's Richard Clark, KB7QHC |
#3
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![]() "art" wrote in message oups.com... Pseudo experts of fractional wavelength antennas. Where does the current flow when it reaches the END of a fractional length? verticle antenna and why? How does this relate to the term "end effect"? If you have already written a book then tell us what the auther said. Art KB9MZ.....XG it turns around and goes right back down the way it came. |
#4
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On 19 Oct, 03:55, "Dave" wrote:
"art" wrote in message oups.com... Pseudo experts of fractional wavelength antennas. Where does the current flow when it reaches the END of a fractional length? verticle antenna and why? How does this relate to the term "end effect"? If you have already written a book then tell us what the auther said. Art KB9MZ.....XG it turns around and goes right back down the way it came. So a electrical generater doesn't keep turning in one direction but instead it occillates at the desired frequency. I have never seen one do that! And "end effect" is the confusion created at the top of the radiator |
#5
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![]() "art" wrote in message ps.com... On 19 Oct, 03:55, "Dave" wrote: "art" wrote in message oups.com... Pseudo experts of fractional wavelength antennas. Where does the current flow when it reaches the END of a fractional length? verticle antenna and why? How does this relate to the term "end effect"? If you have already written a book then tell us what the auther said. Art KB9MZ.....XG it turns around and goes right back down the way it came. So a electrical generater doesn't keep turning in one direction but instead it occillates at the desired frequency. I have never seen one do that! And "end effect" is the confusion created at the top of the radiator 'end effect' is an effect of the capacitance seen from the end of the antenna to ground or the other part of a dipole. how does a generator come into this? you feed current into a wire with an open end, it gets to the end, reverses direction and goes back to where it started. no frequency was stated or implied all you asked was where there 'current' went... that could be any kind of current including a step or pulse or sinusoids of any frequency. |
#6
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On 19 Oct, 06:45, "Dave" wrote:
"art" wrote in message ps.com... On 19 Oct, 03:55, "Dave" wrote: "art" wrote in message groups.com... Pseudo experts of fractional wavelength antennas. Where does the current flow when it reaches the END of a fractional length? verticle antenna and why? How does this relate to the term "end effect"? If you have already written a book then tell us what the auther said. Art KB9MZ.....XG it turns around and goes right back down the way it came. So a electrical generater doesn't keep turning in one direction but instead it occillates at the desired frequency. I have never seen one do that! And "end effect" is the confusion created at the top of the radiator 'end effect' is an effect of the capacitance seen from the end of the antenna to ground or the other part of a dipole. how does a generator come into this? you feed current into a wire with an open end, it gets to the end, reverses direction and goes back to where it started. no frequency was stated or implied all you asked was where there 'current' went... that could be any kind of current including a step or pulse or sinusoids of any frequency.- Hide quoted text - - Show quoted text - The current comes from a generator does it not? So how is that current produced? I see a generator turning in one direction only all the time where you are suggesting that it is occillating. Pretty hard to draw a circuit if it tracks back the way it came. Draw a graph of an occillating current as you would see on a scope that shows two degrees of freedom. Does the "x" direction stop after a half cycle? |
#7
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![]() "art" wrote in message oups.com... On 19 Oct, 06:45, "Dave" wrote: "art" wrote in message ps.com... On 19 Oct, 03:55, "Dave" wrote: "art" wrote in message groups.com... Pseudo experts of fractional wavelength antennas. Where does the current flow when it reaches the END of a fractional length? verticle antenna and why? How does this relate to the term "end effect"? If you have already written a book then tell us what the auther said. Art KB9MZ.....XG it turns around and goes right back down the way it came. So a electrical generater doesn't keep turning in one direction but instead it occillates at the desired frequency. I have never seen one do that! And "end effect" is the confusion created at the top of the radiator 'end effect' is an effect of the capacitance seen from the end of the antenna to ground or the other part of a dipole. how does a generator come into this? you feed current into a wire with an open end, it gets to the end, reverses direction and goes back to where it started. no frequency was stated or implied all you asked was where there 'current' went... that could be any kind of current including a step or pulse or sinusoids of any frequency.- Hide quoted text - - Show quoted text - The current comes from a generator does it not? So how is that current produced? I see a generator turning in one direction only all the time where you are suggesting that it is occillating. Pretty hard to draw a circuit if it tracks back the way it came. Draw a graph of an occillating current as you would see on a scope that shows two degrees of freedom. Does the "x" direction stop after a half cycle? i don't need a generator to create a current. hook a battery to a piece of wire, watch the current travel to the end of the wire then reflect back. its easy to do the measurements and they match exactly the theory. i use this all the time, its called a time domain reflectometer. very handy for finding breaks or bad spots in feed lines or Beverage antennas. use one for a while and you will become much more familiar with the true effect of currents on wires and reflections. |
#8
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"art" wrote
And "end effect" is the confusion created at the top of the radiator ____________ Those wanting a more accurate description can find it here... http://books.google.com/books?id=U-3...n8RnFgaJ57mgyo RF |
#9
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Art wrote:
"And "end effect" is the confusion created at the top of the radiator." When the signal arrives at the open circuit end of the antenna, current can not continue its forward flow. It abruptly stops, no longer producing a magnetic field. Energy from the magnetic field is converted to energy in the electric field for an instant (Cecil`s famous conservation of energy). This produces an insreased voltage at the open circuit end. This incresed voltage has more capacitive effect, akin to the "Miller effect" caused by the higher signal voltage on the plate of an amplifier vacuum tube than on its grid. On a transmission line or on an antenna system, we used to call this capacitive action the "Ferranti effect" Best regards, Richard Harrison, KB5WZI |
#10
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On 19 Oct, 09:04, (Richard Harrison) wrote:
Art wrote: "And "end effect" is the confusion created at the top of the radiator." I was carrying on the train of thought of the poster, I have made it quite clear what my thoughts are. When the signal arrives at the open circuit end of the antenna, current can not continue its forward flow. It abruptly stops, no longer producing a magnetic field. Who says so? I suspect that in the recognition of a measurement problem you theorised what might have , could have etc to match your faulty logic. .. Energy from the magnetic field is converted to energy in the electric field for an instant (Cecil`s famous conservation of energy). This produces an insreased voltage at the open circuit end. This incresed voltage has more capacitive effect, akin to the "Miller effect" caused by the higher signal voltage on the plate of an amplifier vacuum tube than on its grid. All this is faulty logic manufactured to suit your intelligence. Radiation is a function of the release of energy from capacitance and inductance during a cycle i.e. a parallel circuit called a "tank circuit: which can also be seen as a loss less system ala a pendulum. This goes back to what I say about books. Anybody can write one. It is up to the reader to follow the dots of logic displayed to determine agreement not to swallow it and memorise it. On a transmission line or on an antenna system, we used to call this capacitive action the "Ferranti effect" Best regards, Richard Harrison, KB5WZI |
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