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What is the antenna current path or route
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 |
What is the antenna current path or route
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 |
What is the antenna current path or route
"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. |
What is the antenna current path or route
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 |
What is the antenna current path or route
"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. |
What is the antenna current path or route
"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 |
What is the antenna current path or route
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? |
What is the antenna current path or route
art wrote:
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 I don't have to be an engineer to question this one. An electrical "generator" does indeed keep turning in a single direction. It has brushes and split commutator rings to keep the current flowing in only one direction. That is in the very nature of a "generator." The device I suspect that you are alluding to is an "alternator" in which a magnetic field is rotated through a coil of wire and passes through both halves of the coil at the same time. Since in a well designed, single phase alternator the center of the magnetic field and the center of the coil of wire are coincident the current does indeed alternate because unlike a generator the alternator does not include any means of flopping the connections on the coil in time with the magnetic field. So as the negative and positive fields of the magnet pass through each half of the coil of wire in turn the current reverses direction. -- Tom Horne, W3TDH |
What is the antenna current path or route
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 |
What is the antenna current path or route
On Oct 19, 6:52 am, "Richard Fry" wrote:
"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...&dq=antenna+en... RF Thanks, Richard. I notice that article references King, I assume Ronold W. P. King, who wrote some very nice qualitative explanations of various linear and loop antennas in King, Mimno and Wing's "Transmission Lines, Antennas and Waveguides." There's also a nice explanation that I feel is quite accurate in Joseph Boyer's "The Antenna--Transmission Line Analog," from Ham Radio magazine, April and May 1977. I believe I have it somewhere as a PDF, scanned from the article. Cheers, Tom |
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