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Ralph Mowery wrote:
wrote in message ... Once again, SWR is defined in terms of SOURCE impedance and LOAD impedance. The normal LOAD for a transmitter is one end of a piece of coax with an antenna on the other end. The SWR at the near end of a piece of coax may or may not be the same as the SWR at the far end of the coax. -- Jim Pennino Can you show any place where the SWR definition mentions the Source impedance ? I have several times now, but once again: SWR = (1 + |r|)/(1 - |r|) Where r = reflection coefficient. r = (Zl - Zo)/(Zl + Zo) Where Zl = complex load impedance and Zo = complex source impedance. https://en.wikipedia.org/wiki/Reflection_coefficient http://www.antenna-theory.com/tutori...nsmission3.php I have never seen anything that mentions the Source impedance. Just the ratio of the voltage or current going forward and reflected. It is generally not mentioned in Amateur publications. The SWR has to be the same at any point on the coax or transmission line minus the loss in the line. A simple swr meter may show some differance because of the way that kind of meter works. By changing the length of the line , the apparent SWR may be differant at that point. There is no such thing as apparent SWR. It is what it is in a given place. Transmission line transformers. http://highfrequencyelectronics.com/...TraskPart2.pdf Impedance matching. https://en.wikipedia.org/wiki/Impedance_matching -- Jim Pennino |
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