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K7ITM wrote:
OK, so the difference in "FORWARD" current from the bottom to the top is: fwd.bottom.current - fwd.top.current = 1A at 0 degrees - 1 amp at -45 degrees = 1+j0 - sqrt(.5)-j*sqrt(.5) = 1-sqrt(.5) + j*sqrt(.5) (about 0.765 at 67.5 degrees) That is truly magic. Someone must have slept through class that day. Good grief! You can't subtract two currents that are a foot apart from each other. Currents superpose at a point. Currents from each end of the coil a foot apart don't superpose. They don't even know each other exist. Good Grief! Ifor=1A at 0 deg Ifor=1A at -45 deg -----------------X-/////////-Y------------------ Iref=1A at 0 deg Iref=1A at +45 deg The forward current superposes with the reflected current at the bottom of the coil to get 2 amps at zero degrees. The forward current superposes with the reflected current at the top of the coil to get 1.4 amps at zero degrees. The delay through the coil is 45 degrees. Neglecting losses: The energy in the forward wave is the same at the top and bottom of the coil. The energy in the reflected wave is the same at the top and bottom of the coil. There is zero net steady-state energy storage between the top and bottom of the coil. There's no RF battery there. -- 73, Cecil http://www.qsl.net/w5dxp |
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