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Cecil,
You appear to have some unique views of superposition and of standing waves. In simple terms superposition says that one can combine two inputs, and the combined output is equal to the sum of the individual outputs. Not all systems exhibit superposition, of course, but I believe the elementary antennas considered here do indeed follow the principle of superposition with regard to current. Why do you believe the "net" current somehow has different properties than simply the sum of the two component traveling current waves? You use the term "artifact", as if the net current is inconsequential or even incorrect. Does superposition break down? Distributed network vs. DC or AC model is not an issue, since the superposition must be performed independently at each point in the region of interest. (You seem to like to use "net", but "total" or "algebraic sum" mean the same thing. I am not interested in any argument about performing the vector math correctly. That must be assumed.) Standing waves are not static. The current may not "flow", whatever that means, but there is certainly real non-zero current at every point except the exact nodes of the standing wave. If you prefer, the standing wave current oscillates rather than flows, but that is of no special importance here. Why do you believe standing waves are somehow inferior to traveling waves? (This message is absolutely serious. No tricks or trolling. If you want to play word games, see ya later.) 73, Gene W4SZ Cecil Moore wrote: There is forward current flowing into the bottom of the coil and out the top. There is reflected current flowing into the top of the coil and out the bottom. The net current is a standing current wave. If we, as Kraus suggests, assume that the forward current equals the reflected current (relatively small error in doing so) then there is zero net current flowing in and out of the coil. The standing wave current is, well, just standing there and is not "going" anywhere. The gross error that a lot of people are making is that standing wave current flows. If the forward and reflected currents are equal, as Kraus assumes for purpose of discussion, then there is zero net current flow through the coil. Yet, net current is what everyone is measuring. What they are actually measuring is the value of the standing wave current at each end of the coil and it is not flowing. It is only an artifact of the superposition of the two waves that are flowing. |
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