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Jack Smith wrote in message . ..
On Mon, 10 Nov 2003 00:50:55 -0800, Roy Lewallen wrote: Ok. So far, we have your calculation that the output current should be 5% smaller, and 18 degrees shifted in phase (lagging, I presume) from the input; and Cecil's, that the output current should equal the current, both in phase and magnitude. I don't know if Richard is going to do the calculation or not, so I'll wait a little longer. Anyone else like to hazard a prediction? Roy Lewallen, W7EL (1) Input current = output current (2) No phase shift. If you model the circuit using the lumped values for the antenna R and jX components it's easy to see this. Anyone not believing this can try modeling the base inductor as: O----[0.3 ohms R']--[+j192 ohms]---[0.3 ohms R'']----0 Put current through it using your favorite SPICE simulator and compare the current through the R' and the R''. The two plots coincide. Very good Jack, Now use your skills on a inductance that is NOT a lumped load, and don't forget its orientation so that any coupling to ground shows up since the subject of discussion is a loaded whip antenna. Ofcourse if you have a pure lumped load kindly take it to the lab for measurement purposes. Not sure if it will be too heavy now that you have removed the resistance , capacitance and non current carrying parts so keep a wheel barrow at hand. grin Art Jack K8ZOA |
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