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On Sat, 06 Nov 2004 02:34:32 GMT, "Frank"
wrote: Regarding Richard's comments "Assuming the same currents". Not sure I understand, since the feed-point current varies with constant power Hi Frank, That is quite simple. The file VERT1.EZ has as a source, a constant current generator - a fact I pointed out in the summary of my results. Your presumption of constant power is a natural one for the sake of common discussion, but it is not even the default source for EZNEC. [However, having said that, a curiosity of program design has found that the concept of a "new file" has been orphaned. Any time the application is opened, it is opened with LAST.EZ and I cannot recall upon initial acquisition if EZNEC ever started with a blank slate. Given that you cannot have less than 1 wire nor 1 source, then there is on way to force a blank file. Hence the concept of a default resides in the last file opened.] In other words, each and every iteration of antenna, irrespective of its presumed or actual Rr or drivepoint Z had the same current applied to it, 1 Ampere. Now, if ANY resistance had changed, it then follows that the POWER would have changed too (which presents us with that puzzle confused by the expression V=I/R. that came out of the blue) at a linear rate (1² = 1). Note, a doubling of drivepoint Z by the addition of a load does not result in 3dB gain over the former design. I have seen I * I * R bandied about as an "explanation" and yet at least 3dB is remarkably absent in the results. What R is this that everyone speaks of? Certainly not the real component of drivepoint Z. What about the Rr that must've changed? Copper loss absorb it? Ground loss? As I offered, I must've done something wrong, taken the wrong turn, interpreted the modeler in error, -ahem- not read the help file.... I will bet it was that last one - which only reveals no one has. ;-) [aside] So, Wes, I will amend my ways and delve into that treasure of knowledge before returning your work in kind (no point in retread effort) sometime tomorrow morning. [to the audience] C'mon folks, this has to be an especially simple resolution - I'm glad that so many are just as flummoxed (even Reg is uncharacteristically silent in this regard :-) 73's Richard Clark, KB7QHC |
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