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Bart Rowlett wrote:
The currents through two nodes connected in series, without branches, is identical. I think that fact was established before Kirchoff but it's certainly stipulated in circuit theory. Let's deal with concrete examples. Assume a lossless, unterminated transmission line. Because of the standing waves, the net current in that series loop varies from point. It is zero every 1/2WL and in between those zero points, it is at a maximum. That's all I was trying to say - that the series current in a distributed network with standing waves is not constant because it no longer can be considered a "circuit". It must be considered a network as it is an appreciable portion of a wavelength. The phases of the forward current and reflected current are rotating in opposite directions which causes their superposition magnitude to vary from minimum to maximum. The magnitudes of the forward and reflected traveling wave currents can be constant while their phasor sum varies as a standing wave sinusoid. Most of the stuff in this posting is a diversion away from the original argument which is: Does the current through a 75m bugcatcher vary from end to end? Since the net current is the standing wave current in a standing wave antenna, it is mostly standing wave current, not traveling wave current. Kraus even suggests that we can consider the forward current equal to the reflected current in a standing wave antenna for purposes of conceptual discussion which means the net current is not moving at all, i.e. not flowing into the bottom of the coil and out the top as assumed by W8JI on his web page. Balanis clearly states that a standing wave antenna can be analyzed based on the forward current and the backward current. Simulations with EZNEC using the helix option indicates that the net current is not the same at each end of a bugcatcher coil. Essentially the same result occurs using a series inductive stub. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
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