Here's a link to the W8JI radiation resistance topic: http://www.w8ji.com/radiation_resistance.htm
where the antenna efficiency issue is analyzed - using a 1/4 long folded radiator as the example. In this analysis the antenna efficiency is unchanged because total power and ground loss power terms remain constant. Bob NW8L On Tue, 1 Oct 2013 14:48:55 -0700 "Ron D'Eau Claire" <[email protected]> wrote: > The important value is the resistance at the feed point of the > radiator, independent of any matching devices used. > > Adding a 4:1 or other transformer is simply adjusting the impedance > the feed line sees, like any other matching network you might use. It > has no effect on the feed point resistance of the antenna. > > A 1/4 wave long folded radiator has a feed point resistance of 4x the > typical 1/4 wavelength radiator, quite independent of the ground > system. Hence the efficiency is higher. > > 73, Ron AC7AC > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
