This comment made me do a search on Kraus. I found one of his books online for free in the open source archive.org site (this is the streaming link, they also have it in PDF):http://archive.org/stream/Antennas2ndbyjohnD.Kraus1988/Kraus-Antennas-2nd.Edition-1988#page/n0/mode/2up I though others might like to look at it. 73 - Tom - wa4ta
> Date: Wed, 2 Oct 2013 13:36:36 -0400 > From: k3...@comcast.net > To: elecraft@mailman.qth.net > Subject: Re: [Elecraft] Random wires > > No. I expected someone who is an engineer and commands the language > better than I to explain that they are not the same and how they fit > together thereby adding a little enlightenment to this thread. > > 73, > Barry > K3NDM > > On 10/2/2013 1:07 PM, David Gilbert wrote: > > > > What do you expect Krause will tell you? That feedpoint impedance and > > radiation resistance are the same thing?? I guarantee that it will not. > > > > Did you not understand that feedpoint transformations transform the > > combination of all impedances present at that point, and therefore > > leave the relative magnitude of the various components (and therefore > > the efficiency of the system) the same?? Or are you somehow of the > > opinion that a folded element is not a feedpoint transformation?? > > I'm really having trouble understanding your logic here. > > > > Dave AB7E > > > > > > > > On 10/2/2013 9:26 AM, Barry LaZar wrote: > >> Everybody, > >> I see a real problem here. Please someone open up the authority, > >> Krause, and see what he says. His work is the basis of a whole lot of > >> what we have today. > >> > >> 73, > >> Barry > >> K3NDM > >> > >> > >> On 10/1/2013 10:55 PM, Bob Cunnings wrote: > >>> 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" <r...@cobi.biz> 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:Elecraft@mailman.qth.net > >>> > >>> This list hosted by: http://www.qsl.net > >>> Please help support this email list: http://www.qsl.net/donate.html > >>> > >> > >> ______________________________________________________________ > >> Elecraft mailing list > >> Home: http://mailman.qth.net/mailman/listinfo/elecraft > >> Help: http://mailman.qth.net/mmfaq.htm > >> Post: mailto:Elecraft@mailman.qth.net > >> > >> This list hosted by: http://www.qsl.net > >> Please help support this email list: http://www.qsl.net/donate.html > >> > > > > ______________________________________________________________ > > Elecraft mailing list > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/mmfaq.htm > > Post: mailto:Elecraft@mailman.qth.net > > > > This list hosted by: http://www.qsl.net > > Please help support this email list: http://www.qsl.net/donate.html > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
