Stephen, What is the SWR without the tuner ?
73 Ken K5DNL ---------------------------------------------------------- --- On Sun, 1/2/11, Stephen Prior <s...@sjprior.fsnet.co.uk> wrote: > From: Stephen Prior <s...@sjprior.fsnet.co.uk> > Subject: [Elecraft] [K3] KAT3 and 160 with 40m long doublet > To: "elecraft" <elecraft@mailman.qth.net> > Date: Sunday, January 2, 2011, 1:31 PM > I have only just recently added the > KAT3 and I'm very impressed with it, but > given the praise heaped upon it by others I'm slightly > surprised that the > best VSWR I can get on 160m is about 8:1. The antenna > is approximately a > doublet which is a half wave long on 80m I say > 'approximately' as it's > slightly off-centre fed. I have about 7m of 300 ohm > slotted down from the > feedpoint and then into a coaxial choke at roof level for > the remaining 10m > into the back of the K3. Substituting the straight > connection for a 4:1 > balun (Guanella) at the transition between the slotted > feeder and the coax > helps slightly but not by much. > > Unfortunately I don't have a vector analyser, so I > have no idea of the > nature of the reactance that the K3 is seeing. > However, given the > wavelength involved, I would need to add a very significant > length of > coaxial cable if I were to swing the point around the Smith > Chart. > > I have tried to manually tune the KAT3, but unless I > am missing something, > I am am not able to change the L and C values at the same > time as > transmitting, so it's a very tedious process. > > Tomorrow I may well add some extra wire to hang vertically > down from the > ends of the doublet. In the meantime I would be > pleased to hear any > comments. > > Happy New Year! > > 73 Stephen, G4SJP > > > > ______________________________________________________________ > 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
