Having a lot of water around means that the antenna impedance changes with the power level. I have seen this many times here on 160 with wet leaves very close to wires, and sometimes touching. I can watch the SWR vary under a steady 1500 watts, something not seen or far less obvious at 5 watts.
No attempt at explanation. 73, Guy. On Thu, May 26, 2011 at 10:05 AM, Poul Erik Karlshøj (PKA) <[email protected]> wrote: > I don't think the problem is due to good tunes being misses by antenna being > "hit", because when it happens, it is very reproductive, i.e. you can repeat > the ATU tuning and it will always come back to the non-optimum LC combination. > Paul > OZ4UN > > -----Oprindelig meddelelse----- > Fra: [email protected] > [mailto:[email protected]] På vegne af David Cutter > Sendt: 26. maj 2011 14:54 > Til: drewko; [email protected] > Emne: Re: [Elecraft] K3 antenna tuner question > > On 'problem' frequencies, re-doing the tune soon after the first try has > always brought a better swr for me, but I have no wires amongst branches > which I think means you may be getting hit and miss good tunes. > > David > G3UNA > >>A quick way to find the best LC combinations manually is to tune them >>for maximum receiver noise. You can refine this further by using the >>K3's AFV meter to measure the noise level of the different promising >>LC combinations. >> > >> A reminder abou auto tuning-- if you hit ATU TUNE a second time within >> a few seconds of the first tuning operation it is supposed to find a >> better match. However, I have noticed that the second tune sometimes >> gives a worse SWR than the first one. (May be due to the variable >> nature of my antenna-- bare wire through tree branches...) >> >> 73, >> Drew >> AF2Z >> >> >> On Thu, 26 May 2011 07:31:53 -0200, you wrote: >> >>>Another thing about the K3 ATU is, that it sometimes stops at an LC >>>combination which is NOT identical to the LC combination giving the >>>lowest SWR. If that happens you can manually change the L or C to >>>obtain the lowest SWR - but it is a bit cumbersome - and not what you >>>expect from an automatic tuner. I only have this problem when it is >>>raining (antennas are partially hidden in trees and use 450 ohm open >>>feeder and 4:1 baluns in the shack) >>>73 de OZ4UN >>> > > ______________________________________________________________ > 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 > ______________________________________________________________ > 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 > ______________________________________________________________ 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
