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.
I have done this on some problem frequencies to improve the match over that obtained by the auto tuning. I suppose such a "silent" tuning routine could be included in the firmware. Not sure this would yield any different results than the sutomatic SWR tuning method; I suppose it could have the advantage of being able to be performed at a much more leisurely pace than would be desirable using the transmitter. 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
