I saw the problem when operating a Multi-op contesting and the 80M OP was running 1.5kw and the RF is induced into the 160M Phased inverted L array and the combination of induced energy and the SWR reflected power on the array kick the KAT500 back into a retune mode. So, either local energy on Broadcast energy will both make this happen.
I now have built coaxial Stubs and look forward to seeing if this solves my Local energy problem. 73 Bill W4RM -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Igor Sokolov Sent: Monday, December 30, 2013 1:28 PM To: Jeffrey Otterson; [email protected] Subject: Re: [Elecraft] K3/KPA500/KAT500 SWR problem It may be not relevant to this particular case but another reason for weird KAT500 behavior can be strong interfering signal of a neighbor or nearby broadcasting station. I did run into situations where such signals induced up to 5 volts into low band antenna. Then KAT500 counts that signal as reflected and thinks that SWR is very high. One may try to connect broadband spectrum analyzer to the antenna and see what is going on. If it is broadcasting signal well below ham bands then high pass filter between the tuner and antenna can help. 73, Igor UA9CDC ----- Original Message ----- From: "Jeffrey Otterson" <[email protected]> To: <[email protected]> Sent: Monday, December 30, 2013 8:58 PM Subject: Re: [Elecraft] K3/KPA500/KAT500 SWR problem > I, too, have seen this spurious KAT500 retune problem. > > I'm running a similar setup: > K3->KPA500->LP-100A->KAT500->coax->balun->ladder line->hf doublet > > I'lll be happily working 75M and all of a sudden the KAT500 starts > re-tuning, and with the LP-100 alarm going off and the relays chattering > in > the KAT500, it sounds a bit like all hell breaking loose. > > I reverted the KAT500 to firmware version 1.32 and the problem *seems* to > happen less often... That could be my imagination, though. Also I think > that this has happened in MANUAL mode, as well as automatic. > > Perhaps it would be useful to have an option to only re-tune during the > first few seconds of transmit? > > Jeff > ______________________________________________________________ > 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
