I’d guess that something is going on in the tuner. Maybe a leaky gasket and some corrosion.
Logan Sent from my iPhone > On Feb 23, 2018, at 10:00 PM, GaryK9GS <garyk...@wi.rr.com> wrote: > > Hi Chris, > Unless there is something arcing, I would guess RF getting into something. > Maybe the control cable to the auto tuner? > > > 73, > Gary K9GS > -------- Original message --------From: Chris Hallinan <challi...@gmail.com> > Date: 2/23/18 11:42 PM (GMT-06:00) To: "<elecraft@mailman.qth.net>" > <Elecraft@mailman.qth.net> Subject: [Elecraft] KPA500 Faulting on high SWR on > power rise > Greetings from southwest Florida. > > My KPA500 is kicking out with REFL HI warning (high SWR). But here is the > strangeness. My setup is K3->KPA500->40' coax->MFJ 600W remote tuner -> 4:1 > balun -> open wire feedline to 80-meter doublet. In words, I have a remote > autotuner feeding an 80-meter doublet fed with 600-ohm open wire line. A > Balun Designs 4:1 balun provides the interface from the open wire line to > the tuner. > > With the autotuner tuned at low power, the SWR shows 1.5:1 on my KPA500 and > external SWR meter. As I run the power up to 300, 400, 500 watts, > somewhere in there all of a sudden the SWR instantly jumps off the scale, > into the red LEDs on KPA500, and it faults. It's as if the SWR were > dependent on power. > > Even stranger, when I back the power off to say 250 Watts, holding key down > the SWR is stable in the green (<1.5:1), but when I key it at CW rates, the > SWR bounces into the red on every dit and eventually faults, when at steady > state key down it never leaves the green zone! > > I fear it is the tuner falling over, but it should be able to handle the > power. I see this on all bands from 80-20. > > Operating into my 20-meter resonant vertical, with no tuner, everything > works fine. > > Any ideas or hints on how to correct this? > > Thanks, > > Chris > 73 de K1AY > > > -- > Life is like Linux - it never stands still. > ______________________________________________________________ > 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 > Message delivered to garyk...@wi.rr.com > ______________________________________________________________ > 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 > Message delivered to lra...@garlic.com ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
