Sounds like the amplifier key interrupt may not be working. Do you by chance have both the RCA cable and 15 pin ACC cable connected? The wiring diagrams in the KAT500 are important. The amp doesn't switch to standby, instead its key line is broken by the KAT500 so the amp doesn't amplify during ATU tuning.
The ATU won't tune if it sees more than exciter level power. Dick, K6KR Sent from my iPhone > On Nov 12, 2013, at 11:40, Jim Bennett <[email protected]> wrote: > > Folks, sorry if this has been discussed on the reflector before, but I've > looked through the archives and drew a blank. I know I saw it but try as I > may, can't find any related posts. > > I just this week added a KPA500 and KAT500 to my K3 station. Documentation > sez that the KAT500 tunes best when the K3 is set to 25 watts of tune power. > OK, got that set. But, what ideally should happen is that if the amp is in > OPER mode and I press & hold the TUNE button on the K3, the amp should > temporarily go to STBY mode until the tuner has finished doing it's thing. It > doesn't - the amp fires out 450 - 500 watts - not cool. > > Have I missed a setting somewhere that will make this happen, in case I > forget to put the amp in standby mode, before I run a tune cycle? > > Tnx, Jim / W6JHB > ______________________________________________________________ > 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

