The only way the K3 knows that the KPA500 is in operate is via an AuxBus message. So if it misses it for some reason, it won’t switch. Be sure the cable between the radio Aux port and the amp is completely seated and such. And make it a habit to watch the front panel on the K3 when you switch on the KPA or select operate. You should see the KPA500 Operate message. The other way you can check is wiggle the PWR knob and make sure the * is in the window. That tells you that the radio is using the amp power settings.
Ken K6MR From: Tom Doligalski via Elecraft<mailto:[email protected]> Sent: Sunday, July 5, 2020 14:55 To: Fred Jensen<mailto:[email protected]> Cc: [email protected]<mailto:[email protected]> Subject: Re: [Elecraft] Strange Amplifier behavior Interesting! This has begun just in the last few weeks. Thx! Tom W4KX Sent from my iPad > On Jul 5, 2020, at 5:37 PM, Fred Jensen <[email protected]> wrote: > > I can't answer your question but when I still had my KPA500, I had that same > issue. Got in the habit of always checking the power setting before keying > when I put the amp into OPR. > > 73, > Fred ["Skip"] K6DGW > Sparks NV DM09dn > Washoe County > >> On 7/5/2020 2:07 PM, Tom Doligalski via Elecraft wrote: >> I have a relatively old K3, which I use together with a KPA500 and a KAT500. >> Most of the time this works flawlessly. >> >> However, occasionally the K3 gets confused and doesn’t realize that the >> KPA500 is in “Operate” mode (rather an in standby). This results in the K3 >> sending 100 watts to the amp, and the amp faults. >> >> Again, this doesn’t happen often, and I can’t ascertain why it occurs. Most >> of the time all is OK. >> >> The K3, KPA500 and the KAT500 all are running the latest firmware. >> >> Any idea? >> >> 73 >> >> Tom W4KX >> > > ______________________________________________________________ > 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 > Message delivered to [email protected] ______________________________________________________________ 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 Message delivered to [email protected] ______________________________________________________________ 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 Message delivered to [email protected]

